JP5513299B2 - Shading film - Google Patents

Description

The present invention relates to a light-shielding film. More specifically, the present invention relates to a light-shielding film useful for various applications such as optical applications, optical device applications, display device applications, mechanical parts, and electrical / electronic parts.

For example, in addition to optical members such as lens units, the light-shielding film scatters and absorbs light of a desired wavelength in various applications such as optical device members, display device members, mechanical parts, and electrical / electronic parts. It is a film having a light shielding layer for shielding light of a wavelength. For example, in optical applications such as camera modules for digital cameras and mobile phone cameras, a light-shielding film having a light-shielding layer as described above has been developed and improved in order to suppress the generation and expansion of optical noise inside the lens unit. ing.

As a conventional light-shielding film, for example, a film in which a light-shielding layer is laminated on a substrate is known. Among them, as the light shielding layer made of an inorganic material, a heat resistant light shielding film in which a metal carbide film is formed on a heat resistant organic resin film base material containing a black pigment such as carbon black is disclosed (for example, Patent Document 1), which describes that excellent durability can be exhibited even in a high temperature environment.
On the other hand, as the light-shielding layer made of an organic material, a light-shielding sheet in which a synthetic resin layer having both matteness, conductivity, and light-shielding properties is laminated on one side or both sides of a base plastic film is disclosed (for example, , Patent Document 2), it is described that matting property, conductivity and light shielding property can be realized at the same time by blending carbon black into the synthetic resin layer.
Also disclosed is a light-shielding film in which an organic resin layer containing carbon black or the like is provided on both sides of a base film mainly composed of a thermoplastic resin (see, for example, Patent Document 3). It is described that a light-shielding film excellent in light-shielding property and conductivity can be obtained by using both and a conductive carbon black.

Also disclosed as a light-shielding film excellent in light-shielding property and heat resistance is a light-shielding film essentially comprising a curable resin cured product or an organic resin containing a thermoplastic resin having a glass transition temperature of 150 ° C. or higher and a black material. (For example, refer to Patent Document 4). It is described that by using a specific organic resin, the black material can be more uniformly dispersed or dissolved in the organic resin, and the resulting film has excellent light shielding properties. Moreover, it is described that a single-layer structure in which the film is composed only of a light-shielding layer is suitable as the structure of such a light-shielding film.

JP 2010-96842 A JP-A-4-62048 JP-A-9-274218 International Publication No. 2009/014264 Pamphlet

As described above, various light-shielding films have been studied and developed, but in recent years, in the optical field, downsizing of imaging lenses and the like mounted on digital cameras and mobile phones has progressed, downsizing of optical members, Thinning and weight reduction are further demanded. Accordingly, it is desired to reduce the size, thickness, and weight of a light-shielding film used in a digital camera module or the like, or a lens unit having a lens or the like. In addition, since cost reduction is also required, plastic lenses are being used instead of inorganic glass. However, in order to further reduce costs, plastic lenses and various materials can withstand reflowable specifications. It is required to have excellent heat resistance.

However, the conventional light-shielding film has not been able to sufficiently meet the above-described demands for reducing the size and thickness of the optical member and increasing the heat resistance.
For example, in the case of a film laminated with a high hardness inorganic film such as Patent Document 1, when the film is cut into a fine size, the cut surface becomes rough, or the inorganic film is cracked or peeled off. There has been a problem that the light-shielding characteristics deteriorate. Further, since the inorganic film is hard, there is a possibility that the lens is damaged by the fracture surface when the cut film is arranged in the lens unit. In addition, inorganic materials such as metal carbides are expensive and unsuitable for manufacturing reflowable lenses for the purpose of reducing costs.
Moreover, even when the light shielding layer to be laminated is made of an organic material as in the light shielding films described in Patent Documents 2 and 3, there is a limit to thinning the film because of the laminated structure of the base film and the light shielding layer. It was. Further, if the light-shielding film has such a laminated structure, the interface may be peeled off due to stress during cutting, heat in the reflow process, moisture or heat in the use environment. Moreover, it cannot be said that the base material and the light shielding layer have sufficient heat resistance to withstand the reflowable specification.
On the other hand, it can be said that the light-shielding film described in Patent Document 4 still has room for improvement in terms of realizing further reduction in size and thickness.
As described above, the conventional technology has room for ingenuity to develop a light-shielding film that meets the demands for miniaturization, thickness reduction, and heat resistance that are increasing year by year.

The present invention has been made in view of the above-mentioned current situation, has excellent cutting characteristics, is easy to handle even in a minute size, and can be placed with high positional accuracy on a lens unit, etc., and has high yield. An object of the present invention is to provide a light-shielding film having no variation.

The present inventor examined the light-shielding film that can meet the demands for miniaturization, thinning, and heat resistance as described above, and handled the light-shielding film by reducing it to a specific size or less. It has been found that the surface resistance value of the light-shielding film needs to be controlled within a specific range in order to be able to arrange with high positional accuracy. The surface resistance value of the light-shielding film can be controlled by using conductive carbon black. However, when carbon black having a specific structure is used, the cutting characteristics when the film is made fine (cut) are reduced. It has been found that it is excellent and that the surface resistance value can be controlled within the specific range with a small content. Furthermore, it has been found that when the light-shielding film has a single-layer structure composed of a light-shielding layer in which carbon black having the specific structure described above is dispersed, the above-described cutting characteristics are further improved. In order to suppress variations in light shielding properties and conductivity in a minute light shielding body, it is particularly important that carbon black is uniformly dispersed in the light shielding layer of the light shielding film. If carbon black is not uniformly dispersed, the cut surface of the film may be disturbed during cutting. In addition, when carbon black having a specific structure as described above is used, it needs to be dispersed while maintaining the structure, but a specific organic resin is used as a resin constituting the light shielding layer. And found that carbon black can be uniformly dispersed in the resin with a low share without damaging its structure. The light-shielding film having the above-described configuration has a performance suitable for a light-shielding film used for an imaging lens of a digital camera or a mobile phone camera module, and can be easily processed into a shape suitable for mounting. As a result, the present inventors have reached the present invention.

That is, the present invention is a light-shielding film having a light-shielding layer formed using an organic resin and / or its raw material and carbon black as essential components, and the light-shielding film has a single-layer structure composed of a light-shielding layer, The organic resin contains a curable resin cured product or a thermoplastic resin having a glass transition temperature of 150 ° C. or higher, and the organic resin is solvent-soluble or a raw material thereof is solvent-soluble or liquid, and the carbon black is The DBP oil absorption is 200 to 500 ml / 100 g.
The present invention is described in detail below.

The light-shielding film of the present invention has a light-shielding layer formed using an organic resin and / or its raw material and carbon black as essential components, but the light-shielding layer comprises an organic resin and / or its raw material and carbon black. As long as is an essential component, other components may be included, and one or more of these components may be used.

<Carbon black>
The light-shielding layer of the light-shielding film of the present invention is formed with carbon black having a DBP (dibutyl phthalate) oil absorption of 200 to 500 ml / 100 g as an essential component. If the oil absorption exceeds 500 ml / 100 g, the dispersibility of the carbon black will deteriorate, so the hue (black) and conductivity (surface resistance value) of the resulting light shielding layer will not be sufficiently uniform, Coarse particles are formed, and the cutting surface of the resulting light-shielding film may not be sufficiently excellent, for example, the cutting surface may be disturbed during cutting. Further, if the oil absorption is less than 200 ml / 100 g, the degree of development (structure) of the aggregate becomes small, and high conductivity may not be exhibited. More preferably, the oil absorption is 300 to 500 ml / 100 g.

The carbon black preferably has a specific surface area of 100 to 1500 m ² / g. The specific surface area of carbon black is B.I. E. T. T. et al. It can be measured by the method. When the specific surface area is less than 100 m ² / g, it is difficult to form a conductive path in the carbon black, and it is difficult to develop high conductivity with a small amount of addition. On the other hand, if it exceeds 1500 m ² / g, it is difficult to increase the dispersion concentration and addition amount of carbon black, so that only a very small amount can be added, and high conductivity may not be exhibited. The specific surface area is more preferably 500 to 1500 m ² / g or more.

Carbon black usually has various agglomeration forms (aggregates) in which particles serving as basic units are branched into chained or irregular chains by fusion in a transmission electron microscope image, or secondary agglomeration or association. Without being observed in a form that exists independently. The particles serving as the basic unit usually have a substantially spherical or granular form, and it is recognized that the particles are more difficult to be divided. In the carbon black preferably used in the present invention, crystallites called pseudo graphite structures are aggregated to form primary particles.
Although the size of the primary particles is referred to as the primary particle size, the carbon black preferably has a primary particle size of 20 to 100 nm as evaluated by a transmission electron microscope image. More preferably, it is 30-50 nm. It is more preferable that the number average value of the primary particle diameters (average primary particle diameter) is in the above range. In determining the average primary particle size, it is preferable to measure the size of 20 or more primary particles and determine the average of the measured values.
The primary particle may be either a particle having a dense structure without voids or a particle having a sparse structure with a high porosity depending on the aggregate form of crystallites, but a particle having a sparse structure with a high porosity. Particles are preferred.
The degree of density of the primary particle structure can be estimated from the value of the ratio (ds / d) of the specific surface area diameter ds to the average primary particle diameter (d evaluated by a transmission electron microscope).
The specific surface area diameter ds E. T. T. et al. The specific surface area value S measured by the method can be calculated by the following formula.
Specific surface area diameter (nm) = 6000 / (ρ × S)
(In the formula, ρ represents true specific gravity and 1.8 is adopted. S represents specific surface area (m ² / g).)
The ratio (ds / d) of the carbon black used in the present invention is not particularly limited, and usually 0.01 to 1.2 carbon black can be used, preferably 0.5 or less, more preferably 0. .2 or less, particularly preferably 0.02 to 0.2.

The carbon black preferably has a volatile content of 1% or less. When the volatile content exceeds 1%, the number of functional groups present on the surface of the carbon black increases, and electrons are trapped by these functional groups, making it difficult to develop conductivity.

The carbon black is preferably conductive carbon black from the viewpoint of developing high conductivity. Examples of the conductive carbon black include ketjen black, acetylene black, and oil furnace black.

The carbon black having the above-described characteristics can be obtained by adjusting the characteristics in an ordinary carbon black manufacturing method. In producing the light-shielding film of the present invention, those satisfying the above-described characteristics may be appropriately selected from available carbon blacks.

<Organic resin>
The light shielding layer of the light shielding film of the present invention is also formed using an organic resin and / or its raw material as an essential component. The organic resin contains a curable resin cured product or a thermoplastic resin having a glass transition temperature (Tg) of 150 ° C. or higher. In addition, the organic resin is solvent-soluble, or the raw material is solvent-soluble or liquid. An organic resin or its raw material that satisfies such requirements can be handled in a liquid state in the process before curing or before molding, so that carbon black can be uniformly dispersed in the organic resin with a low shear (shearing force). It becomes possible.
In the present specification, “can be handled in a liquid state” means that the viscosity of the product itself or a solution obtained by dissolving the product in a solvent is 100 Pa · s or less at 25 ° C. To do. When the viscosity of the product itself is in the above range, the product is "liquid".
The viscosity can be measured with a B-type viscometer.
The organic resin raw material includes an organic resin precursor, the raw material of the precursor, and a monomer for forming the organic resin.

The organic resin is not particularly limited as long as it contains a curable resin cured product or a thermoplastic resin having a Tg of 150 ° C. or higher and can be handled in a liquid state in a process before curing or molding. However, polyimide resin, epoxy resin, fluorinated aromatic polymer, polyether ketone resin, and polyethylene naphthalate resin are suitable. It is one of the preferred embodiments of the present invention that the organic resin is at least one selected from the group consisting of a polyimide resin, an epoxy resin, a fluorinated aromatic polymer, a polyether ketone resin, and a polyethylene naphthalate resin. . By using such an organic resin, the obtained light-shielding film has excellent heat resistance. More preferably, the organic resin is a polyimide resin or an epoxy resin, and more preferably a polyimide resin.
Among the organic resins described above, there are polyimide resins that do not melt even when heated at a temperature of 400 ° C. or lower and those that can melt. In the polyimide resin in the present specification, the former (which does not melt even when heated at a temperature of 400 ° C. or lower) is a cured curable resin, and the latter (which can be heated and melted at a temperature of 400 ° C. or lower) is thermoplastic. This is called resin. Accordingly, there are polyimide resins that correspond to curable resin cured products and those that correspond to thermoplastic resins.
Among the above, the epoxy resin corresponds to a curable resin cured product, and the fluorinated aromatic polymer, the polyetherketone resin, and the polyethylene naphthalate resin correspond to a thermoplastic resin.

When the organic resin is a curable resin cured product, it is necessary that the raw material (curable resin or the like) can be handled in a liquid state, that is, the precursor is solvent-soluble or liquid. In the present specification, the “cured resin cured product” is a product obtained by curing or semi-curing a curable resin. For example, a form having a crosslinked structure formed by crosslinking a curable resin, etc. One of the preferred forms.
On the other hand, when the organic resin is a thermoplastic resin having a Tg of 150 ° C. or higher, the thermoplastic resin or its raw material can be handled in a liquid state, that is, the thermoplastic resin is solvent-soluble, or The raw material must be solvent-soluble or liquid.

Examples of the polyimide resin include a thermosetting polyimide resin cured product, a thermoplastic polyimide resin, and a polyamideimide resin. As long as they have an imide ring, the compound as a raw material is not limited, but when used for the light-shielding film of the present invention, from the viewpoint of production productivity, cost, heat resistance, A thermosetting polyimide resin is preferable, and an aromatic thermosetting polyimide resin is more preferable.

