JP6981126B2 - Photosensitive Insulating Resin Composition, Sheet Photosensitive Insulating Resin Composition, and Sheet Photosensitive Insulating Resin Composition with Removable Film - Google Patents

Description

The present invention relates to a photosensitive insulating resin composition containing a surface-treated flame retardant, a sheet-shaped photosensitive insulating resin composition, and a sheet-shaped photosensitive insulating resin composition with a peelable film.

In recent years, the field of electronics has been remarkably developed, and in particular, electronic devices have become smaller, lighter, and higher in density, and electronic materials such as printed wiring boards are required to be thinner, more multi-layered, and have higher definition. It is supposed to be done. Even in the case of a thick rigid substrate typified by a conventional glass epoxy substrate or the like, high electrical insulation (hereinafter referred to as insulation) has been required in order to accommodate a narrow space.
However, recent electronic materials such as printed wiring boards and flat cables represented by flexible printed wiring boards (hereinafter referred to as FPCs) can accommodate much narrower spaces than thick rigid boards. Therefore, a higher level of insulation is also required.

Further, due to recent environmental problems, there is a demand for a non-halogen flame retardant material having good flame retardancy without using a halogen flame retardant.
For example, Patent Document 1 discloses that it has (A) a carboxyl group-containing resin, (B) titanium oxide, and (C) a phosphorus compound.

WO2011 / 105277

Patent Document 1 describes that a flame-retardant film can be provided by photo-curing or thermosetting a resin composition for a polyester base material containing a carboxyl group-containing resin, titanium oxide, and a phosphorus compound.
However, it is considered that the above resin composition may have a reduced insulating property under high temperature and high humidity due to impurities derived from the flame retardant.

Improvement of insulation can be expected by increasing the thickness of the insulating layer. However, in the case of FPCs, flat cables, etc., which are required to accommodate narrower spaces, it is difficult to achieve both flame retardancy and insulation. Therefore, the present invention is a photosensitive insulating resin composition for forming an insulating layer suitably used for FPCs, flat cables and the like, and is a photosensitive insulating resin composition capable of achieving both flame retardancy and high insulating properties. The purpose is to provide things.

In order to solve the above problems, the present inventors have made diligent studies, and as a result, by using a flame retardant obtained by surface-treating the surface of a solid flame retardant with an inorganic oxide such as silica, flame retardant and insulating properties are used. The following inventions [1] to [8] have been completed.

[1] A surface-treated flame retardant (A) in which an inorganic oxide adheres to at least a part of the surface of a solid flame retardant at 25 ° C., an active energy ray-curable component (B), and a photopolymerization initiator. A photosensitive insulating resin composition containing (C).

[2] The photosensitive insulating resin composition according to the above [1], wherein 0.01 to 10 parts by mass of an inorganic oxide is attached to 100 parts by mass of a solid flame retardant at 25 ° C.
[3] The photosensitive insulating resin composition according to the above [1] or [2], wherein a silane coupling agent is further adhered to the surface of the surface-treated flame retardant (A).
[4] The photosensitive according to any one of the above [1] to [3], which contains 0.1 to 100 parts by mass of the surface treatment flame retardant (A) with respect to 100 parts by mass of the active energy ray-curable component (B). Insulating resin composition.
[5] The photosensitive insulating resin composition according to any one of the above [1] to [4], wherein the flame retardant solid at 25 ° C. is a phosphinate.
[6] The photosensitive insulating resin composition according to any one of [1] to [4] above, wherein the active energy ray-curable component (B) contains a component (B1) having a carboxyl group.

[7] The photosensitive insulating resin composition according to any one of the above [1] to [4], which is in the form of a sheet.

[8] A sheet-shaped photosensitive insulating resin composition with a peelable film, wherein both sides of the sheet-shaped photosensitive insulating resin composition according to the above [7] are covered with a peelable film.

By using a flame retardant whose surface is surface-treated with an inorganic oxide such as silica, the surface of the solid flame retardant is photosensitive and insulating, which can achieve both the flame retardancy required for FPCs and flat cables and a high degree of insulation. It has become possible to provide a resin composition.

A schematic diagram is shown to explain the insulation evaluation method in the present invention.

<Surface treatment flame retardant (A)>
The flame retardant to be surface-treated in the present invention is not particularly limited except that it is solid at 25 ° C., and examples of the shape include powder granules and the like.
In the present invention, a solid at 25 ° C. means a solid having a melting point of 25 ° C. or higher. However, it may include a decomposition reaction as well as melting at the melting point.

