TWI411625B - Oligomers and thermosetting photosensitive resin compositions - Google Patents

Abstract

Oligomers and thermosetting photosensitive resin compositions are provided. The Oligmers are formed by a reaction product obtained by reacting a diol compound, a polyol compound, an acid dianhydride compound and a double-bond containing a compound having an alcohol group.

Description

Polymer oligomer and thermosetting photosensitive resin composition

The present invention relates to a photopolymerizable, thermosetting photosensitive resin composition, and more particularly to a photosensitive resin composition applied to a flexible printed circuit board.

Printed circuit boards are the main support for the installation and interconnection of electronic components and are essential for all electronic products.

In recent years, due to the demand of the mobile phone and the flat panel display industry, the demand for a thin and light flexible printed circuit board (FPC) has been greatly increased. Furthermore, due to the trend of light, short, portable, high-function, high-density electronic products, and the high-I/O number, miniaturization, and small-area requirements of electronic components, the material properties required for use are becoming stricter. Harsh.

In a flexible printed circuit board process, when a wiring pattern is formed on a substrate by means of screen printing or the like, it is usually necessary to cover a material layer on the outside to protect the protection circuit pattern. In addition, when soldering electronic components on a printed circuit board, in order to protect the portion of the wiring that does not need to be soldered, it is necessary to cover the printed circuit board with a protective layer such as solder resist ink.

The solder resist ink generally used for flexible printed circuit boards is mainly composed of a polyfunctional epoxy resin and a light or heat sensitive compound, and the cured film layer has good heat resistance or solder resistance. It is worth noting that for flexible printed circuit boards, the resistance to bending after the solder resist ink used is particularly important. However, traditional flexible printed circuit boards have good heat resistance. And solder resistance, but after a long time or frequent deflection, the adhesion or yield between the solder resist ink and the substrate and the line is not good.

Therefore, there is a need for a new solder mask ink that solves the above problems.

One of the objects of the present invention is to provide a photopolymerizable, thermosetting photosensitive resin composition which can be applied to paints, inks, photoresists for printed circuit boards, photosensitive insulating layers and the like.

A second object of the present invention is to provide a photosensitive resin composition having good adhesion, solder resistance, heat resistance, high developability, chemical resistance, and buckling property, which can be used as a flexible printed circuit board. Solder resist ink (green paint).

In order to achieve the above object, the present invention provides a high molecular oligomer characterized by reacting a diol compound, a polyol compound, a bis-anhydride compound, and a double bond compound having an alcohol group. The composition of the product. Further, the above polymer oligomer is a random copolymer.

In order to achieve the above object, the present invention further provides a high molecular oligomer having the following structural formula:

Where R ₁ is or ; R ₂ is C ₁ -C ₂₀ alkyl: R ₃ is C ₁ -C ₄ alkyl or ; R ₄ is CH ₃ or hydrogen; m is an integer from 1 to 100; and n is an integer from 1 to 100.

The invention is described in detail below. The photopolymerizable and thermosetting photosensitive resin composition used in the present invention mainly comprises: (1) a resin main body: a bisphenol-based modified product (T1) and optionally a cresol epoxy resin modified product ( C1), at least one of a bisphenol epoxy modified substance (C2) or a phenolic epoxy modified substance (C3); (2) a photosensitive initiator; (3) a photopolymerizable photosensitive monomer and/or Photosensitive oligomer; (4) an epoxy hardener containing at least 2 epoxy groups; and (5) an organic solvent.

The first resin body of the photosensitive resin composition contains a diol-based modified substance (T1) in an amount of 10 to 50 by weight, preferably 20 to 40 by weight; and the second resin body: cresol epoxy resin The substance (C1), the bisphenol epoxy resin modified substance (C2) or the phenolic epoxy resin modified substance (C3), the content of which is 5 to 40 by weight, preferably 10 to 30 by weight; (2) photosensitive The initiator: the content is 1 to 10 by weight, preferably 3 to 7 by weight; (3) the photopolymerizable photosensitive monomer and/or the photosensitive oligomer: the content is 1 to 10 by weight, preferably 3 ~7 by weight; (4) epoxy hardener containing at least 2 epoxy groups; content of 3 to 20 by weight, preferably 6 to 15 by weight; (5) organic solvent; content of 10 to 40 weight ratio, It is preferably 15 to 30 by weight.