As a raw material of the said polyimide resin, it is preferable that they are polyamic acid, the diamine used as the raw material of polyamic acid, tetracarboxylic dianhydride, etc. More preferably, aromatic polyamic acid, aromatic diamine and tetracarboxylic dianhydride are preferable. Moreover, as a polyimide resin, an alicyclic polyimide resin is also suitable. As raw materials for the alicyclic polyimide, it is preferable to use diamine and alicyclic tetracarboxylic dianhydride.

The polyamic acid is not particularly limited as long as it can be converted to polyimide by heating or the like, and various polyamic acids can be used. For example, as a general polyamic acid, the following formula (1);

(In the formula, R ⁵ is a trivalent or tetravalent organic group having at least 2 carbon atoms. R ⁶ is a divalent organic group having at least 2 carbon atoms. It is the number of 1-2.) What has the structural unit (1) represented by this is mentioned.
From the viewpoint of heat resistance, R ⁵ preferably contains a cyclic hydrocarbon, an aromatic ring or an aromatic heterocyclic ring. More preferably, R ⁵ is a trivalent or tetravalent group having 6 to 30 carbon atoms and containing a cyclic hydrocarbon, an aromatic ring or an aromatic heterocyclic ring. Examples of R ⁵ include a phenyl group, a biphenyl group, a terphenyl group, a naphthalene group, a perylene group, a diphenyl ether group, a diphenylsulfone group, a diphenylpropane group, a benzophenone group, a biphenyltrifluoropropane group, a cyclobutyl group, and a cyclopentyl group. Although it is mentioned, it is not particularly limited, and various organic groups can be used.
From the viewpoint of heat resistance, R ⁶ preferably contains a cyclic hydrocarbon, an aromatic ring or an aromatic heterocyclic ring. More preferably, R ⁵ is a divalent group containing a cyclic hydrocarbon, an aromatic ring or an aromatic heterocyclic ring and having 6 to 30 carbon atoms. Examples of R ⁶ include a phenyl group, a biphenyl group, a terphenyl group, a naphthalene group, a perylene group, a diphenyl ether group, a diphenylsulfone group, a diphenylpropane group, a benzophenone group, a biphenyltrifluoropropane group, a diphenylmethane group, and a dicyclohexylmethane group. However, it is not particularly limited, and various organic groups can be used.

The polyamic acid containing the structural unit (1) as a main component may be one in which R ⁵ and R ⁶ are each composed of one kind, or each is composed of two or more kinds. Also good.

Examples of the polyamic acid having the structural unit (1) as a main component include pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, 3,3 ′, 4, From 4'-biphenyltrifluoropropanetetracarboxylic dianhydride, 3,3 ', 4,4'-biphenylsulfone tetracarboxylic dianhydride, and 2,3,5, -tricarboxycyclopentylacetic acid dianhydride One or more carboxylic dianhydrides selected from the group consisting of paraphenylenediamine, 3,3′-diaminodiphenyl ether, 4,4′-diaminodiphenyl ether, 3,4′diaminodiphenyl ether, 3,3′-diamino Diphenylsulfone, 4,4′-diaminodiphenylsulfone, 4,4′-diaminodicyclohexylmethane, and 4 4'-Amino-diphenylene methane synthesized from one or more diamines selected from the group consisting of a polyamic acid (polyimide precursor) are mentioned as preferable. Moreover, as polyamic acid, it is not limited to these, You may use what was manufactured using compounds other than the illustrated carboxylic dianhydride and diamine. The polyamic acid can be synthesized by selectively combining tetracarboxylic dianhydride and diamine and reacting them in a solvent.

Moreover, it is preferable that it is an aromatic diamine as a raw material of a thermosetting polyimide.
Specific examples of the aromatic diamine include paraphenylenediamine (PPD), metaphenylenediamine (MPDA), 2,5-diaminotoluene, 2,6-diaminotoluene, 4,4′-diaminobiphenyl, 3, 3′-dimethyl-4,4′-biphenyl, 3,3′-dimethoxy-4,4′-biphenyl, 2,2-bis (trifluoromethyl) -4,4′-diaminobiphenyl, 4,4′- Bis (3-aminophenoxy) biphenyl, 3,3′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane (MDA), 2,2-bis- (4-aminophenyl) propane, 3,3′-diaminodiphenylsulfone (33DDS), 4,4'-diaminodiphenylsulfone (44DDS), 3,3'-diaminodiphenyl sulfide, 4,4'-diamino Diphenyl sulfide, 3,3′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether (34 ODA), 4,4′-diaminodiphenyl ether (ODA), 1,5-diaminonaphthalene, 4,4′-diaminodiphenyldiethylsilane, 4,4′-diaminodiphenylsilane, 4,4′-diaminodiphenylethylphosphine oxide, 1,3-bis (3-aminophenoxy) benzene (133APB), 1,3-bis (4-aminophenoxy) benzene (134APB) ), 1,4-bis (4-aminophenoxy) benzene, bis [4- (3-aminophenoxy) phenyl] sulfone (BAPSM), bis [4- (4-aminophenoxy) phenyl] sulfone (BAPS), 2 , 2-bis [4- (4-aminophenoxy) pheny Propane (BAPP), 2,2-bis (3-aminophenyl) 1,1,1,3,3,3-hexafluoropropane, 2,2-bis (4-aminophenyl) 1,1,1, 3,3,3-hexafluoropropane and 9,9-bis (4-aminophenyl) fluorene, 3,3'-dichlorobenzidine, 1,5-diaminonaphthalene, 3,3'-dimethyl-4,4'- Biphenyldiamine, benzidine, 3,3′-dimethylbenzidine, 3,3′-dimethoxybenzidine, 4,4′-diaminodiphenylpropane, 2,4-bis (β-amino-t-butyl) toluene, bis (p- β-amino-t-butylphenyl) ether, bis (p-β-methyl-δ-aminophenyl) benzene, bis-p- (1,1-dimethyl-5-amino-pentyl) benzene, 1-i Sopropyl-2,4-m-phenylenediamine, m-xylylenediamine, p-xylylenediamine and the like are preferable. Among them, preferable diamines are paraphenylenediamine (PPD), metaphenylenediamine (MPDA), 4,4′-diaminodiphenylmethane (MDA), 3,3′-diaminodiphenylsulfone (33DDS), and 4,4′-diaminodiphenylsulfone. (44DDS), 3,4'-diaminodiphenyl ether (34 ODA), 4,4'-diaminodiphenyl ether (ODA), 1,3-bis (3-aminophenoxy) benzene (133APB), 1,3-bis (4- Aminophenoxy) benzene (134APB), bis [4- (3-aminophenoxy) phenyl] sulfone (BAPSM), bis [4- (4-aminophenoxy) phenyl] sulfone (BAPS), 2,2-bis [4- (4-Aminophenoxy) phenyl] propane (BAP ) It is.

Also, diamines other than aromatic diamines can be used. For example, di (p-aminocyclohexyl) methane, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, diaminopropyltetramethylene, 3-methylheptamethylenediamine, 4,4-dimethylhepta Methylenediamine, 2,11-diaminododecane, 1,2-bis-3-aminopropoxyethane, 2,2-dimethylpropylenediamine, 3-methoxyhexamethylenediamine, 2,5-dimethylheptamethylenediamine, 5-methylnona Methylenediamine, 2,17-diaminoeicosadecane, 1,4-diaminocyclohexane, 1,10-diamino-1,10-dimethyldecane, 1,12-diaminooctadecane, piperazine, H ₂ N (CH ₂ ) ₃ O (C _{2) 2 OCH 2 NH 2,} H 2 N (CH 2) 3 S (CH 2) 3 NH 2, H 2 N (CH 2) 3 N (CH 2) 2 (CH 2) 3 NH 2 and the like .

As a tetracarboxylic dianhydride used as the raw material of the said thermosetting polyimide resin, an aromatic tetracarboxylic dianhydride is preferable. Specific examples of the aromatic tetracarboxylic dianhydride include pyromellitic dianhydride (PMDA), 1,2,5,6-naphthalene tetracarboxylic dianhydride, 1,4,5,8- Naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride, 2,3,3′4 ′ -Biphenyltetracarboxylic dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride (BPDA), 2,2', 3,3'-benzophenone tetracarboxylic dianhydride, 2, 3,3 ′, 4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride (BTDA), bis (3,4-dicarboxyphenyl) sulfone dianhydride object Bis (2,3-dicarboxyphenyl) methane dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, 1 , 1-bis (3,4-dicarboxyphenyl) ethane dianhydride, 2,2-bis [3,4- (dicarboxyphenoxy) phenyl] propane dianhydride (BPADA), 4,4 ′-(hexa) Fluoroisopropylidene) diphthalic anhydride, oxydiphthalic anhydride (ODPA), bis (3,4-dicarboxyphenyl) sulfone dianhydride, bis (3,4-dicarboxyphenyl) sulfoxide dianhydride, thiodiphthalic acid Anhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 1,2,7 8-phenanthrenetetracarboxylic dianhydride, 9,9-bis (3,4-dicarboxyphenyl) fluorene dianhydride and 9,9-bis [4- (3,4'-dicarboxyphenoxy) phenyl] fluorene A dianhydride etc. can be mentioned. Among them, preferred tetracarboxylic dianhydrides are pyromellitic dianhydride (PMDA), 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (BPDA), 3,3 ′, 4,4 ′. -Benzophenone tetracarboxylic dianhydride (BTDA), 2,2-bis [3,4- (dicarboxyphenoxy) phenyl] propane dianhydride (BPADA), oxydiphthalic anhydride (ODPA), 2,3,3 ', 4-biphenyltetracarboxylic dianhydride, 2,2'-bis (3,4-dicarboxyphenyl) propane dianhydride, perylene-3,4,9,10-tetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, ethylenetetracarboxylic dianhydride and the like. These may be reacted with alcohols such as methanol and ethanol to form ester compounds. These aromatic diamines, aromatic tetracarboxylic acids, and aromatic tetracarboxylic acid anhydrides can be used alone or in combination. Furthermore, a plurality of types of polyimide precursor solutions can be prepared, and these polyimide precursor solutions can be mixed and used.

Examples of the organic polar solvent for reacting the aromatic tetracarboxylic acid (or aromatic tetracarboxylic dianhydride) with the aromatic diamine include N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethyl. Examples include acetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, N-methylcaprolactam, hexamethylphosphoric triamide, 1,2-dimethoxyethane, diglyme and triglyme. Among them, preferred solvents are N, N-dimethylacetamide (DMAc) and N-methyl-2-pyrrolidone (NMP). These solvents can be used alone or as a mixture or mixed with other solvents such as aromatic hydrocarbons such as toluene and xylene.

The thermoplastic polyimide resin is described in detail below.
The thermoplastic polyimide resin is preferably a thermoplastic polyimide resin obtained by polycondensation reaction of a raw material composition containing a diamine component and a tetracarboxylic dianhydride component. The glass transition temperature Tg of the thermoplastic polyimide resin used in the present invention is 150 ° C. or higher.

As the diamine used as a raw material for the thermoplastic polyimide resin, 4,4′-bis (3-aminophenoxy) biphenyl or the like can be used as described above, but is not particularly limited, and the effect of the present invention. Various raw materials can be used as long as the above can be obtained. Examples of the diamine that can be used as a raw material for the thermoplastic polyimide resin are shown below.

