JP2007056162A - Photocurable composition for molded article production involving semi-curing process - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photocurable composition giving a semi-cured molded article whose surfaces contacting with a mold can be released from the mold, has excellent mold releasability, and can be cured in a semi-cured state having a good tackiness with a relatively wide irradiation quantity, and which can perfectly be cured by reirradiation of light to give the hard cured product, on the production of the molded article by a mold transcription method using the photocurable composition. <P>SOLUTION: This photocurable composition is characterized by comprising (A) 10 to 80 mass% of a compound having a methacryloyl group and having a mol. wt. of ≤250, (B) 3 to 30 mass% of a compound having three or more (meth)acryloyl groups and having a (meth)acryloyl group equivalent of ≥4 meq/g, (C) 10 to 70 mass% of a urethane (meth)acrylate having two (meth)acryloyl groups, and (D) 0.1 to 10 mass% of a photoradical polymerization initiator, and having E' of 1×10<SP>8</SP>to 1×10<SP>10</SP>Pa by the dynamic viscoelasticity measurement of the cured product. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a photocurable composition for producing a molded article by mold transfer, and more particularly to a photocurable composition for releasing a composition in a semi-cured state during mold transfer. The present invention belongs to the technical field of photocurable compositions and molded article production.

  The photo-curable composition is applied to the production of various molded products that have been given a fine shape by mold transfer using a mold, etc., taking advantage of the ability to instantly cure a low-viscosity liquid without solvent. As a specific example, a lens sheet such as a projection television is known (for example, Patent Documents 1 and 2).

  In the production of a molded product by mold transfer using a photocurable composition, the photocurable composition is usually completely cured by irradiation with a sufficient amount of light in a state of being sandwiched between a mold and a transparent substrate. The mold is released in a state of being in close contact with the transparent substrate. In this case, if the composition is not completely cured, problems such as bleeding out of unreacted monomers and changes with time in physical properties (for example, hardness and refractive index) may occur.

However, rarely, there is an example in which a part of the photocurable composition is intentionally semi-cured.
For example, in a method for forming a thick film pattern by mold transfer, a photocurable composition is filled in a mold and directly irradiated with light without a transparent substrate, and polymerization of a (meth) acrylate compound occupying most of the photocurable composition. This is a method of making the surface in contact with air semi-cured or uncured by utilizing the fact that oxygen is inhibited by oxygen, and then completely curing this surface after pasting it on the surface of a member to which a pattern shape is to be imparted. Known (Patent Document 3). This method has an advantage that the pattern shape of the mold can be attached to various members.
In such a production method, various (meth) acrylate-based photocurable compositions can be used. However, when attention is paid to the surface in contact with the mold, the composition in this part is not subjected to oxygen inhibition, so that it cures rapidly. However, it was difficult to release as a surface having an attachable tack.

Also, in the mold transfer process in which the photocurable composition is sandwiched between a mold and a transparent substrate and irradiated with light, if the composition is hardened after complete curing, a good tack can be achieved by simply adjusting the amount of light. It was difficult to release as a semi-cured state.
That is, the semi-cured state was uneven depending on the location of the mold, or the semi-cured film was broken and could not be removed cleanly from the mold. Therefore, the surface that is in contact with the mold, that is, the projection of the molded product, can be affixed to another part, the parts of the pattern can be bonded together to create a part with fine pores, Another material could not be attached to the part.

Japanese Patent No. 2623279 (Claims) Japanese Patent No. 3398448 (Claims) JP-A-2004-335243 (Claims)

  An object of the present invention is to produce a molded product by mold transfer using a photocurable composition, and can release the surface in contact with the mold in a semi-cured state, and is excellent in the mold release property, with a relatively wide range of irradiation dose. Thus, a photo-curable composition that can be made into a semi-cured state having a uniform and good tack over the entire surface in contact with the mold, and becomes a hard cured product at room temperature after being completely cured by irradiation with light again. Is to provide.

As a result of intensive studies to solve the above problems, the present inventors have found that a monofunctional methacrylate having a specific molecular weight, a polyfunctional (meth) acrylate having a specific (meth) acryloyl group equivalent, a bifunctional urethane (meth) acrylate, and light It has been found that one containing a radical polymerization initiator and having a specific elastic modulus as a cured product is effective, and the present invention has been completed.
The present invention relates to a compound (A) having one methacryloyl group having a molecular weight of 250 or less, a compound having three or more (meth) acryloyl groups in one molecule and an equivalent of (meth) acryloyl group being 4 meq / g or more. (B) A composition comprising a urethane (meth) acrylate (C) having two (meth) acryloyl groups in one molecule and a radical photopolymerization initiator (D), wherein (A 10) to 80% by mass, (B) 3 to 30% by mass, (C) 10 to 70% by mass and (D) 0.1 to 10% by mass, and the cured product at 25 ° C. and 1 Hz. The present invention relates to a photocurable composition for producing a molded product in which a mold transfer having a storage elastic modulus E ′ of dynamic viscoelasticity measurement in a range of 1 × 10 ⁸ to 1 × 10 ¹⁰ Pa is a semi-curing step.
Hereinafter, the present invention will be described in detail.
In the present specification, acrylate or methacrylate is represented as (meth) acrylate, and acryloyl group or methacryloyl group is represented as (meth) acryloyl group.