For example, (poly) phosphoric acid such as melamine phosphate, melamine polyphosphate, guanidine phosphate, guanidine polyphosphate, ammonium phosphate, ammonium polyphosphate, ammonium phosphate, ammonium polyphosphate, carbamate phosphate, carbamate polyphosphate, etc. Salt-based compounds, organic phosphoric acid ester compounds, phosphazene compounds, phosphonic acid compounds, aluminum diethylphosphinate, aluminum methylethylphosphinate, aluminum diphenylphosphinate, aluminum ethylbutylphosphinate, aluminum methylbutylphosphinate, aluminum polyethylenephosphinate, etc. Phosphoric acid flame retardant such as phosphoric acid compound, phosphin oxide compound, phosphoran compound, phosphoramide compound;
Nitrogen flame retardants such as ammonium carbonate and melamine cyanurate;
Examples thereof include inorganic flame retardants such as aluminum hydroxide, magnesium hydroxide, zirconium hydroxide, barium hydroxide and calcium hydroxide.

As a flame retardant, it is desirable to use a non-halogen flame retardant such as a phosphorus flame retardant or a nitrogen flame retardant in consideration of the environmental impact, which has been popular in recent years, and a phosphazene compound that is more effective in flame retardancy. , Phosphine compounds, melamine polyphosphates, ammonium polyphosphates, melamine cyanurates, hydroxide compounds and the like are preferably used, and among the phosphine compounds, phosphinates are particularly preferable.
Further, in terms of reducing the dielectric constant and the dielectric loss tangent, it is preferable to use a phosphine compound, which is excellent not only in the balance between flame retardancy and insulating property but also in the balance between dielectric property, adhesiveness, flexibility and heat resistance. It becomes possible to obtain a cured product.
In the present invention, these flame retardants can be used alone or in combination of two or more.

The average particle size of these flame retardants is preferably 0.1 to 25 μm. When a flame retardant having an average particle size close to 0.1 μm is used, the reforming effect of the flame retardant can be easily obtained, and the dispersibility and the stability of the dispersion liquid can be easily improved. Further, when a flame retardant having an average particle size close to 25 μm is used, the mechanical properties of the cured product are likely to be improved.
As an index of the average particle size in the present invention, D95 indicates the particle size when the volume integrated value of 95% is included in the particle size distribution.

The surface-treated flame retardant (A) used in the present invention has an inorganic oxide adhered to at least a part of the surface of the solid flame retardant at 25 ° C.
Although not particularly specified as the inorganic oxide to be adhered, silica, alumina, titania, zirconia and the like are preferably used.

The amount of the inorganic oxide to be attached is preferably 0.01 to 10 parts by mass, more preferably 0.1 part by mass to 10 parts by mass, based on 100 parts by mass of the solid flame retardant at 25 ° C. More preferably, it is 0.1 part by mass to 5 parts by mass. Insulation can be improved by using 0.01 parts by mass or more. Further, when the content is 10 parts by mass or less, the flame retardancy is excellent.

The method for adhering the inorganic oxide to at least a part of the surface of the solid flame retardant at 25 ° C. is not particularly limited, but a spray method, a sol-gel method, or the like is used. For example, the raw material of the inorganic oxide is sprayed on the flame retardant which is the target of the surface treatment, or the raw material of the inorganic oxide and the flame retardant which is the target of the surface treatment are mixed to form a slurry, and then the raw material of the inorganic oxide is prepared. By hydrolyzing or firing the flame retardant, an inorganic oxide can be attached to at least a part of the surface of the flame retardant. The slurry can also be obtained by mixing a raw material of a molten inorganic oxide and a flame retardant to be surface-treated, or is a raw material of an inorganic oxide and a target of surface treatment in a so-called organic solvent. It can also be obtained by dispersing with a flame retardant.

In the present invention, a surface-treated flame retardant (A) having an inorganic oxide adhered to at least a part of the surface of a solid flame retardant at 25 ° C. is further attached with a silane coupling agent. Is preferable. Further, by using the one to which the silane coupling agent is attached, the hydrophobicity of the flame retardant surface can be improved, and the insulation performance can be further improved.

The above-mentioned silane coupling agent is not particularly limited, and for example, vinylmethoxysilane, vinylethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycid. Xipropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltriethoxy Silane, 3-acryloxypropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, 3-aminopropyltri Methoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N- (vinylbenzyl)- 2-Aminoethyl-3-aminopropyltrimethoxysilane hydrochloride, tris- (trimethoxysilylpropyl) isocyanurate, 3-ureidopropyltrialkoxysilane, 3-isoxapropyltriethoxysilane, 3-phenylaminopropyltrimethoxy In addition to silane, 1,2-ethanediamine, N- {3- (trimethoxysilyl) propyl}-, N- {(ethenylphenyl) methyl} derivative / hydrochloride, vinyltriacetoxysilane, allyltrimethoxysilane, A silane coupling agent in which the functional group is protected by an alkoxy group, a sulfide / polysulfide-based silane coupling agent, a polymer-type alkoxy oligomer type, a polyfunctional group type silane coupling agent, or the like can be used.