Examples of the diamine that can be used as the raw material for the thermoplastic polyimide resin include m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-aminobenzylamine, p-aminobenzylamine, and 4,4′-diaminodiphenyl ether. 3,3′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, bis (3-aminophenyl) sulfide, bis (4-aminophenyl) sulfide, (3-aminophenyl) (4-aminophenyl) sulfide, bis (3-aminophenyl) sulfoxide, bis (4-aminophenyl) sulfoxide, (3-aminophenyl) (4-aminophenyl) sulfoxide, bis (3-aminophenyl) sulfone, bis (4-aminophenyl) sulfone, ( 3-amino Enyl) (4-aminophenyl) sulfone, 3,3′-diaminobenzophenone, 4,4′-diaminobenzophenone, 3,4′-diaminobenzophenone, 3,3′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, bis [4- (3-aminophenoxy) phenyl] methane, bis [4- (4-aminophenoxy) phenyl] methane, 1,1-bis [4- (3-aminophenoxy) Phenyl] ethane, 1,2-bis [4- (3-aminophenoxy) phenyl] ethane, 1,1-bis [4- (4-aminophenoxy) phenyl] ethane, 1,2-bis [4- (4 -Aminophenoxy) phenyl] ethane, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, 2,2- [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (3-aminophenoxy) phenyl] butane, 2,2-bis [3- (3-aminophenoxy) phenyl] -1 , 1,1,3,3,3-hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, 1, 3-bis (3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, bis [4- (3-aminophenoxy) phenyl] ketone, bis [4- (4-aminophenoxy) phenyl] ketone, bis [4- ( 3-aminophenoxy) phenyl] sulfide, bis [4- (4-aminophenoxy) phenyl] sulfide, bis [4- (3-aminophenoxy) phenyl] sulfoxide, bis [4- (4-aminophenoxy) phenyl] sulfoxide Bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (4- Aminophenoxy) phenyl] ether, 1,4-bis [4- (3-aminophenoxy) benzoyl] benzene, 1,3-bis [4- (3-aminophenoxy) benzoyl] benzene, 4,4′-bis [ 3- (4-Aminophenoxy) benzoyl] diphenyl ether, 4,4′-bis [3- (3-amino Phenoxy) benzoyl] diphenyl ether, 4,4′-bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy] benzophenone, 4,4′-bis [4- (4-amino-α, α-dimethyl) Benzyl) phenoxy] diphenylsulfone, bis [4- {4- (4-aminophenoxy) phenoxy} phenyl] sulfone, 1,4-bis [4- (4-aminophenoxy) phenoxy-α, α-dimethylbenzyl] benzene 1,3-bis [4- (4-aminophenoxy) phenoxy-α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-amino-6-trifluoromethylphenoxy) -α, α -Dimethylbenzyl] benzene, 1,3-bis [4- (4-amino-6-fluorophenoxy) -α, α-dimethylbenzyl] benzene 1,3-bis [4- (4-amino-6-methylphenoxy) -α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-amino-6-cyanophenoxy) -α, α -Dimethylbenzyl] benzene, 3,3'-diamino-4,4'-diphenoxybenzophenone, 4,4'-diamino-5,5'-diphenoxybenzophenone, 3,4'-diamino-4,5'- Diphenoxybenzophenone, 3,3'-diamino-4-phenoxybenzophenone, 4,4'-diamino-5-phenoxybenzophenone, 3,4'-diamino-4-phenoxybenzophenone, 3,4'-diamino-5'- Phenoxybenzophenone, 3,3′-diamino-4,4′-dibiphenoxybenzophenone, 4,4′-diamino-5,5′-dibiphenoxyben Phenone, 3,4′-diamino-4,5′-dibiphenoxybenzophenone, 3,3′-diamino-4-biphenoxybenzophenone, 4,4′-diamino-5-biphenoxybenzophenone, 3,4′-diamino -4-biphenoxybenzophenone, 3,4'-diamino-5'-biphenoxybenzophenone, 1,3-bis (3-amino-4-phenoxybenzoyl) benzene, 1,4-bis (3-amino-4- Phenoxybenzoyl) benzene, 1,3-bis (4-amino-5-phenoxybenzoyl) benzene, 1,4-bis (4-amino-5-phenoxybenzoyl) benzene, 1,3-bis (3-amino-4) -Biphenoxybenzoyl) benzene, 1,4-bis (3-amino-4-biphenoxybenzoyl) benzene, 1,3- (4-amino-5-biphenoxybenzoyl) benzene, 1,4-bis (4-amino-5-biphenoxybenzoyl) benzene, 2,6-bis [4- (4-amino-α, α-dimethyl) Benzyl) phenoxy] benzonitrile, 6,6′-bis (2-aminophenoxy) -3,3,3 ′, 3′-tetramethyl-1,1′-spirobiindane, 6,6′-bis (3-amino Phenoxy) -3,3,3 ′, 3′-tetramethyl-1,1′-spirobiindane, 4,4′-bis (3-aminophenoxy) biphenyl, 1,3-bis (3- (3-aminophenoxy) ) Phenoxy) benzene, bis (3- (3-aminophenoxy) phenyl) ether, bis (3- (3- (3-aminophenoxy) phenoxy) phenyl) ether, bis (4- (3-a Nophenoxy) phenyl) sulfone, 1,3-bis (4- (4-aminophenoxy) -α, α-dimethylbenzyl) benzene, 2,2-bis (4-aminophenoxyphenyl) propane, 1,3-bis (1- (4- (4-aminophenoxy) phenyl) -1-methylethyl) benzene, 1,4-bis (1- (4- (4-aminophenoxy) phenyl) -1-methylethyl) benzene, 1 , 4-Bis (1- (4- (3-aminophenoxy) phenyl) -1-methylethyl) benzene, 2,2-bis (3- (3-aminophenoxy) phenyl) -1,1,1,3 , 3,3-hexafluoropropane, 2,2-bis (3- (4-aminophenoxy) phenyl) -1,1,1,3,3,3-hexafluoropropane and the like. More preferably selected from 1,3-bis (3-aminophenoxy) benzene, 4,4′-bis (3-aminophenoxy) biphenyl, and 1,3-bis (3- (3-aminophenoxy) phenoxy) benzene At least one kind of diamine is used. More preferred diamines are 1,3-bis (3-aminophenoxy) benzene and 1,3-bis (3- (3-aminophenoxy) phenoxy) benzene. These can be used alone or in admixture of two or more.

The tetracarboxylic dianhydride used as a raw material for the thermoplastic polyimide is not particularly limited as long as it can produce a thermoplastic polyimide. For example, the following tetracarboxylic dianhydrides can be used.
As tetracarboxylic dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, pyromellitic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride Oxy-4,4′-diphthalic dianhydride, 2,2-bis [4- (3,4-dicarboxyphenoxy) phenyl] propane dianhydride, ethylene glycol bistrimellitic dianhydride, 2, 2-bis (3,4-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride, 2,2 ′, 3,3′-benzophenone tetracarboxylic dianhydride 1,2-bis (3,4-dicarboxybenzoyl) benzene dianhydride, 1,3-bis (3,4-dicarboxybenzoyl) benzene dianhydride, 1,4-bis (3,4-di Carboxybenzoyl) Zen dianhydride, 2,2′-bis ((3,4-dicarboxy) phenoxy) benzophenone dianhydride, 2,3′-bis ((3,4-dicarboxy) phenoxy) benzophenone dianhydride, 2 , 4′-bis ((3,4-dicarboxy) phenoxy) benzophenone dianhydride, 3,3′-bis ((3,4-dicarboxy) phenoxy) benzophenone dianhydride, 3,4′-bis ( (3,4-Dicarboxy) phenoxy) benzophenone dianhydride, 4,4′-bis ((3,4-dicarboxy) phenoxy) benzophenone dianhydride, and the like can be used.

The thermoplastic polyimide resin can be produced using the above-described raw materials, and is not particularly limited as long as it is a thermoplastic polyimide resin, and various compounds can be used. Examples of the thermoplastic polyimide resin include the following chemical formulas:

It is also one of the preferable forms to have a structural unit represented by The raw material monomer for producing this thermoplastic polyimide resin is 4,4′-bis (3-aminophenoxy) biphenyl, pyromellitic dianhydride, or hydrolysis obtained by opening at least a part of the ring by hydrolysis. A ring-opened product, a phthalic anhydride, or a hydrolyzed ring-opened product in which at least a part thereof is opened by hydrolysis.

As said polyimide resin, an alicyclic polyimide resin can also be used besides an aromatic polyimide resin. Although it does not specifically limit as a raw material which produces | generates an alicyclic polyimide resin, For example, the alicyclic tetracarboxylic dianhydride shown below can be used as a raw material. As the alicyclic tetracarboxylic acid anhydride, the following formula:

A monocyclic aliphatic tetracarboxylic dianhydride represented by the formula:

An aliphatic tetracarboxylic dianhydride having a bicyclo ring structure represented by the following formula:

A tricyclic or higher polyalicyclic tetracarboxylic dianhydride represented by the formula is preferred.

The thermoplastic polyimide resin can be produced by a known method. For example, N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), N, N-dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO), dimethyl sulfate, sulfolane, butyrolactone, cresol, phenol, halogen In a solvent such as fluorinated phenol, cyclohexane, dioxane, tetrahydrofuran, diglyme and triglyme, the tetracarboxylic dianhydride component and the diamine component are mixed at a predetermined ratio to obtain a raw material composition. By reacting the obtained raw material composition within a reaction temperature range of 0 to 100 ° C., a solution of a thermoplastic polyimide precursor is obtained. The polyimide precursor is, for example, polyamic acid. There is a method in which this solution is heat-treated in a high temperature atmosphere of 200 ° C. to 500 ° C. and imidized to obtain a thermoplastic polyimide solution.

The molar ratio of the diamine component to the tetracarboxylic dianhydride component (tetracarboxylic dianhydride component / diamine component) contained in the thermoplastic polyimide raw material is preferably in the range of 0.75 to 1.25, 0 The range of .90 to 1.10 is more preferable, and the range of 1.00 to 0.97 is particularly preferable. This is because the reaction is easy to control and the heat fluidity of the thermoplastic polyimide to be synthesized is good. The total content of the diamine component and the tetracarboxylic dianhydride component in the raw material composition of the thermoplastic polyimide precursor solution is preferably about 5 to 20% by weight.

Polyamideimide resin can also be used as the polyimide resin. The polyamide-imide resin is a polyimide resin having an imide bond and an amide bond derived from a tricarboxylic acid compound (here, “polyimide resin” means a polyimide resin in a broad sense). Such a polyamideimide resin can be obtained by imidizing a polyamideimide precursor polymer.
The polyamideimide precursor polymer is preferably obtained by a reaction between a polyvalent carboxylic acid compound containing at least a tricarboxylic acid compound and a polyvalent amine compound and / or a polyvalent isocyanate compound. As a reaction raw material, 1 type (s) or 2 or more types can each be used, A multiple type polyamideimide precursor polymer can be prepared, and these polymers can also be mixed and used.

The polyvalent carboxylic acid compound is a compound having two or more carboxyl groups or carboxyl group-derived groups in the molecule, and includes anhydrides thereof. Therefore, a tricarboxylic acid compound, which is one type of polyvalent carboxylic acid compound, is a compound having three carboxyl groups or carboxyl group-derived groups in the molecule, and includes anhydrides thereof.
Here, the carboxyl group-derived group is represented by COX, and X is a group represented by a halogen element or OR ⁴ (R ⁴ represents an alkyl group having 1 to 6 carbon atoms or a phenyl group). .

The polyvalent carboxylic acid compound includes at least a tricarboxylic acid compound, and the content ratio of the tricarboxylic acid compound is preferably 30% by mass or more with respect to 100% by mass of the total amount of the polyvalent carboxylic acid compound. . Thereby, further excellent curing transferability can be exhibited. More preferably, it is 50 mass% or more, More preferably, it is 70 mass% or more.

As the tricarboxylic acid compound (including tricarboxylic acid monoanhydride), those containing an aliphatic cyclic hydrocarbon, an aromatic ring or an aromatic heterocyclic ring are suitable. For example, a phenyl group, a biphenyl group, a terphenyl group, Three carboxyl groups or derivatives thereof are bonded to groups such as naphthalene group, perylene group, diphenyl ether group, diphenylsulfone group, diphenylpropane group, benzophenone group, biphenyltrifluoropropane group, cyclobutyl group, cyclopentyl group, cyclohexyl group, etc. And the like. Among these, those containing an aromatic ring are preferable, and trimellitic acid, hydrogenated trimellitic acid, and anhydrides and derivatives thereof are more preferable.

Examples of the polyvalent carboxylic acid compound other than the tricarboxylic acid compound include tetracarboxylic acid compounds and anhydrides thereof. Among them, the aromatic tetracarboxylic dianhydrides shown below are preferable. These may be reacted with alcohols such as methanol and ethanol to form ester compounds.
Pyromellitic dianhydride (PMDA), 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7- Naphthalenetetracarboxylic dianhydride, 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride, 2,3,3′4′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4 4′-biphenyltetracarboxylic dianhydride (BPDA), 2,2 ′, 3,3′-benzophenone tetracarboxylic dianhydride, 2,3,3 ′, 4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride (BTDA), bis (3,4-dicarboxyphenyl) sulfone dianhydride, bis (2,3-dicarboxyphenyl) methane dianhydride , Screw (3,4- Carboxyphenyl) methane dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, 1,1-bis (3,4-dicarboxyphenyl) ethane dianhydride, 2,2- Bis [3,4- (dicarboxyphenoxy) phenyl] propane dianhydride (BPADA), 4,4 ′-(hexafluoroisopropylidene) diphthalic anhydride, oxydiphthalic anhydride (ODPA), bis (3,4 -Dicarboxyphenyl) sulfone dianhydride, bis (3,4-dicarboxyphenyl) sulfoxide dianhydride, thiodiphthalic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3 , 6,7-anthracenetetracarboxylic dianhydride, 1,2,7,8-phenanthrenetetracarboxylic dianhydride, 9,9-bis (3,4-di Carboxymethyl phenyl) fluorene dianhydride and 9,9-bis [4- (3,4'-dicarboxyphenoxy) phenyl] fluorene dianhydride and the like.

Among these, pyromellitic dianhydride (PMDA), 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (BPDA), 3,3 ′, 4,4′-benzophenone tetracarboxylic acid Anhydride (BTDA), 2,2-bis [3,4- (dicarboxyphenoxy) phenyl] propane dianhydride (BPADA), oxydiphthalic anhydride (ODPA), 2,3,3 ′, 4-biphenyltetra Carboxylic dianhydride, 2,2′-bis (3,4-dicarboxyphenyl) propane dianhydride, perylene-3,4,9,10-tetracarboxylic dianhydride, bis (3,4-di Carboxyphenyl) ether dianhydride, ethylenetetracarboxylic dianhydride and the like are preferred.

The polyvalent amine compound is a compound having two or more amino groups in the molecule, and particularly preferably a compound having two amino groups in the molecule (diamine compound). As the diamine compound, an aromatic diamine containing an aromatic ring between two amino groups, an aliphatic diamine composed of an aliphatic group between two amino groups, and a structural unit containing a siloxane bond between two amino groups Siloxane diamine etc. which have can be used.

Specific examples of the aromatic diamine include paraphenylenediamine (PPD), metaphenylenediamine (MPDA), 2,5-diaminotoluene, 2,6-diaminotoluene, 4,4′-diaminobiphenyl, 3, 3′-dimethyl-4,4′-biphenyl, 3,3′-dimethoxy-4,4′-biphenyl, 2,2-bis (trifluoromethyl) -4,4′-diaminobiphenyl, 4,4′- Bis (3-aminophenoxy) biphenyl, 3,3′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane (MDA), 2,2-bis- (4-aminophenyl) propane, 3,3′-diaminodiphenylsulfone (33DDS), 4,4'-diaminodiphenyl sulfone (44DDS), 3,3'-diaminodiphenyl sulfide, , 4′-diaminodiphenyl sulfide, 3,3′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether (34 ODA), 4,4′-diaminodiphenyl ether (ODA), 1,5-diaminonaphthalene, 4,4′- Diaminodiphenyldiethylsilane, 4,4′-diaminodiphenylsilane, 4,4′-diaminodiphenylethylphosphine oxide,

1,3-bis (3-aminophenoxy) benzene (133APB), 1,3-bis (4-aminophenoxy) benzene (134APB), 1,4-bis (4-aminophenoxy) benzene, bis [4- ( 3-aminophenoxy) phenyl] sulfone (BAPSM), bis [4- (4-aminophenoxy) phenyl] sulfone (BAPS), 2,2-bis [4- (4-aminophenoxy) phenyl] propane (BAPP), 2,2-bis (3-aminophenyl) 1,1,1,3,3,3-hexafluoropropane, 2,2-bis (4-aminophenyl) 1,1,1,3,3,3- Hexafluoropropane and 9,9-bis (4-aminophenyl) fluorene, 3,3'-dichlorobenzidine, 1,5-diaminonaphthalene, 3,3'-dimethyl 4,4′-biphenyldiamine, benzidine, 3,3′-dimethylbenzidine, 3,3′-dimethoxybenzidine, 4,4′-diaminodiphenylpropane, 2,4-bis (β-amino-t-butyl) toluene Bis (p-β-amino-t-butylphenyl) ether, bis (p-β-methyl-δ-aminophenyl) benzene, bis-p- (1,1-dimethyl-5-amino-pentyl) benzene, Examples include 1-isopropyl-2,4-m-phenylenediamine, m-xylylenediamine, and p-xylylenediamine.

