JP5492639B2 - Method for producing antiglare sheet, antiglare sheet, and optical member - Google Patents

Description

  The present invention provides, for example, a method for producing an antiglare sheet for use in a flat panel display such as a liquid crystal display or an organic EL display useful as a display device such as a mobile terminal display or a touch panel input device, and the antiglare property. The present invention relates to an optical member using a sheet.

Conventionally, a display device such as a liquid crystal display has a problem that, when illumination light such as a fluorescent lamp or external light such as sunlight enters the display surface, the reflected light interferes with the visibility of the screen. doing.
Therefore, an antiglare layer is provided on the surface of the display device in order to diffuse the reflected light to some extent and improve the visibility of the screen.

As an antiglare layer, for example, Patent Document 1 below discloses a nonglare sheet (antiglare sheet) composed of a nonglare layer containing fine particles having a particle size of 0.5 μm or less and a support layer.
In this method, for example, fine particles of silica (for example, synthetic silicon dioxide), a metal compound (for example, alumina, titania, zirconia, etc.), and a polymer compound (for example, polymethyl (meth) acrylate resin) are added to an ultraviolet curable resin. A non-glare layer is formed by dispersing.

However, in the method for producing an antiglare sheet described in Patent Document 1, an uneven shape is formed on the surface with a filler or the like, and therefore it is difficult to precisely control the uneven shape on the surface in the manufacturing process.
For example, since the fine particles as described above are likely to be aggregated, it is easy to cause poor dispersion in the non-glare layer, and the desired antiglare property may not be exhibited, or the transparency of the antiglare sheet may be reduced. In some cases, it may cause a problem of poor appearance.

In Patent Document 2 below, a solution in which an ionizing radiation curable resin is dispersed in a solvent is applied to a transparent film as a base material, and the solvent is dried and removed. There has been proposed a method of laminating to a resin, irradiating with ionizing radiation, curing the ionizing radiation curable resin, and peeling the shaped film to form desired irregularities on the surface (for example, paragraph [0005] ).
However, in the method for producing an antiglare sheet described in Patent Document 2, not only is it necessary to form a concavo-convex shape on the shaped film, but, for example, a portion (anti-proof) that becomes a concave portion of the shaped film. There is a possibility that the shaping film may be peeled off in a state where the ionizing radiation curable resin is attached to the shaping film in the projection portion of the glare sheet, and the uneven shape of the shaping film is the surface of the antiglare sheet. There is a possibility that it will not be sufficiently reflected as unevenness.
In the case of producing an antiglare sheet having fine surface irregularities, the ionizing radiation curable resin cannot sufficiently enter the fine concave portions of the shaping film, and the irregularity shape of the shaping film is the surface of the antiglare sheet. May not be accurately transferred.

JP-A-9-236702 Japanese Patent No. 3374299

As described above, in a conventional method for producing an antiglare sheet, a method for controlling surface irregularities by a simple method has not been found, and it is difficult to adjust the antiglare property.
Therefore, it is difficult to easily obtain a stable quality optical member using such an antiglare sheet.
In view of such problems, the present invention provides a method for producing an antiglare sheet capable of easily controlling surface irregularities, and an antiglare sheet that is excellent in antiglare property but easy to produce, and thus An object is to stabilize the quality of the optical member.

The present invention according to a method for producing an antiglare sheet for solving the above-mentioned problems includes a polymer component having curability, an incompatible material that is incompatible with the polymer component, and the incompatible material. A polymer solution containing a solvent in which both the polymer component and the polymer component are soluble, and the incompatible substance is a low molecular weight substance that can be removed by evaporation by heating, and the solvent is the low molecular weight A polymer solution which is a solvent having higher volatility than the substance is prepared, and the polymer component and the low molecular weight substance are removed by evaporating and removing the solvent after applying the polymer solution to at least one surface of the sheet-like substrate. A polymer film having surface irregularities formed by phase separation is formed on the surface of the substrate, and the polymer component forming the polymer film is cured to form a cured film. Rutotomoni wherein it is characterized in that to produce the antiglare sheet having 60 to 150 of 60 ° gloss having an uneven surface by evaporation removed by heating the low molecular weight substances.

In addition, the present invention relating to the antiglare sheet is capable of using a curable polymer component, an incompatible material that is incompatible with the polymer component, and both the incompatible material and the polymer component. A polymer solution containing a soluble solvent is prepared, and the incompatible substance is a low molecular weight substance that can be evaporated and removed by heating, and the solvent is a solvent having higher volatility than the low molecular weight substance. After the polymer solution is applied to at least one surface of the sheet-like substrate, the solvent is evaporated and removed, whereby the polymer component and the low molecular weight substance are phase-separated to form a surface. A polymer film having a concavo-convex shape is formed on the surface of the substrate, the polymer component forming the polymer film is cured to form a cured film, and The amount material uneven surface is formed by is being evaporated off by heating, it is characterized by having a 60 to 150 of 60 ° glossiness.

In addition, an ultraviolet curable resin is used as the polymer component and the curing is performed by ultraviolet irradiation on the polymer film, or a thermosetting resin is used as the polymer component and the curing is performed by heating the polymer film. It is preferred that it be implemented either.
The ultraviolet curable resin is preferably a urethane acrylate resin.

