JP2008057004A - Master for electroforming mold and method of manufacturing electroforming mold - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a master for an electroforming mold, free from defects or mottles and having exact fine structure. <P>SOLUTION: The method of manufacturing the master for the electroforming mold comprises: (1) a step for mixing a first material 2 and a second material 1 with each other; (2) a step for forming a sheet having a continuous phase of the second material and a discontinuous or continuous phase of the first material on the surface by micro-phase-separating the first material into the second material; (3) a step for solidifying the second material in the sheet; and (4) a step for obtaining the porous master for the electroforming mold by removing the first material from the sheet. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an electroforming mold master. In detail, it is related with the method of manufacturing the master for electroforming molds which is a porous body obtained using the micro phase separation method. Moreover, this invention relates to the manufacturing method of the electroforming mold using the master for electroforming molds obtained by the said method.

The electroforming mold is used in molding the resin film in order to impart a fine and delicate structure to the resin film. For example, a functional film having antireflection, water repellency, antifouling properties and the like usually has a fine structure on the surface. In order to form such a fine structure on the surface, the functional film is preferably manufactured using an electroforming mold.
In recent years, a pattern of submicron size to several tens of microns, such as an antireflection body (moth eye) having a finer structure, for example, a width of 0.01 μm to 100 μm or 0.1 to 10 μm and a height of 0.01 μm to The necessity to form regular concave patterns or convex patterns of about 100 μm or about 0.1 to 10 μm on the surface of the resin film has increased. In order to form such a fine structure on the surface of the resin film, it is necessary to use an electroforming mold having an extremely fine and accurate structure.
For such an electroforming mold, first, a stainless steel or resin electroforming mold master is prepared, and this master is plated with metal such as electroformed nickel, and the shape of the metal plating is transferred to the electroformed mold material. Manufactured by doing. Therefore, in order to provide an electroformed mold having a fine and accurate structure, it is necessary to manufacture an electroformed mold master having a fine and accurate structure.
When such an electroforming mold master is manufactured from a resin, whether or not an accurate fine structure free from defects and spots can be provided is a major issue. Moreover, when manufacturing a large area electroformed mold master of about 100 to 2000 cm ² at once, it takes a lot of time to produce by the machining method, and there is a difficulty that defects are hardly visible.

Hideyuki Sasaki et al. “Production Method of Electroforming Mold”, Research Report No. 12 (2005), Iwate Industrial Technology Center

A first object of the present invention is to provide a method for producing an electroforming mold master having an accurate fine structure free from defects and spots.
The second object of the present invention is to provide a method for producing a master for an electroforming mold having an accurate fine structure and a large area at a time.
A third object of the present invention is to provide a method for producing an electroformed mold using such an electroformed mold master.

As a result of intensive studies to solve the above-mentioned problems, the present inventors manufactured a porous body using a microphase separation method, and used this as a master for an electroforming mold. The inventors have found that this can be solved, and have reached the present invention.
That is,
1. The present invention is a method for producing an electroforming mold master, comprising the following steps:
(1) mixing the first material and the second material;
(2) A sheet having a surface having a continuous phase of the second material and a discontinuous phase or a continuous phase of the first material on the surface by microphase separation of the first material in the second material. Forming step;
(3) solidifying the second material in the sheet; and
(4) A step of removing the first material from the sheet to obtain a porous electroforming mold master;
The present invention relates to a method for manufacturing a master for an electroforming mold.
2. In the present invention, the discontinuous phase or continuous phase of the first material on the surface of the sheet formed in the step (2) is composed of particles of the first material having a diameter of 0.05 to 10 μm, and is on the surface. It is related with the manufacturing method of the master for electroforming molds of said 1 whose space | interval of the particle | grains of each 1st material is 0.05-10 micrometers.
3. In the present invention, the microphase separation in the step (2) is performed by incompatibility of the second material and the first material by heat or UV polymerization of the second material. The manufacturing method of the master for electroforming molds of 1.
4). The present invention relates to the method for producing a master for an electroforming mold as described in 1 above, wherein the first material and the second material are incompatible with each other.
5. The present invention relates to an electroforming mold master produced by the method according to any one of 1 to 4 above.
6). The present invention is a method for producing an electroformed mold, comprising the following steps:
(a) a step of performing metal plating on the surface of the electroforming mold master according to 5 above; and
(b) removing the master for electroforming mold to obtain an electroforming mold;
The present invention relates to a method for manufacturing an electroforming mold.
7). The present invention further includes, prior to the step (a), a step of installing a porous support on the surface of the electroforming mold master used in the step (a) opposite to the side on which metal plating is performed. And relates to the method according to 6 above.
8). The present invention relates to an electroforming mold manufactured by the method described in 6 or 7 above.

According to the present invention, it is possible to manufacture an electroforming mold master having an accurate fine structure free from defects and spots. Further, according to the present invention, even if the master for electroforming mold has a large area, it has an accurate fine structure. Furthermore, according to the present invention, an electroformed mold having an accurate fine structure can be manufactured.
Moreover, this invention is an electroforming mold which has the fine concavo-convex structure manufactured from the said master for electroforming molds on the surface. The mold is fixed to the metal block with an adhesive or a screw, or if the master for an electroforming mold is 1.0 mm or less, the mold is wound around and fixed to a metallic roll, and a continuous functional sheet. It can also be used as a production mold.