The amount of the silane coupling agent to be attached is preferably 0,005 to 5 parts by mass, more preferably 0.05 to 2 parts by mass with respect to 100 parts by mass of the solid flame retardant at 25 ° C. preferable. When the amount of the silane coupling agent to be attached is 0.005 part by mass or more, the insulating property is improved. Further, the flame retardancy is excellent when the amount of adhesion is 5 parts by mass or less.

The method for further adhering the silane coupling agent to the surface of the surface treatment flame retardant (A) is not particularly limited, but a dry method or a wet method capable of high-precision treatment is preferably used. In this wet method, a silane coupling agent is added to a dispersion liquid in which a surface-treated flame retardant to which an inorganic oxide is attached is dispersed, a silane coupling agent is bonded to the surface of the surface-treated flame retardant, and then the dispersion medium is removed. It is a method of drying.

<Active energy ray-curable component (B)>
Examples of the active energy ray-curable component (B) used in the present invention include a radical-curable component and a cationically curable component.
Examples of the radically curable component include a component having an ethylenically unsaturated double bond, and examples of the functional group having an ethylenically unsaturated double bond are preferably an acryloyl group and a methacryloyl group, and an acryloyl group is preferable.
As the active energy ray-curable component (B) having an acryloyl group, a compound having two or more acryloyl groups in one molecule is preferable.
Further, by using a molecule having an acidic functional group such as a carboxyl group, the unexposed portion can be developed with a basic developer when partially exposed. From the viewpoint of development, the mass average molecular weight is preferably 1000 to 100,000, and particularly preferably 2000 to 50,000. By setting the molecular weight in such a range, it is possible to suppress the swelling of the exposed portion when it comes into contact with the developing solution. Further, in the case of having a functional group such as the above-mentioned carboxyl group, if a component having a functional group capable of being thermosetting with the functional group is blended in the photosensitive insulating resin composition, the exposed portion remaining after development is prepared. Can be further thermoset.
Further, as the active energy curable component, a component having a relatively low molecular weight outside the above molecular weight range can be used for applications such as adjusting the viscosity of the coating liquid.

The photosensitive insulating resin composition of the present invention preferably contains 0.1 to 100 parts by mass of the surface-treated flame retardant (A) with respect to 100 parts by mass of the active energy ray-curable component (B). It is more preferable to contain 80 parts by mass. When the content of the surface-treated flame retardant (A) is 0.1 part by mass or more, the flame retardancy is excellent. Further, when the content is 80 parts by mass or less, a cured coating film having excellent insulating properties can be obtained.

<Photopolymerization initiator (C)>
The photopolymerization initiator (C) used in the present invention is not particularly limited, but pyrazoline compounds, quinones, aromatic ketones, phosphine oxides, benzoin ethers, acridine compounds and the like are preferably used.

The photosensitive insulating resin composition of the present invention preferably contains 0.01 to 30 parts by mass of the photopolymerization initiator (C) with respect to 100 parts by mass of the active energy ray-curable component (B). It is more preferable to contain 1 to 10 parts by mass. From the viewpoint of sensitivity, the content of the photopolymerization initiator is preferably 0.01 part by mass or more, and from the viewpoint of resolution, it is preferably 30 parts by mass or less.

The photosensitive insulating resin composition of the present invention can be obtained by adding a surface-treated flame retardant (A) and a photopolymerization initiator (C) to the active energy ray-curable component (B).
For example, a method of adding a surface-treated flame retardant (A) and a photopolymerization initiator (C) to an active energy ray-curable component (B) and dispersing the surface-treated flame retardant (A) using a three-roll or the like, a surface. Examples thereof include a method of preparing a dispersion liquid containing the treated flame retardant (A) and adding it to a mixture of the active energy ray-curable component (B) and the photopolymerization initiator (C). Further, in order to disperse the surface-treated flame retardant (A) well and to stabilize the dispersed state, a dispersant, a thickener and the like are used within a range that does not affect the performance of the photosensitive insulating resin composition. You can also do it. Alternatively, the surface-treated flame retardant (A) is added to a part or all of the active energy ray-curable component (B) to satisfactorily disperse the surface-treated flame retardant (A), and then the remaining active energy ray-curable component. (B) and the photopolymerization initiator (C) can also be added.