  Further, the low molecular weight substance is preferably an organic compound having a molecular weight of 18 or more and 300 or less, a boiling point of 50 ° C. or more and 350 ° C. or less, and a melting point of less than 23 ° C. It is preferable that it is an organic compound which has this.

Further, antiglare sheet of the present invention preferably has an arithmetic mean roughness of the cured coating film (Ra) is 50nm or more 1500nm or less, a haze value is 50% or less than 2%, the total light transmittance It is preferable that it is 80% or more.
And the manufacturing method of the anti-glare sheet of this invention is suitable for manufacture of such an anti-glare sheet.

  Further, as the substrate, it is preferable to use a transparent substrate having a haze value of 2% or less and a total light transmittance of 80% or more.

  The optical member of the present invention is characterized by using the antiglare sheet as described above.

According to the method for producing an antiglare sheet of the present invention, there is provided a polymer solution containing a polymer component having curability, an incompatible material that is incompatible with the polymer component, and a solvent in which both are soluble. The polymer film in which the polymer component and the low molecular weight substance are phase-separated to form a concavo-convex shape on the surface is prepared by a simple means of coating and drying this on a substrate.
And the anti-glare sheet | seat can be produced by the simple operation | work which implements the process which hardens the said polymer component with respect to this polymer film, and evaporates and removes the low molecular weight substance used as the said incompatible substance.
Therefore, the phase separation state in the polymer film can be adjusted by adjusting the blending conditions such as the amount and type of the polymer component to be used and the incompatible substance and the working conditions such as the drying condition of the polymer solution on the substrate surface.
That is, according to the manufacturing method of the anti-glare sheet of this invention, the unevenness | corrugation of the surface of an anti-glare sheet can be controlled by a simple method.
Moreover, the quality which concerns on an anti-glare performance can be stabilized though it is easy to manufacture the anti-glare sheet of this invention from such a thing.
And by using such an anti-glare sheet, the optical member can also improve the quality stability.

2 is a diagram showing an optical micrograph of an antiglare sheet of Example 1. FIG. It is a figure which shows the optical microscope photograph of the anti-glare sheet | seat of Example 2. FIG. 4 is a view showing an optical micrograph of an antiglare sheet of Example 3. FIG. It is a figure which shows the optical microscope photograph of the anti-glare sheet | seat of Example 4. FIG. It is a figure which shows the optical microscope photograph of the anti-glare sheet | seat of Example 5. FIG. It is a figure which shows the optical microscope photograph of the anti-glare sheet | seat of Example 6. FIG. It is a figure which shows the optical microscope photograph of the anti-glare sheet | seat of Example 7. FIG. It is a figure which shows the optical microscope photograph of the anti-glare sheet | seat of Example 8. FIG. It is a figure which shows the optical microscope photograph of the anti-glare sheet | seat of Example 9. FIG. 6 is a view showing an optical micrograph of a sheet of Comparative Example 1. FIG. 6 is a view showing an optical micrograph of a sheet of Comparative Example 2. FIG. 10 is a view showing an optical micrograph of a sheet of Comparative Example 3. FIG. 6 is a view showing an optical micrograph of a sheet of Comparative Example 4. FIG. It is a figure which shows the optical microscope photograph of the anti-glare sheet | seat of Example 10. FIG. It is a figure which shows the optical microscope photograph of the anti-glare sheet | seat of Example 11. FIG.

Below, embodiment of the manufacturing method of the anti-glare sheet | seat of this invention is described.
The manufacturing method of the anti-glare sheet | seat of this embodiment implements the following processes (a)-(e), and produces an anti-glare sheet | seat.
Step (a) contains a curable polymer component, an incompatible material that is incompatible with the polymer component, and a solvent in which both the incompatible material and the polymer component are soluble. In addition, a polymer solution is produced in which the incompatible substance is a low molecular weight substance that can be evaporated and removed by heating, and the solvent is a highly volatile solvent that is easier to evaporate than the low molecular weight substance. Process.
-Process (b) The process of apply | coating a polymer solution to at least one surface of a sheet-like base material.
Step (c) The surface of the base material is coated with a polymer film in which the solvent contained in the applied polymer solution is evaporated and the polymer component and the low molecular weight substance are phase-separated to form an uneven shape on the surface. Step to make.
Step (d) A step of curing the polymer component forming the polymer film to form a cured film.
Step (e) A step of heating and removing the low molecular weight substance by evaporation.

  First, each material used for the manufacturing method of the anti-glare sheet of this embodiment is demonstrated.

(Polymer component)
It is important that the polymer component used in the polymer solution has curability, and the polymer component can be composed of a single resin or a plurality of types of resins and rubbers, for example, an ultraviolet curable resin, A thermosetting resin can be used as the constituent material.
Further, the polymer component is preferably capable of maintaining the uneven shape formed on the polymer film after removal of the solvent until the end of curing, and is solid or does not exhibit natural flow at normal temperature (for example, 23 ° C.) A semi-solid (gel or grease) is preferable.

Examples of the ultraviolet curable resin include various types such as acrylic, urethane, epoxy, ester, amide, and silicone resins.
In addition, the ultraviolet curable resin contained in the polymer component does not need to be contained only in a polymer state, and may be contained in an ultraviolet curable monomer or oligomer state.
Of these, urethane acrylate resins are suitable as the ultraviolet curable resin.
This urethane acrylate resin is suitable as a polymer component in that it has high hardness and is excellent in scratch resistance.

