TWI707004B - Photosensitive resin composition and preparation method thereof - Google Patents

Abstract

A photosensitive resin composition is provided in the present disclosure. The photosensitive resin composition includes, in parts by weight, 100 parts of modified polyvinyl alcohol, 10 to 50 parts of a photosensitive monomer, 5 to 15 parts of a photoinitiator, 1 to 20 parts of a colorant, 5 to 30 parts of inorganic filler powder and 10 to 50 parts of a blocked polyisocyanate, and an organic solvent. The blocked polyisocyanate is obtained by blocking an isocyanate group in a polyisocyanate with a blocking agent. The blocking agent deblocks the blocked polyisocyanate to give active isocyanate groups after the blocked polyisocyanate is heated to a deblocking temperature above 100 ℃. A method of preparing the photosensitive resin composition is also provided.

Description

Photosensitive resin composition and preparation method thereof

The invention relates to a photosensitive resin composition, in particular to a photosensitive resin composition used for manufacturing ink coatings, dry films, photoresists for printed circuit boards, and solder resist insulating layers, and a preparation method thereof.

At present, the solder resist green paint ink for printed circuit boards is used to provide an external protective layer that is heat-resistant, moisture-resistant and chemical-resistant on the side of the exposed conductive circuit to prevent short circuit caused by lead-tin soldering, and it can also protect The conductive circuit is not corroded by solvents and acid solution, thereby maintaining the good electrical insulation of the printed circuit board.

The packaging of the solder mask green paint ink usually adopts two-component type, namely main agent and hardener. Among them, the main agent mainly includes epoxy acrylate with light curing properties, and the hardener mainly includes epoxy resin with heat curing properties, and the two can be used after being mixed in a corresponding ratio. In order to make the solder resist green paint ink have solubility (ie, developability), epoxy acrylate usually incorporates carboxyl groups (-COOH). However, the epoxy group of epoxy resin reacts slowly with the carboxyl group of epoxy acrylate at room temperature, so that the solder mask green paint ink must be stored at low temperature, which greatly increases storage cost and storage risk.

In view of this, it is necessary to provide a photosensitive resin composition and a preparation method thereof that can solve the above-mentioned problems.

A photosensitive resin composition, in parts by weight, comprising 100 parts of modified polyvinyl alcohol, 10-50 parts of photosensitive monomer, 5-15 parts of photoinitiator, 1-20 parts of colorant, 5-30 parts of inorganic filler powder, 10-50 parts of blocked polyisocyanate, and organic solvent, wherein the blocked polyisocyanate is prepared by using a blocking agent to block isocyanate groups in the polyisocyanate. The blocking agent deblocks the blocked polyisocyanate to obtain active isocyanate groups after heating the blocked polyisocyanate to a deblocking temperature higher than 100°C.

A preparation method of a photosensitive resin composition, comprising: in parts by weight, 100 parts of modified polyvinyl alcohol, 10-50 parts of photosensitive monomer, 5-15 parts of photoinitiator, and 1-20 parts The color material, 5~30 parts of inorganic fillers, and 10~50 parts of blocked polyisocyanate are mixed with organic solvents to prepare a mixture, wherein the blocked polyisocyanate adopts a blocking agent to carry out isocyanate groups in the polyisocyanate. Is prepared by blocking, the blocking agent deblocks the blocked polyisocyanate to obtain active isocyanate groups after heating the blocked polyisocyanate to a deblocking temperature higher than 100°C; and stirring the mixture to make the The modified polyvinyl alcohol, the photosensitive monomer, the color material, the inorganic filler, and the blocked polyisocyanate are dissolved in the organic solvent to prepare the photosensitive resin composition.

Since the photosensitive resin composition of the present invention uses a blocked polyisocyanate for the thermal curing reaction, it needs to be unblocked at a specific temperature to become active, so there is no storage problem. In addition, the photosensitive resin composition formula is easy to operate, and has no solvent volatilization and odor problems.

