TWI675872B - Resin composition for forming shielding layer and production method thereof,shielding layer, and shielding member and production method thereof - Google Patents

Abstract

The present invention provides a resin composition, and a light-shielding layer and a light-shielding member excellent in light-shielding property, black tone, and coating film strength using the resin composition. The resin composition can form carbon black in a resin composition for forming a light-shielding layer. Dispersion stability is excellent, and the light-shielding layer has sufficient light-shielding properties, black tint, and coating film strength, and can reduce warping (curling) of the light-shielding layer, thereby achieving a thin, light-weight light-shielding layer with excellent processability. The resin composition for forming a light-shielding layer of the present invention includes a binder resin containing a cellulose-based resin, and carbon black having a primary particle diameter of 10 nm or more and 50 nm or less.

Description

Resin composition for forming light-shielding layer, method for producing same, light-shielding layer, And light-shielding member and manufacturing method thereof

The present invention relates to a resin composition for forming a light-shielding layer containing a cellulose-based resin and a method for producing the same. The present invention also relates to a light-shielding layer and a light-shielding member using the resin composition for forming a light-shielding layer.

The light-shielding member is a member having a light-shielding layer which is used for various applications such as optical element members, display element members, mechanical parts, and electrical and electronic parts, in addition to optical members such as lens units. Light of a desired wavelength is scattered or absorbed, and the light of that wavelength is shielded.

For example, in optical applications such as high-performance single-lens reflex cameras, compact cameras, camcorders, digital cameras, and camera modules for mobile phones, due to requirements for miniaturization, thinness, and weight, metal materials are being used. The light-shielding member of the optical device is replaced with a plastic material.

As such a light-shielding member, there is known a light-shielding member in which a black colored film containing a thermoplastic resin as a main component is used as a base film, and a light-shielding layer containing carbon black, a lubricant, and a matting agent is provided on both surfaces thereof. (Japanese Patent Laid-Open No. 9-274218).

Also disclosed are a resin composition for forming a light-shielding layer using a solvent-soluble polyfluorene imine resin and carbon black having a specific surface area of 100 m ² / g or more as essential components, and a resin composition for forming the light-shielding layer formed from the resin composition. Light-shielding film (Japanese Patent Laid-Open No. 2012-017419). In addition, a light-shielding film having a black material and an organic resin containing a curable resin cured material or a thermoplastic resin having a glass transition temperature of 150C or higher is disclosed (Japanese Patent Application Publication No. 2010-534342).

However, higher performance light shielding layers are required on the market. Specifically, there is a need for a light-shielding layer that coexists the light-shielding properties of the light-shielding layer and the blackness with the dispersion stability of the resin composition. Furthermore, there is a need for a light-shielding layer that can reduce the warpage (curl) of the light-shielding layer that is generated when the light-shielding layer is formed and that meets the requirements for miniaturization, thinning, and weight reduction of optical members that have been required in recent years.

The present invention has been made in view of the background, and an object thereof is to provide a carbon black in a resin composition, which has excellent dispersion stability, sufficiently maintains the light-shielding property of the light-shielding layer, black tone, and coating film strength, and reduces the light-shielding layer. Warping (curling), a light-shielding layer capable of being thinned and lightened, and having excellent processability; a resin composition for forming a light-shielding layer capable of forming the light-shielding layer; .

As a result of intensive studies to solve the problems, the inventors have found that the problems of the present invention can be solved in the following aspects, and the present invention has been completed. That is, one embodiment of the present invention relates to a resin composition for forming a light-shielding layer, which includes a binder resin containing a cellulose-based resin, and carbon black having a primary particle diameter of 10 nm or more and 50 nm or less.

In addition, another embodiment of the present invention relates to a resin composition for forming a light-shielding layer that further includes a plastic component.

Furthermore, as another embodiment of this invention, the said cellulose resin is a resin composition for light-shielding layer formation which is at least 1 sort (s) chosen from a cellulose and a cellulose derivative.

In addition, another embodiment of the present invention relates to a resin composition for forming a light-shielding layer containing the carbon black in an amount of 1 part by mass to 100 parts by mass based on 100 parts by mass of the cellulose-based resin.

In addition, another embodiment of the present invention relates to a method for producing a resin composition for forming a light-shielding layer, comprising a step of mixing a binder resin containing a cellulose-based resin with carbon black having a primary particle diameter of 10 nm or more and 50 nm or less. .

In addition, another embodiment of the present invention relates to a method for producing a resin composition for forming a light-shielding layer in which the plastic component is further added in the mixing step.

Moreover, another embodiment of this invention is a light-shielding layer formed from the said resin composition for light-shielding layer formation.

In addition, another embodiment of the present invention relates to a light-shielding member including the light-shielding layer.

According to the present invention, an excellent effect is obtained in that a carbon black in a resin composition can be provided, which has excellent dispersion stability, sufficiently maintains the light-shielding property of the light-shielding layer, black tone, and coating film strength, and reduces warping of the light-shielding layer. (Curl), a light-shielding layer that can be reduced in thickness and weight, and has excellent processability; a resin composition for forming a light-shielding layer capable of forming the light-shielding layer; a method for producing the same; and a light-shielding member including the light-shielding layer.