Among these, paraphenylenediamine (PPD), metaphenylenediamine (MPDA), 4,4′-diaminodiphenylmethane (MDA), 3,3′-diaminodiphenylsulfone (33DDS), 4,4′-diaminodiphenylsulfone ( 44DDS), 3,4′-diaminodiphenyl ether (34 ODA), 4,4′-diaminodiphenyl ether (ODA), 1,3-bis (3-aminophenoxy) benzene (133APB), 1,3-bis (4-amino) Phenoxy) benzene (134APB), bis [4- (3-aminophenoxy) phenyl] sulfone (BAPSM), bis [4- (4-aminophenoxy) phenyl] sulfone (BAPS), 2,2-bis [4- ( 4-Aminophenoxy) phenyl] propane (BAPP) It is preferred.

Examples of the aliphatic diamine include di (p-aminocyclohexyl) methane, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, diaminopropyltetramethylene, and 3-methylheptamethylenediamine. 4,4-dimethylheptamethylenediamine, 2,11-diaminododecane, 1,2-bis-3-aminopropoxyethane, 2,2-dimethylpropylenediamine, 3-methoxyhexamethylenediamine, 2,5-dimethylhepta Methylenediamine, 5-methylnonamethylenediamine, 2,17-diaminoeicosadecane, 1,4-diaminocyclohexane, 1,10-diamino-1,10-dimethyldecane, 1,12-diaminooctadecane, piperazine, _{2 N (CH 2) 3 O} (CH 2) 2 OCH 2 NH 2, H 2 N (CH 2) 3 S (CH 2) 3 NH 2, H 2 N (CH 2) 3 N (CH 2) 2 ( CH ₂ ) ₃ NH _{2 and the} like.

Examples of the siloxane diamine include polydimethylsiloxane diamine (silicone oil X-22-161AS (amine equivalent 450), X-22-161A (amine equivalent 840), X-22-161B (amine equivalent 1500), X- 22-9409 (amine equivalent 700), X-22-1660B-3 (amine equivalent 2200), KF-8010 (amine equivalent 415) (above, manufactured by Shin-Etsu Chemical Co., Ltd.)) and the like.

The polyvalent isocyanate compound is a compound having two or more isocyanate groups in the molecule, and particularly preferably a compound (diisocyanate compound) having two isocyanate groups in the molecule.
Examples of the diisocyanate compound include methylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, isophorone diisocyanate, cyclohexyl diisocyanate, p-xylene diisocyanate, m-xylene diisocyanate, 4,4′-bis ( 3-Tolylene) diisocyanate, 3,3′-dichloro-4,4′-diisocyanate biphenyl, 4,4′-diphenylmethane diisocyanate, 4,4′-diphenyl ether diisocyanate, p-phenylene diisocyanate, m-phenylene diisocyanate and the like. .

In the reaction of the polyvalent carboxylic acid compound with the polyvalent amine compound and / or the polyvalent isocyanate compound, the ratio of these components may be appropriately set by adjusting the molecular weight recommended for the polyamideimide precursor polymer. For example, when the total amount of the carboxyl group and the derivative group thereof is 1 mol, it is preferable that the total molar amount of the amino group and the isocyanate group is 0.7 to 1.5 mol. When the amount is more than 1.5 mol, unreacted polyvalent amine compound or polyvalent isocyanate compound tends to remain, and there is a possibility that the film forming property may not be sufficient. When the amount is less than 0.7 mol, gelation occurs. In this case, the film forming property may not be sufficient. More preferably, the total molar amount of amino group and isocyanate group is 0.9 to 1.3 mol.

The above reaction may be carried out by a usual method. For example, the reaction temperature is preferably 80 to 210 ° C. This makes it possible to shorten the reaction time and sufficiently suppress gelation. More preferably, it is 100-190 degreeC, More preferably, it is 120-180 degreeC. The reaction time is preferably 30 minutes to 15 hours, more preferably 1 to 10 hours.

The above reaction may also be performed in the presence of an organic solvent or a catalyst as necessary.
The organic solvent is preferably an organic polar solvent, for example, N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2 -Imidazolidinone, N-methylcaprolactam, hexamethylphosphoric triamide, 1,2-dimethoxyethane, diglyme and triglyme. Among these, N, N-dimethylacetamide (DMAc) and N-methyl-2-pyrrolidone (NMP) are preferable. These solvents can be used alone or as a mixture, or can be used by mixing with other solvents such as aromatic hydrocarbons such as toluene and xylene.
Examples of the catalyst include tertiary amines, alkali metals, alkaline earth metals, metals such as tin, zinc, titanium, and cobalt, or metalloid compounds.

The molecular weight of the polyamideimide resin is preferably 1000 to 200000 as the number average molecular weight. If it is less than 1000, it may not be a resin having excellent heat resistance, and if it exceeds 200000, it may be gelled. More preferably, it is 5000-150,000, More preferably, it is 10,000-100000.
The number average molecular weight can be measured, for example, by a gel permeation chromatograph (GPC) using a standard polystyrene calibration curve.

Thus, the raw materials (polyamic acid, precursor polymer, etc.) of the polyimide resin described above are solvent-soluble, and can be handled in a liquid state before curing (imidization) in the light shielding layer forming step. Therefore, carbon black can be more uniformly dispersed in the organic resin with a low shear (shearing force).

As said polyimide resin, a solvent soluble polyimide resin can also be used besides the thing mentioned above. Solvent-soluble polyimide resin refers to a polyimide resin that is soluble in organic solvents, introducing a flexible molecular chain into the molecular skeleton, or introducing a group that increases the distance between imide rings in the molecule. Thus, the solvent is soluble.
The solvent-soluble polyimide resin is not particularly limited as long as it is soluble in an organic solvent, and conventionally known ones can be widely used. The solvent-soluble polyimide resin can be prepared by imidizing a tetracarboxylic dianhydride and a diamine component, preferably in an inert gas atmosphere.
When such a solvent-soluble polyimide resin is used, carbon black is dispersed in the polyimide resin solution in the process of forming the light shielding layer, so that the carbon black is uniformly dispersed with a low shear (shearing force). Can do.

The said epoxy resin (hardened | cured material) is obtained by making the polyfunctional epoxy compound which is curable resin used as the raw material carry out hardening reaction.
As the polyfunctional epoxy compound, the following compounds are suitable. Epibis type glycidyl ether type epoxy resin obtained by condensation reaction of bisphenols such as bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol and epihalohydrin, and these bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, etc. High molecular weight epibis type glycidyl ether type epoxy resin obtained by further addition reaction with other bisphenols; phenols such as phenol, cresol, xylenol, naphthol, resorcin, catechol, bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol And formaldehyde, acetoaldehyde, propionaldehyde, benzaldehyde, hydroxybenzaldehyde Obtained by condensation reaction of polyhydric phenols obtained by condensation reaction of hydride, salicylaldehyde, dicyclopentadiene, terpene, coumarin, paraxylylene glycol dimethyl ether, dichloroparaxylylene, bishydroxymethylbiphenyl, etc. with epihalohydrin. Novolak aralkyl type glycidyl ether type epoxy resin; aromatic crystalline epoxy resin obtained by condensation reaction of tetramethylbiphenol, tetramethylbisphenol F, hydroquinone, naphthalene diol and the like with epihalohydrin, and the above bisphenols and tetramethyl Aromatic crystalline epoxy tree obtained by addition reaction of biphenol, tetramethylbisphenol F, hydroquinone, naphthalene diol, etc. High molecular weight polymers of the above; alicyclic glycols hydrogenated aromatic skeletons such as bisphenols, tetramethylbiphenol, tetramethylbisphenol F, hydroquinone, naphthalene diol, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, PEG600, propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, PPG, glycerol, diglycerol, tetraglycerol, polyglycerol, trimethylolpropane and its multimer, pentaerythritol and its multimer, glucose, fructose, lactose Aliphatic glycidyl ether type epoxide obtained by condensation reaction of mono / polysaccharides such as maltose and epihalohydrin (3,4-epoxycyclohexane) epoxy resin having an epoxycyclohexane skeleton such as methyl 3 ′, 4′-epoxycyclohexyl carboxylate; condensation of tetrahydrophthalic acid, hexahydrophthalic acid, benzoic acid and epihalohydrin A glycidyl ester type epoxy resin obtained by reaction; a tertiary amine-containing glycidyl ether type epoxy resin solid at room temperature obtained by a condensation reaction of hindatoin, cyanuric acid, melamine, benzoguanamine and epihalohydrin. Among them, the aliphatic glycidyl ether type epoxy resin and the epoxy resin having an epoxycyclohexane skeleton are more preferably used for the purpose of suppressing the appearance deterioration during light irradiation.

The compound having at least one epoxy group is also preferably a compound having flexibility. By including a compound having flexibility, for example, handling properties are excellent in processes such as processing and molding. By using a compound having flexibility, it is particularly suitable, for example, when it is formed into a film shape or the like. As the compound having at least one flexible epoxy group, specifically, a compound having an oxyalkylene skeleton represented by — [— (CH ₂ ) _n —O—] _m — (n is 2 or more) , M is an integer greater than or equal to 1. Preferably, n is 2-12, m is an integer of 1-1000, More preferably, n is 3-6, m is an integer of 1-20.) Polymer epoxy resin (for example, hydrogenated bisphenol type epoxy resin (manufactured by Japan Epoxy Resin, YL-7170, epoxy equivalent 1000, solid hydrogenated epoxy resin); epoxy resin whose oxyalkylene skeleton is oxybutylene (Japan epoxy resin) YL-7217, epoxy equivalent 437, liquid epoxy resin (10 ° C. or higher), YED-216D manufactured by Japan Epoxy Resin); Resin (for example, YE-8100BX, YX6954BX, etc., manufactured by Japan Epoxy Resin Co., Ltd.); alicyclic solid epoxy resin (EHPE-3150, manufactured by Daicel Kogyo Co., Ltd.); alicyclic liquid epoxy resin (Celoxide 2081, manufactured by Daicel Kogyo Co., Ltd.) Among these, more preferred are compounds containing an epoxy group at the terminal, side chain, main chain skeleton, etc. Thus, a compound having at least one epoxy group has flexibility. This is one of the preferred embodiments of the present invention.

In the present invention, a curable resin containing a non-curable component such as a thermoplastic resin and a low molecular weight curable compound can also be used. Examples of the thermoplastic resin include polyethylene, polypropylene, polystyrene, acrylonitrile / styrene copolymer (AS resin), ABS resin made of acrylonitrile / butadiene / styrene, vinyl chloride resin, (meth) acrylic resin, polyamide resin, and acetal resin. , Polycarbonate resin, polyphenylene oxide, polyester, polyimide and the like. As the curable compound, a polyhydric phenol compound, a compound having a polymerizable unsaturated bond, a polyimide resin, and a compound having at least one epoxy group may be appropriately selected and used.

In the present invention, when the raw material of the organic resin is a polyfunctional epoxy compound, the organic resin is preferably one that is cationically cured using a heat latent cation generator. The heat latent cation generator is also called a cationic polymerization initiator, and exhibits a substantial function as a curing agent when the resin composition reaches a curing temperature. By using such a heat-latent cation generator, for example, even when an organic resin raw material that cures at room temperature is used, curing can be prevented from proceeding at room temperature. Can be easily handled. In addition, the moisture resistance of the resulting cured resin composition (organic resin, light-shielding layer) is dramatically improved, and it retains the excellent optical properties of the resin composition even in harsh usage environments, making it suitable for various applications. It can be used for. Normally, if water with a high refractive index is contained in the resin composition or its cured product, it may cause turbidity and a decrease in blackness. However, when the above cationic curable resin composition is used, excellent moisture resistance is exhibited. Since it can do, such turbidity and a fall of blackness are suppressed and it can use it suitably for optical uses, such as a light-shielding film and a lens. Especially in applications such as in-vehicle cameras and bar code readers for home delivery companies, there are concerns over yellowing and deterioration of strength due to prolonged ultraviolet irradiation and high temperature exposure in summer. It is thought that the generation of oxygen radicals is caused by the synergistic effect of exposure to heat rays. By improving moisture resistance, moisture absorption into the cured resin composition is suppressed, and generation of oxygen radicals due to a synergistic effect of ultraviolet irradiation or exposure to heat rays is also suppressed. Exhibits excellent heat resistance for a long time without causing it.

As the heat latent cation generator, the following general formula (2):
_{^{(R 1 b R 2 c R}} 3 d R 4 e Z) + m (MXn) -m (2)
(In the formula, Z represents at least one element selected from the group consisting of S, Se, Te, P, As, Sb, Bi, O, N and halogen elements. R ¹ , R ² , R ³ and R ⁴ is the same or different and represents an organic group, b, c, d and e are 0 or a positive number, and the sum of b, c, d and e is equal to the valence of Z. Cation (R ^{1 _{.M b R 2 c R 3 d}} R 4 e Z) + m are representative of the onium salt, represents a metal or metalloid which is the central atom of a halide complex (metalloid), B, P, as, Al, Ca, It is at least one selected from the group consisting of In, Ti, Zn, Sc, V, Cr, Mn, and Co. X represents a halogen element, and m is the net charge of the halide complex ion. Is the number of halogen elements in the halide complex ion.) It is preferable that it is represented by these.