1. (A) Component The (A) component in the present invention is a compound having one methacryloyl group having a molecular weight of 250 or less. When the molecular weight is larger than 250, it is inferior in adhesion to a transparent plastic substrate such as easy-adhesion-treated PET, polycarbonate, polymethyl methacrylate, MS resin, which is easy to handle as a transparent substrate.
(A) As molecular weight of a component, 130-250 are preferable. A compound having a molecular weight of less than 130 is not preferred because it often has a strong odor.

Specific examples of the component (A) include 2-hydroxyethyl methacrylate (molecular weight 130), 2-hydroxypropyl methacrylate (molecular weight 144), 4-hydroxybutyl methacrylate (molecular weight 158), methoxyethyl methacrylate (molecular weight 144), tetrahydrofur Furyl methacrylate (molecular weight 171), benzyl methacrylate (molecular weight 176), phenoxyethyl methacrylate (molecular weight 206), diethylene glycol monophenyl ether methacrylate (molecular weight 250), phenyl methacrylate (molecular weight 162), cyclohexyl methacrylate (molecular weight 168), 2-ethyl- Hexyl methacrylate (molecular weight 198), isobornyl methacrylate (molecular weight 222) and 2-hydroxy-3-phenoxypropylene Methacrylate (molecular weight 236), and the like.
Among these, 2-hydroxyethyl methacrylate (molecular weight 130), 2-hydroxypropyl methacrylate (molecular weight 144), 4-hydroxybutyl methacrylate (molecular weight 158), tetrahydrofurfuryl methacrylate (molecular weight 171), and benzyl methacrylate (molecular weight 176) are It is particularly preferable since it has excellent adhesion to transparent plastic substrates such as easy-adhesion-treated PET film, polycarbonate, polymethyl methacrylate, and MS resin, and has a relatively low odor.

(A) The mixture ratio of a component is 10-80 mass% in a composition, More preferably, it is 20-70 mass%, More preferably, it is 30-60 mass%. When the proportion of the component (A) is less than 10% by mass, the composition cures rapidly, so that it is difficult to control the semi-cured state, and when it exceeds 80% by mass, the curing rate of the composition becomes slow. Or the viscosity of the composition becomes too low.
As the component (A), two or more compounds may be used in combination.

2. (B) Component (B) component in this invention is a compound which has 3 or more (meth) acryloyl groups in 1 molecule, and (meth) acryloyl group equivalent is 4 meq / g or more.

  (B) By mix | blending component, it gelatinizes in the stage where the reaction rate of the (meth) acryloyl group of the whole composition is low, the flow of the composition in the middle stage of a semi-hardening is suppressed, and the nonuniformity by a place A uniform semi-cured state can be obtained over the entire coated surface. On the other hand, when the composition is composed only of compounds having 2 or less (meth) acryloyl groups in one molecule, the composition flows in the middle stage of semi-curing and the film thickness fluctuates. For example, there are problems such as incomplete semi-cured state where uncured liquid oozes out in some parts even though it becomes tack-free in some parts and cannot be pasted together. Resulting in.

  In the component (B), the upper limit of the number of (meth) acryloyl groups in one molecule is not particularly limited, but is preferably 100 or less, more preferably 20 or less, from the viewpoint of raw materials and productivity. .

The component (B) is a compound having a (meth) acryloyl group equivalent of 4 meq / g or more. When the (meth) acryloyl group equivalent is less than 4 meq / g, it becomes difficult to obtain a uniform semi-cured state in the entire mold location.
Although the upper limit of the (meth) acryloyl group equivalent of (B) component is not specifically limited, The acryloyl equivalent of acrylic acid is 13.9 meq / g, and 12 meq / g or less is preferable.

  The component (B) is preferably a compound having 3 or more (meth) acryloyl groups in one molecule and an (meth) acryloyl group equivalent of 6 meq / g or more, more preferably 4 or more in one molecule. A compound having a (meth) acryloyl group and having a (meth) acryloyl group equivalent of 8 meq / g or more, particularly preferably having 5 or more (meth) acryloyl groups in one molecule and having a (meth) acryloyl group equivalent It is a compound that is 9 meq / g or more.

  Examples of the component (B) include esterified products of polyhydric alcohol and (meth) acrylic acid (hereinafter referred to as poly (meth) acrylate), epoxy (meth) acrylate, urethane (meth) acrylate, and polyester (meth) acrylate. It is done.