An example of an embodiment to which the present invention is applied will be described below. In addition, as long as it conforms to the gist of the present invention, other embodiments are naturally included in the scope of the present invention. The numerical values specified in this specification are obtained by the methods disclosed in the embodiments or the examples. value. In addition, the numerical values “A to B” specified in this specification mean a range that includes the numerical value A and the numerical value B and is larger than the numerical value A and smaller than the numerical value B. In addition, the "film" in this specification includes not only the "film" defined in JIS but also a "sheet" and the like. In addition, as long as there is no special comment, each component appearing in this specification may be used individually by 1 type, and may use 2 or more types together.

"Resin composition for forming light-shielding layer"

The resin composition for forming a light-shielding layer according to this embodiment includes a binder resin containing a cellulose-based resin, and carbon black having a primary particle diameter of 10 nm or more and 50 nm or less. By using the resin composition for forming a light-shielding layer, carbon black can be easily dispersed in a binder resin, and carbon black and a binder resin can be easily mixed. Thereby, the resin composition for light-shielding layer formation which is excellent in light-shielding property and excellent dispersion stability can be provided. From the viewpoint of more effectively preventing warping (curling) by the resin of the light-shielding layer, it is preferable to further contain a plastic component in the resin composition for forming the light-shielding layer.

<Binder Resin>

The binder resin of this embodiment contains a cellulose-based resin.

The cellulose resin is a thermoplastic resin based on cellulose, which is a natural polymer. The cellulose-based resin is a resin having a six-membered ring structure continuously, and therefore has excellent coating film strength. In addition, since it has a structure rich in functional groups in addition to the six-membered ring structure, it is easy to retain and adsorb carbon black on the cellulose resin, and effectively improve the dispersion stability of the carbon black in the resin composition. Make it easy.

Examples of the cellulose-based resin include cellulose and cellulose derivatives. Examples of the cellulose derivative include cellulose ester, cellulose urethane, and cellulose ether.

Examples of cellulose esters include cellulose acetates such as cellulose diacetate and cellulose triacetate; cellulose C3-5 compounds such as cellulose propionate and cellulose butyrate; cellulose acetate propionate Cellulose halides such as cellulose acetate C3-5 halides such as vitamins and cellulose acetate butyrate.

Examples of the cellulose urethane include cellulose phenyl carbamate.

Examples of the cellulose ether include alkyl cellulose, hydroxyalkyl cellulose, hydroxyalkyl alkyl cellulose, carboxyalkyl cellulose, alkyl-carboxyalkyl cellulose, and derivatives of these [ For example, Carboxymethyl Cellulose (CMC) salts (such as alkali metal salts) such as sodium carboxymethyl cellulose].

The cellulose-based resin may be used singly or in combination of two or more.

Furthermore, in consideration of heat resistance during processing or use, a cellulose resin having a glass transition temperature of 100 ° C. or higher is preferred.

In addition, from the viewpoint of material handling properties during processing and durability during use, a solvent-soluble cellulose resin is preferred. As the solvent-soluble cellulose resin, cellulose ester and the like are suitable.

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

Moreover, in the range which does not impair the function of this invention, you may contain the binder resin other than a cellulose resin in the resin composition for light-shielding layer formation.

Examples of the binder resin include poly (meth) acrylic resin, polyester resin, polyvinyl acetate resin, polyvinyl chloride, polyvinyl butyral resin, polystyrene / polybutadiene resin, and polyamino group. Formate resin, alkyd resin, acrylic resin, unsaturated polyester resin, epoxy ester resin, epoxy resin, epoxy acrylate resin, acrylic urethane resin, polyester acrylate resin, polymer Ether acrylate resins, phenol resins, melamine resins, urea resins, diallyl phthalate resins, polyester polyols, acrylic polyols, epoxy polyols and other thermoplastic resins Or thermosetting resin (including isocyanate added as needed) Cross-linking agents such as esters). When a binder resin other than a cellulose resin is used, it may be used alone or as a mixture of two or more.

<Carbon black>

The carbon black contains carbon black having a primary particle diameter of 10 nm or more and 50 nm or less as an essential component. By being in this range, not only the dispersion stability becomes good, and the light-shielding property and the black tone are fully satisfied, but also by using it in combination with a cellulose-based resin, it is possible to maintain sufficient coating film strength, durability, and handling properties. It is also an excellent resin composition for forming a light-shielding layer. The more preferable range of the primary particle diameter is 10 nm or more and 40 nm or less. Further, in the resin composition for forming a light-shielding layer, carbon black exists in the state of aggregates or primary particles aggregated by primary particles. In the case of an aggregate, the average particle diameter is preferably 20 μm or less, and more preferably 10 μm or less.

The size of the primary particles is referred to as a primary particle diameter, and the primary particle diameter of the carbon black can be evaluated by a transmission electron microscope image. It suffices to include carbon black having a primary particle diameter of 10 nm or more and 50 nm or less, but it is more preferable that the number average (average primary particle diameter) of the primary particle diameter is within the above range. In addition to a method using a product having the average primary particle diameter, as will be described in detail later, there is a method of measuring the size of the primary particles using a transmission electron microscope and obtaining an average of, for example, 20 or more measured values. In the case of agglomerates, in the field of view of a transmission electron microscope, particles that can be delineated as primary particles are selected from the agglomerates and the particle size of the primary particles is measured. This can be measured in accordance with ASTM D-3849. The primary particle diameter in the light-shielding layer-forming resin composition or the light-shielding layer. The primary particle diameter was set as the average value when 20 were measured.