Specific examples of the anion (MXn) ^-m of the general formula (2) include tetrafluoroborate (BF ⁴⁻ ), hexafluorophosphate (PF ⁶⁻ ), hexafluoroantimonate (SbF ⁶⁻ ), hexafluoro arsenates ^{(AsF 6-),} hexachloroantimonate (SbCl ^6-), and the like.
Further general formula MXn (OH) ^- anions may be used which is represented by. Other anions include perchlorate ion (ClO ₄ ⁻ ), trifluoromethyl sulfite ion (CF ₃ SO ₃ ⁻ ), fluorosulfonate ion (FSO ₃ ⁻ ), toluenesulfonate ion, and trinitrobenzenesulfone. An acid ion etc. are mentioned.

Specific products of the above-mentioned heat-latent cation generator include diazonium salt types: AMERICURE series (American Can), ULTRASET series (Adeka), WPAG series (Wako Pure Chemical Industries)
Iodonium salt type: UVE series (manufactured by General Electric), FC series (manufactured by 3M), UV9310C (manufactured by GE Toshiba Silicone), Photoinitiator 2074 (manufactured by Rhone-Poulenc), WPI series (manufactured by Wako Pure Chemical Industries)
Sulfonium salt type: CYRACURE series (manufactured by Union Carbide), UVI series (manufactured by General Electric), FC series (manufactured by 3M), CD series (manufactured by Satomer), optomer SP series, optomer CP series (manufactured by Adeka) ), Sun Aid SI series (manufactured by Sanshin Chemical Industry Co., Ltd.), CI series (manufactured by Nippon Soda Co., Ltd.), WPAG series (manufactured by Wako Pure Chemical Industries, Ltd.), CPI series (manufactured by San Apro)
Etc.

Examples of the curing agent other than the thermal latent cation generator include acid anhydrides such as methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, pyromellitic anhydride, and methylnadic acid; Various phenol resins such as phenol novolak resin, cresol novolak resin, bisphenol A novolak resin, dicyclopentadiene phenol resin, phenol aralkyl resin, terpene phenol resin; various phenols and various such as hydroxybenzaldehyde, crotonaldehyde, glyoxal Various phenol resins such as a polyhydric phenol resin obtained by a condensation reaction with aldehydes; one or more of BF ₃ complexes, sulfonium salts, imidazoles and the like can be used. It is also a preferred embodiment that the compound having at least one epoxy group is cured with a polyhydric phenol compound described later.

In curing the resin composition containing the polyfunctional epoxy compound, a curing accelerator can be used. For example, triphenylphosphine, tributylhexadecylphosphonium bromide, tributylphosphine, tris (dimethoxyphenyl) phosphine, etc. 1 type, or 2 or more types, such as an organophosphorus compound, is suitable.
As said hardening temperature, 70-200 degreeC is preferable. More preferably, it is 80-150 degreeC. The curing time is preferably 1 to 15 hours. More preferably, it is 5 to 10 hours.

As the thermoplastic resin having a Tg of 150 ° C. or higher, a fluorinated aromatic polymer, a polyether ketone resin, a polyethylene naphthalate resin, a polyimide resin, or the like is preferable. In the present specification, “fluorinated aromatic polymer” excludes aromatic fluorinated polyether ketone resin.
The thermoplastic resin having a Tg of 150 ° C. or higher is preferably a fluorinated aromatic polymer, a polyimide resin, a polyetherketone resin, or a polyethylene naphthalate resin in that it has a high Tg and can be suitably used for reflowable processing. is there. More preferred are a fluorinated aromatic polymer, a polyimide resin, and a polyether ketone resin, and still more preferred are a polyether ketone resin and a polyimide resin.

The polyimide resin is as described above.
As the polyetherketone resin, an aromatic polyetherketone resin having an aromatic ring and a fluorinated polyetherketone resin (FPEK) partially or wholly fluorinated are preferable. More preferred is a fluorinated polyether ketone resin, and still more preferred is an aromatic fluorinated polyether ketone resin in which a part or all of the aromatic ring is fluorinated. When an aromatic fluorinated polyether ketone resin is used, the raw material is solvent-soluble and can be a light-shielding film having excellent heat resistance.
The aromatic fluorinated polyether ketone resin includes the following structural units:

(In the formula, R represents the following formula:

At least one of the groups represented by It is preferable that the polymer has at least one of the following. More preferably, it is a polymer having at least one of the structural units as a repeating unit, and more preferably, a polymer having the structural unit (I) having the group (1) as a repeating unit, and the group (2). It is a polymer which has structural unit (II) which has as a repeating unit.
The molecular weight of the fluorinated polyetherketone resin is preferably a number average molecular weight of 10,000 to 200,000, more preferably 20,000 to 150,000, and even more preferably 30,000 to 120,000.
The number average molecular weight is measured by GPC (gel permeation chromatography) in terms of styrene. The following conditions are used as GPC measurement conditions.
Model: HLC-8120GPC manufactured by Tosoh Corporation
Column: G-5000HXL + GMHXL-L
Developing solvent: THF
Flow rate: 1 ml / min
Standard: Standard polystyrene used

The thermoplastic resin has a Tg of 150 ° C. or higher. When the temperature is 150 ° C. or higher, the heat resistance and the flexibility can be improved. If the Tg is less than 150 ° C., the heat resistance is not sufficient for the reflowable specification, and there is a possibility that it cannot be suitably used for various applications. Tg is more preferably 180 ° C. or higher, further preferably 190 ° C. or higher, particularly preferably 200 ° C. or higher, and most preferably 230 ° C. or higher. For example, when a light-shielding film is attached to a lens module or the like, it is exposed to a high temperature in the element forming process or the like, but by having a high Tg as shown in the above range, the element forming process or the like. It is possible to prevent deformation at the processing temperature. By making the lens unit having the light-shielding film of the present invention have reflow resistance, automatic mounting by a solder reflow process is possible, and the manufacturing cost can be further reduced. In order to have sufficient heat resistance for the solder reflow process, Tg is particularly preferably 230 ° C. or higher. That is, it is one of the preferred embodiments of the present invention that the light-shielding film of the present invention is used for a lens unit that is subjected to a solder reflow process.

The number average molecular weight of the thermoplastic resin is 10,000 to 200,000, preferably 20,000 to 150,000. More preferably, it is 30000-120,000. If it is 10,000 or less, the resin is not excellent in heat resistance, and if it is 200,000 or more, the polymer may be gelled.

The organic resin may contain other components as long as it contains a curable resin cured product or a thermoplastic resin having a Tg of 150 ° C. or higher, and these components may be used alone or in combination of two or more. it can. When the organic resin contains the above-mentioned other components, the other components need to be handled in a liquid state in the step before curing or before molding. The content of the cured curable resin or the thermoplastic resin having a Tg of 150 ° C. or higher in the organic resin is preferably 50% by mass to 100% by mass with respect to 100% by mass of the total amount of the organic resin. More preferably, it is 70 mass%-100 mass%.

<Light shielding layer forming resin composition>
In the light-shielding film of the present invention, the light-shielding layer is preferably formed from a resin composition for forming a light-shielding layer (hereinafter also simply referred to as “resin composition”) containing an organic resin and / or its raw material and carbon black. . The organic resin and carbon black constituting the resin composition are the same as those described above.
The said resin composition may contain the other component, as long as the organic resin and / or its raw material, and carbon black are essential, and these components can use 1 type (s) or 2 or more types.

In the resin composition, the carbon black is preferably dispersed uniformly. When carbon black is dispersed in the resin composition, when carbon black is uniformly dispersed, the concentration distribution of carbon black in the light shielding layer becomes uniform, and the hue (black) becomes uniform. Further, when carbon black is dispersed at a uniform concentration, the cutting characteristics when the light-shielding film is cut into a fine size are excellent. On the other hand, when carbon black is not present in a dispersed state, when the light shielding layer is formed in the light shielding film, the light shielding layer may not be sufficiently black and may not exhibit better light shielding properties. is there.
The uniform dispersibility of carbon black when dispersed in the light shielding layer forming resin composition can be evaluated by using a transmission electron microscope (TEM).

As a method of dispersing the carbon black, that is, a method of producing a resin composition in which carbon black is dispersed, various methods can be suitably used. For example, (1) an organic resin and / or a raw material thereof can be used as a solvent. (2) A method of dissolving an organic resin and / or its raw material in a dispersion in which carbon black is dispersed; (3) An organic resin or its When the raw material itself is in liquid form, carbon black is mixed and dispersed in these (without using a solvent); (4) In addition, carbon is dispersed in a dispersion in which organic resin and / or the raw material is dispersed in the form of fine particles. A method of mixing and dispersing black, a method of melting and kneading a mixture of an organic resin and / or a raw material thereof and carbon black, etc. Gerare, appropriately selected depending on the carbon black and organic resin, can be used. Among these, (1) to (3) are preferably employed.

The carbon black content is preferably 1% by mass or more and less than 20% by mass with respect to 100% by mass of the total solid content of the organic resin and carbon black. If it is less than 1% by mass, the light-shielding property may not be sufficient, and if it is 20% by mass or more, the resin composition is too high in viscosity and is difficult to handle, and the resulting resin film may be easily broken. More preferably, it is 3 mass% or more, More preferably, it is 5 mass% or more. More preferably, it is 10 mass% or less.

It is preferable that the said resin composition contains a solvent with organic resin and / or its raw material, and carbon black. As the solvent, it is preferable to use a solvent that can dissolve the organic resin or its raw material. When the organic resin contains another resin or a resin raw material, it is preferable that those components are solvent-soluble. This makes it easy to uniformly disperse the carbon black in the resin composition, so that a resin composition in which the carbon black is sufficiently uniformly dispersed is obtained. As a result, the carbon black is sufficiently uniformly distributed. It becomes possible to obtain a film excellent in cutting characteristics and light shielding properties.
In this case, as a method for producing the resin composition, it is preferable to use a method in which a dispersion in which carbon black is dispersed is mixed and dispersed in a solution (resin binder solution) in which an organic resin and / or its raw material is dissolved. It is. Thereby, for example, when a light shielding layer (black layer) is formed by coating or the like using this resin composition, a more uniform blackness can be obtained as the light shielding layer, and excellent light shielding properties can be exhibited. It becomes possible.
When preparing a dispersion in which carbon black is dispersed, it is also a preferred form to use a dispersant such as polyvinylpyrrolidone.

The solvent is appropriately selected according to the type of resin, but ketones such as methyl ethyl ketone (2-butanone), methyl isobutyl ketone (4-methyl-2-pentanone), cyclohexanone, etc .; PGMEA (2-acetoxy-1- Methoxypropane), glycol derivatives such as ethylene glycol mono-n-butyl ether, ethylene glycol monoethyl ether, ethylene glycol ethyl ether acetate (ether compounds, ester compounds, ether ester compounds, etc.); amides such as N, N-dimethylacetamide Esters such as ethyl acetate, propyl acetate, and butyl acetate; pyrrolidones such as N-methyl-pyrrolidone (more specifically, 1-methyl-2-pyrrolidone); aromatic hydrocarbons such as toluene and xylene; ; Cyclohexane Aliphatic hydrocarbons such as heptane; ethers such as diethyl ether and Djibouti ether; and the like.
More preferably, the solvent is methyl ethyl ketone (2-butanone), methyl isobutyl ketone (4-methyl-2-pentanone), cyclohexanone, PGMEA (2-acetoxy-1-methoxypropane), N, N-dimethylacetamide, Ethyl acetate, 1-methyl-2-pyrrolidone (NMP), etc. These solvents are the same (compositionally the same) as the organic resin and its raw material, for example, when the organic resin is a thermoplastic resin. Is particularly preferable.
Further, when the organic resin raw material is a polyamic acid that is a raw material of a polyimide resin, or an aromatic diamine compound that is a raw material of a polyamic acid and an aromatic tetracarboxylic dianhydride, N-methyl- Pyrrolidone, N, N′-dimethylacetamide, aromatic hydrocarbons, and mixtures thereof are more preferred. When the organic resin raw material is a polyfunctional epoxy compound that is a raw material of an epoxy resin, or a polyfunctional epoxy compound and a curing agent, ketones, aromatic hydrocarbons, glycol derivatives, or these More preferably, it is a mixture.

The amount of the solvent used is preferably 150 parts by weight or more, and more preferably 1900 parts by weight or less with respect to 100 parts by weight of the organic resin. More preferably, it is 200 parts by weight or more and 1400 parts by weight or less. When the said resin composition also contains the raw material of an organic resin, it is preferable that content of a solvent exists in the said range with respect to 100 weight part of organic resins and the total amount of the raw material.

In the method for producing the resin composition, as a raw material of the resin composition, a form using carbon black dispersed in a solvent-soluble organic resin or the raw material (carbon black-containing particles) may be used. In this case, a solvent-soluble polyimide resin is particularly suitable as the organic resin.

In the resin composition for forming a light shielding layer, the solid content as the resin solution (the total content of the organic resin and / or its raw material and carbon black) is 4 to 40 mass in 100 mass% of the resin composition. % Is preferred. If it is less than 4% by mass, there are many solvents, and it may take time to dry the film, and the film thickness characteristics may not be sufficient due to aggregation or the like. There is a possibility that it cannot be processed and cannot be made into a film. More preferably, it is 5-35 mass%, More preferably, it is 10-30 mass%.

