JP2011016894A - Electrode coating photocurable composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode coating photocurable composition excellent in electric insulation, particularly in ion migration resistance and providing a cured product whose surface has low tackiness.SOLUTION: The electrode coating photocurable composition comprises: a urethane (meth)acrylate oligomer (A) having terminal (meth)acryloyl groups obtained by reacting a diisocyanate compound (a), a polyester diol (b) having a hydroxyl value of 28-225 mgKOH/g, and a hydroxy group-containing (meth)acrylate (c); a compound (B) having an ≥8C alkyl group or an ≥8C cycloalkyl group and a (meth)acryloyl group in a molecule; a compound (C) having two or more (meth)acryloyl groups in a molecule, other than the component (A); and a photopolymerization initiator (D).

Description

The present invention relates to a photocurable composition for electrode coating, and belongs to a technique for photocurable composition and electrode coating application.
In the present specification, (meth) acrylate means acrylate or (meth) acrylate, and (meth) acryloyl group means acryloyl group or methacryloyl group.

In recent electronic materials, as the performance of devices increases, physical properties such as electrical insulation and moisture resistance may be required for the materials used therefor.
Specifically, electrode terminals used in various applications are required to have electrical insulation, and more specifically, ion migration resistance may be required. In particular, wiring terminals such as flexible printed wiring boards and tape carrier packages are connected to the electrode terminals of the plasma display panel, but high voltage is applied between the terminals, so that ion migration resistance is required. There are many.
Here, ion migration refers to a phenomenon in which an electrode metal to which a voltage is applied moves and precipitates inside and on the surface of an insulating material in a system in contact with the insulating material. As ion migration progresses, it leads to failure of electronic components.

On the other hand, since the photocurable composition is solvent-free, it does not release solvents or the like into the environment, has a low environmental impact, and can be manufactured with low energy because there is no need for heating. Since it is fast-curing, the manufacturing cost can be reduced, so that its application in various fields has been spreading.
The photocurable composition is also used for the purpose of preventing ion migration.
For example, a photocurable moisture-proof insulating coating composition (Patent Document 1) containing urethane (meth) acrylate using polyolefin polyol as a raw material is known.

As physical properties required for the electrode-covering photocurable composition, in addition to ion migration resistance, low tackiness that the surface of the cured product has almost no tack (tack) may be required. When there is a tack on the surface of the cured product, there is a problem that fine dust in the air adheres and the appearance deteriorates, and in the worst case, there is a risk of short circuit due to the attached dust.
In the composition described in Patent Document 1, for the purpose of reducing the tack on the surface of the cured product, a photopolymerizable monomer having an ethylenically unsaturated double bond of 5 to 10 in the molecule (dipentaerythritol hexaacrylate, etc. ) Is used.
However, when the addition ratio becomes high, the adhesiveness of the cured product to the substrate decreases, and the reliability deteriorates. Moreover, in the compounding composition using the photopolymerizable monomer which has 4 or less ethylenically unsaturated double bonds in a molecule | numerator, the hardened | cured material with little surface tack is not obtained.

JP 2008-280414 A

  An object of this invention is to provide the photocurable composition for electrode coating | cover which is excellent in electrical insulation, especially ion migration resistance, and the cured | curing material surface has low tack property.

As a result of various studies, the present inventors have found that a composition containing a specific urethane (meth) acrylate, an alkyl (meth) acrylate having a specific carbon number, and a polyfunctional (meth) acrylate is excellent in electrical insulation, It discovered that the hardened | cured material surface has low tack property, and completed this invention.
Hereinafter, the present invention will be described in detail.

  According to the composition of this invention, it is excellent in electrical insulation, especially ion migration resistance, and the cured | curing material surface has low tack property.

The present invention provides a (meth) acryloyl group at the end obtained by reacting a diisocyanate compound (a), a polyester diol (b) having a hydroxyl value of 28 to 225 mgKOH / g, and a hydroxyl group-containing (meth) acrylate (c). Urethane (meth) acrylate oligomer (A) [hereinafter referred to as component (A)] having an alkyl group having 8 or more carbon atoms or a cycloalkyl group having 8 or more carbon atoms and one (meth) acryloyl group in the molecule Compound (B) [hereinafter referred to as component (B)], compound having two or more (meth) acryloyl groups in the molecule, and compound (C) other than component (A) [hereinafter referred to as component (C)] and The present invention relates to a photocurable composition for electrode coating containing a photopolymerization initiator (D) [hereinafter referred to as component (D)].
Hereinafter, each component will be described.