The photosensitive resin composition according to a preferred embodiment of the present invention can be used to manufacture ink coatings, dry films, photoresists for printed circuit boards, and solder resist insulating layers. The photosensitive resin composition, in parts by weight, includes 100 parts of modified polyvinyl alcohol (PVA, Polyvinyl alcohol), 10 to 50 parts of photosensitive monomer, 5 to 15 parts by weight of photoinitiator, 1 ~20 parts of colorant, 5~30 parts of inorganic filler and 10~50 parts of blocked polyisocyanate. Wherein, the photosensitive resin composition does not include epoxy resin. In this embodiment, the photosensitive resin composition further includes an appropriate amount of organic solvent to adjust the viscosity of the photosensitive resin composition. The modified polyvinyl alcohol is obtained by forming an Acryl group on the side chain of the polyvinyl alcohol. The degree of alcoholysis of the modified polyvinyl alcohol is 78-89%. In addition, a hydroxyl group (-OH) is formed on the side chain of the modified polyvinyl alcohol. The photosensitive monomer is used to increase the viscosity and adhesion of the photosensitive resin composition. The molecular structure of the photosensitive monomer contains a benzene ring and a vinyloxy group. In this embodiment, the number of reactive functional groups of the photosensitive monomer is not less than 2, and the number of vinyloxy groups is between 4 and 30. . Specifically, the functional group of the photosensitive monomer is selected from the following functional groups: (meth)acrylate (Polyethylene Glycol Di(meth)acrylate [PEGD(M)A]), ethoxylated 1,6-hexanediol two Acrylate (Ethoxylated 1,6-Hexanediol Diacrylate[HD(EO)DA]), Ethoxylted bisphenyl fluorene diacrlate[BPF(EO)DA]), ethoxylated bisphenol A bis(formaldehyde) Ethoxylated Bisphenol-A Di(meth)acrylate[BPA(EO)D(M)A]), ethoxylated trimethylolpropane tri(meth)acrylate (Ethoxylated Trimethylolpropane Tri(meth) acrylate[TMP(EO)T(M)A]), Ethoxylated Pentaerythritol Tetraacrylate[PE(EO)TA]) And ethoxylated dipentaerythritol hexaacrylate (Ethoxylated Dipentaerythritol Hexaacrylate [DPE(EO)HA]).

The photoinitiator can be a compound such as α-hydroxy ketone, acetoxy, α-amino ketone and oxime ester, but is not limited thereto. More specifically, the photoinitiator is preferably selected from 2-hydroxy-2-methyl-1-phenyl-1-propanone (abbreviated as 1173), 1-hydroxy-cyclohexyl-phenyl ketone (Abbreviation 184), 2,4,6-trimethylbenzyl-diphenylphosphine oxide (abbreviated as TPO), phenylbis(2,4,6-trimethylbenzyl)phosphine oxide ( (Referred to as 819 or 819DW), 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone (referred to as 907), phenylbis(2,4,6-trimethyl) Benzoyl) phosphine oxide, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone (abbreviated as 369), benzoin dimethyl ether, benzophenone (Abbreviated as BP), isopropyl thioxanthone (ITX), oxazole oxime resin, but not limited to this.

The colorant is used to make the photosensitive resin composition present a desired color, and it can be selected from at least one of pigments and dyes. The pigment may be selected from at least one of inorganic pigments and organic pigments. In this embodiment, the pigment may be selected from one of phthalocyanine blue, phthalocyanine green, crystal violet, permanent yellow, titanium dioxide, carbon black, iron oxide black, and aniline black. The dye may be an organic dye, and more specifically, the dye may be at least one of a natural organic dye and a synthetic organic dye. In this embodiment, the dye can be selected from Kayase Red-B, Black-AN, Blue-N (standard models in the chemical industry) produced by Nippon Kayaku Co., Ltd., Neozapon Red 355, Orasol Black-B produced by BASF Co., Ltd. One of X55, Oracet Yellow-144FE (standard model in the chemical industry), etc.

The inorganic filler is selected from one or more of barium sulfate, talc, silicon dioxide, calcium hydroxide, magnesium hydroxide and calcium carbonate. In this embodiment, barium sulfate is used as the inorganic filler.