The resin composition for forming a light shielding layer preferably has a viscosity (viscosity at 25 ° C. as a resin solution) of 10 cP to 100,000 cP (centipoise). Within this range, the light shielding layer-forming resin composition can be easily applied, dried, solidified, cured or reacted to form a film. More preferably, it is 500 cP to 50,000 cP.
The viscosity can be measured with a B-type viscometer.

The light shielding layer forming resin composition preferably also contains a surface conditioner. The surface conditioning agent can be suitably used for improving the uniformity of the film, specifically, for eliminating holes or eliminating skin. As the surface conditioner, a compound having a high surface tension reducing ability is preferable in terms of a high effect of eliminating holes, and a compound having a high polarity is preferable in terms of a high effect of eliminating yuzu skin.
As the surface conditioner, for example, a silicon-based surface conditioner (silicon-based additive) is preferable. As the silicon-based surface conditioning agent, BYK-300, BYK-301, BYK-302, BYK-306, BYK-307, BYK-310, BYK-315, BYK-320, BYK-322, manufactured by BYK Japan BYK-323, BYK-325, BYK-330, BYK-331, BYK-333, BYK-337, BYK-341, BYK-344, BYK-345, BYK-346, BYK-347, BYK-348, BYK- 349, BYK-370, BYK-375, BYK-377, BYK-378, BYK-UV3500, BYK-UV3510, and BYK-UV3570 (all are trade names). Among these, from the viewpoint of high polarity, BYK-306, BYK-310, BYK-333, BYK-370, BYK-375 and the like are preferable. From the viewpoint of high surface tension reducing ability, BYK-306, BYK-307, BYK-330, BYK-333, BYK-370, BYK-377, BYK-341, BYK-375 and the like are preferable. Moreover, BYK-306, BYK-333, and BYK-375 are particularly preferable because of their high polarity and high surface tension reducing ability.

The resin composition for forming a light shielding layer may further include, for example, a curing agent, a curing accelerator, a reactive diluent, a saturated compound having no unsaturated bond, a pigment, a dye, an antioxidant, and an ultraviolet absorber. , Light stabilizers, plasticizers, non-reactive compounds, chain transfer agents, thermal polymerization initiators, anaerobic polymerization initiators, polymerization inhibitors, adhesion improvers such as inorganic and organic fillers, coupling agents, thermal stability Agent, antibacterial / antifungal agent, flame retardant, matting agent, antifoaming agent, leveling agent, wetting / dispersing agent, anti-settling agent, thickener / anti-sagging agent, anti-coloring agent, emulsifier, slip / scratch You may contain 1 type (s) or 2 or more types, such as an inhibitor, an antiskinning agent, a drying agent, an antifouling agent, an antistatic agent, and a electrically conductive agent (electrostatic adjuvant).

The light-shielding layer of the present invention can be obtained by forming the light-shielding layer-forming resin composition, followed by curing reaction and / or solvent removal. The light shielding layer contains curable resin cured product or thermoplastic resin having a glass transition temperature of 150 ° C. or more and carbon black having a DBP oil absorption of 200 to 500 ml / 100 g as essential components.
As content of each component in the said light shielding layer, curable resin hardened | cured material or a thermoplastic resin (solid content) whose glass transition temperature is 150 degreeC or more is 60-99 mass% with respect to 100 mass% of total amounts of a light shielding layer. It is preferable that More preferably, it is 80-95 mass%.
Carbon black is preferably less than 20% by mass relative to 100% by mass of the total amount of the light shielding layer. 10 mass% or less is preferable at the point which is excellent in a cutting characteristic. Furthermore, it is preferable that it is 1 mass% or more. When it is 1% by mass or more, the light-shielding film (size that fits in a square of 5 mm square or more) has excellent handleability. More preferably, it is 3% by mass or more, and when it is within this range, the surface resistance value of the light-shielding film can be easily reduced to 1 × 10 ¹⁰ Ω / □ or less, and the film has a fine size (for example, 4 mm square). Therefore, it can be suitably used for small imaging lenses such as digital cameras and mobile phone cameras. More preferably, it is 5% by mass or more, and if it is within this range, the surface resistance value of the light-shielding film can be easily reduced to 1 × 10 ⁷ Ω / □ or less, and the film can be further refined (for example, 2 mm). Even if it is cut into a size that fits in a square, it is easy to handle.
The content of the solvent in the light shielding layer is preferably less than 1% by mass with respect to 100% by mass of the total amount of the light shielding layer.

<Light-shielding film>
The light-shielding film of the present invention has a single-layer structure composed of a light-shielding layer (also referred to as a black layer) formed using the organic resin and / or its raw material and carbon black as essential components. That is, the light shielding film is composed of a light shielding layer alone. By adopting such a form, it is possible to reduce the thickness of the light-shielding film without causing problems of interfacial peeling that occurs in the case of a multilayer laminate, and to be used for optical applications (lens units). In this case, the optical path can be shortened, and the lens unit can be reduced in size and thickness.

The thickness of the light-shielding film (in the present invention, the light-shielding layer) is preferably 20 μm or more, more preferably from the viewpoint of easy post-processing of the film and excellent mechanical strength, although it depends on the organic resin of the light-shielding layer. 30 μm or more. The upper limit of the thickness of the light-shielding film (light-shielding layer) depends on the material of the light-shielding layer, but is preferably 200 μm or less in view of sufficient light-shielding performance and application to a lens unit that is required to be thin. More preferably, it is 100 μm or less. A particularly preferable range is 30 to 80 μm.
Here, the thickness of the light shielding layer is a thickness obtained by measuring the light shielding layer with a micrometer. By setting the thickness of the light shielding layer in the above-described range, the light shielding film of the present invention is thinned. For example, when the light shielding film is used for an optical member, the optical path can be shortened. Thereby, this optical member (for example, camera module etc.) can be reduced in thickness.

The light-shielding film preferably has a glossiness of 20 or less on at least one surface. When the glossiness of the light-shielding film exceeds 20, light shielding is not sufficient, and for example, when used as a lens unit, it may cause a malfunction as noise. More preferably, it is 10 or less, More preferably, it is 5 or less.
Furthermore, it is preferable that glossiness is the said range on both surfaces.
The glossiness is measured at a measurement angle (θ) of 60 degrees using a gloss meter VG-2000 manufactured by Nippon Denshoku Industries Co., Ltd.

The light-shielding film preferably has a concavo-convex shape (concavo-convex structure) on the film surface so that the glossiness of the surface is in the above range. By having a concavo-convex shape on the surface, the gloss of the light-shielding film can be reduced, light reflection can be prevented, and light can be shielded. Moreover, the light-shielding film which has uneven | corrugated shape on the surface is suitable also at the point by which the effect of this invention is exhibited in setting it as such a form. Thus, the form in which the light-shielding film has a concavo-convex shape on at least one surface of the film surface is also a preferred form of the present invention, and the glossiness of the light-shielding film will be described later. It is effective to control to the range. More preferably, it has a concavo-convex shape on both sides, and the effect is more fully exhibited.

The surface uneven shape is not particularly limited as long as it has the uneven shape described above, but it is preferable that the uneven shape is formed without containing fine particles other than carbon black in the light-shielding film. When the concave and convex shape is formed by containing fine particles, since the fine particles are usually white or light-colored fine particles, the fine particles existing near the surface of the light-shielding film serve as a light transmission path, and the light-shielding property of the light-shielding film. May not be excellent enough. The fine particles that can be contained in the light-shielding film of the present invention preferably have high heat resistance, but particles having high heat resistance such as spherical silica and silicone resin particles are white. Use of such white (or light-colored) fine particles becomes an obstructive factor for blackening in order to obtain excellent light-shielding properties. Therefore, it is necessary to add a large amount of carbon black. Is disadvantageous. Moreover, when forming uneven | corrugated shape using microparticles | fine-particles, the particle | grains with uniform particle size distribution are required for uniform uneven | corrugated formation, and there exists a possibility that it may become expensive.

A schematic diagram of the light-shielding film of the present invention having a single layer structure is shown in FIG. FIG. 1 (1) is a form in which the unevenness is formed on one side, and (2) is a form in which the unevenness is formed on both sides.
When the light-shielding film of the present invention is produced by the method described later, it is possible to continuously produce a light-shielding film having a single layer structure and unevenness on at least one side, which is not only small and lightweight but also thin. A quality light-shielding film can be obtained at low cost.

The shape of the light-shielding film can be appropriately selected according to the application. When the lens is attached to a lens unit, it can be effectively transmitted through the light other than the optical path by attaching it to a bag for fixing the lens. Reflection can be suppressed, and optical noise can be reduced. That is, in the lens unit, as schematically shown in FIG. 2, it is preferable that a light-shielding film (light-shielding layer) is attached to a ridge that fixes the lens. That is, the positional relationship between the lens and the light shielding layer in the lens unit is preferably that schematically shown in FIG. 3 when viewed as a cross-sectional view of the lens unit. Therefore, the light shielding layer of the light shielding film preferably has a planar shape (ring shape) as schematically shown in FIG. 4 when viewed from the lens unit incident light side. The center of the ring may be a cavity, a transparent film that transmits visible light, or a lens. Preferably, the center of the ring is a cavity.

The size of the light-shielding film is preferably a size that fits in a 4 mm square from the viewpoint of meeting the demand for downsizing the optical member on which the film is mounted. In other words, it is preferable that the light-shielding film that can be cut into a size that fits in a square of 4 mm square is excellent in handleability. The size of the light-shielding film is more preferably set to a size that fits in a 2 mm square since the demand for miniaturization is increasing year by year.

The light-shielding film of the present invention comprises a light-shielding layer in which specific carbon black is uniformly dispersed in an organic resin having excellent heat resistance, and further has excellent conductivity and heat resistance because of a single layer structure. It will be a thing.
In the light-shielding film, it is preferable that the surface resistance value of the light-shielding layer is 1 × 10 ¹⁰ Ω / □ or less. The surface resistance value of the light shielding layer is usually 1 × 10 ¹³ Ω / □ or less, and the light shielding film is excellent in handleability. However, it is suitable for small imaging lenses such as digital cameras and mobile phone cameras. In order to provide a minute light-shielding film at a low cost, it is preferably set to 1 × 10 ¹⁰ Ω / □ or less as described above. When the surface resistance value is 1 × 10 ¹⁰ Ω / □ or less, the light-shielding film can have sufficient conductivity, and even if the film is cut into a size that fits in a 4 mm square, it is easy to handle. It can be excellent. More preferably, it is 1 × 10 ⁷ Ω / □ or less. When the surface resistance value is 1 × 10 ⁷ Ω / □ or less, even if the film is cut into a size that fits in a square of 2 mm square, it can be excellent in handleability, and further miniaturization is required. Can respond.

The heat resistance of the light-shielding film can be evaluated by the degree of change in film shape and the presence or absence of change in light-shielding performance when the film is heated at a high temperature.
Specifically, the change in light-shielding performance (light-shielding performance retention) can be evaluated by the degree of change in the surface glossiness and transmittance of the film before and after heating. It is preferable that the change in glossiness when heated at 200 ° C. for 1 minute is 20% or less, and the change in the same transmittance is 20% or less.
As the change in film shape, the smaller the change in film dimensions (longitudinal and transverse lengths in the plane, the length in the thickness direction) before and after heating, the better the shape retention. Preferably there is. As a specific example of having excellent shape retainability (having heat resistance), when heated at 200 ° C. for 1 minute, the rate of change (dimensional change rate) of each length after heating with respect to before heating is 10% or less. It is to become. When the dimensional change rate is 10% or less, the characteristics of the light-shielding film can be sufficiently exhibited under the conditions normally used in the above-described applications. For example, generation and expansion of optical noise inside the lens unit can be achieved. Can be suppressed. More preferably, it is 5% or less, further preferably 3% or less, and particularly preferably 1% or less.
In addition, what is necessary is just to select suitably the magnitude | size of the sample when measuring a dimensional change rate, for example, the sample of size 50.0 mm x 10.0 mm x width 35-80 micrometers can be used.

The dimensional change rate may be measured under more severe conditions, and the heating temperature is preferably 250 ° C. The heating and holding time is preferably 2 minutes. More preferably, it is 5 minutes, More preferably, it is 10 minutes. A light-shielding film having a dimensional change rate in the above range under such severe conditions is more preferable.
More preferably, the dimensional change rate is more preferably 10% or less when the length is changed after heating (dimensional change rate) after heating at 260 ° C. for 2 minutes. Measurement conditions are preferably performed in an air atmosphere. That is, in the light-shielding film, when the film is heated at 260 ° C. for 2 minutes in an air atmosphere, the dimensional change rate of the length, width, and thickness after heating with respect to before heating is 10% or less. preferable. When the above-mentioned light-shielding film is used for a lens unit, it should be able to sufficiently withstand the solder reflow process because the dimensional change is small by heating at 260 ° C. for 2 minutes (the dimensional change rate is 10% or less). Can do. In this case, the dimensional change rate is more preferably 5% or less, further preferably 3% or less, and particularly preferably 1% or less.
The light-shielding film of the present invention comprises a light-shielding layer in which specific carbon black is uniformly dispersed in an organic resin having excellent heat resistance, and has a single layer structure, and therefore has excellent heat resistance.

The content of carbon black in the light-shielding film can be rephrased as the content of carbon black in the light-shielding layer because the light-shielding film is composed of the light-shielding layer alone. About this, as already stated, it is preferable that it is less than 20 mass% with respect to 100 mass% of total amounts of a light shielding layer. More preferably, it is 10% or less. Further, it is preferably 1% by mass or more, more preferably 3% by mass or more, and further preferably 5% by mass or more.

As a manufacturing method of the light-shielding film of this invention, it is also called the process ("surface uneven | corrugated formation process") which forms uneven | corrugated shape by the transfer method on the surface of the resin film comprised from the resin composition for light-shielding layer formation mentioned above. And a step of drying, solidifying or curing the resin film. Thereby, it is possible to form the concavo-convex shape at a fine level with good reproducibility, and it is possible to precisely control the form such as the size and depth of the concavo-convex shape. That is, it is possible to impart a matting property to the surface based on a uniform and fine uneven shape while having excellent flatness. Furthermore, other steps may be included as necessary.