1. Component (A) Component (A) is composed of diisocyanate compound (a) [hereinafter referred to as compound (a)], polyester diol (b) [hereinafter referred to as compound (b)] having a hydroxyl value of 28 to 225 mg KOH / g, and It is a urethane (meth) acrylate oligomer having a (meth) acryloyl group at the terminal obtained by reacting a hydroxyl group-containing (meth) acrylate (c) [hereinafter referred to as compound (c)].
(A) As a mixture ratio of a component, 1 to 50 weight% is preferable in a composition, More preferably, it is 1 to 20 weight%.
By making this ratio 1% by weight or more, the flexibility of the cured product can be increased, while by making it 50% by weight or less, handling properties such as coating properties of the composition can be facilitated. it can.
Hereinafter, the compounds (a) to (c), which are the raw material compounds of the component (A), will be described, and the production method of the component (A) will be described.

1-1. Compound (a)
As the compound (a), various compounds can be used as long as they have two isocyanate groups in one molecule. Specifically, tolylene diisocyanate, hydrogenated tolylene diisocyanate, diphenylmethane diisocyanate, water Examples thereof include hydrogenated diphenylmethane diisocyanate, tolidine diisocyanate, naphthalene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, and hydrogenated xylylene diisocyanate.

1-2. Compound (b)
The compound (b) is obtained by esterifying a dicarboxylic acid and a diol.

  Various compounds can be used as the dicarboxylic acid, such as adipic acid, sebacic acid, succinic acid, phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, maleic acid, maleic anhydride, itaconic acid and dimer acid. Etc.

  Various compounds can be used as the diol, such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, 1,4-butanediol, 1,6-hexanediol, 1,9-nonanediol, 3- Examples include methyl-1,5-pentanediol, ethylene oxide or propylene oxide adduct of bisphenol A, and dimer diol.

The hydroxyl value of the compound (b) needs to be 28 to 225 mgKOH / g, preferably 37 to 115 mgKOH / g.
By setting this value to 28 mgKOH / g or more, the strength of the cured product can be made sufficient, and by setting it to 225 mgKOH / g or less, the cured product can be made excellent in flexibility.

1-3. Compound (c)
As the compound (c), various compounds can be used as long as they are (meth) acrylates having a hydroxyl group, such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and butanediol mono (meta). ) Acrylate, 2-hydroxyethyl (meth) acrylate modified with caprolactone, glycidol di (meth) acrylate, and the like.
Among these, hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and butanediol mono (meth) acrylate are preferable.

1-4. (A) Component Production Method Component (A) is a compound obtained by reacting the aforementioned compounds (a), (b) and (c).
(A) As a manufacturing method of a component, what is necessary is just to follow a conventional method, the method of making compound (a), (b), and (c) react, and reacting compound (a) and compound (b), and a terminal isocyanate oligomer A method of reacting the isocyanate group of the compound with the hydroxyl group of the compound (c), a method of adding the compound (a) to the mixed liquid obtained by mixing the compound (b) and the compound (c), and the like. Can be mentioned.
(A) In manufacture of a component, you may implement in the photopolymerizable compound other than these, (B) and (C) component mix | blended with a composition.
The obtained component (A) may be dissolved using the components (B) and (C) blended in the composition or a photopolymerizable compound other than these.

  In the production of the component (A), as a chain extender, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, 1,4-butanediol, 1,6-hexanediol, 1,9-nonanediol , 3-methyl-1,5-pentanediol, ethylene oxide or propylene oxide adduct of bisphenol A, dimer diol, and the like may be used.

  The molecular weight of component (A) is preferably 10,000 to 100,000 in terms of weight average molecular weight.

In the present invention, as the reaction ratio of the compounds (a) to (c), the isocyanate group equivalent number (p) of the compound (a) and the total hydroxyl equivalent number (q) of the compound (b) and the compound (c) As an equivalent ratio, (p) :( q) is preferably 0.8 to 1.0: 1.0, more preferably 0.9 to 1.0: 1.0.
Similarly, when using a chain extender, the equivalent ratio of the isocyanate group equivalent number (p) of the compound (a) and the total hydroxyl equivalent number (q) of the compound (b), the compound (c) and the chain extender , (P) :( q) is preferably 0.8 to 1.0: 1.0, more preferably 0.9 to 1.0: 1.0.
By making the isocyanate group equivalent number (p) with respect to 1 equivalent of the number of hydroxyl equivalents (q) 0.8 or more, the insulation reliability can be made excellent, and by making it 1 or less, the photocurability is excellent. It can be.