The photosensitive insulating resin composition of the present invention has an active energy ray-curable component (B), a surface-treated flame retardant (A), a photopolymerization initiator (C), and a volatile liquid such as a so-called organic solvent. It can be used as a liquid photosensitive insulating resin composition containing a medium.
A liquid photosensitive insulating resin composition is applied so as to cover the conductive circuit surface provided on the heat-resistant film such as polyimide, the volatile liquid medium is volatilized, and then the active energy ray is emitted. The photosensitive insulating resin composition can be cured by irradiation, and the conductive circuit surface can be coated with an insulating film.
By irradiating (exposing) the desired pattern with active energy rays by using a photomask or the like, the photosensitive insulating resin composition can be partially cured. For example, if a component having a carboxyl group is used as the active energy ray-curable component (B), the unexposed portion can be removed by the developer with a basic developer.
When the photosensitive insulating resin composition contains a curing agent having a functional group in the active energy ray-curable component (B) and a functional group that can be cured by heating, it is further heated after being cured by the active energy ray. It can also be cured.

<Sheet-like photosensitive insulating resin composition>
A liquid photosensitive insulating resin composition can be applied to a peelable film to volatilize the volatile liquid medium to obtain a sheet-shaped photosensitive insulating resin composition. Another release film is laminated on the other surface of the formed sheet-shaped photosensitive insulating resin composition, and both sides of the sheet-like photosensitive insulating resin composition are covered with the release film. It can also be a sheet-like photosensitive insulating resin composition with a peelable film.
These sheet-shaped photosensitive insulating resin compositions are laminated so as to cover the conductive circuit surface provided on the heat-resistant film such as polyimide, and irradiated with active energy rays to cure the photosensitive insulating resin composition. However, the conductive circuit surface can be covered with an insulating film.
The partial exposure, the use of the developer, and the thermosetting after the active energy ray are the same as in the case of directly using the liquid photosensitive insulating resin composition.
Examples of the peelable sheet include those obtained by peeling a polyester film.

Hereinafter, the present invention will be described in more detail by way of examples, but the following examples do not limit the scope of rights of the present invention in any way. In the examples, "parts" and "%" mean "parts by mass" and "% by mass", respectively.

(Synthesis Example 1) Synthesis of Surface Treatment Flame Retardant (A1) and Adjustment of Dispersion Obtained in 800 ml of an ethanol solution (concentration: 0.4%) of tetraethyl orthosilicate (hereinafter, also referred to as TEOS) by the method described below. Add 10 g of aluminum phosphinate 1 having a D95 particle size of 5 μm _{, adjust the pH to 12 with concentrated NH 3} water, stir for 3 hours, filter, and wash with ethanol to remove silica on the surface of aluminum phosphinate 1. An attached surface-treated flame retardant (A1) was obtained.
When the amount of silica adhering to the surface was determined by ICP emission spectroscopic analysis described later, it was 0.01 part by mass with respect to 100 parts by mass of aluminum phosphinate 1.

<Adjustment of dispersion of surface-treated flame retardant>
Add 15 parts of DISPERBYK-2155 (manufactured by BIC Chemie Japan Co., Ltd.) as a dispersant to 100 parts by mass of the surface treatment flame retardant (A1), and the solid content concentration becomes 35% by mass with the MEK solvent. Was compounded. Then, the mixture was shaken with Scandex for 1 hour to prepare a dispersion of the surface-treated flame retardant (A1).

(Synthesis Examples 2 to 7)
In the same manner as in Synthesis Example 1 except that the amount of aluminum phosphinate 1 added to the ethanol solution of TEOS was changed, the amount of silica adhering to the surface was 0.1 with respect to 100 parts by mass of aluminum phosphinate 1. 0.5, 1, 5, 10, 50 parts by mass of the surface-treated flame retardants (A2) to (A7), and a dispersion having a solid content of 35% by mass were prepared.

(Synthesis Examples 8 to 13)
10 parts by mass of Z-6610 manufactured by Toray Dow Corning Co., Ltd., which is a silane coupling agent, and 10 parts by mass of ethanol while stirring 100 parts by mass of the surface treatment flame retardant (A1) in a mixer and stirring in a nitrogen atmosphere. Was sprayed and heated and stirred at 150 ° C. for 2 hours to remove the solvent and cooled. In this way, a surface-treated flame retardant (A8) in which a silane coupling agent is further adhered to the surface of the surface-treated flame retardant (A1) is obtained, and a dispersion having a solid content of 35% by mass is obtained in the same manner as in Synthesis Example 1. It was adjusted.
The dispersions of (A9) to (A13) were prepared in the same manner except that the amount of the silane coupling agent used for spraying was changed.
The amount of the silane coupling agent in the surface-treated flame retardants (A8) to (A13) was determined by the method described later, and the aluminum phosphinate 1 in the surface-treated flame retardant (A1) was 100. The amount of the silane coupling agent was 0.01, 0.1, 0.2, 0.5, 2.0, 7.0 parts by mass with respect to the mass part.