Examples of the thermosetting resin include various types such as acrylic, urethane, epoxy, ester, melamine, urea, silicone, and phenolic resins.
This thermosetting resin may also be contained in a monomer or oligomer state.
Many types of these UV curable resins and thermosetting resins are available on the market, and a wide range of varieties of resin types and combinations to be used can be prepared, and the uneven shape on the surface of the antiglare sheet can be adjusted. It is excellent in that it is easy to do.

(Incompatible material)
The material is not particularly limited as long as it is incompatible with the polymer component as described above and can be removed by evaporation after being heated after the polymer component is cured.

However, if the solvent described later and the temperature conditions for its removal by evaporation are approximated, temperature control with high accuracy is required to evaporate and remove the solvent while leaving the low molecular weight substance in the above-mentioned "Step (c)". I will let you.
On the other hand, when a material having a high boiling point is used, not only a great amount of heat energy is required at the time of evaporation and removal in the above-mentioned “step (e)”, but there is a possibility that the base material and the cured film are thermally deteriorated.
From such a viewpoint, the low molecular weight substance used as an incompatible substance for the polymer component is preferably an organic compound having a boiling point of 50 ° C. or higher and 350 ° C. or lower, and is a substance having a boiling point of 100 ° C. or higher and 320 ° C. or lower. More preferably.
Further, the organic compound is preferably an organic compound having a melting point of less than 23 ° C, more preferably a melting point of less than 20 ° C.

Further, the low molecular weight substance preferably has a molecular weight of 300 or less, more preferably less than 250, and particularly preferably less than 200.
However, since a substance having a very low molecular weight is likely to be evaporated at the time of evaporation of the solvent, the low molecular weight substance preferably has a molecular weight of 18 or more.

Specific examples of such low molecular weight substances include alcohols such as hexyl alcohol, heptyl alcohol, octyl alcohol, furfuryl alcohol, tetrahydrofurfuryl alcohol, benzyl alcohol; methyl acetoacetate, ethyl acetoacetate, benzoic acid Esters such as methyl acid, ethyl benzoate, propyl benzoate, butyl benzoate, 2-ethylhexyl acetate, cyclohexyl acetate, benzyl acetate, trimethyl phosphate, triethyl phosphate; cyclohexanone, methylcyclohexanone, isophorone, acetophenone, diacetone alcohol, Ketones such as diisobutyl ketone, methyl-n-amyl ketone, methyl-n-hexyl ketone, methyl-n-heptyl ketone; ethylene glycol, diethylene glycol, Liethylene glycol, trimethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, glycerin, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentane Polyhydric alcohols such as diol, hexylene glycol, 1,3-octylene glycol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monophenyl ether, ethylene glycol monohexyl ether, ethylene glycol mono Methoxymethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol Monobutyl ether, diethylene glycol ethyl methyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, triethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol Polyhydric alcohol ethers such as monoethyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monobutyl ether; ethylene glycol monomethyl ether acetate, Examples thereof include polyhydric alcohol ester derivatives such as tylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol diacetate, and glycerin triacetate.
These may be a single or a mixture of two or more types, and the phase separation state with the polymer component by adjusting the type of substances used, the combination method, the ratio of the amount when combined, The uneven shape can be adjusted.
The low molecular weight substance is preferably an organic compound having a hydroxyl group.
The organic compound having a hydroxyl group generally has low compatibility with a polymer component, and has a boiling point that does not evaporate in the step (b) of applying a polymer solution or the step (c) of evaporating a solvent. It is suitable as a low molecular weight substance in that it can be easily obtained.

  By adopting a material that can be removed by evaporation such as this low molecular weight material as an incompatible material, it can be removed by a relatively simple device such as a heating device. Therefore, it is an important requirement to use this low molecular weight substance as an incompatible substance.

The incompatibility of the polymer component and the low molecular weight substance can be confirmed, for example, as follows.
(Example of incompatible determination method)
Place 10 g of polymer component and 10 ml of low molecular weight material in a 50 ml screw tube.
Then, when the lid of the screw tube is closed and shaken sufficiently and left to stand for 1 minute or longer, it is possible to determine that the material that is not visually uniform is incompatible.
In addition, if the low molecular weight substance is compatible with the resin, an uneven shape due to phase separation is not formed, so it is also possible to observe the shape of the surface of the polymer film (cured film) after drying and / or curing. Judgment whether it is melted is possible.

(solvent)
As the solvent constituting the polymer solution together with the polymer component and the low molecular weight substance, it is important that the polymer component and the low molecular weight substance are soluble.
In addition, it is important that a substance having higher volatility (easily evaporated) than the low molecular weight substance is selected as the solvent.
In addition, as this solvent, what consists of the single substance which becomes a good solvent with respect to both the said polymer component and the said low molecular weight substance, the mixed solvent in which several good solvents are mixed, or a polymer component and low molecular weight A mixed solvent of a poor solvent and a good solvent that are hardly soluble or insoluble in one or both of the substances may be used.

As the solvent, when a water-soluble polymer or the like is used as the polymer component, water or the like can be used, but usually an organic solvent can be preferably used.
Specific examples of the organic solvent that can be used include aliphatic hydrocarbons such as hexane, heptane, cyclohexane, and methylcyclohexane; aromatic hydrocarbons such as toluene, xylene, and benzene; diethyl ether, diisobutyl ether, and the like. Ethers of methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, isobutyl acetate, etc .; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone; alcohols such as methanol, ethanol, propanol, N, N-dimethylformamide, N, Examples include amides such as N-dimethylacetamide and N-methylpyrrolidone.