)中具有反應活性的異氰酸酯基團(-NCO)進行封閉而制得，且所述封閉劑在所述封閉型聚異氰酸酯被加熱到高於常溫之一預設溫度(即解封閉溫度，100~180℃)後才會解封閉所述封閉型異氰酸酯基團得到具有反應活性的異氰酸酯基團(-NCO)。由於所述感光樹脂組合物中不包括環氧樹脂，且所述封閉型聚異氰酸酯在高於該解封閉溫度時，所述異氰酸酯基團才會被解封閉而與所述改質聚乙烯醇中的羥基進行交聯反應形成網狀結構，而在低於該解封閉溫度(如常溫，低於100℃)時，所述異氰酸酯基團被封閉而無反應活性，從而有利於所述感光樹脂組合物在常溫下存儲。 The blocked polyisocyanate is a block agent (BL) to polyisocyanate (chemical formula is

) Is prepared by blocking the reactive isocyanate group (-NCO), and the blocking agent is heated to a preset temperature higher than normal temperature in the blocked polyisocyanate (that is, the deblocking temperature, 100~ After 180° C.), the blocked isocyanate group can be unblocked to obtain a reactive isocyanate group (-NCO). Since the photosensitive resin composition does not include epoxy resin, and when the blocked polyisocyanate is higher than the deblocking temperature, the isocyanate groups will be deblocked and be combined with the modified polyvinyl alcohol. The hydroxyl group undergoes cross-linking reaction to form a network structure, and when the deblocking temperature is lower than the deblocking temperature (such as normal temperature, lower than 100°C), the isocyanate group is blocked without reactivity, which is beneficial to the photosensitive resin combination The objects are stored at room temperature.

)可由六亞甲基二異氰酸酯(Hexamethylene diisocyanate，HDI，即R為-(CH₂)₆-) 聚合而成(簡稱HDI聚異氰酸酯)，或由異佛爾酮二異氰酸酯 (Isophorone diisocyanate，IPDI，即R為

)聚合而成(簡稱IPDI聚異氰酸酯)。所述異氰酸酯基團的封閉和解封閉反應如下反應式所示：R-N=C=O+BL-

R-NH-(=O)-BL In this embodiment, the polyisocyanate may be an aromatic polyisocyanate or an aliphatic polyisocyanate. Wherein, the aromatic polyisocyanate can be polymerized by 2,4-toluene diisocyanate (2,4-Toluene diisocyanate, TDI) (abbreviated as TDI polyisocyanate), or can be composed of diphenylmethane diisocyanate (4,4'- Diphenyl-methane diisocyanate, MDI) polymerized (abbreviated as MDI polyisocyanate). The aliphatic polyisocyanate (chemical formula is

) Can be polymerized by hexamethylene diisocyanate (Hexamethylene diisocyanate, HDI, that is, R is -(CH ₂ ) ₆ -) (referred to as HDI polyisocyanate), or by isophorone diisocyanate (Isophorone diisocyanate, IPDI, namely R is

) Polymerization (referred to as IPDI polyisocyanate). The blocking and unblocking reactions of the isocyanate group are shown in the following reaction formula: RN=C=O+BL-

R-NH-(=O)-BL

The blocking agent can be selected from ε-caprolactam (ε-CAP), ketoxime (methylethylketoxime, MEKO), dimethylpyrazole (3,5-dimethylpyrazole, DMP) and diethylmalonate (diethylmalonate). , DEM), etc. The type of the blocking agent will affect the deblocking temperature and thermal curing temperature of the isocyanate group. Wherein, when the blocking agent is caprolactam, the deblocking temperature of the isocyanate group is 160-180°C; when the blocking agent is ketoxime, the deblocking temperature of the isocyanate group is 140 -160℃; when the blocking agent is dimethyl leather, the deblocking temperature of the isocyanate group is 110-120℃; when the blocking agent is diethyl propionate, the isocyanate group The unblocking temperature is 100-120℃.

The organic solvent may be methyl ethyl ketone (MEK), diethylene glycol butyl ether and the like. In this embodiment, methyl ethyl ketone (MEK) is used as the organic solvent.

A preferred embodiment of the present invention also provides a method for preparing the above-mentioned photosensitive resin composition, which includes the following steps: Step 1: In parts by weight, 100 parts of modified polyvinyl alcohol and 10-50 parts of photosensitive resin Body, 5~15 parts of photoinitiator, 1~20 parts of colorant, 5~30 parts of inorganic filler, and 10~50 parts of blocked polyisocyanate mixed with an organic solvent to prepare a mixture; Step 2: Stir the mixture to dissolve the modified polyvinyl alcohol, the photosensitive monomer, the colorant, the inorganic filler, and the blocked polyisocyanate in the organic solvent, thereby preparing the photosensitive Resin composition.