(Synthesis Examples 14-18)
Except for the use of aluminum phosphinate 2 with a D95 of 10 μm, aluminum phosphinate 3 with a D95 of 20 μm, red phosphorus, magnesium phosphinate hexahydrate, and melamine cyanurate with a D95 of 10 μm instead of aluminum phosphinate 1. Surface-treated flame retardants (A14) to (A18) having 0.5 parts by mass of silica adhering to the surface and each dispersion were obtained in the same manner as in Synthesis Example 3.

(Synthesis Example 19)
50 g of aluminum phosphinate 1 (D95 particle diameter 5 μm) was dispersed in 950 g of pure water, this flame retardant slurry was placed in a reactor with a reflux base, and the pH of the dispersion was adjusted to 11 with a 1 wt% NaOH aqueous solution. Then, the mixture was heated at 95 ° C. for 30 minutes with stirring to obtain a basic slurry of the flame retardant.
Next, _{1250 g of an aqueous solution of sodium aluminate (Na 2} O / Al ₂ O ₃ = molar ratio 1/2) having a concentration of 0.5% by weight as _{Al 2} O ₃ was added at a rate of 5 g / min to the basic slurry of the flame retardant. To obtain a dispersion of aluminum phosphinate 1 having an alumina surface treatment layer.
A cation exchange resin is added to the dispersion and ion exchange is performed until the pH reaches 3, then a slurry containing a flame retardant is separated from the cation exchange resin, dried, and aluminum phosphinate having an alumina surface treatment layer (aluminum phosphinate having an alumina surface treatment layer). A19) was obtained.

(Synthesis Example 20)
Add 200 g of aluminum phosphinic acid 1 (D95 particle diameter 5 μm) _{to a mixed solution of 130 g of isopropyl alcohol and 7.56 g of titanium tetraisopropoxide (Ti [OCH (CH 3} ) ₂ ] ₄ )) and mix at room temperature. Titanium tetraisopropoxide was adsorbed on the surface of aluminum phosphinate 1 with stirring. Next, a mixed aqueous solution of 1.93 g of ion-exchanged water and 1.93 g of isopropyl alcohol is gradually added thereto, and titanium tetraisopropoxide is hydrolyzed, washed, heated, and has a titanium oxide surface-treated layer. Aluminum phosphinate (A20) was obtained.

(Synthesis Example 21)
200 g of aluminum phosphinate 1 (D95 particle diameter 5 μm) was added to 500 g of pure water to obtain an aqueous slurry.
While stirring 500 g of this slurry, the temperature was raised to 40 ° C., and while maintaining this temperature and the pH of the slurry at 7, a 100 g / l zirconium oxychloride aqueous solution corresponding to 1% by mass in terms of _{ZrO 2 with respect to 1 aluminum phosphinate was used.} And 30% sodium hydroxide were added simultaneously over 60 minutes and aged over 30 minutes. This slurry was washed and solid-liquid separated. The obtained solid was heated and calcined at 900 ° C. for 1 hour to obtain aluminum phosphinate (A21) having a zirconium oxide surface treatment layer.

<Quantification of silica surface treatment by ICP emission spectroscopic analysis>
Weigh 0.25 g of surface-treated flame retardant, add 7 ml of nitric acid, and heat continuously at 150 ° C for 2 minutes, 180 ° C for 2 minutes, and 210 ° C for 10 minutes using a microwave-type wet decomposition apparatus. Then, after decomposition treatment with nitric acid, 50 ml of distilled water was used to make a constant solution, and ICP measurement (device name: ICP emission spectroscopic analyzer SPECTRO ARCOS manufactured by AMETEK, Inc.) was performed at room temperature.

<Measurement method of D95 particle size>
D95 indicates the particle size when the volume integrated value of 95% is included in the particle size distribution of the flame retardant. The particle size of the flame retardant was measured using Microtrac MT3000EX (manufactured by Nikkiso Co., Ltd.). A measurement sample was prepared by dispersing 0.5 g of a flame retardant while stirring a 1% aqueous solution of sodium dodecylbenzenesulfonate. The measurement was carried out by inputting the refractive index of water and the refractive index of the flame retardant, and adjusting the sample concentration so that the measurement time was 20 seconds and the Signal Level was within the green range.

(Adjustment example) Adjustment of dispersion of untreated flame retardant Instead of surface-treated flame retardant (A1), aluminum phosphinate 1 with D95 of 5 μm, aluminum phosphinate 2 with D95 of 10 μm, and aluminum phosphinate 3 with D95 of 20 μm Using aluminum hydroxide having a D95 of 0.3 μm, red phosphorus having a D95 of 5 μm, and silica having a D95 of 1 μm, a dispersion of an untreated flame retardant was obtained in the same manner as in the case of Synthesis Example 1.