As the component (A), a tin catalyst used in a conventional urethanization reaction can also be used.
However, in the present invention, since the metal component derived from the catalyst is reduced in the component (A) to be obtained, and the insulation reliability of the composition becomes superior, the component (A) is used as a urethanization catalyst. The following metal is preferably produced using a metal compound represented by the following general formula (1) as a catalyst.
M (X) _n (1)
[In Formula (1), M represents Fe or Zn, X is the same or different and represents a β-diketone, a halogen atom, an acyloxy group, or an alkoxy group, and n represents an integer of 2 or 3. ]
Since these metal compounds have excellent activity with respect to conventional tin catalysts, the desired component (A) can be produced with a small amount of use.

M represents Fe or Zn, and Fe is preferable in that it is superior in catalytic activity.
Examples of the β-diketone represented by X include acetylacetone, 2,4-hexanedione, 3,5-heptanedione, 2-methylhexane-3,5-dione, and 6-methylheptane-2,4-dione. 2,6-dimethylheptane-3,5-dione, 4,6-nonanedione, 2,8-dimethylnonane-4,6-dione, 2,2,6,6-tetramethylheptane-3,5-dione , Tridecane-6,8-dione, methyl acetoacetate, ethyl acetoacetate, isopropyl acetoacetate, tert-butyl acetoacetate, methyl propionyl acetate, ethyl propionyl acetate, isopropyl propionyl acetate, propionyl tert-butyl and hexafluoroacetylacetone Among these, acetylacetone is inexpensive and urethanized The preferred because it is excellent in the activity of the response.
Examples of the halogen atom represented by X include a chlorine atom and a bromine atom, and a chlorine atom is preferable.
As the acyloxy group represented by X, for example, an acyloxy group having 3 to 20 carbon atoms is preferable. Specifically, a pentanoyl group, a hexanoyl group, a 2-ethylhexanoyl group, an octanoyl group, a nonanoyl group, a decanoyl group, A dodecanoyl group, an octadecanoyl group, etc. are mentioned.
As the alkoxy group represented by X, for example, an alkoxy group having 1 to 10 carbon atoms is preferable, and examples thereof include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, a butoxy group, and a 2-ethylhexyloxy group. be able to.
X may be any one of the above, or a combination of two or more.
Among these, X is preferably acetylacetone, hexafluoroacetylacetone or a halogen atom, and acetylacetone is more preferred from the viewpoint of excellent solubility in a reaction solution or a composition.

Among these, an iron β-diketone complex represented by the following formula (2) is preferable because it is particularly excellent in the reactivity of the urethanization reaction.
Fe (X ′) ₃ (2)
[In Formula (2), X ′ represents a β-diketone. ]
As the β-diketone represented by X ′, the β-diketone represented by the above X can be selected.

  N representing the number of X is an integer of 2 or 3, and since production stability is good, n is 3 when M is Fe, and n is 3 when M is Zn.

  As specific examples of the metal compound, when X is a β-diketone, for example, tris (acetylacetonato) iron, tris (2,2,6,6-tetramethyl-3,5-heptanedionate) iron , Tris (tetrafluoroacetylacetonate) iron, bis (acetylacetonato) iron, bis (2,2,6,6-tetramethyl-3,5-heptanedionate) zinc, bis (tetrafluoroacetylacetonate) Zinc etc. are mentioned. When X is a halogen atom, for example, ferric chloride and zinc chloride are exemplified. When X is an acyloxy group, for example, tris (2-ethylhexanoic acid) iron, iron naphthenate, bis (2-ethylhexanoic acid) zinc, zinc naphthenate and the like can be mentioned. When X is an alkoxy group, for example, triethoxy iron, triisopropoxy iron, diethoxy zinc, diisopropoxy zinc and the like can be mentioned.

  Among these, those in which M is Fe and n is 3 are more preferable because of excellent catalytic activity of the urethanization reaction. Specific examples include tris (acetylacetonato) iron and ferric chloride. Tris (acetylacetonato) iron represented by the formula (2) is particularly preferable because of its excellent catalytic activity.

The component (A) can be produced by urethanizing the compounds (a), (b) and (c) by heating and stirring in the presence of the metal compound and, if necessary, in the presence of a reaction solvent.
In this case, the compounds (a), (b) and (c) can be charged and reacted together (hereinafter referred to as “one-step reaction”), and the compounds (a) and (b) are reacted to form an isocyanate group. After producing the containing prepolymer, the compound (c) can also be added (hereinafter referred to as “two-stage reaction”).
The ratio of the compounds (a), (b) and (c) is as described above.