  Specific examples of poly (meth) acrylates include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate and pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol penta ( Poly (meth) acrylates of polyhydric alcohols such as (meth) acrylate and dipentaerythritol hexa (meth) acrylate; tri (meth) acrylate of trimethylolpropane ethylene oxide adduct, tri (propylene oxide) adduct of trimethylolpropane ( Tri (meth) acrylate, pentaerythritol ethylene oxide adduct tri (meth) acrylate, pentaerythritol propylene oxide adduct tri Poly (meth) acrylates of polyhydric alcohol alkylene oxide adducts such as (meth) acrylate, tetra (meth) acrylate of ethylene oxide adduct of pentaerythritol, tetra (meth) acrylate of propylene oxide adduct of pentaerythritol; and isocyanuric acid And tri (meth) acrylate of ethylene oxide adduct, and tri (meth) acrylate of propylene oxide adduct of isocyanuric acid.

  Specific examples of the epoxy (meth) acrylate include epoxy (meth) acrylate obtained by adding (meth) acrylic acid to trimethylolpropane triglycidyl ether.

  Specific examples of urethane (meth) acrylate include urethane (meth) acrylate obtained by adding pentaerythritol tri (meth) acrylate to isophorone diisocyanate and urethane (meth) obtained by adding dipentaerythritol penta (meth) acrylate to isophorone diisocyanate. An acrylate etc. are mentioned.

  Specific examples of the polyester (meth) acrylate include polyester (meth) acrylate composed of phthalic anhydride, trimethylolpropane, and (meth) acrylic acid.

  In addition to the above, (meth) acrylates of dendrimer polyols and the like can be mentioned.

  (B) The mixture ratio of a component is 3-30 mass% in a composition, More preferably, it is 3-20 mass%, Most preferably, it is 4-10 mass%. When the proportion of the component (B) is less than 3% by mass, the effect of addition is small, the semi-cured state becomes uneven depending on the location, and the releasability from the metal decreases. On the other hand, when the amount is more than 30% by mass, it hardens rapidly, so that it is difficult to control the semi-cured state or the adhesiveness when the semi-cured product is pasted and completely cured is lowered.

As the component (B), an acrylate is preferable to a methacrylate from the viewpoint of excellent curability when a semi-cured composition is completely cured under air.
As the component (B), two or more compounds may be used in combination.

3. (C) Component (C) component in this invention is urethane (meth) acrylate which has two (meth) acryloyl groups in 1 molecule.
The molecular weight of the component (C) is preferably a number average molecular weight of 500 to 5,000, more preferably 1,000 to 4,000. When the molecular weight of the component (C) is less than 500, the flexibility of the semi-cured state may be impaired, and when the molecular weight is greater than 5,000, the phase separation in the semi-cured state causes the uniformity of the semi-cured product. It may be damaged.

Various components can be used as the component (C). For example, diols (x) such as polyether diol, polyester diol, polycarbonate diol, alkane diol having 2 to 9 carbon atoms and hydrogenated polybutadiene diol, and isophorone. Diisocyanates (y) such as diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate and tolylene diisocyanate, and 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate and 2-hydroxy-3-phenoxypropyl methacrylate Examples thereof include urethane (meth) acrylate synthesized from the compound (z) containing one hydroxyl group and one (meth) acryloyl group in one molecule.
Here, a plurality of types of compounds may be used as the (x), (y), and (z) components of the raw material. As the component (y), isophorone diisocyanate and hexamethylene diisocyanate are particularly preferable from the viewpoint of little yellowing.

  The component (C) can be easily synthesized by the addition reaction of the components (x), (y) and (z). Specifically, after (x) component is added and reacted in a solution in which a catalyst such as a tin compound is dissolved in (y) component, the remaining isocyanate is reacted with the hydroxyl group of (z) component to synthesize. Can do. The charging ratio (x) / (y) between (x) and (y) is preferably in the range of 0.25 to 0.80. The amount of component (z) to be charged is preferably an amount that contains an equimolar or more hydroxyl group with the isocyanate remaining after component (y) reacts with component (x).

  (C) The mixture ratio of a component is 10-70 mass% in a composition, Preferably it is 20-60 mass%, More preferably, it is 30-50 mass%. (C) When the ratio of a component is less than 10 mass%, the viscosity of a composition will become low too much and workability | operativity will deteriorate or the composition of a semi-hardened state will become easy to tear. Moreover, when more than 70 mass%, the compounding ratio of (A) component and (B) component will decrease too much, and it will become a composition unsuitable for a semi-hardening process.

As the component (C), an acrylate is preferable to a methacrylate from the viewpoint of curability when a semi-cured composition is completely cured under air.
As the component (C), two or more compounds may be used in combination.

4). Component (D) The component (D) of the present invention is a photoradical polymerization initiator, and various compounds can be used as long as they generate a radical upon irradiation with light. As light, ultraviolet light or visible light is used, preferably 200 to 450 nm light, more preferably 250 to 400 nm light, and particularly preferably 300 to 380 nm ultraviolet light. Also, the radiation spectrum of the light irradiated in the two steps can be changed, for example, visible light in the semi-curing process and ultraviolet light in the complete curing process.