This solvent is an important component for preparing a polymer solution in which a polymer component and a low molecular weight component are uniformly dispersed, and obtaining a coating film having a uniform surface shape when applied, and before applying the polymer solution. When phase separation occurs, it becomes difficult to obtain a uniform surface shape.
Moreover, the effect that the viscosity of a polymer solution can be adjusted to the viscosity suitable for apply | coating to a base material can be exhibited by making this polymer contain in a polymer solution.

  For this solvent as well as the polymer component and low molecular weight component, the uneven shape of the polymer film can be changed by changing the type of substance used and the content in the polymer solution (the blending ratio with the polymer component and low molecular weight component). Adjustments can be made.

In the main components constituting these polymer solutions, when the amount of the low molecular weight substance added is excessive with respect to the polymer component or the like, a polymer solution in which the polymer component and the low molecular weight substance are uniformly dissolved is prepared. Therefore, the amount of the solvent required for the adjustment becomes too large, and there is a possibility that the adjustment of the concentration is restricted.
Therefore, the content of the low molecular weight substance contained in the polymer solution is preferably 0.1 parts by weight or more and 150 parts by weight or less with respect to 100 parts by weight of the polymer component contained in the polymer solution. More preferably, the amount is at least 75 parts by weight.

Moreover, when the viscosity of this polymer solution is too high, streaks and unevenness are likely to occur in the polymer film, making it difficult to apply uniformly.
Accordingly, the polymer solution is preferably adjusted so that its viscosity is 5 Pa · s or less, and is preferably adjusted to 3 Pa · s or less, in that the coating operation (step b) can be easily performed. More preferably.

In addition, when the content of the solvent in the polymer solution is small and the concentration of the polymer solution is too high, it is difficult to uniformly dissolve the polymer component and the low molecular weight component that are not compatible with each other.
Therefore, the polymer solution is preferably adjusted with the solvent so that its concentration is in the range of 0.1 wt% to 40 wt%, and is adjusted to be 1 wt% to 30 wt%. More preferably.
And the uneven | corrugated shape in a polymer film can be adjusted by changing the density | concentration of this polymer solution.

  In addition, when an ultraviolet curable resin is employ | adopted as the said polymer component, it is preferable to contain the photoinitiator further in the said polymer solution.

(Photopolymerization initiator)
Examples of the photopolymerization initiator include 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone and α-hydroxy-α, α′-dimethyl, although it depends on the ultraviolet curable resin used. Α-ketol compounds such as acetophenone, 2-methyl-2-hydroxypropiophenone, 1-hydroxycyclohexyl phenyl ketone; methoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone Acetophenone compounds such as 2-methyl-1- [4- (methylthio) -phenyl] -2-morpholinopropane-1; benzoin ether compounds such as benzoin ethyl ether, benzoin isopropyl ether and anisoin methyl ether; benzyldimethyl Ketal and other Aromatic compounds such as 2-naphthalenesulfonyl chloride; photoactive oxime compounds such as 1-phenone-1,1-propanedione-2- (o-ethoxycarbonyl) oxime; benzophenone, benzoyl Benzophenone compounds such as benzoic acid and 3,3′-dimethyl-4-methoxybenzophenone; thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2 Thioxanthone compounds such as 1,4-dichlorothioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone; camphorquinone; halogenated ketone; acyl phosphinoxide; acyl phosphonate It is done.
The blending amount of the photopolymerization initiator is usually 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight with respect to 100 parts by weight of the ultraviolet curable resin. It can be included in the solution.

(Base material)
The material of the sheet-like base material on which the polymer solution is applied is not particularly limited, but examples thereof include polyester polymers such as polyethylene terephthalate and polyethylene naphthalate; cellulose systems such as diacetyl cellulose and triacetyl cellulose. Polymer: Acrylic polymer such as polycarbonate polymer and polymethyl methacrylate; Styrene polymer such as polystyrene and acrylonitrile-styrene copolymer; Polyethylene, polypropylene, polyolefin having cyclic or norbornene structure; Olefin such as ethylene-propylene copolymer Polymers: vinyl chloride polymers, amide polymers such as nylon and aromatic polyamide, etc .; imide polymers, sulfone polymers, polyethersulfone polymers -Polyether ether ketone polymers, polyphenylene sulfide polymers, vinyl alcohol polymers, vinylidene chloride polymers, vinyl butyral polymers, arylate polymers, polyoxymethylene polymers, epoxy polymers and blends of the above polymers , As a forming material thereof.
In consideration of being used for an optical member, it is preferable to use a transparent substrate having a transparency having a haze value of 2% or less and a total light transmittance of 80% or more.

  In addition, although further detailed description is omitted here, in the present invention, as the polymer solution and the base material, those other than those exemplified above can be appropriately employed, and conventionally, the antiglare sheet is used. Various materials that are employed can be employed in the present invention in a method of use according to the purpose.

Subsequently, each process in the manufacturing method of the anti-glare sheet in this embodiment is demonstrated.
(Step a: Preparation of polymer solution)
For the preparation of the polymer solution, a conventionally known polymer solution preparation method can be employed. For example, the polymer component, the low molecular weight substance, and the solvent are dispersed by a mixing and stirring means such as a mixer or a homogenizer. Examples thereof include a method for preparing a polymer solution by mixing.