1. Manufacturing method of master for electroforming mold The present invention, as described above, the following steps;
(1) mixing the first material and the second material;
(2) A sheet having a surface having a continuous phase of the second material and a discontinuous phase or a continuous phase of the first material on the surface by microphase separation of the first material in the second material. Forming step;
(3) solidifying the second material in the sheet; and
(4) removing the first material from the sheet to obtain a porous electroforming mold master;
The present invention relates to a method for producing a master for an electroforming mold having Among these, the microphase separation methods are roughly divided into the following three methods.
A. B. Microphase separation method by melt mixing / common solvent mixing C. Microphase separation by thermal or UV polymerization Direct Microphase Separation Method Here, “microphase separation” refers to a substance having two or more types of phase components, in which no other phase components are present in the continuous phase (sea) of one type of phase components. Structure in which continuous phases (islands) are dispersed (sea-island structure, see sheet (3) in FIG. 1 (a)), or other phase constituents in the continuous phase of one phase constituent A co-continuous structure in which other continuous phases are entangled three-dimensionally with each other (see FIG. 3, FIG. 3 is a diagram in which the continuous phase of the phase component is left and the other continuous phases of the other phase components are removed). A structure (island) in which a discontinuous phase or other continuous phase is dispersed in the continuous phase (the sea) is formed on the surface of the substance, forming particles on the order of micrometers. Say state.
The average particle diameter (constant direction diameter) of the particles appearing on the surface is, for example, 0.05 to 10 μm in diameter, preferably 0.1 to 1 μm, and more preferably 0.2 to 0.5 μm. Moreover, the space | interval of the particles which appeared on the surface is 0.05-10 micrometers, for example, Preferably, it is 0.1-1 micrometer, More preferably, it is 0.2-0.5 micrometer.
Hereafter, the manufacturing method of the master for electroforming molds of this invention is explained in full detail for every said method of AC.

(A) Microphase separation method by melt mixing / common solvent mixing In this method, the first material and the second material are melted or dissolved or dispersed in a solvent to obtain a mixed solution. Alternatively, in the process of evaporating the solvent, the first material and the second material are microphase-separated, and then only the first material is removed to obtain an electroforming mold master that is a porous body. is there. Specifically, the manufacturing method of the master for electroforming molds by the microphase separation method by melt mixing / common solvent mixing has the following processes.

(A-1) Step (1) In the step (1), the first material and the second material are mixed.
Here, as the first material, a polymer, an oligomer, a monomer, a mixture thereof, and the like are preferable.
Polymers include water-soluble polymers such as polyvinyl acetate, polyvinyl alcohol, polyoxazoline, polyethylene glycol, polyethylene oxide, sodium polyacrylate, polyacrylamide; polyvinyl chloride, polyvinyl phenol, polyvinyl methyl ether, polyester, polyacetate Water-insoluble polymers such as polyether sulfone, polymethyl methacrylate (PMMA), polyacrylonitrile, polyvinyl pyridine, and polyacrylic acid.

As an oligomer, the polyfunctional oligomer shown to the following resin raw materials 1-9 is mentioned.
A resin raw material 1 that is a rigid component and represented by Chemical Formula 1.
<Chemical Formula 1>

A resin raw material 2 that is a rigid component and represented by Chemical Formula 2.
<Chemical formula 2>



A resin raw material 3 that is a flexible component and represented by Chemical Formula 3.
<Chemical formula 3>

A resin raw material 4 that is a flexible component and represented by Chemical Formula 4.
<Chemical Formula 4>


A resin raw material 5 that is a flexible component and represented by Chemical Formula 5.
<Chemical formula 5>

Resin raw material 6 (monofunctional oligomer) which is a flexible component and represented by Chemical Formula 6.
<Chemical formula 6>

A resin raw material 7 obtained by adding 4 mol EO to the resin raw material 5.
A resin raw material 8 which is a rigid component and has a structure in which the aromatic ring of the resin raw material 5 is hydrogenated.
A resin raw material 9 which is a rigid component and is a urethane acrylate containing imide acrylate, preferably a urethane acrylate mixture comprising the following components A and B.
A component: trimer of hexamethylene diisocyanate + hexamethylene diisocyanate B component: hydroxypropyl acrylate + pentaerythritol triacrylate

The glass transition temperature (Tg) of the resin raw materials 1 to 9 used in the present invention is, for example, 40 ° C or higher, preferably 60 ° C or higher, more preferably 80 ° C or higher.
As a raw material for manufacturing the said polyfunctional oligomer, the monomer represented by the following Chemical formulas 1-18 is mentioned, for example.