As the surface unevenness forming step, it is preferable to form the unevenness by bringing the resin composition for forming the light shielding layer into contact with the transfer layer, and a specific method depending on the composition and characteristics of the resin composition for forming the light shielding layer May be appropriately selected. For example,
Transfer method (1): After applying a resin composition for forming a light-shielding layer to a transfer layer (for example, a surface irregular base material), drying / solidifying, or curing or reaction (for example, reacting polyamic acid to make a polyimide) ) To form a film and form irregularities (this is also referred to as a substrate mold transfer method). In this case, usually, after forming irregularities, the molded resin composition for forming a light shielding layer is peeled off from the transfer layer. Moreover, as a transfer layer, any of frosted glass and a mat film (surface unevenness PET etc.) is preferable.
Transfer method (2): A light-shielding layer forming resin composition is formed in a film in advance, and the film is chemically or compositionally intermediate, or semi-dried, semi-cured, or unreacted / half-reacted. A method of forming irregularities by bringing a film-like material into contact with a transfer layer after making it into a state. In this case, the transfer layer is preferably any one of frosted glass, mat film (surface irregular PET, etc.), and mat roll.
Transfer method (2 '): A light shielding layer forming resin composition is formed into a film, and the film is chemically, compositionally dried, solidified, cured, or transferred. A method of forming irregularities by contacting a layer. In this case, the transfer layer is preferably frosted glass or matte film (surface irregular PET or the like). When the organic resin is a thermoplastic resin (polyimide or PEEK), the transfer method (2 ′) is to apply pressure under heating to bring the transfer layer into contact (mat roll treatment, sandwiched by ground glass, etc.). It is also preferable to form irregularities by the above.
That is, a method of forming irregularities by bringing a light-shielding layer forming resin composition previously formed into a film into contact with the transfer layer, such as transfer method (2) and transfer method (2 ′), is also a preferable transfer method. One.
Two or more of the above transfer methods (1), (2) and (2 ′) may be used in appropriate combination.
In addition, the manufacturing method of the light-shielding film which has such uneven | corrugated shape on the surface is described in detail in the 57th-72nd paragraph of the international publication 2009/014264 pamphlet, for example.

<Lens unit>
The light-shielding film of the present invention can constitute a lens unit together with a lens and a lens barrel. Since such a lens unit is configured using a light-shielding film having a light-shielding layer formed from the above-described resin composition for forming a light-shielding layer, it has reflow resistance and heat resistance, and is used for optical applications and optical devices. It is particularly useful for applications, and can be used as display device applications, mechanical parts, electrical / electronic parts, and the like. In particular, it is suitable for imaging device applications such as a digital camera, a mobile phone camera, an in-vehicle camera, and a surveillance camera that require excellent image quality with a fine shape because of excellent cutting characteristics and contamination resistance. Such a lens unit including the light-shielding film, the lens, and the lens barrel is also one aspect of the present invention.
The lens unit includes the light-shielding film, the lens, and the lens barrel. However, it is sufficient that each of the lens units is provided with at least one, and the number to be mounted is appropriately set according to the use of the lens unit. It may be possible to provide a plurality.

In the present specification, the “lens unit having reflow resistance” is a lens unit having at least excellent shape retention of the light shielding film and excellent light shielding performance retention. The preferred form is the same as the shape-retaining property and the light-shielding performance retaining property in the light-shielding film described above.

In the lens unit, the lens may be any material that can transmit and transmit a wavelength in the visible light region, and may be any one of an organic material, an inorganic material, and an organic / inorganic composite material. Two or more kinds may be used. The organic material (for example, thermoplastic resin composition, curable resin composition) is excellent in processability, and the inorganic material (for example, glass) is excellent in transparency / thermal expansion coefficient, for example, an organic / inorganic composite material (for example, The organic-inorganic composite resin composition) having both characteristics is suitable. A lens made of any material can be suitably used, but a material having reflow resistance (heat resistant material) is preferable.
Thus, the form which the light-shielding film and lens which comprise a lens unit have reflow resistance is one of the preferable forms of this invention. Since both the light-shielding film and the lens have sufficient heat resistance, automatic mounting becomes possible, the mounting cost is sufficiently reduced, and it can be suitably used for optical applications such as a camera module. As described above, the light-shielding film of the present invention is suitable for an imaging lens unit used for a camera module, and particularly suitable for an imaging lens unit used for a camera module subjected to a solder reflow process. That is, the lens unit is preferably an imaging lens unit used for a camera module, and particularly preferably an imaging lens unit used for a camera module used in a solder reflow process.

As a preferred specific example of an organic material as the material of the lens, a curable resin composition having a resin (raw material) mainly comprising a compound having at least one epoxy group is cured from the viewpoint of excellent colorless transparency and heat resistance. Cured resin cured product such as a material obtained by curing a curable resin composition containing a compound having a polymerizable unsaturated bond as a main resin (raw material); a phenol resin as a main resin (raw material) Tg of a material obtained by curing a curable resin composition, a material obtained by curing using a silicone resin as a main resin (raw material), a thermoplastic resin comprising a silicone resin, a polycycloolefin resin, a polycarbonate resin, etc. is 150 ° C. The above thermoplastic resin. Curing means conventionally known curing such as curing by heat or curing by irradiation with active energy rays, and the curable resin composition further includes the above main compound, a curing catalyst for accelerating curing, and curing. A conventionally known material such as an accelerator or a curing agent is used in combination. In the above, “main” means 70% by mass or more based on the total amount of the resin (raw material).
Particularly preferred as the material is a material obtained by curing a curable resin composition containing an epoxy group-containing compound as a main resin (raw material). About the epoxy group containing compound and the compound which has a polymerizable unsaturated bond, the aspect regarding the same kind compound in the light shielding resin composition for light shielding films can be applied.
The organic material component of the organic / inorganic composite material is preferably the preferred organic material.

The lens is preferably obtained by curing a curable resin composition. By using a curable resin composition, it is possible to perform complicated processing that cannot be performed with an inorganic material (for example, glass) at low cost, and a lens having heat resistance that cannot be achieved when a thermoplastic resin composition is used. In the processing (molding) and mounting on the lens unit, there is an advantage that it is suitable for an industrial production process and can be performed efficiently. The lens is preferably obtained by curing a curable resin composition, but the curable resin composition preferably includes a compound having at least one epoxy group as an organic resin component. The curable resin composition is more preferably an organic-inorganic composite resin composition having an inorganic component.
In the present invention, as described above, the lens is preferably obtained by curing a curable resin composition. Among these, a lens obtained by cationically curing a curable resin composition containing an epoxy group-containing compound as a main resin material and containing a cationic curing catalyst such as a thermosetting curing agent is preferable.

As the compound having at least one epoxy group, an epoxy compound exemplified as an organic resin contained in the light-shielding film can be suitably used. Among them, epibis type glycidyl ether type epoxy resin; novolak aralkyl type glycidyl ether type epoxy resin; aromatic crystalline epoxy resin; aliphatic glycidyl ether type epoxy resin; epoxy resin having epoxy cyclohexane skeleton; glycidyl ester type epoxy Resin; Tertiary amine-containing glycidyl ether type epoxy resin and the like are preferable. Moreover, what contains non-hardening components, such as a thermoplastic resin, and a low molecular weight curable compound can also be used as curable resin. As a usage form of the curable resin composition (thermosetting epoxy resin composition) used for the lens, a form described as a light-shielding film to be described later can be suitably used, and in particular, a thermal latent curing agent is used. Form is preferred. In addition, since curable resin composition is used for a lens use, when using as a light-shielding film, it is preferable not to contain essential black fine particles.

The organic-inorganic composite resin composition preferably contains an organic resin and inorganic fine particles or organopolysiloxane. Organic resins having a high Abbe number are those having an Abbe number of 45 or more, forms that are curable resins, forms that essentially contain an alicyclic epoxy compound, and those having a molecular weight of 700 or more. Form is preferred. The inorganic fine particles have a form obtained by a wet method, a form having an average particle diameter of 400 nm or less, and a pH of 3.4 to 11 at 25 ° C. when dispersed in a solution. Form is preferred. As an organic inorganic composite resin composition, the form in which an unsaturated bond is 10 mass% or less and the form containing a flexible component are preferable.

The lens preferably has a thickness of less than 1 mm. By setting the thickness of the lens (the maximum thickness of the region where the image is captured) to less than 1 mm, the optical path length can be shortened and the lens unit can be further reduced, combined with the use of the light-shielding film. The thickness of the lens is more preferably less than 800 μm, and still more preferably less than 500 μm.
The Abbe number of the lens is not particularly limited. For example, when the Abbe number is 45 or more, the wavelength dispersion of light is reduced, the resolution is increased, and the optical characteristics can be improved. If it is less than 45, for example, bleeding may be observed, sufficient optical characteristics may not be exhibited, and a material suitable for the lens unit may not be obtained. The Abbe number is more preferably 50 or more, still more preferably 55 or more, particularly preferably 58 or more, and most preferably 60 or more.

The lens constituting the lens unit is a single lens whose optical properties (Abbe number, refractive index, etc.) and lens shape (concave, convex, curvature, etc.) are controlled according to the target resolution, or Used in combination. The number of lenses used may be one, or two or more. In the case of a single lens, it is preferable to use a lens having a high Abbe number in that the wavelength dispersion of light is reduced, the resolution is increased, and the optical characteristics are excellent. The combination is arbitrary, and various combinations can be applied. For example, it is preferable to use a combination of a lens having a high Abbe number and a lens having a low Abbe number.

The material of the lens barrel constituting the lens unit may be any of an organic material, an inorganic material, and an organic / inorganic composite material. These may be used alone or in combination of two or more. From the viewpoint of weight reduction, it is preferable to use an organic material or an organic / inorganic composite material.

The lens unit is not particularly limited as long as it includes a light-shielding film, a lens, and a lens barrel, but a mode having other members such as an infrared cut filter, a sea moss sensor, a barrel, and an adhesive is preferable. The adhesive is used to fix a member such as a lens or a light shielding film to the unit.
The arrangement of each component of the lens unit is not particularly limited as long as the characteristics as the lens unit are exhibited. However, as described above, the light-shielding film is attached to the edge where the light-shielding layer fixes the lens. It is preferable that it is the arrangement | positioning. As the positional relationship between the light-shielding film and the lens, there are a form in which the lens is on the incident light side and a form in which the light-shielding film is on the incident light side. It is preferable that two light-shielding films are arranged on the incident light side from the lens.
As the shape of the light-shielding film, as described above, it is preferable that the light-shielding layer has a ring shape and the center of the ring is a cavity. With such an arrangement and shape, the light shielding function can be sufficiently exhibited. Specifically, as schematically shown in FIG. 5B, when the central portion is a transparent film, the light path length is increased by having the light-shielding film. On the other hand, if the central portion is hollow, the optical path length does not increase as schematically shown in FIG. Since the lens unit is required to be downsized, it is preferable that the lens unit has a light-shielding layer in a ring shape and has a hollow center. In the case of a light-shielding film, if a light-shielding film is provided between the lens and the seamos sensor, the optical path length can be shortened by reducing the thickness of the light-shielding film located between the lens and the seamos sensor. The lens unit can be made smaller and the thickness of the unit can be made thinner.

In the lens unit, the arrangement of the light-shielding film and the lens is arranged in the order of the light-shielding film, one or more lenses, and the Cimos sensor along the traveling direction of the incident light as shown in FIG. Form is preferred. When there are two or more lenses, a form in which a light-shielding film is provided on each lens is more preferable. Thus, if a plurality of light-shielding films are used, unnecessary light can be sufficiently blocked. The light shielding film may be disposed between the lenses. In addition, when using other functional layers, such as the infrared cut filter mentioned later, it is preferable to provide in the form where those effects are fully exhibited. In FIG. 2, the infrared cut filter is disposed at a position closest to the sea moss sensor. The infrared cut filter may be disposed so as to be positioned on the incident light surface of the lens unit.

The size of the lens unit of the present invention is preferably small because it can be suitably used for various applications. The thickness of the lens unit is preferably 50 mm or less. By setting it as such thickness, it can use suitably for various optical members, such as a camera module. More preferably, it is 30 mm or less as a thickness of a lens unit, More preferably, it is 10 mm or less.

When a light-shielding film having a transparent film at the center is used, the length of the lens unit can be made smaller as the light-shielding film located between the lens and the sea moss sensor is thinner. Specifically, the camera module has a light-shielding film, a lens, and a seamos sensor. FIG. 2 and FIG. 5 schematically show an example of the camera module. Note that these figures refer to materials from the Electronic Journal 81st Technical Seminar (Electronic Journal 81st Technical Seminar). When a light-shielding film is arranged on the camera module as shown in FIG. 5B, the focal length is extended, so that the back focus is extended and the module is enlarged. As shown in FIG. 5B, when the light-shielding film is positioned between the incident light surface and the lens and the Simos sensor, the thickness of the light-shielding film is t and the refractive index n is about 1.5, the back focus Is extended by about t / 3, and the module becomes large. However, the light-shielding film can be made thin, the focal length can be shortened, and the module can be made small. Thereby, for example, the optical path length of an optical size of 1/10 inch is preferably 120% or less in the case of no light-shielding film. More preferably, it is 110% or less, More preferably, it is 105% or less.

Since the light-shielding film of the present invention has the above-described configuration, it has excellent cutting characteristics, is easy to handle even with a fine size, and can be placed on a lens unit or the like with high positional accuracy. Is high and does not vary in performance. In response to the demands for such a light-shielding film lens unit to be reduced in size and thickness, and because it is composed of a heat-resistant resin film, it is especially suitable for reflow camera lens units, especially for thermal behavior and adhesion tracking. From the point of view of properties, it can be preferably used in combination with a heat-resistant resin lens and a hybrid lens. In addition, the lens unit provided with such a light-shielding film is useful for various applications such as optical members, optical device members, display device members, mechanical parts, electrical / electronic parts, etc. Suitable for telephone camera module.