  Specific examples of the preferred component (D) include 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184 manufactured by Ciba Specialty Chemicals), 2-hydroxy-2-methyl-1-phenyl-propan-1-one (Darocur 1173 manufactured by Ciba Specialty Chemicals), 2-methyl- [4- (methylthio) phenyl] -2-morpholino-1-propanone (Irgacure 907 manufactured by Ciba Specialty Chemicals), benzyldimethyl ketal (Ciba -Specialty Chemicals Irgacure 651), 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone (Ciba Specialty Chemicals Irgacure 2959), 2-Benzyl-2-dimethyl Amino- -(4-morpholinophenyl) -butanone (Irgacure 369 manufactured by Ciba Specialty Chemicals), diethoxyacetophenone (First Cure DEAP manufactured by First Chemical), oligo [2-hydroxy-2-methyl-1- [4- (1-Methylvinyl) phenyl] propane] (ESACURE KIP150, ESACURE ONE, etc. manufactured by Lamberti), 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] -phenyl } -2-Methyl-propan-1-one (Irgacure 127 manufactured by Ciba Specialty Chemicals), Irgacure 754 manufactured by Ciba Specialty Chemicals, 1- [4- (4-benzoylphenylsulfanyl) phenyl]- 2-methyl -2- (4-methylphenylsulfonyl) propan-1-one (ESACURE 1001M manufactured by Lamberti), benzophenone, 4-phenylbenzophenone, 2,4,6-trimethylbenzophenone, 4-benzoyl-4'-methyl-diphenyl sulfide (SPEMDCURE BMS manufactured by LAMBSON), methylbenzoyl formate (SPEEDCURE MBF manufactured by LAMBSON), 2-isopropylthioxanthone, 2,4-diethylthioxanthone, diphenyl- (2,4,6-trimethylbenzoyl) phosphine oxide (LAMBSON) SPEDCURE TPO), bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (IL from Ciba Specialty Chemicals) Gacure 819), bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide (CGI403 manufactured by Ciba Specialty Chemicals), benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether , Benzoin isobutyl ether, camphorquinone and the like.

(D) The mixture ratio of a component is 0.1-10 mass% in a composition, More preferably, it is 0.5-6 mass%, Most preferably, it is 1-4 mass%. If it is less than 0.1% by mass, the effect of initiating the polymerization is insufficient, and if it exceeds 10% by mass, the physical properties of the cured product are deteriorated and the problem of odor from the decomposition product of the initiator is undesirable.
As the component (D), two or more kinds of compounds may be used in combination.

5. Other components Although the composition of this invention makes the said (A), (B), (C) and (D) component essential, a various compound can be mix | blended as needed.

For the purpose of adjusting the viscosity of the composition and adjusting the physical properties of the cured product, it is possible to incorporate ethylenically unsaturated compounds (hereinafter referred to as other unsaturated compounds) other than the components (A), (B) and (C). It is.
Other unsaturated compounds include (meth) acrylic acid, (meth) acrylate, vinyl ether, N-vinylpyrrolidone and N-vinylcaprolactone, N-alkylacrylamide, and more preferably (meth) acrylate. The blending ratio of other unsaturated compounds is preferably 60% by mass or less in the composition, more preferably 0 to 45% by mass, still more preferably 0 to 30% by mass, and particularly preferably 0 to 15% by mass. is there.

Other unsaturated compounds include compounds having one (meth) acryloyl group (hereinafter referred to as monofunctional (meth) acrylate) and compounds having two (meth) acryloyl groups (hereinafter referred to as bifunctional (meth) acrylate). Said].
Specific examples of monofunctional (meth) acrylates include butyl acrylate, 2-ethylhexyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, methoxyethyl acrylate, tetrahydrofurfuryl acrylate, cyclohexyl acrylate, isobornyl acrylate, Benzyl acrylate, phenyl acrylate, phenoxyethyl acrylate, brominated phenoxyethyl (meth) acrylate, diethylene glycol monophenyl ether acrylate, polyethylene glycol monophenyl ether (meth) acrylate, polyethylene glycol mono (2-ethylhexyl) ether (meth) acrylate, polypropylene Glycol monophenyl ether (meth) acrylate, Uryl (meth) acrylate, (meth) acrylate of alkylene oxide adduct of paracumylphenol, (meth) acrylate of alkylene oxide adduct of phenylphenol, (meth) acrylate of alkylene oxide adduct of nonylphenol, 2-hydroxy-3 -Phenoxypropyl acrylate, N- (2- (meth) acryloyloxyethyl) hexahydrophthalimide, N- (2-acryloyloxyethyl) tetrahydrophthalimide and the like.