In addition, the content of carbon black having a primary particle diameter of 10 nm or more and 50 nm or less in the light-shielding layer-forming resin composition is preferably 1 to 100 parts by mass of the cellulose-based resin in terms of light-shielding properties and depth of appearance. The mass range is not less than 100 parts by mass, more preferably not less than 5 parts by mass and not more than 75 parts by mass, and particularly preferably within the range of not less than 10 parts by mass and not more than 50 parts by mass. By being in this range, a thin film can be realized, and the light-shielding property can be changed while suppressing the content of carbon black. Good results are preferred.

Furthermore, in consideration of the antistatic property, it is preferable that the specific surface area of Brunauer-Emmett-Teller (BET) of carbon black is 50 m ² / g or more. If the BET specific surface area is less than 50 m ² / g, it may be difficult to form a conductive path in carbon black, and it may be difficult to develop high conductivity with a small amount of addition. The BET specific surface area of the carbon black is more preferably 50 m ² / g or more and 1500 m ² / g or less. If it exceeds 1500 m ² / g, it is difficult to increase the dispersion concentration or the amount of carbon black added, so there is a concern that only a very small amount can be added without exhibiting light-shielding properties. It is more preferably 75 m ² / g or more and 500 m ² / g or less.

Further, the carbon black preferably dibutyl phthalate (Dibutyl phthalate, DBP) oil absorption 100cm ³ / 100g or more. DBP (dibutyl phthalate) oil absorption amount is set by the 100cm ³ / 100g or more, the level of development can be increased aggregation (structure) of the body, and to improve conductivity. In addition, the affinity with the resin can be improved, and the film strength can be improved more effectively. More preferably 100cm ³ / 100g or more, 500cm ³ / 100g or less.

In addition, the resin composition for forming a light-shielding layer may contain carbon black having a primary particle size of more than 50 nm, carbon black having a primary particle size of less than 10 nm, an organic pigment, an inorganic pigment, and the like, as long as the function of the present invention is not impaired. Particles such as metallic pigments. These can be used individually by 1 type or in mixture of 2 or more types.

<Plastic component>

As another preferable example of the resin composition for light-shielding layer formation of this embodiment, there is a form which further contains a plastic component. Here, the plasticity component refers to a component that imparts plasticity to a cellulose resin as a binder resin, and generally includes not only a plasticizer, but also polyester, polyether, polycarbonate, and polybutylene. Diene, or derivatives of these. Alternatively, a polyhydric alcohol may be used. The plastic component may be used alone or in combination of two or more.

By containing a plastic component, the internal stress of cellulose-based resin properties is reduced, When the light-shielding layer is formed, it is possible to effectively suppress warping (curling) of the light-shielding member that is considered to be affected by internal stress that is a characteristic of the resin. In addition, the plastic component can be used as a pretreatment agent for particles such as carbon black, organic pigments, inorganic pigments, and metal pigments, and can also be added when preparing a resin composition for forming a light-shielding layer.

When used as a pretreatment agent, dispersion stability of particles such as carbon black, organic pigments, inorganic pigments, and metal pigments can be ensured. When a light-shielding layer is formed, precipitation and unevenness caused by the particles can be suppressed.

Preferable examples of the plastic component include a functional group capable of reacting with a carboxyl group at a linear end or a branched end, a functional group capable of reacting with a hydroxyl group, and a functional group capable of reacting with an isocyanate group. At least any one of polyester, polyether, polycarbonate, polybutadiene, or derivatives of these.

Among these, a polyester or a polyether is preferable from the viewpoint of the balance of plasticity and toughness, and a polyester is particularly preferable.

In addition, a polyol is also preferably used, and a polyester polyol is more preferred.

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. From the viewpoint of reactivity, a hydroxyl group is preferred.

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. From the viewpoint of reactivity, an isocyanate group is suitable.

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. However, it is suitable from the viewpoint of reactivity. Is hydroxyl. 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 the polyester include a combination of at least one dicarboxylic acid with a polyol, An ester compound containing a terminal hydroxyl group obtained by esterifying at least one of a polyhydric phenol or a polyhydric alcohol such as an alkoxy modification thereof, and modifying the terminal hydroxyl group into an amino group, a carboxyl group, an epoxy group, and an N-hydroxyl group. Methyl or N-alkoxymethyl ester compounds and the like.

Examples of the dicarboxylic acid include terephthalic acid, isophthalic acid, phthalic acid, 1,5-naphthalenedicarboxylic acid, p-oxybenzoic acid, p- (hydroxy) benzoic acid, 1, Dicarboxylic acids such as 4-cyclohexanedicarboxylic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, and the like.

Examples of the polyol include 1,3-propanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 2-methyl-1,4-butanediol, 1 2,2-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-hexanediol, 1,7-heptanediol, 2-methyl-1,7-heptanediol, 3- Methyl-1,7-heptanediol, 4-methyl-1,7-heptanediol, 1,8-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 Diethylene glycol, diethylene glycol, dipropylene glycol, cyclohexanedimethanol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, trimethylolpropane, 1,1,1-trimethylolpropane Ethylene glycol, glycerol, erythritol, xylitol, sorbitol, mannitol and the like.

Examples of the polyphenol include catechol, resorcinol, hydroquinone, hexylresorcinol, trihydroxybenzene, and dimethylolphenol.

Commercially available polyesters include, for example, Kuraray polyols P-510, P-1010, P-1510, P-2010, P-3010, and P- 4010, P-5010, P-6010, P-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, Sumitomo Bayer Carbamate Desmophen 650MPA, 651MPA / X, 670, 670BA, 680X, 680MPA, 800, 800MPA, 850, 1100, 1140, 1145, 1150, 1155, 1200, 1300X, 1652, manufactured by Sumitomo Bayer Urethane , 1700, 1800, RD181, RD181X, C200, Vylon 200, 560, 600, GK130, GK860, GK870, 290, GK590, GK780, GK790, etc. manufactured by Toyobo.