(Process b: Application to base material)
Any coating method can be used as a coating method of the polymer solution to the substrate.
When producing an anti-glare sheet with a small area, it can be hand-painted using a baker type applicator, a doctor blade, a bar coater or the like.
On the other hand, when coating continuously with a coating machine, a reverse coater, a direct gravure coater, a direct bar coater, a reverse bar coater, a die coater, and the like can be appropriately selected according to the target coating amount.
In addition, the shape of the polymer film obtained can be changed by changing the coating method.

Application of the polymer solution at this time is usually such that when a polymer solution prepared without containing a low molecular weight substance is applied to the substrate and dried, the thickness of the polymer film is in the range of 0.1 μm to 100 μm. It is preferable to carry out by setting the coating conditions so as to be.
However, since the surface shape of the polymer film after solvent evaporation can be adjusted by changing the coating thickness of this polymer solution, the coating thickness of the polymer solution is not limited to this range, The coating thickness can be arbitrarily set, and the uneven shape can be adjusted by adjusting the coating thickness.

(Step c: Solvent removal, formation of phase separation state)
In the case of using a polymer solution composed of the materials exemplified above, the substrate coated with the polymer solution can be removed by evaporating (volatilizing) the solvent while maintaining the substrate at an ambient temperature close to room temperature.
As a method for removing the solvent, a general heating device can be applied. Examples of the heating device include a thermal convection dryer, a thermal circulation dryer, a vacuum dryer, a floating oven, and the like.
If the atmospheric temperature at this time is too high, the low molecular weight substance may be evaporated. On the other hand, if the atmospheric temperature is set too low, it takes a long time to evaporate the solvent.
Therefore, in the case where the organic solvent and the low molecular weight substance exemplified above are used, it is usually preferable to select a temperature condition of 0 ° C. or higher and 80 ° C. or lower to evaporate the solvent. It is more preferable to perform evaporation of the solvent by selecting a temperature condition of not lower than 70 ° C. and lower than 70 ° C.
In particular, it is preferable to evaporate the solvent by selecting a temperature condition of 15 ° C. or more and 50 ° C. or less.

In particular, when evaporating and removing the organic solvent, the surface irregularity shape of the polymer coating obtained after drying can be changed by applying air to the surface of the coating.
Then, by evaporating and removing the solvent, the polymer component and the low molecular weight substance undergo phase separation, and an uneven shape is formed on the surface of the polymer film after drying.
Further, as described above, the uneven shape of the final film surface can be varied by changing the ratio of the low molecular weight substance to the polymer component.
In particular, the concave portion of the polymer coating is formed at a location corresponding to the location of the low molecular weight substance after phase separation, and the shape reflects the shape of the low molecular weight substance before evaporation. Increasing the amount tends to increase the recess.
Therefore, a desired recess can be formed by adjusting the amount of the low molecular weight substance.

(Process d: Curing)
The polymer film formed on the surface of the substrate in the previous “step c” can be used to cure the polymer component while maintaining the phase separation state of the surface from the viewpoint of controlling the final surface irregularity shape. preferable.
In order to reflect the phase separation state of the polymer film before curing in the cured film after curing, a state in which the phase separation between the polymer component and the low molecular weight substance is maintained, or a part of the low molecular weight substance during the curing Even in the case of being removed by evaporation, it is preferable to cure the polymer component in a state where the trace remains as a recess.

Therefore, it is usually preferable to quickly cure the resin after applying the polymer solution to the substrate and evaporating and removing the solvent.
Therefore, it can be said that an ultraviolet curable resin capable of quickly curing the polymer film is suitable as the polymer component.
That is, it is preferable to quickly cure the ultraviolet curable resin forming the polymer film by irradiating ultraviolet rays after evaporating and removing the solvent.
In the case where a thermosetting resin is used, the solvent removal by evaporation (step c) and the curing step can be performed as a series of steps.
That is, after the polymer solution is applied to the substrate, the solvent is evaporated and removed by heating the coating film, and after the solvent is removed, heating is continued to cause a thermosetting reaction in the thermosetting resin. A cured film can also be formed.
In this case, it is preferable to cure the thermosetting resin before the low molecular weight substance evaporates and the surface of the polymer film is leveled by the softening of the thermosetting resin.
That is, the heating causes competition between the softening of the polymer film and the progress of the curing reaction of the polymer component, but it is preferable to select conditions that give priority to this curing reaction.
As a result, it is possible to form a cured film in which the low molecular weight substance is left to form recesses on the surface.

(Process e: Removal of low molecular weight substance)
The removal of the low molecular weight substance from the cured coating is preferably performed at a temperature at which the low molecular weight substance can be evaporated in a short time.
Note that the temperature at that time need not be higher than the boiling point of the low molecular weight substance.
For example, water having a boiling point of 100 ° C. can be evaporated at room temperature, and ethylene glycol having a boiling point of 197 ° C. is evaporated at a temperature of about 60 ° C.
When this ethylene glycol is used as a low molecular weight substance, the heating temperature is preferably set to 80 ° C. or higher if the purpose is to quickly evaporate and remove.
Further, when glycerin having a boiling point of 290 ° C. is used as a low molecular weight substance, it is preferable to set the heating temperature to 80 ° C. or higher. For the purpose of rapid evaporation, the heating temperature is set to 100 ° C. or higher. Is desirable.
However, in view of the heat resistance of the substrate, it is important to set an appropriate temperature.
For example, in the case where a polyethylene terephthalate film is used as a base material, it is desirable to set the heating temperature to 140 ° C. or lower, preferably 130 ° C. or lower so that wrinkles due to heat shrinkage can be prevented. .
As a method for evaporating and removing low molecular weight substances by heating, a general heating device can be applied. Examples of the heating device include a thermal convection dryer, a thermal circulation dryer, a vacuum dryer, a floating oven, and the like. Is mentioned.