FIG. 1 is a schematic cross-sectional view showing one preferred form of the light-shielding film. FIG. 2 is a schematic cross-sectional view showing the configuration of a camera module which is one of the preferred forms of the lens unit. FIG. 3 is a schematic cross-sectional view showing the relationship between the light-shielding film and the lens in the lens unit. FIG. 4 is a schematic plan view showing one of preferred forms of the light-shielding film in the lens unit. FIG. 5 is a schematic diagram showing the extension of back focus depending on the presence or absence of a light-shielding film.

The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples. Unless otherwise specified, “part” means “part by weight” and “%” means “% by mass”.

<Preparation of ketjen black (conductive carbon black) dispersion>
In a reactor equipped with a thermometer, a cooling tube, a gas introduction tube, and a stirrer, N, N-dimethylacetamide 187.78 parts, polyvinylpyrrolidone (manufactured by Wako Pure Chemical Industries, Ltd., K-30) 1.22 parts, 11 parts of Ketjen Black (manufactured by Lion Corporation, EC300J, DBP oil absorption 365 ml / 100 g) was charged. After pre-dispersing for 10 minutes at a stirring speed of 600 rpm, 600 parts of zirconia beads were added to a stirring speed of 1200 rpm. Subsequently, the temperature was raised to 50 ° C., and the mixture was stirred for 3 hours after reaching 50 ° C. The mixture was cooled to 45 ° C. with stirring at a stirring speed of 1200 rpm, and then suction filtered through a SUS 500 mesh to separate the beads and the dispersion. The viscosity of the obtained carbon black dispersion CB-1 was measured at 25 ° C. with a B-type viscometer and found to be 4800 cP, a solid content of 5.52%, and a particle size of 0.28 μm.

<Preparation of acetylene black (conductive carbon black) dispersion>
In a reactor equipped with a thermometer, a cooling tube, a gas introduction tube, and a stirrer, N, N-dimethylacetamide 187.78 parts, polyvinylpyrrolidone (manufactured by Wako Pure Chemical Industries, Ltd., K-30) 1.22 parts, 11 parts of acetylene black (manufactured by Denki Kagaku Kogyo KK, HS-100, DBP oil absorption 140 ml / 100 g) was charged. After pre-dispersing for 10 minutes at a stirring speed of 600 rpm, 600 parts of zirconia beads were added to a stirring speed of 1200 rpm. Subsequently, the temperature was raised to 50 ° C., and the mixture was stirred for 3 hours after reaching 50 ° C. The mixture was cooled to 45 ° C. with stirring at a stirring speed of 1200 rpm, and then suction filtered through a SUS 500 mesh to separate the beads and the dispersion. The obtained carbon black dispersion CB-2 had a viscosity of 150 cP at 25 ° C., a solid content of 5.53%, and a particle size of 0.27 μm.

The physical properties of each carbon black dispersion were evaluated by the following methods.
(Viscosity measurement)
Manufactured by Tokyo Keiki Co., Ltd., B-shaped viscose clock (model: B8L), rotor 2. Measurement temperature 25 ° C
6 rpm

(Particle size measurement)
The particle size at 25 ° C. was measured using a dynamic light scattering particle size distribution device LB-500 manufactured by HORIBA.

<Preparation of coating liquid (curable resin composition in which carbon black is dispersed in polyamic acid)>
Preparation Example 1
I. S. Table 1 shows poly (amide) imide varnish Pyre-ML RC5083 (solid content 18.5%) manufactured by T, Ketjen black dispersion CB-1 obtained above, and BYK-306 manufactured by BYK Japan Japan. The curable resin composition (1) was obtained by mixing with a reactor equipped with a thermometer, a cooling pipe, a gas introduction pipe, and a stirrer at a weight ratio, followed by pressure filtration with a SUS 500 mesh. The mixing conditions and pressure filtration conditions are shown below.

(Mixing conditions)
Stirrer blades: First, a two-stage paddle RC5083 and BYK-306 were stirred for 15 minutes in a nitrogen atmosphere. Thereafter, CB-1 was charged while stirring, and stirring was performed for 60 minutes after charging.

(Pressure filtration conditions)
Pressure filter used: ADVANTEC, KST-293-10-JA

Preparation Examples 2-4
The same raw materials used in Preparation Example 1 were mixed and pressure filtered at the weight ratio shown in Table 1 to obtain curable resin compositions (2), (3) and (4).

Preparation Examples 5-6
In Preparation Example 1, a carbon black dispersion CB-2 was used instead of the carbon black dispersion CB-1, and each raw material was mixed and pressure filtered at a weight ratio shown in Table 1 to obtain a curable resin composition ( 5) and (6) were obtained.

<First transfer and production of single layer film>
The curable resin compositions (1) to (6) obtained in Preparation Examples 1 to 6 were used as first mold films (transfer materials), respectively, and matte pet films manufactured by Teijin DuPont (brand: PSG, thickness 100 μm). ), Dried at 140 ° C. for 5 minutes, and then peeled to obtain curable resin films (1) to (6) on which one side was transferred. The coating conditions are shown below.
Coating method: Slot die coating width: 25cm
Drying furnace temperature: 140 ° C
Drying time: 5 minutes

The thickness, solid content concentration, glossiness of the mat pet film contact surface and the like of the obtained curable resin films (1) to (6) were measured by the methods shown below, and the results are shown in Table 2.

(Thickness measurement)
Measured with a micrometer.
(Glossiness measurement)
Regarding the obtained curable resin film, the glossiness of the transferred surface was measured.
The glossiness was determined by measuring the glossiness at a measurement angle (θ) of 60 degrees using a handy gloss watch (Gloss Checker IG-331) manufactured by Horiba, Ltd. In addition, the said glossiness measured 5 places and described the range of dispersion | variation (the upper limit and lower limit of a measured value) as a measured value.

(Solid content of film)
The solid content in the curable resin film was determined as follows. That is, using a small piece of film as a sample, TG-DTA (manufactured by BRUKER AXS, TG-DTA 2000SA) was used to measure the weight loss from room temperature to 350 ° C. at a heating rate of 10 ° C./min. Was the solvent content, and the remainder was the solid content.

(How to determine imidization rate)
The imidation ratio on the surface of the curable resin film was determined by the following measurement method and calculation method.
Measuring device: FT-IR (Thermo Nicolet NEXTUS670)
Measurement method: ATR method measurement (Ge prism) 1 time reflection Accumulation times 32 times Resolution 4 cm ⁻¹
Calculation method of imidation ratio First, a curable resin film not subjected to a transfer process by lamination was completely imidized. The imidation conditions were the same as the production of the cured resin film. Next, the FT-IR of the non-contact surface of the base film completely imidized was measured. The peak area ratio of the measurement results from the benzene ring imido group for ^{(1500cm -1) (1775cm -1)} , which is 100% imidization rate. In order to obtain the imidization ratio of the curable resin film, FT-IR is measured, the peak area ratio is obtained in the same manner, and the imidization ratio is calculated from the 100% reference peak area ratio. That is, for example, if the peak area ratio of a 100% imidized film is 0.1, and the peak area ratio of the curable resin film is 0.05, the imidization ratio is 50%.

<Second transfer: transfer by transfer roll>
Transfer films (1) to (6) were produced on the first mold film non-contact surfaces of the curable resin films (1) to (6) by the transfer roll method using the second mold film, respectively.
That is, using a thermal calender device provided with a pair of transfer rolls (roll A, roll B), the curable resin film and the second mold film are connected to the first mold film non-contact surface of the curable resin film. Is transferred to the first mold film non-contact surface of the curable resin film by supplying it between the transfer rolls so as to come into contact with the second mold film (to be in a laminated state). Transfer resin films (1) to (6) were obtained by peeling from the mold film. As a result of measuring the glossiness of the second transfer surface of the obtained transfer resin film by the same method as described above, the 60 ° glossiness was 3 to 5.
As the second mold film, matte pet film (brand: PSG, thickness 100 μm) manufactured by Teijin DuPont was used.
At the time of transfer, a rubber roll is used as the transfer roll A on the curable resin film side, and a SUS roll is used as the transfer roll B on the second mold film side. In the transfer step, the surface of the transfer roll A Was held at 150 ° C. and the surface of the transfer roll B was heated at 140 ° C., respectively. Other transfer conditions are as follows.
Supply speed of curable resin film and second mold film: 1 m / min for both
Pressure applied between transfer rolls during transfer: 20 N / mm linear pressure

<Production of cured resin film (light-shielding film)>
The transfer resin films (1) to (6) were heated and cured under the following heating conditions in an inert oven to obtain cured resin films (1) to (6), respectively.
Heating condition: Heated to 350 ° C. over 5 hours from room temperature in a nitrogen atmosphere (temperature rising rate: about 1 m / min). It was heated and held for 20 minutes after reaching 350 ° C.

About cured resin film (1)-(6) obtained above, thickness, the glossiness of both surfaces, visible light transmittance | permeability, heat resistance, and electroconductivity were evaluated by the method shown below. The results are shown in Table 3.
Table 3 shows the values on the first transfer surface with respect to the glossiness and the surface resistance value, but the glossiness and the surface resistance value on the second transfer surface were the same values in any film.

(Thickness measurement)
Measured with a micrometer.
(Glossiness measurement)
Regarding the obtained film (cured resin film), the glossiness of the transferred surface (first transfer surface and second transfer surface) was measured.
The glossiness was determined by measuring the glossiness at a measurement angle (θ) of 60 degrees using a handy gloss watch (Gloss Checker IG-331) manufactured by Horiba, Ltd. In addition, the said glossiness measured 5 places and described the range of dispersion | variation as a measured value (the upper limit and lower limit of a measured value).

(Visible light transmittance)
The transmittance | permeability in 380-780 nm was measured using the ultraviolet visible spectrophotometer (Shimadzu UV-3100 (made by Shimadzu Corp.)). The transmittance is the total light transmittance at each wavelength.

(Heat resistance test)
The produced cured resin film was cut into the following sizes and used as test pieces.
Test piece: 50 mm × 10 mm size film The test piece was subjected to a heat test under the following test conditions, and the dimensional change in the length direction of the test piece before and after the test was measured and evaluated.
Test conditions: Heat treatment at 260 ° C. for 2 minutes (Test pieces are put into a hot air dryer heated and maintained at 260 ° C. and taken out after 2 minutes)
When the dimensional change rate in the length direction was less than 3%, ◯ and 3% or more were rated as x.

(Surface resistance measurement)
The measurement was performed using a digital super insulation meter / microammeter DSM-8104 (manufactured by Hioki Electric Co., Ltd.) as the measuring apparatus and a plate sample electrode SME-8310 (manufactured by Hioki Electric Co., Ltd.) as the measuring electrode. The measurement conditions are shown below.
Measurements were made on both sides of the film.
Measurement conditions Measurement voltage: 0.1V
Integration time (SAMPL): 300 ms
Discharge 10 seconds-> Charge 45 seconds-> Measurement (measurement) 15 seconds

Examples 1-4, Comparative Examples 1-2
About cured resin film (1)-(6), the handleability and cutting characteristic of a film were evaluated by the method shown below. The results are shown in Table 4.

(Film handling test)
Each cured resin film of a predetermined size was prepared, the center of the film was grabbed and lifted with dental tweezers (Cook type K1-1, manufactured by Koyama Dental Industry Co., Ltd.), and the film dropability test was conducted when it was no longer grasped. At this time, the number of things that did not stick to the tweezers due to electrification and fell down was counted. The number of tests was 10, and the number of drops is shown in Table 4.

(Cutting characteristics)
A punchability test was performed using a Thomson blade.
Thomson blade shape: A donut-shaped punched film having an inner diameter of 2 mm and an outer diameter of 3.5 mm was observed with a scanning electron microscope (SEM) at 250 times and 500 times. The case where there was no spillage that was not punched into the fracture surface was marked with ◯, and the case where there was a break was marked with ×.

From the results shown in Table 4, it can be seen that a film having a lower surface resistance value is less likely to stick to tweezers, and is excellent in handleability even when miniaturized.
In addition, a film using a carbon black having a DBP oil absorption in the range of 200 to 500 ml / 100 g (carbon black dispersion CB-1) must be out of the above range (carbon black dispersion CB-2). It was found that the cutting characteristics were excellent compared to the film used.

1: light shielding layer 3: light shielding film 4: lens 5: infrared cut filter 6: barrel 7: sensor lens 8: edge t: thickness of light shielding film

Claims (4)

A light-shielding film having a light-shielding layer formed with an organic resin and / or its raw material and carbon black as essential components,
Light-shielding film I single-layer structure der consisting shielding layer, the surface resistance value is 1 × ¹⁰ 10 Ω / □ or less,
The organic resin contains a curable resin cured product or a thermoplastic resin having a glass transition temperature of 150 ° C. or higher,
The organic resin is solvent-soluble or the raw material is solvent-soluble or liquid,
The carbon black, a ketjen black, Ri DBP oil absorption of 300 ~500ml / 100g der,
The light-shielding film, wherein a content of the carbon black is 1% by mass or more and 10% by mass or less with respect to a total solid content of 100% by mass of the organic resin and the carbon black . 2. The light-shielding film according to claim 1, wherein the organic resin is at least one selected from the group consisting of a polyimide resin, an epoxy resin, a fluorinated aromatic polymer, a polyether ketone resin, and a polyethylene naphthalate resin. . The light-shielding film according to claim 1 or 2 , wherein the light-shielding film has a size that fits in a square of 4 mm square. Lens unit, characterized in that it comprises a light-shielding film according to any one of claims 1 to 3, the lens, and a lens barrel.

Images