Examples of the polyether include polyalkylene glycols such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol, and modification of terminal hydroxyl groups to amino, carboxyl, and epoxy An ether compound composed of an amino group, an N-methylol group, an isocyanate group, or an N-alkoxymethyl group.

As commercially available polyethers, for example, Desmophen 250U, 550U, 1600U, 1900U, 1915U, 1920D manufactured by Sumitomo Bayer Urethane Co., Ltd., and Takenate manufactured by Mitsui Chemicals Co., Ltd. are available. M631, M605, etc.

Among these, Takenate M631 and M605 manufactured by Mitsui Chemicals are suitable. Since an isocyanate group is present at the terminal of the plastic component, it is hardened and film-enlarged by itself. Therefore, improvement in toughness and solvent resistance of the coating film is expected.

Examples of the polycarbonate include a polycarbonate diol represented by the following general formula, and a terminal hydroxyl group modified to an amino group, a carboxyl group, an epoxy group, an N-methylol group, or an N- An alkoxymethyl carbonate compound.

H- (OR-OCO-) _n R-OH

Among them, R: an alkylene chain, diethylene glycol, and the like.

Examples of commercially available polycarbonates include Kuraray polyols PNOC-1000, PNOC-2000, PMHC-2050, PMHC-2050R, PMHC-2070, PMHC-2070R, PMHC-2090R, C manufactured by Kuraray Corporation. -2090 and so on.

Examples of polybutadiene include α, ω-polybutadiene diol, α, β-polybutadiene diol, and modification of terminal hydroxyl groups into amino, carboxyl, and epoxy groups , N-hydroxymethyl or N-alkoxymethyl butadiene compound.

As commercially available polybutadiene, for example, NISSO-PBG-1000, G-2000, G-3000, GI-1000, GI-2000, GI-3000, GQ-1000, GQ- 2000 and so on. Examples of commercially available polybutadiene having two or more epoxy groups include, for example, NISSO-PB BF-1000, EPB-13, EPB-1054, and the like manufactured by Soda Corporation of Japan.

The polystyrene-equivalent weight average molecular weight of the plastic component is preferably 500 or more and 50,000 or less, and more preferably 1,000 or more and 25,000 or less. When the weight average molecular weight exceeds 50,000, solubility in a solvent and compatibility with a cellulose-based resin may decrease. When the weight average molecular weight is less than 500, sufficient plasticity may not be imparted. When the plastic component is cured, the weight average molecular weight before curing is used.

The plastic component is preferably cured when the light-shielding member is formed or after the light-shielding member is formed. The curing of the plastic component is preferably a method of crosslinking with a cellulose resin. As a result, the apparent molecular weight is increased, and it is expected to suppress or prevent the transfer (bleed-out) of the plastic component and increase the film strength. In addition to the method of cross-linking with a cellulose-based resin, curing of the plastic component may be performed by cross-linking other components, hardeners, or plastic components, or these methods may be used in combination with cross-linking with a cellulose-based resin .

From the viewpoint of suppressing warping (curling) of the light-shielding member, the content of the plastic component is preferably 1 part by mass or more and 50 parts by mass or less, and more preferably 3 parts by mass or more and 50 parts by mass based on 100 parts by mass of the cellulose-based resin. It is more preferably 5 parts by mass or more and 40 parts by mass or less, and particularly preferably in a range of 10 parts by mass or more and 30 parts by mass or less. By setting it to 1 part by mass or more and 50 parts by mass or less, even if a cellulose-based resin is used, a light-shielding member having excellent coating film strength and effectively suppressing warping (curling) of the light-shielding layer can be easily produced.

As long as the function of the present invention is not impaired, the resin composition for forming a light-shielding layer according to this embodiment can use a conventional additive such as a stabilizer (antioxidant, ultraviolet absorption). Additives, light stabilizers, heat stabilizers, etc.), flame retardants, flame retardant additives, impact modifiers, fillers (or reinforcing agents), dispersants, antistatic agents, foaming agents, antibacterial agents, lubricants Wait. These additives may be only one kind or a combination of two or more kinds.

In addition, the resin composition for forming a light-shielding layer according to this embodiment is excellent in light-shielding properties even if it does not substantially use inorganic fillers such as silicon dioxide or aluminum oxide, or is conventionally used to suppress reflection of incident light such as resin beads. This matting agent is also excellent in light-shielding properties. However, there is no problem even if a matting agent is used in combination with the required optical density and configuration in accordance with the intended use.

<The manufacturing method of the resin composition for light-shielding layer formation>

Next, an example of the manufacturing method of the resin composition for light-shielding layer formation of this embodiment is demonstrated. However, the manufacturing method of the resin composition for light-shielding layer formation of this invention is not limited to the following method. First, carbon black with a primary particle size of 10 nm or more and 50 nm or less is mixed with a cellulose-based resin and a solvent, and a plastic component or other component is added as necessary, and a kneader, a double roll mill, a three roll mill, a ball mill, The resin composition for forming a light-shielding layer can be manufactured by performing dispersion | distribution by various dispersing apparatuses, such as a horizontal sand mill, a vertical sand mill, a ring-type bead mill, or an attritor. The degree of dispersion can be appropriately adjusted according to the application. For example, it can be dispersed to the extent of disentanglement. The degree of dispersion can be adjusted according to the degree of unevenness of the desired film surface. In this case, other carbon blacks, organic pigments, and the like may be dispersed simultaneously, and each of them may be mixed.