By carrying out the steps as described above, for example, a cured film in which the size of the low molecular weight substance during phase separation is reflected in the state of the recesses on the surface can be formed on the antiglare sheet. .
In general, low molecular weight substances are dispersed in various sizes on the surface of the polymer coating, so that irregularities over a large and small range can be formed. Unevenness having a diameter of about 100 μm can be formed on the surface of the antiglare sheet.

  In addition, it is preferable that the unevenness | corrugation in the surface of an anti-glare sheet (irregularity of a cured film) has a predetermined | prescribed surface roughness from a viewpoint of the reflective performance of light, and the arithmetic mean roughness (( When Ra) is measured, it is preferably formed such that the value thereof is any value within the range of 50 nm to 1500 nm. Furthermore, it is preferable to have an arithmetic average roughness (Ra) of 50 nm or more and 1200 nm or less.

The 60 ° gloss is preferably 60 or more and 150 or less, and more preferably 65 or more and 130 or less, from the viewpoint of antiglare properties.
Further, the antiglare sheet preferably has a haze value of 2% or more and 50% or less in terms of ensuring the sharpness of the display image when used in a display device or the like. More preferably, it is 30% or less.
And when using for a display apparatus etc., it is further preferable that the total light transmittance is 80% or more, and it is more preferable that it is 85% or more.

Such an antiglare sheet can be easily adjusted in terms of antiglare property, light transmittance, and the like because surface irregularities are adjusted by a simple method.
Therefore, by the above method, an antiglare sheet suitable for constituting an optical member such as a polarizing plate having an excellent balance between light transmittance and antiglare property can be easily produced.
In addition to the “polarizing plate”, the antiglare sheet produced by the production method of the present embodiment is also useful for an optical member such as a touch panel.
In addition, in this embodiment, although the above illustrations are performed as a manufacturing method of an anti-glare sheet, this invention is not limited to the said illustration, For example, except materials illustrated above, for example. It is also possible to adopt or perform operations other than those exemplified above.

  EXAMPLES Next, although an Example is given and this invention is demonstrated in more detail, this invention is not limited to these.

First, the measuring method regarding each characteristic is demonstrated.
(1) Measuring method of total light transmittance The total light transmittance was measured using "Murakami Color Research Laboratory Co., Ltd. model name: Hazemeter HM-150" according to JIS K 7361.
The measurement was performed so that the surface of the cured coating faced the light source.
(2) Measuring method of haze Haze was measured using "Murakami Color Research Laboratory make, model name: Haze meter HM-150" according to JIS K7136.
The measurement was performed so that the surface of the cured coating faced the light source.
(3) Measuring method of 60 degree glossiness According to JIS K7105, 60 degree glossiness was measured using "byk Gardner make, model name: micro-TRI-gloss".
(4) Arithmetic mean roughness measurement method Arithmetic mean roughness (Ra) is calculated according to JIS K 0601 (2001), “Nihon Beco Co., Ltd., model name: high brightness non-contact three-dimensional surface shape roughness. It measured using "total Wyko NT9100".
The measurement was performed at a magnification of 10 times.

Example 1
100 parts by weight of urethane acrylate-based UV curable resin (polymer component: manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name: Shikou UV-7640B), 8 parts by weight of special grade glycerin (manufactured by Wakken Pharmaceutical Co., Ltd.) , A photopolymerization initiator (product name: Irgacure 184, manufactured by Ciba Specialty Chemicals), 4 parts by weight, 107 parts by weight of ethyl acetate as an organic solvent, and 205 parts by weight of ethanol are mixed to form a polymer solution having a solid content concentration of 25% Adjusted.
The obtained polymer solution was a colorless and transparent uniform solution.
The polymer solution was applied to one side of a polyethylene terephthalate (PET) film (thickness: 100 μm) serving as a base material.
The polymer solution was applied using a 12th Meyer bar so that the cured film when the 25% polymer solution to which no low molecular weight substance was added was applied, dried and cured to have a cured film thickness of about 3 μm.
The PET film coated with this polymer solution was dried at 23 ° C. for 1 minute, and then irradiated with ultraviolet rays (metal halide lamp, UV irradiation amount 450 mJ / cm ² ) to form a cured film on the PET film, and then heated in a hot air oven Was heated at 120 ° C. for 2 minutes to evaporate and remove the low molecular weight substance, and an antiglare sheet having an uneven surface was produced.
The blending amount, solid content concentration, coating method, and air drying conditions of each material are shown in Table 1, optical properties (total light transmittance, haze, 60 ° gloss) and arithmetic average roughness are shown in Table 2, and optical micrographs are shown. It is shown in 1.