<Chemical Formula 1>




<Chemical formula 2>

<Chemical formula 3>

<Chemical Formula 4>

<Chemical formula 5>

<Chemical formula 6>

<Chemical formula 7>

<Chemical Formula 8>

<Chemical formula 9>





<Chemical formula 10>

<Chemical Formula 11>

<Chemical formula 12>

<Chemical formula 13>

<Chemical formula 14>

<Chemical formula 15>

<Chemical formula 16>

<Chemical formula 17>

<Chemical formula 18>

  Examples of the monomer used as the first material include acrylic monomers such as sodium acrylate monomer, methyl methacrylate monomer (MMA), acrylate monomer, and acrylonitrile monomer; and other vinyl monomers.

The second material is preferably a polymer that forms a hydrogen bond or an ether bond with the first material. For example, polyvinyl chloride, polyvinyl phenol, polyvinyl methyl ether, polyester, polyacetate, polyether sulfone, polymethyl methacrylate (PMMA), polyacrylonitrile, polyvinyl pyridine, polyacrylic acid, polyacrylamide and copolymers thereof Can be mentioned. Particularly effective materials are polyether sulfone and polymethyl methacrylate (PMMA). In order to improve compatibility with the first material, when the first and second materials are polymer materials, the polymer material is combined with the first polymer material (block or graft). What was copolymerized can also be used as the second material.
Further, when the first material is a polymer, a monomer can be used as the second material. Examples of the monomer used include the monomer used in the first material.

The first material and the second material are mixed by melt mixing or common solvent mixing.
In the case of melt mixing, the first material and the second material are heated and melted to form a liquid and mixed. In the case of melt mixing, it is preferable that the melting points of the first material and the second material are close to each other because both materials can be mixed at the same temperature. In addition, when melted, it is appropriate to form a microphase separation structure in which the first material and the second material are phase-separated from each other. A suitable material satisfying such conditions is a combination of a first material and a second material, and examples thereof include polyether sulfone-polyoxazoline, PMMA-polyethylene oxide, and the like.

  In the case of common solvent mixing, the first material and the second material are dissolved in a solvent that is commonly dissolved in these materials. As the solvent, a highly soluble organic solvent is suitable. Examples of such organic solvents include methylene chloride, hexane, benzene, acetone, methyl ethyl ketone (MEK), dimethylformamide (DMF), dimethylacetamide (DMAC), tetrahydrofuran (THF), other alcohols, ethers, and ketones. Etc. The solvent is appropriately selected according to the polymer or oligomer used as the first and second materials. In addition, it can be confirmed that the common solvent containing the first material and the second material is well microphase-separated by being white turbid in appearance and accompanied by strong light scattering. This is because phases having different refractive indexes exist locally at intervals of about the wavelength of visible light due to microphase separation.

(A-2) Step (2) In step (2), the first material is microphase-separated into the second material, and the continuous phase of the second material and the first material are formed on the surface. A sheet having a discontinuous phase or a continuous phase is formed.
Specifically, a discontinuous phase (island) composed of the first material is dispersed in a continuous phase (sea) composed of the second material (sea-island structure, diagram). 1 (a) sheet (3)) or a co-continuous structure in which another continuous phase composed of the second material is entangled three-dimensionally with the continuous phase composed of the first material (See FIG. 3).
On the surface of the sheet, there is a second material forming the continuous phase (sea) and a first material forming the discontinuous phase or another continuous phase. Regardless of whether it is an island structure or a co-continuous structure, a sea-island structure appears in which the first material is dispersed in the second material.
The average particle diameter (constant direction diameter) of the first material particles appearing on the surface is, for example, 0.05 to 10 μm in diameter, preferably 0.1 to 1 μm, more preferably 0.2 to 0.5 μm. It is. Moreover, the space | interval of the particle | grains of the 1st material which appeared on this surface is 0.05-10 micrometers, for example, Preferably, it is 0.1-1 micrometer, More preferably, it is 0.2-0.5 micrometer.
Note that the average particle diameter (constant direction diameter) of the first material particles and the distance between the first material particles are the same values in the other methods B and C unless otherwise specified. Is appropriate.

In the microphase separation, when the first and second materials are mixed in a common solvent, (i) at the same time as mixing into the solvent, or (ii) in the process of evaporation of the solvent, The first material forms the sea-island structure or a co-continuous structure (FIG. 3).
For example, in the case of melt mixing, the first and second materials are mixed in a molten state with a stirrer and / or kneaded with an extruder or the like and uniformly mixed, and then the phase separation structure is controlled while controlling the temperature. Can be adjusted. Here, the temperature control depends on the types of the first and second materials to be used, but considering the melt fluidity and thermal decomposition temperature of the polymer material, for example, Tg of the material to be used is 50 to 350 ° C., preferably Is preferably about Tg + 80 to 300 ° C.
In the case of mixing the common solvent, the microphase separation can be adjusted by controlling the mixing ratio of the first material, the second material, and the common solvent, the evaporation rate of the solvent, the evaporation temperature, and the like.

In order for the first and second materials to form a sea-island structure or a co-continuous structure in the solvent, it is necessary to increase the contact between the first and second materials. In order to increase the contact between the first and second materials, it is necessary that the solvent be present in a sufficiently small amount. Therefore, when the first and second materials are mixed in a common solvent, it is possible to adjust the degree of microphase separation by adjusting the amount of the common solvent. Further, for the same reason, microphase separation may further proceed in the process of removing the solvent in the subsequent steps (3) and (4).
The particle size and interval of the first material when the first and second materials are mixed in a common solvent are the same as those when melt-mixed as described above.

