JP6202129B1 - Manufacturing method of light-shielding member - Google Patents

Abstract

An object of the present invention is to provide excellent dispersibility and stability of carbon black in a resin composition, and sufficiently maintain the light-shielding property, blackness and coating strength of the light-shielding layer, and there is no warpage (curl) of the light-shielding layer. To provide a resin composition capable of forming a light-shielding layer excellent in processability due to reduction in thickness and weight, and a light-shielding layer and a light-shielding member excellent in light-shielding property, blackness, and coating film strength using the same. Objective. A resin composition for forming a light shielding layer comprising a binder resin and carbon black, wherein the binder resin is a fiber-based resin, and a primary particle diameter of the carbon black is 10 nm or more and 50 nm or less. This is solved by the resin composition for forming a light shielding layer. [Selection figure] None

Description

  The present invention provides a light-shielding member effective for various uses such as optical use, opto-device use, display device use, mechanical parts, electrical / electronic parts, etc., light-shielding layer constituting the light-shielding member, and formation of the light-shielding layer The present invention relates to a resin composition for forming a light shielding layer.

For example, the light-shielding member scatters and absorbs light of a desired wavelength in various applications such as an optical device such as a lens unit, an optical device member, a display device member, a mechanical component, and an electric / electronic component. It is a member having a light shielding layer for shielding light of a wavelength.
For example, optical applications such as high-performance single-lens reflex cameras, compact cameras, video cameras, digital cameras, and camera modules for mobile phone cameras were made of metal materials due to demands for miniaturization, thickness reduction, and weight reduction. A light-shielding member of an optical device is being replaced with a plastic material.

As such a light-shielding member, a light-shielding member in which a light shielding layer containing carbon black and a matting agent is provided on a base film is known. (Patent Document 1)
Further, a light-shielding layer-forming resin composition comprising a solvent-soluble polyimide resin as an organic resin and a specific carbon black as essential components, and a light-shielding film having a light-shielding layer formed from the light-shielding layer-forming resin composition Is disclosed. (Patent Document 2)

JP-A-9-274218 JP 2012-017419 A

However, in these conventional light-shielding members, a resin warp (curl) occurs at the time of forming the light-shielding layer, and there is a problem in practical use, or optical members that have recently been required to be reduced in size, thickness, and weight. The request is not fully met.
Furthermore, it has been difficult for the conventional resin composition for forming a light shielding layer to achieve both the light shielding property and blackness and the stability of the resin composition.

  Therefore, the present invention is excellent in the dispersibility and stability of the carbon black in the resin composition, and sufficiently maintains the light-shielding property, blackness, and coating strength of the light-shielding layer, and the shading (curl) of the light-shielding layer is maintained. And a light-shielding layer and a light-shielding member excellent in light-shielding property, blackness, and coating film strength using the resin composition capable of forming a light-shielding layer excellent in processability due to reduction in thickness and weight For the purpose.

  As a result of intensive studies to solve the above problems, the inventors of the present invention are resin compositions for forming a light shielding layer containing a binder resin and carbon black, wherein the binder resin is a fiber-based resin, and the carbon The primary particle size of black is 10 nm or more and 50 nm or less, and by the resin composition for forming a light shielding layer, the light shielding properties, blackness, and coating strength of the light shielding layer and the dispersibility and stability of the resin composition are compatible. Has been found to be possible, leading to the present invention.

  The present invention also relates to a resin composition for forming a light shielding layer, which further contains a plastic component.

Moreover, this invention relates to the light shielding layer formed from the said resin composition for light shielding layer formation.
The present invention also relates to a light shielding member having the light shielding layer.

  The resin composition for forming a light shielding layer of the present invention can easily disperse carbon black in a resin composition by using a fiber-based resin as a binder resin and a specific carbon black. It is possible to form a light-shielding layer that is excellent in properties, blackness, and coating film strength, and has no warpage (curl) of the light-shielding layer. Furthermore, since the light-shielding member of the present invention can be used as a single layer having only a light-shielding layer that does not have a base film, it can be made thinner and lighter.

  Hereinafter, the present invention will be described in detail.

  The resin composition for forming a light shielding layer of the present invention contains a binder resin and carbon black, the binder resin is a fiber-based resin, and the primary particle diameter of the carbon black is 10 nm or more and 50 nm or less. Features. Moreover, the resin composition for light shielding layer formation is a more preferable thing by the point which prevents the curvature (curl) by resin of a light shielding layer by containing a plastic component.

<< Light shielding layer forming resin composition >>
The resin composition for forming a light shielding layer of the present invention contains a binder resin and carbon black, the binder resin is a fibrous resin, and the primary particle diameter of the carbon black is 10 nm or more and 50 nm or less. With such a light shielding layer forming resin composition, the carbon black can be easily dispersed, and the carbon black and the binder resin can be easily mixed. Thereby, it can be excellent in light-shielding properties and in dispersibility and stability.