(Example 1)
Photopolymerization started for 100 parts by mass of "KAYARAD ZAR1035" manufactured by Nippon Kayaku Co., Ltd., which is an epoxy acrylate resin having a carboxyl group as an active energy ray-curable component (B) and has a mass average molecular weight of 13,000. As the agent (C), 1 part by mass of Speed Cure TPI manufactured by LAMBSON was added.
Further, 143 parts (including 50 parts of the surface-treated flame retardant (A1)) of a dispersion (solid content 35% by mass) of the surface-treated flame retardant (A1) was added, and diluted with a MEK solvent so that the solid content concentration became 15%. Then, a liquid photosensitive insulating resin composition was prepared.
This liquid photosensitive insulating resin composition is uniformly applied onto a peel-treated polyester film so that the film thickness after drying is 25 μm, dried, and one side is covered with the peelable film. The shape of the photosensitive insulating resin composition was formed.

[Examples 2 to 7]
The same as in Example 1 except that the dispersions of the surface-treated flame retardants (A2) to (A7) having different amounts of silica adhering to the surface were used instead of the dispersion of the surface-treated flame retardant (A1). A liquid and sheet-like photosensitive insulating resin composition was formed and evaluated in the same manner.

[Examples 8 to 13]
Instead of the dispersion of the surface-treated flame retardant (A1), as shown in Table 2, the dispersions of the surface-treated flame retardants (A8) to (A13) to which the silane coupling agent was further adhered to the surface were used. Liquid and sheet-like photosensitive insulating resin compositions were formed in the same manner as in Example 1 and evaluated in the same manner.

[Examples 14 to 23]
The solid content of the surface-treated flame retardant (A1) with respect to 100 parts by mass of "KAYARAD ZAR1035" manufactured by Nippon Kayaku Co., Ltd., which is an epoxy acrylate resin having a carboxyl group which is an active energy ray-curable component (B). Liquid and sheet-like photosensitive insulating resin compositions in the same manner as in Example 1 except that the amount of the dispersion of the surface-treated flame retardant (A1) was changed so that the amount was the amount shown in Table 3. Was formed and evaluated in the same manner.

[Examples 25 to 26]
The active energy ray-curable component (B) is an acrylate resin having a carboxyl group instead of "KAYARAD ZAR1035" manufactured by Nippon Kayaku Co., Ltd., which is an epoxy acrylate resin having a carboxyl group. , "ZFR1401" manufactured by Nippon Kayaku Co., Ltd. with a mass average molecular weight of 15,000, and "UX-3204" manufactured by Nippon Kayaku Co., Ltd. with a mass average molecular weight of 13,000, which is an acrylate resin having no carboxyl group. In the same manner as in Example 1, liquid and sheet-like photosensitive insulating resin compositions were formed and evaluated in the same manner.
Although Example 24 is the same as that of Example 3, it is described as Example 24 according to Table 4 for the sake of clarity.

[Example 27]
When mixing "KAYARAD ZAR1035", which is an epoxy acrylate resin having a carboxyl group, and a dispersion of a photopolymerization initiator (C) and a surface treatment flame retardant (A1), jER1031S (jER1031S) was added to 100 parts of the "KAYARAD ZAR1035". A liquid photosensitive insulating resin composition was prepared in the same manner as in Example 1 except that the amount was 50 parts (manufactured by Mitsubishi Chemical Co., Ltd.).
This liquid photosensitive insulating resin composition is uniformly applied onto a peel-treated polyester film so that the film thickness after drying is 25 μm, dried, and one side is covered with the peelable film. The shape of the photosensitive insulating resin composition was formed.

[Examples 29 to 33]
As the surface-treated flame retardant (A), the same as in Example 3 except that the dispersions of the surface-treated flame retardants (A14) to (A18) were used instead of the dispersion of the surface-treated flame retardant (A3). , Liquid and sheet-like photosensitive insulating resin compositions were formed and evaluated in the same manner.
Although Example 28 is the same as that of Example 3, it is described as Example 28 according to Table 5 for the sake of clarity.

[Examples 34 to 39]
Adjusted in Adjustment Examples 20 to 25 so as to replace 15 parts by mass of the surface-treated flame retardant (A3) contained in the photosensitive insulating resin composition in Example 3 with the untreated flame retardant. Liquid and sheet-like photosensitive insulating resin compositions were formed and evaluated in the same manner as in Example 3 except that the dispersion of the untreated flame retardant was used.