Wherein, the main reaction mechanism of the photosensitive resin composition is the first stage of UV light curing (radical polymerization), the photosensitive monomer group cross-linking; the second stage of high temperature thermal curing, the blocked polyisocyanate is deblocked to produce active The isocyanate group (-NCO) then cross-links with the hydroxyl group (-OH) of the PVA side chain to form a denser network structure and improve the basic physical properties.

In this embodiment, the organic solvent is methyl ethyl ketone. It can be understood that the content of the organic solvent can be changed according to actual needs, as long as the components can be dissolved in it. Hereinafter, the present invention will be specifically described in conjunction with examples and comparative examples.

Example 1

Add 100 parts of photosensitive polyvinyl alcohol polymer (molecular weight 40000g/mol, degree of alcoholysis 78%), 20 parts of acrylate monomer dipentaerythritol hexaacrylate (DPHA), 8 parts of photoinitiator in order in a 500ml reaction flask (819DW), 10 parts of colorant, 100 parts of pure water, 15 parts of barium sulfate and 20 parts of water-based blocked polyisocyanate, which are stirred and dissolved to complete the configuration of the photosensitive resin composition.

Example 2

In a 500ml reaction flask, 100 parts of photosensitive polyvinyl alcohol polymer (molecular weight 40000g/mol, alcoholysis degree 78%), 20 parts of acrylate monomer ethoxylated trimethylolpropane triacrylate [TMP( 15EO)TA], 8 parts of photoinitiator (819DW), 10 parts of colorant, 100 parts of pure water, 15 parts of barium sulfate and 20 parts of water-based blocked polyisocyanate, stirred and dissolved to complete the configuration of the photosensitive resin composition .

Example 3

Add 100 parts of photosensitive polyvinyl alcohol polymer (molecular weight 40000g/mol, alcoholysis degree 78%) and 20 parts of acrylate monomer ethoxy bisphenol A diacrylate [BPA(20EO)DA ], 8 parts of photoinitiator (819DW), 10 parts of colorant, 100 parts of pure water, 15 parts of barium sulfate and 20 parts of water-based blocked polyisocyanate, stirred and dissolved to complete the configuration of the photosensitive resin composition.

Comparative example 1

Add 100 parts of acrylate prepolymer (molecular weight 10000g/mol, acid value 100mgKOH/g), 20 parts of photosensitive monomer dipentaerythritol hexaacrylate (DPHA), and 8 parts of photoinitiator (819DW) into a 500ml reaction flask. ), 10 parts of colorant and 15 parts of barium sulfate, stirred and dissolved to complete the configuration of the photosensitive resin composition.

Comparative example 2

Add 100 parts of epoxy acrylic resin (molecular weight 10000g/mol, acid value 100mgKOH/g) and 20 parts of photosensitive monomer ethoxylated trimethylolpropane triacrylate [TMP(15EO)TA into a 500ml reaction flask in sequence ], 8 parts of photoinitiator (819DW), 10 parts of colorant, 15 parts of barium sulfate and 30g of MEK, stirred and dissolved to complete the configuration of the photosensitive resin composition.

Comparative example 3

Add 100 parts of epoxy acrylic resin (molecular weight 10000g/mol, acid value 100mgKOH/g), 20 parts of photosensitive monomer ethoxy bisphenol A diacrylate [BPA(20EO)DA], 8 Parts of photoinitiator (819DW), 10 parts of colorant, 15 parts of barium sulfate, and 30g of MEK are stirred and dissolved to complete the configuration of the photosensitive resin composition.

The photosensitive resin compositions prepared in Examples 1 to 3 and the resin compositions prepared in Comparative Examples 1 to 3 were used to prepare circuit boards, respectively. 100 grids of the above circuit boards Adhesion test, alkali resistance test, acid resistance test, heat resistance test, flexibility test and normal temperature storage test. Among them, the alkali resistance test is to put the above-mentioned circuit board into a 10% NaOH solution with a quality concentration to observe whether the photosensitive solder resist layer on the circuit board falls off. The acid resistance test is to put the above-mentioned circuit board into a 10% HCl solution with a quality concentration of 10% to observe whether the photosensitive solder resist layer on the circuit board falls off. The flexibility test is to test the number of times the above-mentioned printed circuit board bends 180 degrees continuously. The heat resistance test is to test that the photosensitive solder resist layer does not produce blistering, peeling, etc. when the test temperature is 260°C, 30sec and the test time is 30 seconds. The normal temperature storage test is to store the photosensitive resin composition prepared in the above Examples 1 to 3 and the resin composition prepared in Comparative Examples 1 to 3 respectively for 1 month before preparing a circuit board, and repeat the above-mentioned Hundred Adhesion Test And heat resistance test to analyze whether the test results are different. If there is no difference in the test results, it indicates that there is no quality during the storage process; otherwise, it indicates that the storage process has undergone qualitative changes. Please refer to the information in Table 1 for the test results.