<Binder resin>
The binder resin of the present invention contains a fiber-based resin.
(Fiber base resin)
The fiber-based resin is a thermoplastic resin based on a fiber that is a natural polymer, and is a resin having a continuous structure with a six-membered ring structure, and thus has excellent coating strength. In addition, since it has a six-membered ring structure and a structure rich in functional groups, carbon black can be held and adsorbed, and can be easily dispersed and mixed.
Examples of these fiber-based resins include cellulose and cellulose derivatives.
Examples of the cellulose derivative include cellulose ester, cellulose carbamate, and cellulose ether.

Examples of the cellulose ester include cellulose acetate such as cellulose diacetate and cellulose triacetate; cellulose C3-5 acylate such as cellulose propionate and cellulose butyrate; cellulose acetate C3 such as cellulose acetate propionate and cellulose acetate butyrate Examples include cellulose acylate such as 5-acylate.
Examples of the cellulose carbamate include cellulose phenyl carbamate.
Examples of the cellulose ether include alkyl cellulose, hydroxyalkyl cellulose, hydroxyalkylalkyl cellulose, carboxyalkyl cellulose, alkyl-carboxyalkyl cellulose, and derivatives thereof [for example, CMC salts such as sodium carboxymethyl cellulose (alkali metal salts and the like). Etc.].
These 1 type (s) or 2 or more types can be mixed and used.

In consideration of heat resistance during processing and use, a fiber-based resin having a glass transition temperature of 100 ° C. or higher is preferable.
Preferably, a solvent-soluble fiber-based resin is used from the viewpoint of material handleability during processing and durability during use.
As the solvent-soluble fiber resin, cellulose ester is more preferable.

  The number average molecular weight of the fiber-based resin is preferably 10,000 or more, more preferably 20,000 or more in terms of polystyrene. When the number average molecular weight is less than 10,000, sufficient film strength may not be obtained.

Further, the resin composition for forming a light shielding layer may contain a binder resin other than the fiber-based resin as long as the function of the present invention is not impaired.
As this binder resin, poly (meth) acrylic acid resin, polyester resin, polyvinyl acetate resin, polyvinyl chloride, polyvinyl butyral resin, polystyrene / polybutadiene resin, polyurethane resin, alkyd resin, acrylic resin, unsaturated polyester resin, Epoxy ester resin, epoxy resin, epoxy acrylate resin, urethane acrylate resin, polyester acrylate resin, polyether acrylate resin, phenol resin, melamine resin, urea resin, diallyl phthalate resin, polyester polyol, acrylic polyol And thermoplastic resins such as polyol resins such as epoxy polyols or thermosetting resins (including cross-linking agents such as isocyanate to be added if necessary). It may be used by mixing two or more kinds.

<Carbon black>
As carbon black, carbon black whose primary particle diameter is 10 nm or more and 50 nm or less is contained as an essential component. More preferably, it is 10 nm or more and 40 nm or less.
By being in this range, not only can the dispersibility be good and the light-shielding property and blackness can be sufficient, but also when used with a fiber-based resin, the coating strength is sufficiently maintained and durability is maintained. In addition, a resin composition for forming a light shielding layer having excellent handling properties can be obtained.

  The primary particle size is referred to as a primary particle size. The primary particle size of the carbon black is evaluated by a transmission electron microscope image, and the number average value (average primary particle size) of the primary particle sizes is as described above. More preferably, it is in the 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 content of carbon black having a primary particle diameter of 10 nm to 50 nm in the resin composition for forming a light shielding layer is based on 100 parts by weight of the fiber-based resin from the viewpoint of light shielding properties and depth of appearance. The range is preferably from 1 to 100 parts by weight, more preferably from 5 to 75 parts by weight, and particularly preferably from 10 to 50 parts by weight. Within this range, a thin film can be formed, which is preferable because the light shielding property is improved while suppressing the carbon black content.

In consideration of antistatic properties, carbon black having a BET specific surface area of 50 m ² / g or more is preferable. When the BET specific surface area is less than 50 m ² / g, it is difficult to form a conductive path in carbon black, and it may be difficult to develop high conductivity with a small amount of addition. Further, carbon black having a BET specific surface area of 50 m ² / g or more and 1500 m ² / g or less is more preferable. If it exceeds 1500 m ² / g, it becomes difficult to increase the dispersion concentration and the amount of carbon black added, so that only a very small amount can be added, and the light-shielding property may not be exhibited. More preferably ^{75 m} 2 / g or more, or less 500m ² / g.

Further, carbon black is preferably DBP (dibutyl phthalate) oil absorption of carbon black is 100 ^cm 3/100 g or more. DBP If (dibutyl phthalate) oil absorption amount is less than 100 cm ^3/100 g, the development degree of aggregate (structure) is reduced, there may not express high conductivity, affinity with resin is also reduced coating There is also a risk of strength reduction. More preferably 100 ^cm 3/100 g or more, or less ⁵⁰⁰ cm 3 / 100g.