Further, when a monomer is used as the first (or second) material, microphase separation occurs when the monomer is polymerized by heat or UV. When a monomer is used as the first (or second) material, the first (or second) material (monomer) is mixed with the second (or first) material (continuous phase) in the mixing in the first (1) step. It is preferable because it is easy to disperse in the polymer matrix. Uniform microscopic microdomains can be formed by polymerizing the monomers after forming a uniform dispersion. The same applies when an oligomer is used as the first (or second) material.
As a method for polymerizing the monomer or oligomer, the following two types of bulk polymerization are suitable for forming a good microphase separation structure.

First, as the first method, an azo initiator or peroxide polymerization initiator that generates a radical by cleavage at a desired temperature in a mixture of the first and second materials, for example, 1 to 10,000 ppm, preferably Is added in an amount of 10 to 1000 ppm. Then, thermal polymerization is performed at a temperature of 50 to 150 ° C. At this time, there is a method of controlling the phase separation state by performing polymerization in several stages through several temperature steps. Specifically, for example, a low temperature initiator such as peroxide having a 10-hour half-life temperature of 50 to 58 ° C. is used as an initial stage, and the polymerization is carried out at a temperature below the boiling point of the monomer (for example, 60 to 80 ° C.). Peroxides include peroxyesters such as t-hexyl peroxypivalate, t-butyl peroxypivalate, t-butylperoxyneohexanoate, 2,4-dichlorobenzoyl peroxide, o-methylbenzoylper Although diacyls, such as an oxide, are mentioned, Peroxyester is especially preferable. Next, a high temperature initiator such as 2,2 ′-(azobis) isobutyronitrile is used in combination at a stage where the polymerization rate (for example, 70 to 90%) has advanced to some extent beyond the gelation process, and the glass transition temperature ( Tg) Phase separation proceeds (for example, 120 to 150 ° C.) while maintaining fluidity at a sufficiently higher temperature. The rate of phase separation depends greatly on the temperature of the system, and in order to efficiently cause phase separation particularly in a phase separation type at a high temperature (for example, a polymer mixture having a lower critical temperature (LCST)) than the LCST. Must also be hot.
Since the microphase separation state is greatly influenced by the temperature of the system, the polymerization temperature must be carefully set with sufficient consideration.
Moreover, as a 2nd method, the method of using UV polymerization initiators, such as Irgacure which causes cleavage by an ultraviolet-ray (UV light) instead of the polymerization initiator used by the 1st method, is mentioned. By using such a UV polymerization initiator, the polymerization can be completed at a desired temperature in a short time.

Here, the UV polymerization initiator may be used in combination with a sensitizer. By using a sensitizer in combination, an energy sensitization reaction occurs, the photosensitive wavelength is expanded, and the deep curing of the polymer can be improved.
As the sensitizer, for example, ITX (2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one Irgacure907 initiator: Ciba Specialty Chemicals Co., Ltd. may be used in combination. Good.
When a photopolymerization initiator having an absorption peak in a long wavelength region of 360 nm or longer is used as the UV polymerization initiator, the photosensitive wavelength is increased and the curing of the deep portion of the polymer can be improved.
Examples of such UV polymerization initiators include BAPO {bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide}, MBAPO {2,4,6-trimethylbenzoyl-diphenylphosphine oxide}. It is done.
Further, a UV polymerization initiator having photo-fading property may be used as the UV polymerization initiator. By using such a UV polymerization initiator, the absorption band of the UV polymerization initiator itself disappears during the photopolymerization reaction, so that light can improve the deep curing of the polymer.
Examples of such UV polymerization initiators include acylphosphine oxide: MBAPO {2,4,6-trimethylbenzoyl-diphenylphosphine oxide}, titanocene initiator: bis (η5-2,4-cyclopentadiene- 1-yl) -bis (2,6-difluoro-3- (1H-pyrrol-1-yl) -phenyl) titanium, oxime ester: OXE {1,2-octanedione, 1- [4- (phenylthio )-, 2- (O-benzoyloxime)]}.

(A-3) Step (3) In the step (3), the second material is solidified. Specifically, the mixture of the first material and the second material that have been subjected to microphase separation is cooled by cooling in the case of melt mixing, or by gradually evaporating the solvent in the case of common solvent mixing. Solidify the two materials.
Cooling is performed to a temperature below the melting point of the polymer or the like used as the second material. However, when using a polymer mixture having a lower critical temperature (LCST) (for example, a polyethersulfone / polyoxazoline mixture), the first material and the second material are completely compatible with each other below the lower critical temperature. Therefore, it is necessary to quench and fix the microphase separation structure using liquid nitrogen or the like. Although the cooling temperature depends on the type of polymer or the like used as the second material, it is cooled to, for example, Tg-10 ° C. or less, preferably Tg-20 ° C. to Tg-30 ° C. In the case of rapid cooling, for example, cooling is performed at 1 to 40 ° C./second, preferably 10 to 30 ° C./second.
The evaporation of the solvent is performed by raising the mixture of the first and second materials containing the solvent to a temperature equal to or higher than the boiling point of the solvent by a known method. For example, it is preferable to use an apparatus with a drying facility including a vacuum devolatilization and a solvent recovery mechanism.