[Examples 41 to 43]
Liquid and sheet as in Example 3 except that the dispersions of the surface-treated flame retardants (A19) to (A21) synthesized and adjusted in Synthesis Examples 19 to 21 were used instead of the surface-treated flame retardant (A3). A photosensitive insulating resin composition in the form of a state was formed and evaluated in the same manner.
Although Example 40 is the same as that of Example 3, it is described as Example 40 according to Table 7 for the sake of clarity.

[Comparative Examples 1 to 7]
In Comparative Examples 1 to 6, 50 parts of each of the following dispersions of the untreated flame retardant obtained in the adjusted example were used instead of the surface-treated flame retardant (A1), except that 50 parts of each was used.
Further, in Comparative Example 7, a dispersion of aluminum phosphinate 1 and a dispersion of silica were used in combination of 25 parts by mass instead of the surface-treated flame retardant (A1).
Liquid and sheet-like photosensitive insulating resin compositions were formed in the same manner as in Example 1 and evaluated in the same manner.
Comparative Example 1: Dispersion of aluminum phosphinate 1 having a D95 of 5 μm Comparative Example 2: Dispersion of aluminum phosphinate 2 having a D95 of 10 μm Comparative Example 3: Dispersion of aluminum phosphinate 3 having a D95 of 20 μm
Comparative Example 4: Dispersion of aluminum hydroxide with D95 of 0.3 μm Comparative Example 5: Dispersion of red phosphorus with D95 of 5 μm Comparative Example 6: Dispersion of silica with D95 of 1 μm Comparative Example 7: Hosphin with D95 of 5 μm A dispersion of aluminum acid 1 and a dispersion of silica having a D95 of 1 μm.

The flame-retardant and electrically insulating properties of the sheet-shaped photosensitive insulating resin composition whose one side was covered with the peelable film obtained in Examples and Comparative Examples were evaluated by the following methods. The results are shown in Tables 1-7.

(1) Flame retardancy (preparation of sample for flame retardancy evaluation)
A polyimide film [manufactured by Toray DuPont Co., Ltd. [Kapton 50EN]] having a thickness of 12.5 μm was prepared as a heat-resistant resin film.
Except for Example 31, the heat-resistant resin film is laminated at 80 ° C. on the side of the sheet-like photosensitive insulating resin composition whose one side is covered with the releaseable film and which is not covered with the releaseable film. ^{Then, the peelable film was irradiated with ultraviolet rays of 2000 mJ / cm 2} with a high-pressure mercury lamp (80 W / cm, ozoneless) to cure the sheet-shaped photosensitive insulating resin composition.
In Example 31, as in the other examples, ultraviolet rays are irradiated through the peelable film under the same conditions, the sheet-shaped photosensitive insulating resin composition is cured by the ultraviolet rays, and then the temperature is 160 ° C. for 60 minutes. It was heated and further thermoset.
In the obtained laminate, a heat-resistant resin film, a cured product of the photosensitive insulating resin composition, and a peelable film are laminated in this order.

(Evaluation of flame retardancy)
The obtained laminate was cut into a size of 20 cm × 20 cm, the peelable film was peeled off, and then the heat-resistant resin film was rolled into a cylinder so as to face outward to obtain a test piece for evaluation.
A thin vertical combustion test conforming to the UL94 standard was performed on this test piece, and the result was judged according to the length of combustion according to the following criteria.
A ... Combustion distance ≤ 1 cm
B ... 1 cm <combustion distance ≤ 3 cm
C ... 3 cm <combustion distance ≤ 5 cm
D ・ ・ ・ 5cm <Combustion distance ≤ 7cm
E ・ ・ ・ 7cm <Combustion distance ≤ 10cm
F ・ ・ ・ 10cm <Combustion distance

(2) Electrical insulation (preparation of sample for insulation evaluation)
A printed wiring board having three types of comb-shaped copper circuit patterns (conductor pattern width / space width = 50 μm / 50 μm, 100 μm / 100 μm, 200 μm / 200 μm) formed on a polyimide film was prepared (see FIG. 1 (1)). ).
Except for Example 31, the circuit surface of the printed wiring board at 80 ° C. is on the side not covered with the peelable film of the sheet-like photosensitive insulating resin composition whose one side is covered with the peelable film. After laminating, the sheet-shaped photosensitive insulating resin composition was cured by irradiating ^{the peelable film with ultraviolet rays of 2000 mJ / cm 2} with a high-pressure mercury lamp (80 W / cm, ozoneless).
In Example 31, as in the other examples, ultraviolet rays are irradiated through the peelable film under the same conditions, the sheet-shaped photosensitive insulating resin composition is cured by the ultraviolet rays, and then the temperature is 160 ° C. for 60 minutes. It was heated and further thermoset.
In the obtained laminate, the circuit surface of the printed wiring board, the cured product of the photosensitive insulating resin composition, and the peelable film are laminated in this order.