  In addition, in the resin composition for forming a light shielding layer, carbon black having a primary particle diameter of more than 50 nm, carbon black having a primary particle diameter of less than 10 nm, an organic pigment, and an inorganic pigment as long as the function of the present invention is not impaired. In addition, particles such as metal pigments may be included. These 1 type (s) or 2 or more types can be mixed and used.

<Plastic component>
The light shielding layer forming resin composition of the present invention preferably contains a plastic component.
The plastic component in the present invention refers to a component capable of imparting plasticity to a fiber-based resin as a binder resin, and is not limited to what is generally called a plasticizer, but also polyester, polyether, polycarbonate, Polybutadiene or derivatives thereof are also included.
A polyol can also be used.
A plastic component can also be used 1 type or in combination of 2 or more types.

By including the plasticizer component, it is possible to relieve the internal stress of the fiber resin characteristics, and it is possible to suppress warpage (curl) of the light-shielding member that is considered to be the influence of the internal stress of the resin characteristics when forming the light-shielding layer.
The plastic component may be used as a pretreatment agent for particles of carbon black, organic pigments, inorganic pigments, metal pigments, and the like, and may be added when preparing the light shielding layer forming resin composition.
When used as a pretreatment agent, the dispersion stability of carbon black, organic pigments, inorganic pigments, metal pigments, and other particles can be secured, and sedimentation and unevenness due to particles can be suppressed when forming a light shielding layer. It becomes.

Specifically, as the plastic component, at least one of a functional group capable of reacting with a carboxyl group, a functional group capable of reacting with a hydroxyl group, and a functional group capable of reacting with an isocyanate group at a linear terminal or a branched terminal Polyesters, polyethers, polycarbonates, polybutadienes, or derivatives thereof having the following can be used.
Among these, polyester or polyether is preferable from the viewpoint of balance between plasticity and toughness, and polyester is particularly preferable.
Moreover, it is also preferable to use a polyol, and more preferably a polyester polyol.

Examples of the functional group capable of reacting with a carboxyl group include a hydroxyl group, an epoxy group, an amino group, and an isocyanate group. A hydroxyl group is preferable in terms of reactivity.
Examples of the functional group capable of reacting with a hydroxyl group include a hydroxyl group, an epoxy group, an amino group, and an isocyanate group, and an isocyanate group is preferable in terms of reactivity.
Examples of the functional group capable of reacting with an isocyanate group include a hydroxyl group, an amino group, a carboxyl group, an epoxy group, an N-methylol group, and an N-alkoxymethyl group. A hydroxyl group is preferable in terms of reactivity. . The functional group capable of reacting with a carboxyl group, the functional group capable of reacting with a hydroxyl group, and the functional group capable of reacting with an isocyanate group may be the same functional group or different functional groups.

  Examples of polyesters include terminal hydroxyl group-containing ester compounds obtained by esterifying at least one dicarboxylic acid and at least one polyol such as a polyhydric alcohol, a polyhydric phenol, or an alkoxy modified product thereof, and a terminal. And an ester compound in which the hydroxyl group is modified to an amino group, a carboxyl group, an epoxy group, an N-methylol group, or an N-alkoxymethyl group.

  Examples of dicarboxylic acids include terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalic acid, p-oxybenzoic acid, p- (hydroxy) benzoic acid, 1,4-cyclohexanedicarboxylic acid, succinic acid, adipic acid And dicarboxylic acids such as azelaic acid, sebacic acid, and dodecanedicarboxylic acid.

  Examples of polyhydric alcohols include 1,3-propanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 2-methyl-1,4-butanediol, 1,2-dimethyl- 1,4-butanediol, 2-ethyl-1,4-butanediol, 1,5-pentanediol, 2-methyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 2,2 , 4-trimethyl-1,3-pentanediol, 3-ethyl-1,5-pentanediol, 1,6-hexanediol, 2-methyl-1,6-hexanediol, 3-methyl-1,6-hexane Diol, 1,7-heptanediol, 2-methyl-1,7-heptanediol, 3-methyl-1,7-heptanediol, 4-methyl-1,7-heptanediol, 1, -Octanediol, 2-methyl-1,8-octanediol, 2-ethyl-1,8-octanediol, 3-methyl-1,8-octanediol, 4-methyl-1,8-octanediol, 1, 9-nonanediol, ethylene glycol, propylene glycol, neopentyl glycol, diethylene glycol, dipropylene glycol, cyclohexane dimethanol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, trimethylolpropane, 1,1,1-trimethylolpropane ethylene Examples include glycol, glycerin, erythritol, xylitol, sorbitol, and mannitol.