(A-4) Step (4) In the step (4), the first material is removed to obtain a porous electroforming mold master.
Examples of the method for removing the first material include (i) a method using a solvent and (ii) a method using a supercritical fluid.
(i) A method using a solvent is a method of dissolving and removing only the first material using a solvent that can dissolve the first material but not the second material. Examples of the solvent (removal solvent) used for the removal include toluene, hexane, methyl ethyl ketone (MEK), 2-methyl-2,4-pentanediol (MPO), hexanol (HEX), octanol, methanol, ethanol, (warm ) Water or an aqueous solution (for example, water and methanol mixed solution, sodium hydroxide aqueous solution) and the like. In particular, when a water-soluble polymer is used as the first material, water is a good removal solvent. For example, when a water-soluble polymer such as polyoxazoline is used as the first material and a water-insoluble polymer such as polyethersulfone is used as the second material, water is used as a removal solvent. Thus, the first material can be selectively removed. Water is easily available and is preferably used as a safe solvent.

  (ii) The method using a supercritical fluid is a method using, for example, a supercritical fluid of carbon dioxide or water as a removal solvent. A supercritical fluid is carbon dioxide or water under temperature and pressure above the critical point, and is an object having gas diffusivity and liquid solubility. This supercritical fluid can satisfactorily remove remaining low-molecular organic substances, solvents, monomers, oligomers, and the like from the second material. However, this method cannot be used to remove the polymer because the supercritical fluid has the ability to dissolve and extract low-molecular substances but does not have the ability to dissolve and extract the polymer. Therefore, the method using a supercritical fluid is particularly effective when a monomer or oligomer other than a polymer is used as the first material.

By removing the first material by the methods (i) and (ii) above, a porous electroforming mold master can be obtained. The pore size of the obtained porous body is, for example, 0.05 to 10 μm, preferably 0.1 to 1 μm. Moreover, the porosity of the obtained porous body is, for example, 30 to 70%, preferably 40 to 60%. It should be noted that the pore size and porosity of the porous body are suitably the same values in the methods B and C described later unless otherwise specified.
This porosity is controlled by the mixing temperature condition of the first and second materials, the evaporation rate of the solvent, the molecular weight of the polymer, the mixing ratio of the first and second materials, and the like. A compatibilizing agent can also be used to reduce the size of the pores. Examples of the compatibilizing agent include a block copolymer having a monomer unit constituting the first material and a monomer unit constituting the second material.

  Through the steps as described above, an electroforming mold master by the microphase separation method of the present invention can be manufactured. By using such a method, it is possible to form a random microporous structure on the order of 0.05 to 1 μm, which is below the limit in the case of producing a porous body by machining, and a porous body having a dense and excellent uniformity can be obtained. can get. Thus, it is difficult to reproduce the dense structure obtained by the phase separation phenomenon by machining, including an increase in area. Moreover, since random processing is difficult in machining, non-uniformity is easily visually recognized. The present invention overcomes these disadvantages in machining.

(B) Microphase separation method by thermal or UV polymerization In this method, the microphase separation proceeds by a thermal or photopolymerization process. Specifically, since the microphase separation between the first material and the second material proceeds by a thermal or photopolymerization process, the second material is solidified (insolubilized) by a crosslinking reaction or the like. Only the material can be dissolved away with a solvent.

(B-1) Step (1) In the step (1), the first material and the second material are mixed.
Here, as the first material, a polymer, a low molecular material and a mixture thereof are suitable.
Examples of the polymer include all the polymers exemplified as the first and second materials in (A) above.
Low molecular weight materials include non-polymerizable materials, preferably non-polymerizable liquids such as toluene, hexane, methyl ethyl ketone (MEK), 2-methyl-2,4-pentanediol (MPO), hexanol (HEX), Solvents such as octanol, methanol, ethanol, (warm) water, or aqueous solutions (eg, water and methanol mixed solution, sodium hydroxide aqueous solution), water-soluble inorganic substances (salts) such as sodium salicylate, naphthalene, iodine, sublimation dyes Sublimable substances such as

As the second material, a polyfunctional oligomer having a crosslinkable functional group is suitable.
As this polyfunctional oligomer, the polyfunctional oligomer shown to the said resin raw materials 1-9 is mentioned.
A suitable combination of the first material and the second material is to improve the compatibility of both materials to obtain uniform mixing, and to remove the polymer when the first material is a polymer. From the viewpoint of ease of treatment, polyfunctional urethane acrylate-polyethylene oxide, polyfunctional urethane acrylate-polyoxazoline, polyfunctional urethane acrylate-PMMA and the like can be mentioned. In addition, the first material and the second material are preferably those that do not react with each other (that does not undergo polymerization or crosslinking).