When the solubility of carbon black or organic pigments is high, as long as the solubility of the resin or solvent specifically used is high, and it is dissolved by stirring, and the state of foreign matter is not confirmed, the above may be omitted. Dispersive steps.

The resin composition for forming a light-shielding layer according to this embodiment uses a specific carbon black and a cellulose-based resin, and has excellent dispersibility and fluidity. Therefore, it is possible to produce an excellent light-shielding property without performing fine dispersion treatment, and change over time. A suppressed stable resin composition was also obtained.

In addition, as described above, when a plastic component is used, it is also preferable to use carbon black as a pretreatment agent by using the plastic component, and to use the plastic component to treat the carbon black together with a cellulose-based resin, and a solvent as needed. The resin composition for forming a light-shielding layer is mixed or dispersed. In this case, the dispersion stability is good, and when the light-shielding layer is formed, it is possible to more effectively suppress precipitation and unevenness due to particles.

"Shading layer"

The light-shielding layer of this embodiment is formed of a resin composition for forming a light-shielding layer containing a binder resin as a cellulose-based resin and carbon black having a primary particle diameter of 10 nm or more and 50 nm or less. The light-shielding layer is preferably obtained by applying a resin composition for forming a light-shielding layer by a general method. By using a cellulose-based resin as a binder resin and a specific carbon black, carbon black can be easily dispersed in a resin composition. It is not only a thin film, but also has excellent light-shielding properties, black tone, and coating strength, and is effective. Warping (curling) caused by the resin is suppressed.

The light-shielding layer can be formed into a layer by a wet coating method using a resin composition for forming a light-shielding layer containing a material constituting each layer. For example, the light-shielding layer can be formed by using dip coating, roll coating, bar coating, die coating, blade coating, or air knife. A conventionally known coating method such as coating is applied to a substrate and dried to obtain it.

The light-shielding layer according to this embodiment may be formed by a transfer method in accordance with the structure (structure) of the target light-shielding member or the like.

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

Examples of the peelable substrate include synthetic resin films such as polyester films, polyimide films, polystyrene films, and polycarbonate films, and substrates such as synthetic paper, paper, and metal plates.

In addition, the peelable substrate can be roughened. Peelable substrate with roughened surface By forming a light-shielding layer on the roughened surface of the material and peeling off the peelable base material, a light-shielding layer having an uneven shape on the surface can be easily obtained.

The method of roughening the surface of a base material is not specifically limited. For example, a matte layer coating liquid containing a binder resin and a matte agent is applied to the surface of a support and dried to thereby roughen it. In addition, the surface of the substrate can be roughened by, for example, a sandblasting process in which fine sand is blown onto the surface of the object at a high speed, and the object can be passed between the metal engraving roller and the elastic roller. Embossing, chemical etching of the surface of the object with chemicals.

The substrate and the light-shielding layer are configured to be peelable. In order to releasably constitute the base material and the light-shielding layer, it is preferred that the base material, the matte layer, or the light-shielding layer contain a material having an excellent mold release effect, or that the substrate or the matte layer be subjected to a release treatment. Examples of the material having excellent mold release effects include alkyd resin compounds, fluorine compounds, and silicone compounds.

The degree of roughening of the substrate varies depending on the required gloss, but the arithmetic mean roughness Ra (arithmetic mean roughness) (JIS B0601: 2001) is preferably 0.3 μm to 6.0 μm, and more preferably 0.5 μm to 5.0 μm, and more preferably 1.0 μm to 4.0 μm. By setting Ra to 0.3 μm or more, the gloss can be easily suppressed to be low, and by setting 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 in view of workability during peeling, it is preferably set to about 25 μm to 250 μm.

The thickness of the light-shielding layer varies depending on the required optical density and the configuration of the light-shielding member, but it is preferably 0.5 μm or more and 100 μm or less, and more preferably 1 μm or more and 50 μm or less. It is particularly preferably 2 μm or more and 30 μm or less. By setting it to 0.5 μm or more, pinholes and the like are hardly generated in the light-shielding layer, and sufficient light-shielding properties are easily obtained. Moreover, when it is 100 micrometers or less, productivity can be ensured and a thin film can be achieved.

However, when formed by a transfer method, the thickness of the light-shielding layer must be greater than the thickness of the transfer material. Faceted arithmetic mean roughness Ra (arithmetic mean roughness) (JIS B0601: 2001).

Since the light-shielding layer of this embodiment is excellent in the strength of the coating film, even in films such as 2 μm or more and 30 μm or less, not only the light-shielding property and the black tint are sufficient, but also the handleability is excellent.

The surface resistance value of the light-shielding layer is preferably 1 × 10 ¹⁰ Ω / □ or less. By setting the surface resistance value to the above range, the light-shielding member can have sufficient conductivity. It is more preferably 1 × 10 ⁸ Ω / □ or less.

《Light-shielding member》

The light-shielding member according to this embodiment includes a light-shielding layer formed of a resin composition for forming a light-shielding layer, the resin composition for forming the light-shielding layer including a binder resin containing a cellulose-based resin, and a primary particle diameter of 10 nm or more and 50 nm or less. Carbon black. Since the light-shielding member of this embodiment has a high strength of the coating film of the light-shielding layer, it may be constituted by a single layer of the light-shielding layer having no base material. At this time, the thickness of the light-shielding member may be, for example, a film of 3 μm or more and 30 μm or less, and not only the film, but also excellent light-shielding properties, handling properties, stability, and processability. Of course, it can also be set as the laminated body of a base material, a light-shielding layer, etc. according to a use.