Examples of the polyhydric phenol include catechol, resorcin, hydroquinone, hexyl resorcin, trihydroxybenzene, dimethylolphenol and the like.
Examples of commercially available polyesters include Kuraray Polyol P-510, P-1010, P-1510, P-2010, P-3010, P-4010, P-5010, P-6010, and P- manufactured by Kuraray Co., Ltd. 2011, P-2013, P-520, P-1020, P-2020, P-1012, P-2012, P-530, P-1030, P-2030, PMHC-2050, PMHC-2050R, PMHC-2070, PMHC-2090, PMSA-1000, PMSA-2000, PMSA-3000, PMSA-4000, F-2010, F-3010, N-2010, PNOA-1010, PNOA-2014, O-2010, manufactured by Sumitomo Bayer Urethane Co., Ltd. Of Desmophene 650MPA, 651MPA / X, 670,670 A, 680X, 680MPA, 800, 800MPA, 850, 1100, 1140, 1145, 1150, 1155, 1200, 1300X, 1652, 1700, 1800, RD181, RD181X, C200, Byron 200, 560, 600 manufactured by Toyobo Co., Ltd. , GK130, GK860, GK870, 290, GK590, GK780, GK790, and the like.

  Examples of polyethers include polyalkylene glycols such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol, and a terminal hydroxyl group as an amino group, carboxyl group, epoxy group, N-methylol group, isocyanate group, or N- Examples include ether compounds modified to alkoxymethyl groups.

Examples of commercially available polyethers include Desmophen 250U, 550U, 1600U, 1900U, 1915U, 1920D manufactured by Sumitomo Bayer Urethane Co., Ltd., Takenate M631, M605 manufactured by Mitsui Chemicals, and the like.
Among these, Takenate M631 and M605 manufactured by Mitsui Chemicals are preferred. Since it has an isocyanate group at the end of the plastic component, it is expected to improve the toughness and solvent resistance of the coating film because it is cured and thickened by itself.

Examples of the polycarbonate include polycarbonate diols represented by the following general formula, and carbonate compounds in which the terminal hydroxyl group is modified with an amino group, carboxyl group, epoxy group, N-methylol group or N-alkoxymethyl group. .
H- (O-R-OCO-) nR-OH
R: alkylene chain, diethylene glycol, etc.)

  Examples of the commercially available polycarbonate include Kuraray polyol PNOC-1000, PNOC-2000, PMHC-2050, PMHC-2050R, PMHC-2070, PMHC-2070R, PMHC-2090R and C-2090 manufactured by Kuraray Co., Ltd. .

  Examples of polybutadiene include α, ω-polybutadiene glycol, α, β-polybutadiene glycol, and butadiene having a terminal hydroxyl group modified with an amino group, a carboxyl group, an epoxy group, an N-methylol group, or an N-alkoxymethyl group. Compounds.

  Examples of commercially available polybutadiene include NISSO-PB G-1000, G-2000, G-3000, GI-1000, GI-2000, GI-3000, GQ-1000, and GQ-2000 manufactured by Nippon Soda Co., Ltd. Can be mentioned. Examples of the polybutadiene having two or more commercially available epoxy groups include NISSO-PB BF-1000, EPB-13, and EPB-1054 manufactured by Nippon Soda Co., Ltd.

  The plastic component has a polystyrene-equivalent weight average molecular weight of preferably 500 or more and 50,000 or less, more preferably 1,000 or more and 25,000 or less. When the weight average molecular weight exceeds 50,000, the solubility in a solvent and the compatibility with a fiber resin may decrease. Moreover, when it is less than 500, sufficient plasticity may not be imparted. In addition, when hardening a plastic component, it is the weight average molecular weight before hardening.

The plastic component is preferably cured during or after the formation of the light-shielding member.
Curing the plastic component increases the apparent molecular weight, and is expected to suppress or prevent the migration (bleed) of the plastic component and improve the coating strength.

  The content of the plastic component is preferably 1 part by weight or more and 50 parts by weight or less, more preferably 3 parts by weight or more with respect to 100 parts by weight of the fiber-based resin, from the viewpoint of suppressing warpage (curling) of the light shielding member. It is 50 parts by weight or less, more preferably 5 parts by weight or more and 40 parts by weight or less, and particularly preferably 10 parts by weight or more and 30 parts by weight or less. By being in this range, even if a fiber-based resin is used, it becomes easy to obtain a light-shielding member that is excellent in coating film strength and has no warpage (curl) of the light-shielding layer.

  If the resin composition for forming a light shielding layer of the present invention does not impair the function of the present invention, a conventional additive such as a stabilizer (antioxidant, ultraviolet absorber, light stabilizer, heat stabilization) Agents), flame retardants, flame retardant aids, impact resistance improvers, fillers (or reinforcing agents), dispersants, antistatic agents, foaming agents, antibacterial agents, lubricants, and the like. These additives may be used alone or in combination of two or more.

  In addition, the resin composition for forming a light shielding layer of the present invention has substantially reduced reflection of incident light and has excellent light shielding properties, such as inorganic fillers such as silica and alumina, and resin beads. Even if it does not use the matting agent that is used in the above, it has excellent light shielding properties. However, there is no problem even if a matting agent is used in combination with the required optical density and configuration depending on the application to be used.