In addition, since reaction mixture will become high viscosity and stirring may become difficult when the molecular weight of (A) component produced | generated by this reaction becomes high, a reaction solvent can also be mix | blended in a reaction component.
The reaction solvent is preferably one that does not participate in the urethanization reaction, and examples thereof include aromatic compounds such as toluene and xylene, and organic solvents such as dimethylformamide.
The amount of the organic solvent to be used may be appropriately set according to the viscosity of the component (A), but is preferably set to be 0 to 70% by weight in the reaction solution.
Here, the reaction solution means the total amount of the raw material compound when only the raw material compound is used, and means the total amount including these when the reaction solvent or the like is used in addition to the raw material compound. Specifically, it is used to mean a solution in which the compounds (a), (b), (c) and a reaction solvent used as necessary are combined. same as below.

As the reaction solvent, together with the organic solvent or in place of the organic solvent, the component (B), the component (C) and other photopolymerizable compounds used as components of the composition (collectively referred to as curable components) Can also be blended. When the urethane (meth) acrylate obtained is mixed with a curable component and the resulting urethane (meth) acrylate is mixed with the curable composition, the composition is applied and then dried, unlike when the organic solvent is mixed. This is preferable because it is not necessary.
What is necessary is just to set suitably the compounding quantity in the case of mix | blending a sclerosing | hardenable component with a reaction component according to the ratio of the sclerosing | hardenable component finally mix | blended with a composition, For example, 10 to 70 weight% in a reaction solution, Furthermore, it is preferable to set so that it may become 10 to 50 weight%.

  The compounding amount of the metal compound may be a catalytic amount, for example, 0.01 to 1,000 wtppm is preferable with respect to the reaction solution, and more preferably 0.1 to 1,000 wtppm. When the compounding amount of the metal compound is 0.01 wtppm or more, the urethanization reaction can be preferably progressed, and when it is 1,000 wtppm or less, coloring of the obtained component (A) can be suppressed. .

  In the case of a one-stage reaction, the metal compound can be added when the polyol, the organic polyisocyanate and the hydroxyl group-containing (meth) acrylate are charged, and in the case of a two-stage reaction, the metal compound can be added when the polyol and the organic polyisocyanate are charged.

  In the urethanization reaction, a small amount of a chain extender may be blended for the purpose of adjusting the molecular weight. As the chain extender, those usually used in the urethanization reaction can be used, and the same as the above-described low molecular weight polyol can be exemplified.

In the urethanization reaction, a polymerization inhibitor is preferably used for the purpose of preventing the polymerization of the (meth) acryloyl group of the raw material or product, and oxygen-containing gas may be introduced into the reaction solution.
Examples of the polymerization inhibitor include hydroquinone, tert-butyl hydroquinone, hydroquinone monomethyl ether, 2,6-di-tert-butyl-4-methylphenol, 2,4,6-tri-tert-butylphenol, benzoquinone, phenothiazine and the like. Organic polymerization inhibitors, inorganic polymerization inhibitors such as copper chloride and copper sulfate, and organic salt polymerization inhibitors such as copper dibutyldithiocarbamate. A polymerization inhibitor may be used individually by 1 type, or may be used in combination of 2 or more types arbitrarily. As a ratio of a polymerization inhibitor, 5-20,000 wtppm is preferable in a reaction liquid, More preferably, it is 25-3,000 wtppm.
Examples of the oxygen-containing gas include air, a mixed gas of oxygen and nitrogen, a mixed gas of oxygen and helium, and the like.

  The reaction temperature may be appropriately set according to the raw materials used and the structure and molecular weight of the intended component (A), but is preferably 10 to 150 ° C, more preferably 30 to 120 ° C. The reaction time may be appropriately set according to the raw material to be used and the structure and molecular weight of the target component (A), but is usually preferably 1 to 70 hours, and more preferably 2 to 30 hours.