  Specific examples of the bifunctional (meth) acrylate include 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, tricyclodecane dimethylol di (meth) acrylate, bisphenol A Di (meth) acrylate of ethylene oxide (0-10 mol) adduct, di (meth) acrylate of ethylene oxide (0-10 mol) adduct of bisphenol F, ethylene oxide (0-10 mol) addition of bisphenol S Di (meth) acrylate of the product, di (meth) acrylate of ethylene oxide (0-10 mol) addition of thiobisphenol, di (meth) acrylate of ethylene oxide (0-10 mol) addition of brominated bisphenol A, Polyethylene glycol di (meth) acrylate Polypropylene glycol di (meth) acrylate, di (meth) acrylate of hydroxypivalic acid neopentyl glycol ester, epoxy (meth) acrylate obtained by adding (meth) acrylic acid to bisphenol A type epoxy resin, bisphenol F type epoxy resin ( Examples include epoxy (meth) acrylate added with (meth) acrylic acid, di (meth) acrylate of polybutadiene having both terminal hydroxyl groups, polyester (meth) acrylate composed of phthalic anhydride, ethylene glycol, and (meth) acrylic acid.

  A sensitizer can be used in combination with the composition of the present invention for the purpose of improving curability and the like. Examples of the sensitizer include diethyl thioxanthone and isopropyl thioxanthone. Although a mixture ratio can be adjusted according to the objective, it is preferable to make it in the range of 0-3 mass% in a composition.

In the composition of the present invention, for the purpose of improving weather resistance, one or more weather resistance improvers selected from ultraviolet absorbers, light stabilizers and antioxidants can be blended.
Examples of the ultraviolet absorber include benzotriazole-based ultraviolet absorbers such as 2- (5-methyl-2-hydroxyphenyl) benzotriazole and 2- (3,5-di-t-amyl-2-hydroxyphenyl) benzotriazole. Agents and the like.
Examples of the light stabilizer include bis (1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate and 2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-n. Hindered amine light stabilizers such as bis (1,2,2,6,6-pentamethyl-4-piperidyl) butylmalonate, and 2,4-di-t-butylphenyl-3,5-di-t- Examples thereof include benzoate light stabilizers such as butyl-4-hydroxybenzoate.
Examples of the antioxidant include hindered phenols such as 2,6-di-t-butylhydroxytoluene and hindered amines such as bis- (2,2,6,6-tetramethylpiperidinyl-4-sebacate). And sulfur-based antioxidants such as dioxyl-3,3′-dithiopropionate.
The blending ratio of the weather resistance improver may be appropriately set according to the purpose, but is preferably in the range of 0 to 3% by mass in the composition.

  The composition of the present invention includes polymers such as polymethyl methacrylate, polystyrene, polyvinyl acetate, polyester and polycarbonate, petroleum resins, hydrogenated petroleum resins, and the like for the purpose of increasing viscosity and improving adhesion to transparent substrates. A tackifier such as rosin ester can be blended. The blending ratio can be appropriately set according to the purpose, but is preferably 60% by mass or less, more preferably 40% by mass or less in the composition.

  In the composition of the present invention, a so-called phosphoric acid (meth) acrylate having a phosphoric acid group for the purpose of improving adhesion when a semi-cured composition is attached to an inorganic base material such as glass or ITO, It is also possible to mix a silane coupling agent. The blending ratio is preferably 5% by mass or less in the composition, but when the mold is made of metal, it is preferably blended to such an extent that the releasability from the mold is not impaired. The following is preferable.

  In the composition of the present invention, inorganic fine particles such as silica and alumina can be blended for the purpose of imparting thixotropy, reducing the cure shrinkage, and improving the hardness of the cured product. The blending ratio can be appropriately set according to the purpose, but is preferably 60% by mass or less in the composition, more preferably 40% by mass or less.

6). Measured value of dynamic viscoelasticity of cured product In the composition of the present invention, a completely cured product, that is, a cured product irradiated with light until the reaction rate hardly changes at room temperature is hard.
Specifically, the storage elastic modulus E ′ of dynamic viscoelasticity measurement at 25 ° C. and 1 Hz of the cured product is in the range of 1 × 10 ⁸ to 1 × 10 ¹⁰ Pa, preferably 1 × 10 ⁹ to 1. The range is × 10 ¹⁰ Pa. More preferably, the temperature at which the ratio of loss elastic modulus E ″ to E ′ (tan δ) (loss tangent, hereinafter simply referred to as tan δ) is 40 ° C. or higher, and more preferably 60 ° C. to It is 140 ° C, particularly preferably 70 ° C to 120 ° C. Those having a storage elastic modulus E ′ at 25 ° C. of 1 Hz of less than 1 × 10 ⁸ Pa are not preferable as a molded product because they easily deform when a force is applied. Referring to the temperature at which tan δ is maximized, this temperature is a temperature that is a measure of the glass transition temperature Tg, and is preferably higher in terms of the heat resistance of the molded product. It may be difficult to control the state.

7). Method for Producing Molded Product Using Mold Transfer as Semi-Curing Process The composition of the present invention is used after being irradiated with light in a state of being sandwiched between a mold having an inverted shape of the molded product and a transparent substrate. At this time, the amount of irradiation is adjusted appropriately to make the composition a semi-cured state having tack.
The semi-cured composition is released from the mold in close contact with the transparent substrate. A sectional view showing an example of the member in this state is shown in FIG. Here, the photocurable composition is in a semi-cured state. This convex part can be affixed to another material, and can also be affixed with the semi-cured composition obtained similarly.
After the projections are attached, the composition is completely cured by irradiation with light again. The affixed portion is in a bonded state, and the composition as a whole becomes a hard cured product, thereby completing a molded product. In this step, since no adhesive is required for bonding the molded product that has been transferred to the mold, the cost can be reduced, and there is no problem that the adhesive drips into the concave portions of the mold.