(Example 2)
An anti-glare sheet was prepared in the same manner as in Example 1 except that “(Nippon Gosei Chemical Co., Ltd., trade name: Murasaki UV-1700B)” was used as the urethane acrylate ultraviolet curable resin.
Table 1 shows the compounding amount, solid content concentration, coating method, and air-drying conditions of each reagent, Table 2 shows the optical characteristics (total light transmittance, haze, 60 ° glossiness), and optical micrographs. It is shown in 2.

(Example 3)
An antiglare sheet was prepared in the same manner as in Example 1 except that “first grade ethylene glycol (manufactured by Kishida Chemical Co., Ltd.)” was used as the low molecular weight substance.
Table 1 shows the compounding amount, solid content concentration, coating method, and air-drying conditions of each reagent, Table 2 shows the optical characteristics (total light transmittance, haze, 60 ° glossiness), and optical micrographs. 3 shows.

(Example 4)
Example 1 except that 20 parts by weight of “special grade glycerin (manufactured by Wakken Yakuhin)” was used as the low molecular weight substance and “mixed solvent of 104 parts by weight of ethyl acetate and 187 parts by weight of ethanol” was used as the solvent. An antiglare sheet was prepared by the method described above.
Table 1 shows the compounding amount, solid content concentration, coating method, and air-drying conditions of each reagent, Table 2 shows the optical characteristics (total light transmittance, haze, 60 ° glossiness), and optical micrographs. 4 shows.

(Example 5)
An antiglare sheet was prepared in the same manner as in Example 1 except that “a mixed solvent of 107 parts by weight of ethyl acetate, 185 parts by weight of ethanol, and 20 parts by weight of n-hexane” was used as the solvent.
Table 1 shows the compounding amount, solid content concentration, coating method, and air-drying conditions of each reagent, Table 2 shows the optical characteristics (total light transmittance, haze, 60 ° glossiness), and optical micrographs. As shown in FIG.

(Example 6)
An antiglare sheet was prepared in the same manner as in Example 1 except that “a mixed solvent of 104 parts by weight of ethyl acetate and 304 parts by weight of ethanol” was used as the solvent, and the solid content concentration of the polymer solution was 20% by weight. .
Table 1 shows the compounding amount, solid content concentration, coating method, and air-drying conditions of each reagent, Table 2 shows the optical characteristics (total light transmittance, haze, 60 ° glossiness), and optical micrographs. It is shown in FIG.

(Example 7)
Except for the application of the polymer solution "using a 16th Meyer bar" so that the cured film when dried and cured by applying a 25% organic solvent solution without addition of a low molecular weight substance is about 4 μm. An antiglare sheet was prepared in the same manner as in Example 1.
Table 1 shows the compounding amount, solid content concentration, coating method, and air-drying conditions of each reagent, Table 2 shows the optical characteristics (total light transmittance, haze, 60 ° glossiness), and optical micrographs. 7 shows.

(Example 8)
Example 1 except that the bar coater was changed to a “baker type applicator” and a 25% organic solvent solution without addition of a low molecular weight substance was applied and dried and cured so that the cured film was about 3 μm. An anti-glare sheet was prepared in the same manner as described above.
Table 1 shows the compounding amount, solid content concentration, coating method, and air-drying conditions of each reagent, Table 2 shows the optical characteristics (total light transmittance, haze, 60 ° glossiness), and optical micrographs. It is shown in FIG.

Example 9
An antiglare sheet was produced in the same manner as in Example 1 except that the air drying condition was “drying while applying air to the surface of the polymer coating for 1 minute at 23 ° C.”.
Table 1 shows the compounding amount, solid content concentration, coating method, and air-drying conditions of each reagent, Table 2 shows the optical characteristics (total light transmittance, haze, 60 ° glossiness), and optical micrographs. 9 shows.

(Example 10)
An antiglare sheet was produced in the same manner as in Example 1, except that 8 parts by weight of “primary ethylene glycol (manufactured by Kishida Chemical Co., Ltd.)” was used as the low molecular weight substance and 312 parts by weight of “ethyl acetate” was used as the organic solvent. Was made.
Table 1 shows the compounding amount, solid content concentration, coating method, and air-drying conditions of each reagent, Table 2 shows the optical characteristics (total light transmittance, haze, 60 ° glossiness), and optical micrographs. 14 shows.

(Example 11)
The same method as in Example 1 was used except that “acrylic ultraviolet curable resin (manufactured by Nippon Kayaku Co., Ltd., trade name: KAYARAD DPHA (dipentaerythritol penta / hexaacrylate))” was used as the ultraviolet curable resin. An antiglare sheet was prepared.
Table 1 shows the compounding amount, solid content concentration, coating method, and air-drying conditions of each reagent, Table 2 shows the optical characteristics (total light transmittance, haze, 60 ° glossiness), and optical micrographs. As shown in FIG.

(Comparative Example 1)
A film was produced in the same manner as in Example 1, except that “primary ethylene glycol diacetate (manufactured by Wakken Pharmaceutical Co., Ltd.)” that was compatible with urethane acrylate-based ultraviolet curable resin was used as the low molecular weight substance. .
Table 1 shows the compounding amount, solid content concentration, coating method, and air-drying conditions of each reagent, Table 2 shows the optical characteristics (total light transmittance, haze, 60 ° glossiness), and optical micrographs. 10 shows.