<Method for producing light-shielding layer-forming resin composition>
The resin composition for forming a light shielding layer of the present invention comprises a carbon black having a primary particle size of 10 nm to 50 nm and a fiber-based resin, together with a plastic component, a solvent, etc., as necessary, a kneader, a two-roll mill, It can be produced by finely dispersing using various dispersing means such as a roll mill, a ball mill, a horizontal sand mill, a vertical sand mill, an annular bead mill, or an attritor. At this time, other carbon blacks, organic pigments, and the like may be simultaneously dispersed, or those separately dispersed may be mixed.
In addition, when the solubility of carbon black, organic pigment, etc. is high, specifically, the solubility in the resin or solvent used is high. There is no need to manufacture in a dispersed manner.
Since the resin composition for forming a light shielding layer of the present application uses a specific carbon black and a fiber-based resin, the dispersibility and the fluidity are very excellent. It is possible to produce a stable resin composition that is excellent in light-shielding properties and that suppresses changes over time.

  Further, as described above, when a plastic component is used, carbon black is used as a pretreatment agent depending on the plastic component, and together with the plastic component-treated carbon black, a fiber-based resin, and a solvent, if necessary. It is also preferable that the resin composition for forming a light shielding layer is obtained by mixing or dispersing. In this case, the dispersion stability is good, and when the light shielding layer is formed, it can be more excellent in suppressing sedimentation and unevenness due to particles.

《Light shielding layer》
The light shielding layer of the present invention contains a binder resin and carbon black, the binder resin is a fiber-based resin, and the primary particle diameter of the carbon black is from 10 nm to 50 nm. It is the light shielding layer formed. Especially, it is preferable to obtain the resin composition for light shielding layer formation by coating a resin composition by a general method.
With such a light-shielding layer, it is not only excellent in light-shielding properties, blackness, and coating film strength, but also free from warpage (curl) due to resin.

  The light-shielding layer can be formed by a wet coating method using a resin composition for forming a light-shielding layer containing a material constituting each layer, such as dip coating, roll coating, bar coating, die coating, blade coating, air knife coating, etc. It can obtain by apply | coating on a base material by the conventionally well-known coating method of (1), and making it dry.

  The light shielding layer of the present invention can also be formed by a transfer method according to the structure (configuration) of the target light shielding member.

As the transfer method, known techniques such as a roll transfer method and a mold transfer method can be used.
For example, a light shielding layer can be obtained by forming a light shielding layer on a peelable substrate and peeling the peelable substrate. A light-shielding layer single layer obtained by peeling off a peelable substrate from a light-shielding film having a peelable substrate and a light-shielding layer obtained by such a method can also be used as a light-shielding member.

Examples of the base material that can be peeled include base materials such as synthetic resin films such as polyester film, polyimide film, polystyrene film, and polycarbonate film, synthetic paper, paper, and metal plate.
Moreover, the peelable base material may be roughened. A light-shielding layer is formed on the roughened surface of the peelable substrate having a roughened surface, and the peelable substrate is peeled to obtain a light-shielding layer having an uneven surface shape. Can do.
The method for roughening the substrate surface is not particularly limited. For example, it can be roughened by applying and drying a mat layer coating solution containing a binder resin and a matting agent on the surface of the support. Others include sand blasting that sprays fine sand onto the surface of the object at high speed, embossing that is performed by passing the object between a metal engraving roll and an elastic roll, and chemical etching that treats the surface of the object with chemicals. The material surface can be roughened.
The base material and the light shielding layer are configured to be peelable. In order to make the base material and the light shielding layer peelable, the base material, the mat layer, or the light shielding layer contains a material having an excellent release effect, or a release treatment is performed on the base material or the mat layer. It is preferable. Examples of the material having an excellent release effect include alkyd resin compounds, fluorine compounds, and silicone compounds.

Although the degree of roughening of the substrate varies depending on the required gloss, the arithmetic average roughness Ra (arithmetic average roughness) (JIS B0601: 2001) is preferably 0.3 to 6.0 μm, and 0 It is more preferable to set it as 0.5-5.0 micrometers, and it is still more preferable to set it as 1.0-4.0 micrometers. By making Ra 0.3 μm or more, the gloss can be easily kept low, and by making it Ra 6.0 μm or less, the peelable substrate can be easily peeled from the light shielding layer.
The thickness of the peelable substrate is not particularly limited, but is preferably about 25 to 250 μm in consideration of workability at the time of peeling.

The thickness of the light shielding layer varies depending on the required optical density and the structure of the light shielding member, but is preferably 0.5 μm or more and 100 μm or less, more preferably 1 μm or more and 50 μm or less, and particularly preferably 2 μm or more and 30 μm or less. is there. By setting the thickness to 0.5 μm or more, pinholes or the like can be hardly generated in the light shielding layer, and sufficient light shielding properties can be easily obtained. Further, when the thickness is 100 μm or less, productivity can be ensured and thinning can be achieved.
However, the thickness of the light shielding layer, when formed by the transfer method, needs to be larger than the arithmetic average roughness Ra (arithmetic average roughness) (JIS B0601: 2001) for roughening the transfer material.