2. (B) Component The composition of the present invention comprises a compound having an alkyl group having 8 or more carbon atoms or a cycloalkyl group having 8 or more carbon atoms and one (meth) acryloyl group in the molecule of component (B) [hereinafter, Monofunctional (meth) acrylate]] as an essential component.
In this invention, insulation reliability is improved by containing (B) component.
Specific examples of the component (B) include monofunctional (meth) acrylates having an alkyl group having 8 or more carbon atoms such as 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, and stearyl (meth) acrylate. It is done. Examples of the monofunctional (meth) acrylate having a cycloalkyl group having 8 or more carbon atoms include isobornyl (meth) acrylate. The alkyl group having 8 or more carbon atoms may be a compound in which an alkyl group is bonded to an aromatic ring, and specific examples include nonylphenoxyethyl (meth) acrylate and the like.
(B) As a mixture ratio of a component, 10 to 97 weight% is preferable in a composition, More preferably, it is 30 to 90 weight%.
By making this proportion 10% by weight or more, the insulation reliability can be improved, while by making it 97% by weight or less, the strength of the cured product can be made sufficient.

3. Component (C) The component (C) is a compound having two or more (meth) acryloyl groups in the molecule. However, it is a compound excluding the component (A).
The composition of this invention can reduce the adhesiveness of the cured | curing material surface by including (C) component as an essential component.

  Component (C) includes ethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, and alkylene glycol di (meth) acrylate such as propylene glycol di (meth) acrylate and tripropylene glycol di (meth) acrylate. Glycol di (meth) acrylates such as 1,6-hexanediol di (meth) acrylate and neopentyl glycol di (meth) acrylate; bisphenol A di (meth) acrylate or its halogen aromatic nucleus substitution and bisphenol F di (meta) ) Bisphenol type di (meth) acrylate such as acrylate or its halogen aromatic nucleus substitution; dimethylol tricyclodecane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, Polyol poly (meth) acrylates such as trimethylolpropane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate and dipentaerythritol hexa (meth) acrylate; Poly (meth) acrylate; and di- or tri (meth) acrylate of isocyanuric acid alkylene oxide.

Among these compounds, the component (C) is preferably a compound having 2 or more and 4 or less (meth) acryloyl groups in the molecule so as not to lower the adhesion of the cured product to the substrate.
Examples of the compound include those mentioned above, and preferred examples include bisphenol A di (meth) acrylate or a halogen aromatic nucleus substitute thereof and bisphenol F di (meth) acrylate or a halogen aromatic nucleus substitute thereof. Bisphenol-type di (meth) acrylate; trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, polyol poly (meth) acrylate of pentaerythritol tetra (meth) acrylate; and poly (alkylene oxide adduct of the polyol) (Meth) acrylate etc. are mentioned.
Further, among these, pentaerythritol tetraacrylate and bisphenol A ethylene oxide-modified diacrylate are particularly preferable because the adhesiveness of the cured product surface is effectively reduced.

(C) As a mixture ratio of a component, 1-30 weight% is preferable in a composition, More preferably, it is 1-20 weight%.
By making this ratio 1% by weight or more, the tackiness of the surface of the cured product can be reduced. On the other hand, by making it 30% by weight or less, a cured product having flexibility can be obtained.

4). (D) Component The composition of the present invention is used after being cured by irradiation with light such as ultraviolet rays or visible light, and is blended with a photopolymerization initiator which is the (D) component.
The component (D) may be a compound usually used in a photocurable composition, and specifically, 1-hydroxycyclohexyl phenyl ketone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl). ) -Butanone-1,2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propane- 1-one, 2,2-dimethoxy-1,2-diphenylethane-1-one, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2, 4,4-trimethyl - pentyl phosphine oxide, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one and bis (eta ⁵ -2 4- cyclopentadien-1-yl) - bis (2,6-difluoro-3-(1H-pyrrol-1-yl) - phenyl) titanium, and the like.
(D) A component may be used independently or may be used in combination of 2 or more types.

  (D) As a component, the compound which does not contain phosphorus element or sulfur element is preferable, and specifically, 1-hydroxycyclohexyl phenyl ketone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl)- Butanone-1,2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propane-1- ON and 2,2-dimethoxy-1,2-diphenylethane-1-one and the like.

Among these, α-aminoalkylphenone photopolymerization initiators are more preferable because the cured product has a low tack.
As the α-aminoalkylphenone photopolymerization initiator, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one (as a commercially available product, Irgacure 907 manufactured by Ciba Japan) The following brackets are the same), 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one (Irgacure 369), 2-dimethylamino-2- (4-methyl -Benzyl) -1- (4-morpholino-4-yl-phenyl) -butan-1-one (Irgacure 379) and the like.

(D) As a mixture ratio of a component, it is preferable that it is 1 to 10 weight% in a composition, and 3 to 7 weight% is more preferable.
By making this proportion 1% by weight or more, the tackiness of the cured product surface can be reduced, and by making it 10% by weight or less, the strength of the resulting cured product can be increased.