(B-2) Steps (2) and (3) In step (2), the second material is a continuous phase, and the first material is a discontinuous phase or a continuous phase (co-continuous structure). ), The first material is microphase-separated into the second material.
In this microphase separation method by heat or UV polymerization, the third step (3) for solidifying the second material is also performed simultaneously with the second step (2). Specifically, heat or light (UV) is applied to the mixture of the first material and the second material to heat or UV polymerize the second material. By applying heat or light (UV), the second material is polymerized and the second material is cross-linked. As a result, the second material becomes incompatible with the first material, and microphase separation occurs. At this time, the second material is insoluble in the removal solvent of the first material.

(B-3) Step (4) In the step (4), the first material is removed to obtain a porous electroforming mold master.
Examples of the method for removing the first material include (i) a method using a solvent and (ii) a method using a supercritical fluid.

(C) Direct Microphase Separation Method This method mixes heat and light (UV) of the first and second materials by mixing the first and second materials that are different from each other in incompatibility or polarity. ) A method for achieving microphase separation without performing polymerization, removal of the first material with a solvent, or the like. Specifically, the manufacturing method of the master for electroforming molds by the direct microphase separation method includes the following steps.
(C-1) Step (1) In the step (1), the first material and the second material are mixed.
Here, as the first material, a low molecular material such as an oligomer, a monomer, or a solvent is used.
Examples of the oligomer include polyfunctional oligomers shown in the above resin raw materials 1 to 9; highly polar oligomers such as polyfunctional oligomers containing halogen such as fluorine, chlorine and bromine atoms; generally halogen atoms such as urethane acrylate. And oligomers with low polarity such as polyfunctional oligomers not containing.
Examples of the monomer include water-soluble monomers such as sodium acrylate; hydrophobic monomers such as vinyl monomers such as MMA, acrylate, acrylonitrile, and styrene monomer; halogens such as acrylonitrile monomer and fluorinated methacrylate A highly polar monomer including MMA; and a low polarity monomer such as MMA.
These monomers and oligomers are not added for polymerization, but are simply microphase-separated in the second material and then removed in the form of monomers and oligomers.

  As the second material, water-soluble polymers such as polyvinyl acetate, polyvinyl alcohol, polyoxazoline, polyethylene glycol, polyethylene oxide, sodium polyacrylate, polyacrylamide; polyvinyl chloride, polyvinyl phenol, polyvinyl methyl ether, polyester, Hydrophobic polymers such as polyacetate, polyether sulfone, polymethyl methacrylate (PMMA), polyacrylonitrile, polyvinyl pyridine, polyacrylic acid, polyacrylamide, cellulose acetate; polyvinyl chloride, polyacrylonitrile; polyfluorinated ( Highly polar high containing fluorine-containing polymers such as (meth) acrylate, polytetrafluoroethylene (PTFE) and polyvinylidene fluoride (PVF), and other halogen molecules such as bromine Child; PMMA, benzyl methacrylate, polyacrylate, polycarbonate - Boneto, polystyrene, and a less polar polymer containing no halogen.

(C-2) Step (2) In the step (2), the second material is used as a continuous phase, and the first material is used as a discontinuous phase or a continuous phase in the second material. The first material is microphase separated.
In the direct microphase separation method, microphase separation can be achieved by simply mixing the first material and the second material due to differences in physical properties such as compatibility or polarity between the first material and the second material. Arise. In order to achieve such microphase separation by the direct microphase separation method, materials having different physical properties such as water solubility and polarity are used as the first material and the second material. For example, when a hydrophobic low molecular weight material is used as the first material, a water-soluble polymer is used as the second material. In addition, when a low-molecular material with high polarity is used as the first material, a high-polarity polymer is used as the second material.
For example, acetone, which is a solvent of the second material, and MPD, which is a poor solvent for the second material, can be used as the first material, and cellulose acetate can be used as the second material.

(C-3) Step (3) In the step (3), the second material is solidified. Specifically, a low-molecular material such as a solvent, an oligomer, or a monomer, which is the first material, is solidified by evaporation or freeze-drying.

(C-4) Step (4) In the step (4), the first material is removed to obtain a porous electroforming mold master.
Examples of the method for removing the first material include a method using the dry process of the above-described step (3). That is, the (4) step is performed simultaneously with the (3) step. In order to solidify the second material, the first material can be removed by evaporating or lyophilizing a low molecular material such as a solvent that is the first material. However, in some cases, it cannot be completely removed by the dry process, and in that case, it can be removed using a supercritical fluid. Specifically, carbon dioxide is used as a supercritical fluid, and the supercritical fluid is subjected to the step (3), for example, a thin film having a thickness of about 0.1 to 1 mm or a sheeted material ( For example, the first material can be completely removed by penetrating a porous ceramic or a porous metal plate in a high-pressure closed container at a desired temperature that can maintain a critical state.