(Evaluation of insulation)
The peelable film was peeled off from the laminate to prepare a test piece for evaluating the insulating property (see FIG. 1 (2)). In the figure, for the sake of explanation, the comb-shaped copper circuit is shown so as to be visible through the cured product of the photosensitive insulating resin composition.
Under two types of atmospheres, a temperature of 60 ° C. and a relative humidity of 85%, and a temperature of 80 ° C. and a relative humidity of 85%, a DC voltage of 50 V was continuously applied to the copper circuit of the test piece for insulation evaluation for 100 hours, respectively. The time (hr) until the leak touch (short) was measured under one atmosphere. The evaluation criteria are as follows.
A ... No leak touch until 100 hours later at any temperature and circuit pattern.
B ... Leak touch occurred within 100 hours under the conditions of a temperature of 85 ° C. and a circuit pattern of 50/50, but no leak touch occurred until after 100 hours under conditions other than the above.
C ... Leak touch occurred within 100 hours under the conditions of a temperature of 85 ° C. and circuit patterns of 50/50 and 100/100, but no leak touch occurred until after 100 hours under conditions other than the above.
D ... Leak touch occurred within 100 hours under the conditions of temperature 85 ° C. and all circuit patterns, but no leak touch occurred until after 100 hours under the conditions of temperature 60 ° C. and all circuit patterns.
E ... Leak touch occurred by 100 hours under the condition of temperature 85 ° C. and all circuit patterns, and leak touch occurred by 100 hours under the condition of circuit pattern 50/50 at temperature 60 ° C. At a temperature of 60 ° C., no leak touch occurred until after 100 hours under at least one of the circuit patterns 100/100 and 200/200.
F ... Leak touch occurred within 100 hours under all conditions.

As shown in Examples 1 to 7 of Table 1, when the amount of adhered silica is increased, the flame retardancy tends to decrease and the insulating property tends to improve.

As shown in Examples 8 to 13 of Table 2, the insulating property is improved by increasing the amount of the attached silane coupling agent, but tends to be deteriorated by increasing the amount of the added silane coupling agent.

As shown in Examples 14 to 23 of Table 3, the more the surface-treated flame retardant is added, the better the flame retardancy, but the worse the insulating property tends to be.

As shown in Examples 24 to 27 of Table 4, when the active energy ray is cured and then thermally cured, the crosslink density is improved, and both flame retardancy and insulating property are improved.

As shown in Examples 28 to 33 of Table 5, flame retardancy is improved by using a surface-treated flame retardant having a small particle size. This is because a small particle size flame retardant having a large surface area is more advantageous in terms of flame retardancy mechanism.

As shown in Examples 40 to 43 of Table 7, silica is preferable as the inorganic oxide to be adhered to the surface of the flame retardant from the viewpoint of improving the insulating property.

As shown in Comparative Examples 1 to 6 in Table 8, when no surface-treated flame retardant is added, the flame retardancy is significantly deteriorated. Further, as shown in Comparative Example 7, even when silica is simply blended as a dispersion without adhering to the flame retardant in advance, the flame retardancy deteriorates and the insulating property is not so effective.

1: Polyimide film 2: Cathode electrode connection point 2': Cathode electrode connection point 3: Anode electrode comb signal wiring 3': Anode electrode connection point 4: Cured product of photosensitive insulating resin composition

Claims (7)

A surface-treated flame retardant (A) obtained by adhering an inorganic oxide to at least a part of the surface of the phosphinate, which is a solid flame retardant at 25 ° C., by a spray method or a sol-gel method, and an active energy ray-curable component ( A photosensitive insulating resin composition containing B) and a photopolymerization initiator (C). The photosensitive insulating resin composition according to claim 1, wherein 0.01 to 10 parts by mass of an inorganic oxide is attached to 100 parts by mass of phosphinate, which is a solid flame retardant at 25 ° C. The photosensitive insulating resin composition according to claim 1 or 2, wherein a silane coupling agent is further attached to the surface of the surface treatment flame retardant (A). The photosensitive insulating resin composition according to any one of claims 1 to 3, which contains 0.1 to 100 parts by mass of the surface-treated flame retardant (A) with respect to 100 parts by mass of the active energy ray-curable component (B). thing. The photosensitive insulating resin composition according to any one of claims 1 to 4 , wherein the active energy ray-curable component (B) contains a component (B1) having a carboxyl group. The photosensitive insulating resin composition according to any one of claims 1 to 5 , which is in the form of a sheet. The sheet-shaped photosensitive insulating resin composition with a peelable film, wherein both sides of the sheet-shaped photosensitive insulating resin composition according to claim 6 are covered with a peelable film.

Images