5. Other components Although the composition of this invention makes the said (A)-(D) component essential, a various component can be mix | blended as needed.
Specifically, photopolymerizable compounds (hereinafter, referred to as (E) component), thermal polymerization initiators (hereinafter referred to as (F) component), (A) to (C) components other than silane coupling agents (hereinafter referred to as (E) component). Other examples include photopolymerizable compounds), polymerization inhibitors, antioxidants, antifoaming agents, leveling agents, ultraviolet absorbers, pigments, and the like. Besides these, known and conventional ones can also be added.

In this invention, since the composition can be made excellent in the adhesiveness with respect to glass by mix | blending the silane coupling agent of (E) component, it is preferable.
As the component (E), a silane compound having an unsaturated double bond is preferable. Specifically, vinyltrimethoxysilane, vinyltriethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxy Silane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane and the like can be mentioned.
(E) A component may be used independently or may be used in combination of 2 or more types.

(E) As a compounding ratio of a component, 10 weight% or less is preferable in a composition, More preferably, it is 0.1 to 5 weight%.
By making this proportion 10% by weight or less, the insulation reliability can be improved. Furthermore, the adhesiveness with respect to the glass after a thermal shock test can be improved by setting it as 0.1 weight% or more.

Although the present invention exhibits the above-described excellent effects, the curability may be insufficient when the film thickness is large or where light is difficult to reach. In this case, it is preferable to add a thermal polymerization initiator of the component (F) because excellent curability can be exhibited even in such a case.
As the component (F), various compounds can be used, and organic peroxides and azo initiators are preferable.

As the organic peroxide, a compound having a 10-hour half-life temperature of 100 ° C. or more is preferable because of excellent storage stability of the composition.
Specific examples of the organic peroxide include 1,1-bis (t-butylperoxy) 2-methylcyclohexane, 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane, , 1-bis (t-hexylperoxy) cyclohexane, 1,1-bis (10t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclohexane, , 2-bis (4,4-di-butylperoxycyclohexyl) propane, 1,1-bis (t-butylperoxy) cyclododecane, t-hexylperoxyisopropyl monocarbonate, t-butylperoxymaleic acid, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, 2,5-dimethyl 2,5-di (m-toluoylperoxy) hexane, t-butylperoxyisopropyl monocarbonate, t-butylperoxy 2-ethylhexyl monocarbonate, t-hexylperoxybenzoate, 2,5-dimethyl-2, 5-di (benzoylperoxy) hexane, t-butylperoxyacetate, 2,2-bis (t-butylperoxy) butane, t-butylperoxybenzoate, n-butyl-4,4-bis (t- Butylperoxy) valerate, di-t-butylperoxyisophthalate, α, α′-bis (t-butylperoxy) diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl-2,5-di (t -Butylperoxy) hexane, t-butylcumyl peroxide, di-t-butylperoxide Id, p-menthane hydroperoxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3, diisopropylbenzene hydroperoxide, t-butyltrimethylsilyl peroxide, 1,1,3 Examples include 3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, t-hexyl hydroperoxide, and t-butyl hydroperoxide.
Organic peroxides are commercially available, and preferred specific examples include perbutyl Z (t-butyl peroxybenzoate), park mill D (dicumyl peroxide), perbutyl D (di-t-) manufactured by NOF Corporation. Butyl peroxide), park mill P (diisopropylbenzene hydroperoxide), and the like.

Specific examples of the azo compound include 1,1′-azobis (cyclohexane-1-carbonitrile), 2- (carbamoylazo) isobutyronitrile, 2-phenylazo-4-methoxy-2,4-dimethylvaleronitrile. Azodi-t-octane and azodi-t-butane.
These may be used alone or in combination of two or more. Moreover, an organic peroxide can also be made into a redox reaction by combining with a reducing agent.

  When mix | blending (F) component with a composition, it can also heat after light irradiation as needed.

(F) As a mixture ratio of a component, 10 weight% or less is preferable in a composition, More preferably, it is 0.01-5 weight%.
By making this proportion 10% by weight or less, the insulation reliability can be improved. Furthermore, by setting it as 0.01 weight% or more, it can be excellent in thermosetting.

  Other photopolymerizable compounds include styrene, vinyl toluene, vinyl acetate, N-vinyl pyrrolidone, N-vinyl formamide, N-vinyl caprolactam, cyclohexyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, n-hexyl ( Known and commonly used ones such as (meth) acrylate, phenoxyethyl (meth) acrylate, (meth) acryloylmorpholine, diethylene glycol diacrylate and the like can be mentioned.