2. Characteristics of the electroforming mold master The electroforming mold master obtained as described above has a diameter of 0.05 to 10 μm on the surface, preferably 0.1 to 1 μm, more preferably 0.2 to 0. An approximately circular regular concave pattern of 5 μm appears. Moreover, the space | interval of the concave patterns which appeared on this surface is 0.05-10 micrometers, for example, Preferably, it is 0.1-1 micrometer, More preferably, it is 0.2-0.5 micrometer.
The size of the electroforming die master, for example, 10000～200000Mm ^2, preferably a 10000～100000Mm ^2, thickness 1Myuemu～1000myuemu, preferably from 10 to 100 [mu] m.

3. Method for producing electroformed mold The method for producing an electroformed mold of the present invention comprises the following steps:
(a) A step of performing metal plating on the surface of the master for electroforming mold of the present invention;
(b) removing the master for electroforming mold of the present invention to obtain an electroforming mold;
including.
In addition, the method for producing the electroforming mold of the present invention includes the step (a),
(a ′) a step of disposing a porous support on the surface of the electroforming mold master;
Then, in the step (a), metal plating may be performed on the surface of the electroforming mold master opposite to the side on which the porous support is disposed.
Furthermore, the method for producing the electroforming mold of the present invention, before the step (b),
(b ′) a step of disposing a reinforcing material on the surface of the metal plating side of the electroplating mold master subjected to metal plating;
May be added.
Hereinafter, the steps (a), (a ′), (b), and (b ′) will be described in detail.

In the step (a), metal plating is performed on the surface of the electroforming mold master of the present invention. Specifically, a metal is reduced and deposited on the master surface for an electroforming mold by an electrochemical reaction in a plating bath. For example, if a <sulfuric acid nickel [Ni (NH ₂ SO ₃ H)] + saccharin> bath is used as the plating bath, nickel is used as the anode, an electroforming mold master is used as the cathode, and current flows through both electrodes, electroforming Nickel is deposited on the mold master surface. Nickel sulfamate is useful from the viewpoints of lowering internal stress (preventing warpage of the electroforming mold), improving the deposition speed, and improving the flexibility of the deposited nickel. Saccharin helps reduce internal stress in electroformed molds. In addition, when metal plating of Ni—Co alloy having high hardness and few burrs is performed, it is appropriate to use a cobalt sulfamate [Co (NH ₂ SO ₃ H)] bath.
Below, an example of the suitable plating bath described in "Guide for electroforming nickel sulfamate plating" of Showa Chemical is shown.
Table 1 Example of components in plating bath (values are based on 1 liter of plating bath)
*) 1000g / l when using 60% aqueous solution

As the metal to be plated, nickel, chromium and the like are preferable from the viewpoint of the oxidation resistance of the mold surface.
Prior to the step (a), the electroforming mold master of the present invention may be washed with an organic solvent or pure water and dried. For cleaning, ultrasonic cleaning, degreasing treatment, or the like can be used.
When the electroforming mold master of the present invention is non-conductive, a conductive film is formed on the surface of the electroforming mold master of the present invention on which metal plating is performed prior to the step (a). Examples of the conductive film forming material include conductive polymers such as polyacetylene, silver, nickel, chromium, and gold. These conductive films may be applied by silver mirror reaction, electroless plating, vapor deposition, ion sputtering, or the like.

Prior to the step (a), a porous support is disposed on the surface of the electroforming mold master of the present invention opposite to the side on which metal plating is performed, and the electroforming mold master of the present invention is disposed. It may be supported (step (a ′)).
Examples of the porous support include metal, glass, and ceramic. The porous support has regular pores of about 1 to 10000 μm, preferably about 10 to 1000 μm.
The hole does not need to penetrate from one surface of the porous support to the other surface, but when it penetrates, the hole is from the surface on the side where the master for an electroforming mold of the present invention is carried. A reverse taper structure in which the pore diameter gradually increases in the thickness direction of the porous support is preferable (see FIG. 1 (c ′)).
Such a reverse-tapered hole is produced, for example, by performing drilling or laser processing by etching from the surface opposite to the surface on which the electroforming mold master of the present invention is carried.
The porous support may be supported after the electroforming mold master is produced, or may be supported by producing the electroforming mold master on the porous support.
By supporting the porous support, an effect of helping to easily separate the mold and the master for electroforming mold after the electroforming mold is produced can be expected. Also, when producing an electroforming mold master on a porous support, the electroforming mold master enters the inside of the hole, the electroforming mold master is fixed by the anchor effect, and the first material is removed. During the dry process and polymerization of various materials, it is possible to suppress the occurrence of peeling and shrinkage of the material to be the master for the electroforming mold, and the deformation and wrinkling of the material.