  Since the light-shielding layer of the present invention is excellent in coating film strength, it is excellent not only in light-shielding property and blackness but also in handleability even in a thin film of 2 μm or more and 30 μm or less.

The surface resistance value of the light shielding layer is preferably 1 × 10 ¹⁰ Ω / □ or less. When the surface resistance value is in the above range, the light-shielding member can have sufficient conductivity. More preferably, it is 1 × 10 ⁸ Ω / □ or less.

《Light-shielding member》
The light shielding member of the present invention includes a binder resin and carbon black, wherein the binder resin is a fiber-based resin, and the carbon black has a primary particle diameter of 10 nm to 50 nm. It has a light shielding layer formed. Since the light-shielding member of the present invention has a high coating film strength of the light-shielding layer, the light-shielding member can be configured as a single light-shielding layer without a substrate. At this time, the thickness of the light-shielding member can also be a thin film of, for example, 3 μm or more and 30 μm or less, and the film can be excellent in light-shielding property, handling property, stability, and workability even though it is a thin film.

  The thickness of the light-shielding member varies depending on the required optical density and configuration, but is preferably 0.5 μm or more and 100 μm or less, more preferably 1 μm or more and 50 μm or less, and particularly preferably 2 μm or more and 30 μm or less. By setting the thickness to 0.5 μm or more, sufficient light shielding properties can be easily obtained. Further, when the thickness is 100 μm or less, productivity can be ensured, and reduction in thickness and weight can be achieved.

  Further, on the light shielding layer, an adhesive layer for adhering the light shielding layer to an optical application, an optical device application, a display device application, a mechanical component, an electric / electronic component, or the like may be provided. The adhesive layer can be formed from various adhesives such as pressure-sensitive adhesives such as acrylic adhesives, urethane adhesives, polyester adhesives, and silicone adhesives, and heat-sensitive adhesives. Moreover, you may provide a separator on the light shielding layer as needed.

  For the adhesive layer, a light-shielding layer coating solution containing the material constituting each layer is applied onto a substrate by a conventionally known coating method such as dip coating, roll coating, bar coating, die coating, blade coating, air knife coating, and the like, and dried. Can be obtained.

Regardless of its form, the light-shielding member of the present invention preferably has a glossiness of at least 20 on one surface. When the glossiness of the light-shielding member exceeds 20, the light-shielding property 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 can be 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 member preferably has an uneven shape (uneven structure) on the surface of the member so that the glossiness of the surface is in the above range. By having an uneven shape on the surface, the gloss of the light-shielding member can be eliminated, light reflection can be prevented, and light can be shielded. Moreover, the light-shielding member which has an uneven | corrugated shape on the surface is suitable also in the point by which the effect of this invention is exhibited by setting it as such a form. Thus, if the light-shielding member has an uneven shape on at least one surface of the member surface, it is effective for controlling the glossiness of the light-shielding member within the glossiness range described later. More preferably, it has a concavo-convex shape on both sides, and the effect is more fully exhibited.

Here, when the light shielding member has a layer other than the light shielding layer, the uneven shape is preferably formed on the surface of the light shielding layer opposite to the surface on which the layer other than the light shielding layer is formed.
That is, it is preferable that the light-shielding member has a concavo-convex shape on at least one light-shielding layer. By forming the concavo-convex shape in the light shielding layer, reflection of light can be suppressed and the light shielding property can be sufficiently improved. More preferably, the light shielding layers on both surfaces of the light shielding layer of the light shielding member are uneven. When the light-shielding layer is not formed on the surface of the light-shielding member, the uneven shape is preferably formed on both the light-shielding layer and the layer on the surface of the light-shielding member.

As the uneven shape, for example, the surface may not be smooth to the extent that incident light is scattered without being specularly reflected. Moreover, it is preferable that the unevenness | corrugation of the surface is a magnitude | size suitable for scattering the light which it wants to shield. For example, when a light shielding member is used for a lens unit, light in the visible light region, the ultraviolet region, the infrared region, and the like is effectively scattered.
In this case, the arithmetic average roughness Ra (arithmetic average roughness) (JIS B0601: 2001) is preferably 0.3 μm or more. More preferably, it is 0.5 micrometer or more, More preferably, it is 1.0 micrometer or more, Most preferably, it is 2.0 micrometers or more.

  When it has a base material, synthetic resin films, such as a polyester film, a polyimide film, a polystyrene film, a polycarbonate film, are mentioned as a base material. Among them, a polyester film is preferably used, and a stretched polyester film, particularly a biaxially stretched polyester film, is particularly preferable in terms of excellent mechanical strength and dimensional stability. Moreover, a polyimide film is used suitably for the use for a heat resistant use.

  Although the film thickness of a base material changes with uses and structures of a light-shielding member, it is preferably 1 μm or more and 100 μm or less, more preferably 2 μm or more and 50 μm or less, and particularly preferably 4 μm or more and 30 μm or less. By setting the thickness to 1 μm or more, the productivity of the light shielding member can be ensured. Further, when the thickness is 100 μm or less, it is possible to reduce the thickness and weight.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited at all by these. “Parts” means “parts by weight” and “%” means “% by weight”.