  Examples of the polymerization inhibitor include known ones such as hydroquinone, hydroquinone monomethyl ether, benzoquinone, pt-butylcatechol, 2,6-di-tert-butyl-4-methylphenol.

6). Production / Use Method The present invention may be produced by stirring and mixing the essential components (A) to (D) and other components as necessary.
When the component (D) or / and the component (F) do not dissolve in the composition at room temperature, the component may be heated as necessary.
The viscosity of the composition may be appropriately set according to the purpose of use, but is preferably 50 to 200 mPa · s (25 ° C.) when the composition is used by spray coating.

The method of using the composition of the present invention may follow a conventional method.
For example, there may be mentioned a method in which a composition is applied or injected to an electrode intended for coating and then the composition is cured by light irradiation.
As a coating method, a conventional method may be followed, and the above-mentioned viscosity can be used for spray coating.
Light irradiation conditions may be appropriately set according to the purpose, and irradiation is performed at about 100 to 3000 mJ / cm ² using a high-pressure mercury lamp, a metal halide lamp, a xenon lamp, a chemical lamp, or the like that emits light in a wavelength range of 150 to 450 nm. do it.

  Specific examples of electrodes to which the composition of the present invention can be applied include, for example, electrode terminals of plasma display panels, terminals on mounting substrates used for mobile devices (cell phones, digital cameras, digital video cameras, etc.), outdoor devices ( Examples include terminals of substrates used in water heaters, air conditioner outdoor units, etc., terminals on mounting substrates used in water-circulating devices such as washing machines, warm water washing toilet seats, and dishwashers.

  Examples will be specifically described below, but the present invention is not limited to these examples. In the following, “parts” and “%” mean “parts by weight” and “% by weight”, respectively, unless otherwise specified.

○ Production Example 1 [Production of component (A)]
In a 1 L flask equipped with a stirrer, thermometer, oxygen / nitrogen mixed gas (hereinafter referred to as 5% ON) pipe having an oxygen concentration of 5%, 59.99 g (0.27 mol) of isophorone diisocyanate (hereinafter referred to as IPDI), Nonylphenoxyethyl acrylate (Toagosei Co., Ltd.) using 0.26 g (1.18 × 10 ⁻³ mol) of 2,6-di-t-butyl-4-methylphenol (hereinafter referred to as BHT) as a diluent Aronix M-111 (hereinafter referred to as M-111) was charged to 220.41 g (0.73 mol).
The contents were stirred while blowing 5% ON to bring the inside of the flask to 70 ° C.
Tris (acetylacetonato) iron [Nursem ferric iron manufactured by Nippon Chemical Industry Co., Ltd. Hereinafter referred to as nursem) 0.005 g (1.4 × 10 ⁻⁵ mol) was added, and thereafter, neopentyl glycol having a hydroxyl value of 55 mg KOH / g and polyester diol derived from adipic acid were gradually added. Finally, 440.51 g of polyester was charged. Thereafter, 2.43 g (0.027 mol) of 1,4-butanediol was added, and the temperature in the flask was raised to 80 ° C.
2-hydroxyethyl acrylate (HEA) when the weight average molecular weight (hereinafter referred to as Mw) of the contents exceeded 32,000 in the molecular weight measurement by GPC (converted to standard polystyrene; the same shall apply hereinafter). 11.36 g (0.098 mol) was added. At this time, 0.005 g (1.4 × 10 ⁻⁵ mol) of nursem was added again.
Subsequent IR measurement confirmed that the isocyanate group had disappeared, and the synthesis was completed.
The obtained reaction mixture was a mixture containing 30% of urethane acrylate oligomer (hereinafter referred to as UA) having Mw of 40 to 50,000 as measured by molecular weight measurement by GPC.

○ Example 1
18.6 parts of the reaction mixture obtained in Production Example 1 (UA: 13 parts + M-111: 5.6 parts), pentaerythritol tetraacrylate [Aronix M-450 manufactured by Toagosei Co., Ltd. Hereinafter, 5 parts of M-450], isobornyl acrylate [manufactured by Osaka Organic Chemical Co., Ltd.]. Hereinafter, 62 parts of IBXA], lauryl acrylate [manufactured by Osaka Organic Chemical Co., Ltd.] Hereinafter referred to as LA), 10 parts of M-111, 4.4 parts of M-111, a photopolymerization initiator [Irgacure 369 manufactured by Ciba Japan Co., Ltd. (Hereinafter referred to as Irg-369) was added and mixed uniformly to prepare a photocurable composition. The viscosity of the obtained composition was 150 mPa · s (25 ° C.).
Using the obtained composition, it confirmed according to the following evaluation. The results are shown in Table 1. Table 1 shows the final composition of each component in the composition.