In the step (b), the electroforming mold master of the present invention is removed.
The removal of the electroforming mold master is performed by peeling off the electroforming mold master while paying attention so that a part of the electroforming mold master does not adhere to or remain on the metal plating side. When a part of the electroforming mold master adheres to the metal plating side, the electroforming mold master is cleaned with a solvent, ultrasonic cleaning, plasma cleaning with high energy rays (gamma ray, electron beam, UV, X-ray), electrolysis Degreasing (a method in which a metal-plated surface is used as an electrode, a decomposition gas generated by electrolysis of water or the like is generated from the metal-plated surface and degreased using the bubbling effect), high energy rays (gamma rays, electron beams, UV The remaining electroforming mold master is completely removed from the surface of the metal plating by using a method utilizing resin degradation or thermal decomposition caused by X-ray).
Thus, the electroforming mold containing metal plating is obtained by completely removing the master for electroforming mold of the present invention. However, irregular projections may occur in the electroforming mold. This is because the shape of the deep part of the porous body is transferred to the metal plating. Such a protrusion becomes a major peeling obstacle at the time of releasing a plastic molding using an electroforming mold, for example. Therefore, after removing the electroforming mold master, it is preferable to finely polish the protrusions by electrolytic polishing (the metal plating surface is anodically dissolved in a specific solution and the protrusions are removed and smoothed).

(b) Prior to the step, a reinforcing material may be disposed on the surface of the metal plating side of the electroplating mold master subjected to metal plating, and then the electroforming mold master may be removed. This reinforcing material is applied to reinforce the strength of the electroformed mold. As the reinforcing material, an inorganic material such as a polymer such as an epoxy resin, a metal such as glass, cement, ceramic, iron, nickel, or chromium can be used.
The thinner the metal plating, the more preferable (a) since it takes less time for processing. The thickness of the metal plating is usually 10 mm or less, preferably 1 mm or less, more preferably 0.5 mm or less. On the other hand, when no reinforcing material is used, it is preferable from the viewpoint of strength that the thickness of the electroforming mold is 10 to 30 mm.

4). Manufacturing Process of Electroforming Mold Master and Electroforming Mold Next, the manufacturing process of the electroforming mold master will be described with reference to FIG.
First, the first material 1 and the second material 2 are mixed (step (1)), the first material is microphase-separated into the second material (FIG. 1 (a)), and the microphase A separated mixture 3 is obtained (step (2)). Thereafter, the second material is solidified (not shown), and the first material is removed to obtain a porous electroforming mold master 4 (FIG. 1B). FIG. 1C shows a cross-sectional view of this electroforming mold master. FIG. 1 (c ′) shows a cross-sectional view of an electroforming mold master carrying a porous support having an inversely tapered structure.

Further, the manufacturing process of the electroforming mold will be described with reference to FIG.
First, the inside of the plating bath 7 is prepared, and the anode 6 of nickel or the like and the cathode of the electroforming mold master 4 optionally provided with a conductive film are placed in the plating bath 7 (FIG. 2 (d)). A current is passed through both electrodes to deposit metal plating on the surface of the master for an electroforming mold. A mold frame 9 is fitted into the obtained electrocasting mold master provided with the metal plating 8, and a reinforcing material 10 is poured (FIG. 2 (e)). Thereafter, the reinforcing material is cured (FIG. 2 (f)). After the reinforcing material is cured, the electroforming mold master 4 is removed, and the mold 9 is removed to obtain the electroforming mold 11 (FIG. 2 (g)).

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the invention described in the claims, and these are also included in the scope of the present invention.

It is drawing for demonstrating the manufacturing method of the master for electroforming molds of this invention. It is drawing for demonstrating the manufacturing method of the electroforming metal mold | die of this invention. It is a microscope picture which shows the co-continuous structure of the master for electroforming molds of this invention.

Explanation of symbols

1: First material 2: Second material 3: Microphase-separated mixture 4: Electroformed mold master 5: Porous support 6 having an inverted taper structure 6: Anode 7: Plating bath 8: Metal plating 9: Formwork 10: Reinforcement material 11: Electroforming mold

Claims (8)

A method for producing an electroforming mold master, comprising the following steps;
(1) mixing the first material and the second material;
(2) A sheet having a surface having a continuous phase of the second material and a discontinuous phase or a continuous phase of the first material on the surface by microphase separation of the first material in the second material. Forming step;
(3) solidifying the second material in the sheet; and
(4) removing the first material from the sheet to obtain a porous electroforming mold master;
The manufacturing method of the master for electroforming molds characterized by having. The discontinuous or continuous phase of the first material on the surface of the sheet formed in the step (2) is composed of particles of the first material having a diameter of 0.05 to 10 μm, and each of the first materials on the surface The manufacturing method of the master for electroforming molds of Claim 1 whose space | interval of the particle | grains of material is 0.05-10 micrometers. The microphase separation in the step (2) is performed by incompatibility of the second material and the first material by heat or UV polymerization of the second material. Of manufacturing a master for an electroforming mold. The method for manufacturing a master for an electroforming mold according to claim 1, wherein the first material and the second material are incompatible with each other. The master for electroforming molds manufactured by the method of any one of Claims 1-4. A method for producing an electroforming mold, comprising the following steps:
(a) applying metal plating on the surface of the electroforming mold master according to claim 5; and
(b) removing the master for electroforming mold to obtain an electroforming mold;
A method for producing an electroforming mold, comprising: Before the step (a), further comprising the step of installing a porous support on the surface opposite to the side on which the metal plating of the electroforming mold master used in the step (a) is performed. 6. The method according to 6. An electroforming mold manufactured by the method according to claim 6 or 7.