The materials used in the examples are shown below.
<Carbon black>
The physical property values of carbon black used in Examples and Comparative Examples are summarized below.

[Example 1]
A mixture having the following composition was uniformly stirred and mixed with a shaker (Scandex SK450: manufactured by Fast & Fluid Management) to obtain a resin composition 1 for forming a light shielding layer.
<Light shielding layer forming resin composition 1>
・ Binder resin: 10.8 parts
CAP482-20 (cellulose ester): Eastman Kodak Co., Ltd., carbon black (CB-1): 2.2 parts Diluting solvent (methyl ethyl ketone): 43.5 parts Diluting solvent (toluene): 43.5 parts

[Example 2]
A light shielding layer forming resin composition 2 was obtained in the same manner as in Example 1 except that the carbon black (CB-1) of the light shielding layer forming resin composition 1 was changed to carbon black (CB-2).

[Example 3]
A mixture having the following composition was uniformly stirred and mixed with a shaker (Scandex SK450: manufactured by Fast & Fluid Management) to obtain a resin composition 3 for forming a light shielding layer.
<Light shielding layer forming resin composition 3>
・ Binder resin: 10.6 parts
CAP482-20 (cellulose ester): Eastman Kodak Co., Ltd., carbon black (CB-1): 2.2 parts, plastic component: 1.6 parts polyester polyol (Kuraray polyol F-3010: Kuraray Co., Ltd.)
Diluting solvent (methyl ethyl ketone): 42.8 parts Diluting solvent (toluene): 42.8 parts

[Example 4]
A resin composition 4 for forming a light shielding layer was obtained in the same manner as in Example 3 except that the plastic component of the resin composition 3 for forming the light shielding layer was changed to polyether (Desmophen 250U: manufactured by Sumitomo Bayer Urethane Co., Ltd.). .

[Example 5]
A mixture having the following composition was uniformly stirred and mixed by a shaker (Scandex SK450: manufactured by Fast & Fluid Management) to obtain a resin composition 5 for forming a light shielding layer.
<Light shielding layer forming resin composition 5>
Binder resin: 10.8 parts Fiber-based resin CAP482-20 (cellulose ester): manufactured by Eastman Kodak Co., Ltd.Carbon black (CB-1): 2.2 partsPlastic component: 0.2 parts Polyester polyol (Kuraray) Polyol F-3010: Kuraray Co.)
Diluting solvent (methyl ethyl ketone): 43.4 parts Diluting solvent (toluene): 43.4 parts

[Example 6]
A mixture having the following composition was uniformly stirred and mixed by a shaker (Scandex SK450: manufactured by Fast & Fluid Management) to obtain a resin composition 6 for forming a light shielding layer.
<Light shielding layer forming resin composition 6>
-Binder resin: 10.4 parts Fiber-based resin CAP482-20 (cellulose ester): Eastman Kodak Co., Ltd.- Carbon black (CB-1): 2.2 parts-Plastic component: 5.0 parts Polyester polyol (Kuraray) Polyol F-3010: Kuraray Co.)
Diluting solvent (methyl ethyl ketone): 41.2 parts Diluting solvent (toluene): 41.2 parts

[Comparative Example 1]
A mixture having the following composition was uniformly stirred and mixed with a shaker (Scandex SK450: manufactured by Fast & Fluid Management) to obtain a resin composition 7 for forming a light shielding layer.
<Light shielding layer forming resin composition 7>
-Binder resin: 21.0 parts acrylic polyol
(Acridic A807: manufactured by DIC Corporation)
・ Isocyanate: 3.5 parts (Bernock DN950: manufactured by DIC Corporation)
Carbon black (CB-1): 2.1 parts Diluting solvent (methyl ethyl ketone): 36.7 parts Diluting solvent (toluene): 36.7 parts [Comparative Example 2]
A light shielding layer forming resin composition 8 was obtained in the same manner as in Example 1 except that the carbon black (CB-1) of the light shielding layer forming resin composition 1 was changed to carbon black (CB-3).

[Comparative Example 3]
A mixture having the following composition was uniformly stirred and mixed with a shaker (Scandex SK450: manufactured by Fast & Fluid Management) to obtain a resin composition 9 for forming a light shielding layer.
<Light shielding layer forming resin composition 9>
-Binder resin: 36.6 parts polyimide resin
(PIAD200A: Arakawa Chemical Industries)
Carbon black (CB-1): 2.4 parts Diluting solvent (cyclohexanone): 30.5 parts Diluting solvent (methylcyclohexane): 30.5 parts

[Evaluation of light-shielding member]
About the light-shielding member obtained by the Example and the comparative example, optical density, coating-film intensity | strength, and the brightness were evaluated. The results are shown in Table 4.