The thickness of the light-shielding member varies depending on the required optical density and structure, but is preferably 0.5 μm or more and 200 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. When the thickness is 0.5 μm or more, sufficient light-shielding properties are easily obtained. In addition, by setting the thickness to 100 μm or less, productivity can be secured, and thickness reduction and weight reduction can be achieved.

In addition, the light-shielding member may have an adhesive layer on the light-shielding layer for adhering the light-shielding layer to an optical member, an optical element member, a display element member, a mechanical part, or an electric / electronic part. The adhesive layer may be formed of various adhesives such as pressure-sensitive adhesives such as acrylic adhesives, urethane adhesives, polyester adhesives, and silicone adhesives, and thermal adhesives. In addition, a light-shielding member may be provided with a spacer on a light-shielding layer as needed.

Adhesive layer can be applied by dip coating, roll coating, bar coating, die coating, blade coating, air knife coating A coating solution for a light-shielding layer containing a material constituting each layer, such as a conventionally known coating method, is applied to a substrate and dried to obtain it.

It is preferable that the light-shielding member of the present embodiment has a gloss of at least one surface of 20 or less regardless of its form. By setting the glossiness of the light-shielding member to 20 or less, the light-shielding property can be effectively improved. For example, when used as a lens unit, the risk of noise becoming a cause of malfunction can be effectively prevented. It is more preferably 10 or less, and still more preferably 5 or less. Furthermore, it is preferable that the glossiness of both surfaces is the said range. The gloss was measured using a gloss meter VG-2000 manufactured by Nippon Denshoku Industries Co., Ltd. and measured at a measurement angle (θ) of 60 degrees.

In order to set the glossiness of the surface of a light-shielding member to the said range, there is a method of making the surface of a member into uneven | corrugated shape (concave-convex structure). By having an uneven shape on the surface, it is possible to suppress the gloss of the light-shielding member, prevent reflection of light, and effectively improve light-shielding properties. In addition, by using a light-shielding member having an uneven shape on the surface, the light-shielding effect of the present invention can be more effectively exhibited. In this way, in order to control the glossiness of the light-shielding member within a range of glossiness described later, it is effective to have a method having an uneven shape on at least one surface of the surface of the light-shielding member. It is more preferable to have a method of having a concave-convex shape on both sides, and the effect of light-shielding properties is more fully exhibited.

Here, when the light-shielding member has a layer other than the light-shielding layer, it is preferable to form a concave-convex shape on the surface of the light-shielding layer in which the light-shielding layer is not joined to another layer. That is, it is preferable that the light-shielding member has an uneven shape on the light-shielding layer on at least one side. By forming a concave-convex shape on the light-shielding layer, the reflection of light is suppressed, and the light-shielding property becomes sufficiently excellent. It is more preferable to provide an uneven shape on the light-shielding layers on both surfaces of the light-shielding layer of the light-shielding member. When the light-shielding layer is not located on the surface of the light-shielding member (when the light-shielding layer is located in the middle layer of the laminated structure), it is preferable to form an uneven shape on both the light-shielding layer and the surface of the light-shielding member.

The concave-convex shape may be, for example, a degree to which incident light is not specularly reflected and scattered, and the surface may not be smooth. In addition, it is preferable that the unevenness of the surface An appropriate size (shape) for light-shielding light scattering. For example, when a light-shielding member is used for a lens unit, it is a person who efficiently diffuses light in a visible light region, an ultraviolet region, and an infrared region.

In this case, the arithmetic average roughness Ra (arithmetic average roughness) (JIS B0601: 2001) is preferably 0.3 μm or more. It is more preferably 0.5 μm or more, even more preferably 1.0 μm or more, and particularly preferably 2.0 μm or more.

When a substrate is provided, examples of the substrate include synthetic resin films such as polyester films, polyimide films, polystyrene films, and polycarbonate films. Among them, a polyester film can be suitably used, and a polyester film subjected to stretching processing, particularly biaxial stretching processing is particularly preferred from the viewpoint of excellent mechanical strength and dimensional stability. In addition, when used in a heat-resistant application, a polyimide film can be suitably used. From the viewpoint of improving light-shielding properties in cooperation with the light-shielding layer, a colorant such as carbon black may be contained in the base material as necessary.

The film thickness of the substrate varies depending on the use and configuration of the light-shielding member, but 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 making it 1 micrometer or more, the productivity of a light-shielding member can be ensured. In addition, when the thickness is 100 μm or less, thickness reduction and weight reduction can be achieved.

[Example]

Hereinafter, the present invention will be described in more detail by examples, but the present invention is not limited to these examples at all. In addition, "part" means "mass part", and "%" means "mass%".

The materials used in the examples are shown below.

<Carbon black>

The physical property values of carbon black used in the examples and comparative examples are summarized below. When the average primary particle diameter of carbon black is measured by a transmission electron microscope, it is measured according to ASTM D-3849. Twenty were selected from a transmission electron microscope image, and the average value was made into the value of average primary particle diameter.

[Table 1]

[Example 1]

The mixture with the following composition was uniformly stirred and mixed with an oscillator (Skandex SK450: manufactured by Fast & Fluid Management) to obtain a resin composition 1 for forming a light-shielding layer.