○ Evaluation (1) Surface tackiness The obtained composition was spray-coated at a thickness of 50 μm on a ZEONOR film, and UV-cured using the light of a metal halogen lamp in the atmosphere (UV: UV-A, Irradiation energy: 1000 mJ / cm ² ).

  The surface tack of the evaluation test film was measured by finger touch. The results are shown in Table 1. In Table 1, “◯” in the item “surface tack” means that the surface tack was not observed at room temperature, and “x” means that the surface tack was observed.

(2) Insulation reliability The obtained composition was applied at a thickness of 30 μm on a comb-shaped glass cloth base epoxy resin copper-clad laminate (electrode width: 318 μm, pitch: 318 μm), and light from a metal halogen lamp Was cured with ultraviolet light (ultraviolet light: UV-A, irradiation energy: 1000 mJ / cm ² ).

Using the sample for evaluation obtained by the above method, in a state where a voltage of 20 V is continuously applied in an atmosphere of a temperature of 80 ° C. and a humidity of 95% RH, the time until the resistance value becomes 10 ⁸ Ω or less is set. Measured and evaluated for ion migration resistance.

○ Examples 2 to 4, Comparative Example 1 and 2
A photocurable composition was produced in the same manner as in Example 1 except that the components shown in Table 1 were used in the proportions shown in Table 1. The viscosity of the obtained composition was almost the same as in Example 1.
Evaluation was performed in the same manner as in Example 1 using the obtained composition. The results are shown in Table 1.

Abbreviations in Table 1 mean the following, except for those described above.
KBM-503: 3-methacryloxypropyltrimethoxysilane, KBM-503 manufactured by Shin-Etsu Chemical Co., Ltd.
M-211B: ethylene oxide-modified diacrylate of bisphenol A, M-211B manufactured by Toagosei Co., Ltd.
TI1000: terminal acrylic modified of hydrogenated polybutadiene, TEAI-1000 manufactured by Nippon Soda Co., Ltd.

From the results of Examples 1 to 4, the compositions of the present invention were excellent in insulation reliability, with no surface tack observed.
On the other hand, the composition of Comparative Example 1 containing no component (C) was excellent in insulation reliability but was insufficient in surface tackiness.
In addition, when a terminal acrylic modified product of hydrogenated polybutadiene (TI1000) was used instead of the component (A), surface tack was not observed, but insulation reliability was insufficient.

Since the photocurable composition for electrode coating of the present invention is excellent in electrical insulation, it can be used for coating various electronic and electrical devices as an electrode coating application.

Claims (8)

  A diisocyanate compound (a), a urethane having a (meth) acryloyl group at the end, obtained by reacting a polyester diol (b) having a hydroxyl value of 28 to 225 mg KOH / g and a hydroxyl group-containing (meth) acrylate (c) (meta ) Acrylate oligomer (A), compound (B) having an alkyl group having 8 or more carbon atoms or a cycloalkyl group having 8 or more carbon atoms and one (meth) acryloyl group in the molecule, and two or more (meth) molecules in the molecule A photocurable composition for electrode coating comprising a compound having an acryloyl group and containing a compound (C) other than the component (A) and a photopolymerization initiator (D). The photocurable composition for electrode coating according to claim 1, wherein the components (A) to (D) are contained in the composition at the following ratio.
(A) component: 1 to 50% by weight
(B) component: 10 to 97% by weight
Component (C): 1 to 30% by weight
(D) Component: 1 to 10% by weight   The photocurable composition for electrode coating according to claim 1, wherein the component (C) is a compound having 2 to 4 (meth) acryloyl groups in the molecule.   The photocurable composition for electrode coating according to claim 3, wherein the component (C) is pentaerythritol tetraacrylate.   The photocurable composition for electrode coating according to claim 3, wherein the component (C) is ethylene oxide-modified diacrylate of bisphenol A.   The photocurable composition for electrode coating according to any one of claims 1 to 5, wherein the component (D) is an α-aminoalkylphenone photopolymerization initiator.   The photocurable composition for electrode coating according to any one of claims 1 to 6, further comprising a silane coupling agent (E).   The electrode-coated photocurable composition according to claim 7, wherein the component (E) is contained in an amount of 10% by weight or less.