(Comparative Example 2)
A film was produced in the same manner as in Example 1 except that “low molecular weight substance was not added”.
Table 1 shows the compounding amount, solid content concentration, coating method, and air-drying conditions of each reagent, Table 2 shows the optical characteristics (total light transmittance, haze, 60 ° glossiness), and optical micrographs. 11 shows.

(Comparative Example 3)
A film was produced in the same manner as in Example 2 except that “low molecular weight substance was not added”.
Table 1 shows the compounding amount, solid content concentration, coating method, and air-drying conditions of each reagent, Table 2 shows the optical characteristics (total light transmittance, haze, 60 ° glossiness), and optical micrographs. 12 shows.

(Comparative Example 4)
A film was produced in the same manner as in Example 1 except that the organic solvent was not added and the solid content concentration was 93% by weight. Since no organic solvent was added, the applied solution was divided into two layers at the visual level.
Table 1 shows the compounding amount, solid content concentration, coating method, and air-drying conditions of each reagent, Table 2 shows the optical characteristics (total light transmittance, haze, 60 ° glossiness), and optical micrographs. It is shown in FIG.

From the above, it can be seen that according to the present invention, an antiglare sheet having excellent antiglare properties can be obtained.
And as shown above, it turns out that an anti-glare sheet is obtained by a simple method.

Claims (19)

A polymer solution containing a curable polymer component, an incompatible material that is incompatible with the polymer component, and a solvent in which both the incompatible material and the polymer component are soluble is prepared. In addition, a polymer solution in which the incompatible substance is a low molecular weight substance that can be evaporated and removed by heating, and the solvent is a solvent having higher volatility than the low molecular weight substance, is prepared. The surface of the base material is coated with at least one surface of a sheet-like base material, and the solvent is evaporated and removed to phase-separate the polymer component and the low molecular weight substance to form an uneven shape on the surface. And the polymer component forming the polymer film is cured to form a cured film, and the low molecular weight substance is heated to evaporate and remove. Antiglare sheet manufacturing method, characterized in that to produce the antiglare sheet having 60 to 150 of 60 ° gloss having an uneven surface.   The method for producing an antiglare sheet according to claim 1, wherein an ultraviolet curable resin is used as the polymer component, and the curing is carried out by irradiating the polymer film with ultraviolet rays.   The method for producing an antiglare sheet according to claim 1, wherein a thermosetting resin is used as the polymer component, and the curing is performed by heating the polymer film.   The method for producing an antiglare sheet according to claim 2, wherein the ultraviolet curable resin is a urethane acrylate resin.   The low molecular weight substance is an organic compound having a molecular weight of 18 to 300, a boiling point of 50 ° C to 350 ° C, and a melting point of less than 23 ° C. A method for producing an antiglare sheet according to claim 1.   The method for producing an antiglare sheet according to any one of claims 1 to 5, wherein the low molecular weight substance is an organic compound having a hydroxyl group. Antiglare sheet manufacturing method according to any one of the cured arithmetic average roughness of the film (Ra) is claims 1 to 6 is 50nm or more 1500nm or less.   The production of an antiglare sheet according to any one of claims 1 to 7 for producing an antiglare sheet having a haze value of 2% to 50% and a total light transmittance of 80% or more. Method.   The method for producing an antiglare sheet according to any one of claims 1 to 8, wherein a transparent substrate having a haze value of 2% or less and a total light transmittance of 80% or more is used as the substrate. A polymer solution is prepared that contains a curable polymer component, an incompatible material that is incompatible with the polymer component, and a solvent in which both the incompatible material and the polymer component are soluble. In addition, a polymer solution is produced in which the incompatible substance is a low molecular weight substance that can be evaporated and removed by heating, and the solvent is a solvent having higher volatility than the low molecular weight substance. The base material is formed of a polymer film in which a concavo-convex shape is formed on the surface by phase separation of the polymer component and the low molecular weight substance by being evaporated and removed after being applied to at least one surface of a sheet-like base material The polymer component forming the polymer film is cured to form a cured film, and the low molecular weight substance is heated to be evaporated and removed. Antiglare sheet uneven surface is formed, characterized in that it has a 60 to 150 of 60 ° gloss by.   The antiglare sheet according to claim 10, wherein an ultraviolet curable resin is used as the polymer component, and the curing is performed by ultraviolet irradiation on the polymer film.   The antiglare sheet according to claim 10, wherein a thermosetting resin is used as the polymer component, and the curing is performed by heating the polymer film.   The antiglare sheet according to claim 11, wherein the ultraviolet curable resin is a urethane acrylate resin.   The low molecular weight substance is an organic compound having a molecular weight of 18 to 300, a boiling point of 50 ° C to 350 ° C, and a melting point of less than 23 ° C. The anti-glare sheet according to claim 1.   The antiglare sheet according to any one of claims 10 to 14, wherein the low molecular weight substance is an organic compound having a hydroxyl group. Antiglare sheet according to any one of claims 10 to 15 arithmetic average roughness of the cured coating film (Ra) is 50nm or more 1500nm or less.   The antiglare sheet according to any one of claims 10 to 16, which has a haze value of 2% to 50% and a total light transmittance of 80% or more.   The antiglare sheet according to any one of claims 10 to 17, wherein a transparent substrate having a haze value of 2% or less and a total light transmittance of 80% or more is used as the substrate.   An optical member, wherein the antiglare sheet according to any one of claims 10 to 18 is used.