<Resin Composition 1 for Shading Layer Formation>

‧Binder resin: 10.8 parts

Cellulose resin

CAP482-20 (cellulose ester): manufactured by Eastman Kodak

‧Carbon black (CB-1): 2.2 parts

‧Dilution solvent (methyl ethyl ketone): 43.5 parts

‧Diluted solvent (toluene): 43.5 parts

[Example 2]

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

[Example 3]

The mixture with the following composition was uniformly stirred and mixed with an oscillator (Skandex SK450: manufactured by Suriname Management Co., Ltd.) to obtain a resin composition 3 for forming a light-shielding layer.

<Resin Composition 3 for Shading Layer Formation>

‧Binder resin: 10.6 parts

Cellulose resin

CAP482-20 (cellulose ester): manufactured by Eastman Kodak

‧Carbon black (CB-1): 2.2 parts

‧Plasticity: 1.6

Polyester polyol (Kuraray polyol F-3010: manufactured by Kuraray)

‧Dilution solvent (methyl ethyl ketone): 42.8 parts

‧Dilution solvent (toluene): 42.8 parts

[Example 4]

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 a light shielding layer was changed to a polyether (Desmophen 250U: manufactured by Sumitomo Bayer Carbamate). Resin composition 4.

[Example 5]

The mixture with the following composition was uniformly stirred and mixed with an oscillator (Skandex SK450: manufactured by Suriname Management Co., Ltd.) to obtain a resin composition 5 for forming a light-shielding layer.

<Resin Composition 5 for Shading Layer Formation>

‧Binder resin: 10.8 parts

Cellulose resin

CAP482-20 (cellulose ester): manufactured by Eastman Kodak

‧Carbon black (CB-1): 2.2 parts

‧Plasticity: 0.2

Polyester polyol (Kuraray polyol F-3010: manufactured by Kuraray)

‧Dilution solvent (methyl ethyl ketone): 43.4 parts

‧Dilution solvent (toluene): 43.4 parts

[Example 6]

The mixture with the following composition was uniformly stirred and mixed with an oscillator (Skandex SK450: manufactured by Suriname Management Co., Ltd.) to obtain a resin composition 6 for forming a light-shielding layer.

<Resin Composition 6 for Shading Layer Formation>

‧Binder resin: 10.4 parts

Cellulose resin

CAP482-20 (cellulose ester): manufactured by Eastman Kodak

‧Carbon black (CB-1): 2.2 parts

‧Plasticity component: 5.0 parts

Polyester polyol (Kuraray polyol F-3010: manufactured by Kuraray)

‧Dilution solvent (methyl ethyl ketone): 41.2 parts

‧Dilution solvent (toluene): 41.2 parts

[Comparative Example 1]

The mixture with the following composition was uniformly stirred and mixed with an oscillator (Skandex SK450: manufactured by Suriname Management Co., Ltd.) to obtain a resin composition 7 for forming a light-shielding layer.

<Resin Composition 7 for Shading Layer Formation>

‧Binder resin: 21.0 parts

Acrylic polyol

(Acrydic A807: manufactured by DIC)

‧Isocyanate: 3.5 parts

(Burnock DN950: Made by Dickson)

‧Carbon black (CB-1): 2.1 parts

‧Dilution solvent (methyl ethyl ketone): 36.7 parts

‧Diluted solvent (toluene): 36.7 parts

[Comparative Example 2]

A resin composition 8 for forming a light-shielding layer was obtained in the same manner as in Example 1 except that the carbon black (CB-1) of the resin composition 1 for forming a light-shielding layer was changed to carbon black (CB-3).

[Comparative Example 3]

The mixture with the following composition was uniformly stirred and mixed with an oscillator (Skandex SK450: manufactured by Suriname Management Co., Ltd.) to obtain a resin composition 9 for forming a light shielding layer.

<Resin Composition 9 for Shading Layer Formation>

‧Binder resin: 36.6 parts

Polyimide resin

(PIAD200A: manufactured by Arakawa Chemical Industries, Ltd.)

‧Carbon black (CB-1): 2.4 parts

‧Dilution solvent (cyclohexanone): 30.5 parts

‧Dilution solvent (methylcyclohexane): 30.5 parts

[Evaluation of light-shielding member]

The light-shielding members obtained in Examples and Comparative Examples were evaluated for pigment cohesiveness, optical density, coating film strength, brightness index, and the like. The results are shown in Table 2.

(Method for forming light-shielding layer)

The obtained resin composition for forming a light-shielding layer was coated on a release-treated surface of a substrate (Filmbyna DG2: manufactured by Fujimori Industry Co., Ltd. with a thickness of 50 μm), and dried to form a 20 μm-thick film. Light-shielding layer.

In this example, the obtained light-shielding layer single layer was evaluated as a light-shielding member. That is, it measured using the light shielding layer single layer which peeled a base material.

In addition, in the evaluation results, "○" was set to be excellent, "△" was set to be practical, and "×" was set to NG level.

[Evaluation item]

1. pigment cohesiveness

The dispersion stability of the resin composition for forming a light-shielding layer was judged by the cohesiveness evaluation of a pigment.

The formed light-shielding layer was cut into a size of 10 cm × 10 cm, and the surface of the light-shielding layer was visually observed, thereby counting the pigment aggregates.

"○" was used for pigment aggregates of 5 or less, "△" was used for pigment aggregates of 10 or less, and "×" was used for pigment aggregates of more than 10.