Here, the form of the mold is not limited, and may be flat or cylindrical.
As the material of the mold, a material in which the (meth) acrylic photocurable composition hardly adheres is preferable. Specific examples include metals such as aluminum and nickel, polyolefins, and cured products of photocurable compositions that have a relatively high crosslink density and do not swell uncured (meth) acrylate-based compositions.

The form of the transparent substrate may be a plate, a sheet, or a film. When the mold is cylindrical, it is preferable to use a film-like transparent substrate.
As a transparent base material, the thing excellent in adhesiveness with the photocurable composition of this invention is preferable. Preferable examples include easy-adhesion-treated PET film, polycarbonate, polymethyl methacrylate, MS resin, triacetyl cellulose, and the like. Polyolefin and glass subjected to surface treatment such as corona treatment can also be used. When glass is used, it is preferable to treat the surface with a silane coupling agent or the like in advance.

FIG. 2 is a cross-sectional view of a component having fine tubular voids formed inside by bonding the convex surfaces of the component shown in FIG. 1 and irradiating light again to completely cure and bond the composition. The fine tube thus obtained can be filled with a liquid by capillary action or the like.
Various liquids can be used, and functional liquid molecules, functional substance solutions and dispersions, and the like can also be used.
Specifically, liquid crystal molecules, dye solutions, pigment dispersions, luminescent substance solutions, colloidal solutions of gold, platinum, palladium and other metal ultrafine particles, photocatalytic titanium oxide and other metal oxide ultrafine particles Various liquids such as a solution of the above, a solution of metal chalcogenide ultrafine particles such as zinc sulfide, and a solution of metal complex can be exemplified.
In the case of a solution or dispersion, when the solvent or dispersion medium is evaporated, a functional substance is left in the microtubule. In the case of a metal complex solution, it is possible to irradiate light to cause photoreduction inside the microtubule to deposit metal, or to coat the inner wall. Further, the inner wall of the fine tube may be coated by a silver mirror reaction with a solution of ammoniacal silver nitrate and reducing sugar or the like. Here, a substance that promotes metal deposition may be previously dispersed in the photocurable composition of the present invention. For example, fine particles such as palladium may be added to the photocurable composition in advance, and the inner wall of the fine tube may be coated with a metal by impregnating the fine tube with an electroless nickel plating solution. When the inner wall of the microtube is coated with metal and the light is totally reflected, an optical waveguide is given as an application example. Here, the shape of the inner wall of the fine tube may not be smooth, and may have a finer pattern shape than the fine tube. Various gases can be circulated through the microtube. Various shapes of the fine tube are possible, and not only a linear shape but also a branched shape or a specific pattern can be given. Further, linear patterns may be orthogonally bonded to form a lattice, or closed holes may be used. Thus, it becomes possible to create molded products having various fine shapes by allowing the portion in contact with the mold, that is, the convex portion of the composition, to be attached.

When the convex portion of the composition having a specific shape is in a semi-cured state, various materials can be attached to the convex portion. After pasting, if the light is irradiated again from the transparent substrate side and completely cured, the pasted material is adhered to the convex portion. If a black material is used as a material to be pasted, a black matrix for a liquid crystal display can be manufactured.
FIG. 3 shows that after a black material is pasted on the convex surface of the component shown in FIG. 1, the composition is cured by light irradiation again to form a black matrix, and then the red, green, It is sectional drawing of the color filter which gave blue printing. A completely cured composition is hard at room temperature, so that it does not deform even when a slight force is applied, and is suitable for such applications.

If a conductive material such as fine metal particles or ITO is used instead of the black material in FIG. 3, an electronic circuit can be created by transferring the shape of the mold. For example, in the case of ITO, a transparent circuit can be created without performing etching.
The molded product in the present invention includes such a part having a specific fine pattern on the surface or inside.

Various light sources can be used as the light source irradiated to the composition of the present invention, but those containing light having a wavelength of 200 to 450 nm are preferable. Suitable light sources include high pressure mercury lamps, metal halide lamps, UV electrodeless lamps (for example, H bulbs manufactured by Fusion), LEDs that emit ultraviolet rays, and the like. The LED can be suitably used in a semi-curing process where it is necessary to control irradiation intensity and irradiation amount.
Moreover, the wavelength distribution of the light irradiated in two processes can also be changed, for example, 350-400 nm in a semi-curing process and 250-400 nm in a complete curing process. Examples of the method for changing the wavelength distribution include a method for changing a light source and a method for attaching a wavelength selection filter to a light irradiation device in a semi-curing process, for example.