The photosensitive resin composition and its preparation method use modified polyvinyl alcohol to have photosensitivity, which can improve the basic physical properties of the film surface through UV crosslinking and thermal curing secondary crosslinking, so that the photosensitive resin composition has better properties Flexibility, acid and alkali resistance and heat resistance; at the same time, the photosensitive resin composition formula is easy to operate, no solvent volatilization and odor problems; in addition, because the heat curing reaction uses a blocked polyisocyanate, it must be specified It becomes active after temperature unblocking, so there is no storage problem.

In summary, this publication clearly meets the requirements of a patent for invention, so it filed a patent application in accordance with the law. However, the above are only the preferred embodiments of the present invention, and cannot limit the scope of patent application in this case. All the equivalent modifications or changes made by persons familiar with the technique of the present application in accordance with the spirit of the present invention shall be covered by the scope of the following patent applications.

Claims (10)

A photosensitive resin composition, in parts by weight, comprising 100 parts of modified polyvinyl alcohol, 10-50 parts of photosensitive monomer, 5-15 parts of photoinitiator, 1-20 parts of colorant, 5-30 parts of inorganic filler powder, 10-50 parts of blocked polyisocyanate, and organic solvent, wherein the blocked polyisocyanate is prepared by using a blocking agent to block isocyanate groups in the polyisocyanate. Caprolactam is used as the blocking agent, which deblocks the blocked polyisocyanate to obtain active isocyanate groups after the blocked polyisocyanate is heated to a deblocking temperature of 160-180°C. The photosensitive resin composition according to the first item of the patent application, wherein the modified polyvinyl alcohol is obtained by forming an acrylate group on the side chain of the polyvinyl alcohol. According to the photosensitive resin composition described in item 1 of the scope of the patent application, the side chain of the modified polyvinyl alcohol is further formed with a hydroxyl group. The photosensitive resin composition according to item 3 of the scope of patent application, wherein the hydroxyl group of the modified polyvinyl alcohol can undergo a crosslinking reaction with the reactive isocyanate group to form a network structure. The photosensitive resin composition described in item 1 of the scope of patent application, wherein the alcoholysis degree of the modified polyvinyl alcohol is 78-89%. The photosensitive resin composition as described in item 1 of the scope of patent application, wherein the molecular structure of the photosensitive monomer contains a benzene ring and a vinyloxy group, and the number of reactive functional groups of the photosensitive monomer is greater than or equal to 3. The number of said vinyloxy groups is between 4-30. The photosensitive resin composition according to item 1 of the scope of patent application, wherein the photoinitiator is selected from α-hydroxy ketone compounds, phosphine oxides, α-amino ketone compounds and oxime ester compounds At least one of. The photosensitive resin composition as described in item 1 of the scope of patent application, wherein the polyisocyanate is an aliphatic polyisocyanate, and the aliphatic polyisocyanate is formed by polymerizing hexamethylene diisocyanate. According to the photosensitive resin composition described in item 1 of the scope of the patent application, wherein the sealing agent is selected from one of self-lactam, ketoxime, dimethyl aniline and diethyl propionate. A preparation method of a photosensitive resin composition, comprising: in parts by weight, 100 parts of modified polyvinyl alcohol, 10-50 parts of photosensitive monomer, 5-15 parts of photoinitiator, and 1-20 parts The color material, 5~30 parts of inorganic fillers, and 10~50 parts of blocked polyisocyanate are mixed with organic solvents to prepare a mixture, wherein the blocked polyisocyanate adopts a blocking agent to carry out isocyanate groups in the polyisocyanate. It is prepared by blocking, the blocking agent adopts caprolactam, and the blocking agent deblocks the blocked polyisocyanate after heating the blocked polyisocyanate to a deblocking temperature of 160-180°C to obtain an active isocyanate Group; and stirring the mixture to dissolve the modified polyvinyl alcohol, the photosensitive monomer, the colorant, the inorganic filler and the blocked polyisocyanate in the organic solvent, thereby preparing the Photosensitive resin composition.