2. Optical density

The optical density of the obtained light-shielding layer was measured using an optical densitometer (TD-904: manufactured by GretagMacbeth) in accordance with JIS K7651: 1988. Ultraviolet (UV) filters were used for the measurement.

The density of the area where the optical density exceeds 4.0 and cannot be measured is set to "○", and the density of the optical density is set to "x" or less.

3. Coating film strength

The tensile strength (breaking strength) was measured in accordance with JIS K 7161.

The light-shielding layer having a width of 10 mm and a length of 50 mm was stretched at a speed of 200 mm / min using a tensile tester (manufactured by Tester Sangyo), and the load when the light-shielding layer was cut was measured.

Those who broke under a load of 250 g or more were designated as “○”, and those who broke under a load of less than 250 g were designated as “×”.

4.Brightness Index

A spectrophotometer (SE-6000: manufactured by Nippon Denshoku Co., Ltd.) was used to measure the brightness index L * of the light-shielding layer in reflected light. The brightness index L * is 100 for whiteness, and 0 for black.

A case where L * is 40 or less is designated as "○", and a case where L * is more than 40 is 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 curl of the four sides of the end portion of the light-shielding layer was measured.

Furthermore, when the degree of curl becomes severe, different ends overlap each other, and the light-shielding member becomes cylindrical. In this case, since the measurement of curl becomes difficult, the diameter of a circle that becomes a cylindrical shape is measured. When the curl becomes serious, the overlap of the ends further increases, and the diameter becomes smaller.

Set the average value of the curl on the four sides of the end to within ± 20mm as "○", and set the average value of the curl on the four sides of the end to be greater than ± 20mm or a tube with a diameter of 50mm or more as "△", A cylindrical shape having a diameter of less than 50 mm is set to "×".

6.Antistatic

Using a resistivity meter (Loresta GP: manufactured by Mitsubishi Chemical Analytech or Hiresta UX: manufactured by Mitsubishi Chemical Analytech) to measure the surface resistivity of the light-shielding layer, the 1 × 10 ⁸ Ω / □ or less is set by "○", will be greater than 1 × 10 ⁸ Ω / □, and is 1 × ¹⁰ 10 Ω / □ or less is set by "△", more than 1 × ¹⁰ 10 Ω / □ is set to "×".

As shown in Table 2, it was confirmed that the resin composition for forming a light-shielding layer of the present embodiment suppresses pigment aggregation by containing a binder resin as a cellulose-based resin and carbon black having a primary particle diameter of 10 nm to 50 nm. In addition, the carbon black in the resin composition is excellent in dispersion stability. In addition, it was confirmed that good results were obtained in that the light-shielding layer formed by using the resin composition for forming a light-shielding layer of this example sufficiently maintained the light-shielding property, the black tint, and the strength of the coating film, and also suppressed the warpage of the light-shielding layer ( curly).

The light-shielding member having a light-shielding layer in this embodiment is excellent in optical density, coating film strength, and light-shielding properties even if it is a single layer that is only a light-shielding layer. Therefore, it is possible to reduce the size, thickness, and weight.

In addition, when the light-shielding member has a base material, as in the case of the single-layer light-shielding layer, a result excellent in optical density, coating film strength, and light-shielding properties can also be obtained.

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

Claims (11)

A resin composition for forming a light-shielding layer, comprising: a binder resin containing a cellulose-based resin; and carbon black having a primary particle diameter of 10 nm to 50 nm. The BET specific surface area of the carbon black is 50 m ² / g ~ 1500m ² / g. The resin composition for forming a light-shielding layer according to item 1 of the patent application scope further includes a plastic component. The resin composition for forming a light-shielding layer according to claim 1 or claim 2, wherein the cellulose-based resin is at least one selected from cellulose and cellulose derivatives. The resin composition for forming a light-shielding layer according to claim 1 or claim 2, wherein the carbon black contains 1 to 100 parts by mass of the carbon black with respect to 100 parts by mass of the cellulose-based resin. . A method for producing a resin composition for forming a light-shielding layer, comprising a step of mixing a binder resin containing a cellulose-based resin with carbon black having a primary particle diameter of 10 nm or more and 50 nm or less, and the BET specific surface area of the carbon black It is 50 m ² / g to 1500 m ² / g. The method for producing a resin composition for forming a light-shielding layer according to item 5 of the scope of patent application, wherein a plastic component is further added in the mixing step. A light-shielding layer is formed of the resin composition for forming a light-shielding layer according to any one of claims 1 to 4 of the scope of patent application. A light-shielding member includes the light-shielding layer according to item 7 of the scope of patent application. A method for manufacturing a light-shielding member, comprising the steps of forming a light-shielding layer including a resin composition for forming a light-shielding layer on a peelable substrate, and thereafter peeling the peelable substrate from the light-shielding layer. Step, wherein the thickness of the light-shielding layer is 0.5 to 100 μm, and includes a binder resin and carbon black, the binder resin is a cellulose resin, and the primary particle diameter of the carbon black is 10 nm or more and 50 nm or less, The BET specific surface area of the carbon black is 50 m ² / g to 1500 m ² / g. Dibutyl phthalate oil absorption range of the patent application as a method for producing nine light-shielding member, wherein the carbon black is 100cm ³ / 100g or more, 500cm ³ / 100g or less. The method for manufacturing a light-shielding member according to claim 9 or claim 10, wherein the cellulose-based resin is at least one of cellulose and a cellulose derivative.