According to the composition of the present invention, in the production of a molded product by mold transfer using a photocurable composition, the surface in contact with the mold can be released in a semi-cured state, and the mold release property is also excellent. Further, the semi-cured product has a uniform and good tack over the entire surface in contact with the mold. Further, the cured product of the composition of the present invention has a hardness capable of maintaining the shape even when a slight force is applied. Therefore, it becomes possible to create a new member having a structure in which the convex portion of the molded product is attached.
In addition, the composition of the present invention makes it possible to produce a member conventionally made by utilizing development or etching by mold transfer, thereby leading to cost reduction.

This invention is a composition which consists of said (A)-(D) component, Comprising: In composition, (A) is 10-80 mass%, (B) is 3-30 mass%, (C) 10 to 70 mass% and 0.1 to 10 mass% of (D) are contained, and the storage elastic modulus E ′ of dynamic viscoelasticity measurement at 25 ° C. and 1 Hz of the cured product is 1 × 10 ⁸ to 1 × 10 ¹⁰ Pa. The present invention relates to a photocurable composition for producing a molded product in which a mold transfer within the range is a semi-curing step.
Preferred embodiments include the following (1) to (3).
(1) The preferred compounds described above are used as the components (A) to (D).
(2) The components (A) to (D) are used in the preferred proportions described above.
(3) As the components (A) to (D), the above-described preferable compounds are used, and are used in the above-described preferable ratio.
The composition of the present invention can be used for manufacturing a molded product in which mold transfer is a semi-curing process. As a preferable production method, the composition is irradiated with light in a state of being sandwiched between a mold having an inverted shape of a molded product and a transparent base material to be in a semi-cured state, and released from the mold in a state of being in close contact with the transparent base material. There is a method in which the material is affixed to the material and irradiated with light again to be completely cured.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited to these examples.

<Synthesis Example 1>
A 2 L separable flask was charged with 333 g of isophorone diisocyanate, 0.53 g of 2,6-di-t-butyl-p-cresol and 0.53 g of di-n-butyltin dilaurate, and the mixture was stirred and heated in advance. Then, 500 g of polytetramethylene glycol having a number average molecular weight of 1000, which had been melted, was dropped by a dropping funnel. After completion of the dropwise addition, the mixture was reacted at 60 ° C. for 2 hours, and then 232 g of 2-hydroxyethyl acrylate was dropped from the dropping funnel.
After completion of dropping, the reaction was carried out at 70 ° C. for 2 hours to obtain urethane acrylate corresponding to the component (C) of the present invention. This is denoted as UA-1.

<Examples 1 to 7, Comparative Examples 1 to 5>
Preparation of composition The photocurable composition was prepared by stirring and mixing the components shown in Tables 1 and 2 according to a conventional method. In addition, the numerical value of the compounding composition in a table | surface represents the mass%, and the symbol of a component represents the following compounds. Moreover, the molecular weight was described about (A) component, and the acrylic equivalent was described about (B) component.

● (A) component ・ THFMA: Tetrahydrofurfuryl methacrylate, molecular weight 170 [Acrylate THF manufactured by Mitsubishi Rayon Co., Ltd.]
-IBXMA: isobornyl methacrylate, molecular weight 222 [Kyoeisha Chemical Co., Ltd. light ester IB-X]
BzMA: benzyl methacrylate, molecular weight 176 [Acrylic ester BZ manufactured by Mitsubishi Rayon Co., Ltd.]
POMA: Phenoxyethyl methacrylate, molecular weight 206 [Kyoeisha Chemical Co., Ltd. light ester PO]

Component (B) M402: Dipentaerythritol penta- and hexaacrylate, acrylic equivalent of about 10.1 meq / g [Aronix M-402 manufactured by Toagosei Co., Ltd.]
M305: pentaerythritol tri- and tetraacrylate, acrylic equivalent of about 10.6 meq / g [Aronix M-305 manufactured by Toagosei Co., Ltd.]

● (C) component UA-1: urethane acrylate of Synthesis Example 1

● Component (D) I-184: 1-hydroxy-cyclohexyl-phenyl-ketone [Irgacure 184 manufactured by Ciba Specialty Chemicals Co., Ltd.]

● Other components ・ M211B: Diacrylate of about 4 mol of bisphenol A ethylene oxide adduct [Aronix M-211B manufactured by Toagosei Co., Ltd.]
POA: Phenoxyethyl acrylate [Kyoeisha Chemical Co., Ltd. light acrylate POA]
M120: diethylene glycol mono (2-ethylhexyl) ether acrylate [Aronix M-120 manufactured by Toagosei Co., Ltd.]

O Evaluation About the obtained composition, the mold release property from the mold | die (here an aluminum plate is used) in a semi-hardened state, and the dynamic viscoelasticity of hardened | cured material were evaluated in accordance with the following method. The results are shown in Tables 1 and 2.