(Method of forming light shielding layer)
On the release treatment surface of the base material (film binder DG2: manufactured by Fujimori Kogyo Co., Ltd., thickness 50 μm), the obtained resin composition for forming a light shielding layer was applied and dried to form a light shielding layer having a thickness of 20 μm.
In this example, the obtained light shielding layer single layer was evaluated as a light shielding member.
In the evaluation results, “◯” is excellent and “Δ” is a practical level.

[Evaluation item]
1. Pigment aggregation The dispersibility and stability of the resin composition for forming a light-shielding layer were determined by evaluating the pigment aggregation.
The formed light shielding layer was cut into a size of 10 cm × 10 cm, and pigment aggregates were counted by visually observing the surface of the light shielding layer.
The case where the number of pigment aggregates was 5 or less was “◯”, the case where it was 10 or less, “Δ”, and the case where more than 10 were “×”.
2. Optical density About the obtained light shielding layer, optical density was measured using the optical densitometer (TD-904: Gretag Macbeth) based on JISK7651: 1988. For the measurement, a UV filter was used.
An optical density exceeding 4.0 and a density in a non-measurable region was indicated by “◯”, and an optical density of 4.0 or less was designated “X”.

3. Coating film strength Tensile strength (breaking strength) was measured according to JIS K 7161.
The light shielding layer having a width of 10 mm and a length of 50 mm was pulled at a speed of 200 mm / min with a tensile tester (Tester Sangyo Co., Ltd.), and the load when the light shielding layer was cut was measured.
Those broken at a load of 250 g or more were designated as “◯”, and those broken at a load of less than 250 g were designated as “x”.

4). Lightness Index Using a spectral color difference meter (SE-6000: Nippon Denshoku), the brightness index L * of the reflected light of the light shielding layer was measured. The lightness index L * is a numerical value where 100 means whiteness and 0 means blackness.
A case where L * was 40 or less was designated as “◯”, and a case where L * exceeded 40 was designated as “X”.

5. Curl The formed light-shielding layer was cut into a size of 10 cm × 10 cm, the light-shielding layer was placed on a smooth glass plate, and the curls on the four edges of the light-shielding layer were measured.
When the degree of curling becomes tight, different end portions overlap each other and the light shielding member becomes cylindrical. In that case, since the measurement of curl becomes difficult, the diameter of the cylindrical circle is measured.
When the curl becomes tight, the overlap between end portions increases and the diameter decreases.
When the average curl of the four edges is within ± 20 mm, “◯” is given, and when the cylinder is larger than ± 20 mm and having a diameter of 50 mm or more, “△” is given, and the cylinder is less than 50 mm in diameter. Was marked “x”.

6). Measure the surface resistivity of the light-shielding layer using an antistatic resistance meter (Lorestar GP: manufactured by Mitsubishi Chemical Analytech or Hirester UX: manufactured by Mitsubishi Chemical Analytech), and less than 1 × 10 ⁸ Ω / □ "〇" things, the 1 × 10 ⁸ Ω / □ those larger of 1 × ¹⁰ 10 Ω / □ or less "△", was what more than 1 × ¹⁰ 10 Ω / □ as "×".

  As shown in Table 2, the resin composition for forming a light shielding layer of the present invention contains a binder resin that is a fiber-based resin and carbon black having a primary particle diameter of 10 nm or more and 50 nm or less. The carbon black in the resin composition was excellent in dispersibility and stability. In addition, the light-shielding layer formed by using the resin composition for forming a light-shielding layer of the present invention is capable of suppressing the warpage (curl) of the light-shielding layer while sufficiently maintaining the light-shielding property, blackness, and coating strength. Showed good results.

  From the above results, the light-shielding member having the light-shielding layer of the present invention is excellent in optical density, coating film strength, and light-shielding property even with a single light-shielding layer alone, and can be reduced in size, thickness, and weight. It was confirmed that there was.

  Further, when the light shielding member had a base material, the optical density, the coating film strength, and the light shielding properties were all excellent as in the case of the single light shielding layer.

  Therefore, the light-shielding member of the present invention can be suitably used for various applications such as optical applications, optical device applications, display device applications, mechanical parts, and electrical / electronic parts.

Claims (3)

Forming a light shielding layer comprising a resin composition for forming a light shielding layer on a peelable substrate;
A method for producing a light-shielding member, comprising a step of peeling the peelable substrate from the light-shielding layer,
The light shielding layer has a thickness of 0.5 to 100 μm and includes a binder resin and carbon black,
The binder resin is a fiber-based resin,
The primary particle size of the carbon black is 10 nm or more and 50 nm or less.
Manufacturing method of light-shielding member. DBP oil absorption amount of carbon black, ¹⁰⁰ cm 3 / 100g or more, ⁵⁰⁰ cm 3 / method for manufacturing the light-shielding member according to claim 1, wherein a 100g or less. The method for producing a light-shielding member according to claim 1 or 2, wherein the fiber-based resin is at least one of cellulose and a cellulose derivative.