● Semi-curing experiment 0.1mm thick tape is pasted around a 7cm * 15cm aluminum plate to form a frame, and the composition is put in it, on which an easy-adhesion treated PET film [Cosmo Shine manufactured by Toyobo Co., Ltd.] A4300] was laminated. Next, the mixture was passed through a conveyor type ultraviolet irradiation device and irradiated with ultraviolet rays. The ultraviolet irradiation conditions are a 160 W / cm high-pressure mercury lamp, a lamp height of 10 cm, a conveyor speed of 10 m / min (1 pass 600 mJ / cm ² ) or 20 m / min (1 pass 300 mJ / cm ² ).
This was repeated several times, and the state of the cured film at the irradiation energy shown in Tables 1 and 2 was confirmed by pressing against the rubber sheet. The state of the semi-cured film was evaluated in the following four stages. In the case where the semi-cured state varies depending on the location even with the same irradiation amount, all the states are described.
1: Liquid 2: Semi-cured state in which liquid oozes out to rubber sheet 3: Semi-cured state in which liquid is not oozed out with tack (good adhesive coating film)
4: Hardened state without tack

The semi-curability was evaluated as follows.
◯: When a good pressure-sensitive adhesive coating film (semi-cured film state 3) is obtained at two or more doses in Tables 1 and 2, and there is no non-uniformity of the semi-cured state depending on the location.
Δ: When a good pressure-sensitive adhesive coating film (state 3) is obtained at the one-step irradiation amount in Tables 1 and 2, and there is no non-uniformity in the semi-cured state depending on the location.
X: When a good adhesive coating film (state 3) cannot be obtained in the entire location, that is, when nonuniformity occurs depending on the location, or curing is too fast to obtain a good adhesive coating film (state 3). If.

The releasability from the mold was evaluated in the following two stages.
○: In a semi-cured state, when the composition is transferred to the easy-adhesion treated PET without breaking.
X: When the composition is broken and partially remains on the aluminum side in the semi-cured state.

● Measurement of dynamic viscoelasticity of cured product A 1 mm thick rubber sheet with a 5 mm * 50 mm rectangular hole is attached to a 50 μm thick untreated surface PET film to form a frame, which is placed on a glass plate, The composition was put in this frame, and a PET film having an untreated surface was laminated from above. A glass plate is further placed on this, sandwiched between clips, and cured by irradiating UV with a 130 mW / cm ² high-pressure mercury lamp for 30 seconds each on the front and back, then the glass and PET film are removed, and UV is additionally applied for 2 minutes on each side. Irradiated.
The dynamic viscoelastic spectrum of the cured product was measured with a DMS-6100 manufactured by Seiko Instruments Inc. at a frequency of 1 Hz in a range of −50 ° C. to 200 ° C. Tables 1 and 2 list the storage elastic modulus E ′ (Pa) at 25 ° C. and the temperature at which tan δ is maximized.

From the results of Tables 1 and 2, the composition of the present invention was excellent in semi-curing property and excellent in mold release property in a semi-cured state.
On the other hand, the compositions of Comparative Examples 1 and 2 that do not contain the component (B) and the compositions of Comparative Examples 4 and 5 in which the proportion of the component (B) is outside the scope of the present invention are semi-curable. It was inferior to.
Comparative Example 3 was excellent in the semi-curing property and the releasability from the mold in the semi-cured state even without the component (B). Compared to the above composition, the composition is as soft as about 1/100, and is not suitable when it is required to maintain the shape even when a slight load is applied.

  The photocurable composition of the present invention can be used for the production of molded articles, and more specifically, can be preferably used for the production of optical articles, display materials, electronic parts and the like.

Sectional drawing of the component of the state which released the composition as a semi-hardened state, when transferring a mold shape to a transparent base material using a photocurable composition. FIG. 2 is a cross-sectional view of a component having a fine tube inside, which is prepared by bonding the convex surfaces of the component shown in FIG. 1 and irradiating light again to completely cure and bond the composition. After a black material is pasted on the convex surface of the component shown in FIG. 1, light irradiation is performed again to completely cure and bond the composition to form a black matrix, and then red, green, and blue printing is performed on the concave portion by an inkjet method or the like. Sectional drawing of the applied color filter.

Explanation of symbols

11 Photocurable composition 12 Transparent substrate 23 Fine tube 31 Black matrix 32 Red portion of color filter 33 Green portion of color filter 34 Blue portion of color filter

Claims (1)

Compound (A) having one methacryloyl group having a molecular weight of 250 or less, Compound (B) having three or more (meth) acryloyl groups in one molecule and a (meth) acryloyl group equivalent of 4 meq / g or more, A composition comprising a urethane (meth) acrylate (C) having two (meth) acryloyl groups in one molecule and a radical photopolymerization initiator (D), wherein (A) is 10 to 10 in the composition. 80% by mass, 3 to 30% by mass of (B), 10 to 70% by mass of (C) and 0.1 to 10% by mass of (D), the dynamic viscoelasticity of the cured product at 25 ° C. and 1 Hz A photocurable composition for producing a molded product having mold transfer as a semi-curing step, wherein the measured storage elastic modulus E ′ is in the range of 1 × 10 ⁸ to 1 × 10 ¹⁰ Pa.

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