The diol-based modified substance (T1) in the above (1) resin main body can be, for example, tricyclo[5,2,1,0 ^2,6 ]indole dimethanol (Tricyclo[5,2,1,0 ^{2, 6} ] decanedimethanol) obtained by reacting a diol-based compound, a bis-anhydride compound, a polyol compound, and a double bond compound having an alcohol group. Preferably, the bis-alcohol-based modifier (T1) has an acid value of between about 10 and 200 mg KOH/g and a weight average molecular weight of from about 1,000 to about 100,000 g/mol.

The bis-anhydride compound suitable for the synthesis of the above diol-based modified material (T1) is, for example, pyromellitic dianhydride, benzophenone tetracarboxylic dianhydride, diphenyltetracarboxylic dianhydride. (biphenyl tetracarboxylic dianhydride), diphenyl sulfo tetracarboxylic dianhydride, butan tetracarboxylic dianhydride, or ethylene glycol bis (anhydro- Trimellitate)) or a combination thereof.

Polyol compounds suitable for the synthesis of the above-mentioned diol-based modified material (T1) include, for example, polytetramethylene glycol, bisphenol-A ethylene oxide addition (ethylene oxide) Additament), propylene oxide additament of bisphenol-A, copolymer of methacrylic acid ester (meth), methacrylic acid polyol (meth) Acrylic polyol) copolymer, butadiene copolymer, polybutadiene polyol, or alkyl alcohol at both ends of dimethyl polysiloxane A phenolic polyol or a combination thereof containing a phenol molecule.

The double bond compound having an alcohol group suitable for the synthesis of the above diol-based modified material (T1) is, for example, 2-hydroxy ethyl acrylate, 2-hydroxy-ethyl methacrylate (2-hydroxyethyl(meth)acrylate), 2-hydroxyl propyl(meth)acrylate, glycidoldi(meth)acrylate, or top three A polyhydroxy compound such as pentaerythritol tri(meth)acrylate or a combination thereof.

Suitable as the above (2) photoinitiator includes: acetophenone, such as 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinepropan-1-one (2-methyl-1-4-(methylthio)phenyl)-2-morpholinopropane-1-one), 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2 -2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, diethoxyacetophenone, 1-hydroxyl ring 1-hydroxy cyclohexyl phenyl ketone, etc.; Benzoquinone, such as Benzoquinone methyl ether, Benzoquinone ethyl ether, Benzoquinone propyl Ether), Benzoquinone isobutyl ether, etc.; Thioxanthone, such as 2-isopropyl thioxanthone, 2-chlorosultone (2-chloro) Thioxanthone); ketal, such as acetophenone ketal (acetophenonedimethyl ketal), Benzyldimethyl ketal, etc.; benzophenones such as benzophenone, 4,4-bismethyl-aminobenzophenone ( 4,4-bismethylaminobenzophenone); phosphine oxides, such as 2,4,6-trimethylbenzoyldiphenyl phosphine oxide; Compound (Metallocene), such as Bis(.eta.5,2,4-cyclopentadiene-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl)titanium; hydroxyketone (Hydroxyketones), such as 1-hydroxy-cyclohexyl-phenyl-ketone; Phenylglyoxylate or Oxime. These may be used singly or in combination of two or more kinds, and may also be a tertiary amine such as triethanolamin or methyldiethanolamin or N,N-dimethylaminobenzoic acid ethyl ester (N, N-dimethylamino benzoic acid ethylester), a benzoic acid accelerator such as N,N-dimethylamino benzoic acid isoamylester.

Suitable hardeners for the above-mentioned photosensitive resin composition are, for example, bisphenol F novolak epoxy, phenol novolac epoxy or bisphenol A novolak epoxy. ) or a combination thereof.

Suitable as the above (3) photopolymerizable photosensitive monomer and/or photosensitive oligomer photosensitive resin: carbitol (meth) acrylate, diethylene glycol ethyl ether acetate Carbitol acetate, benzene Phenoxy ethyl (meth)acrylate, acryloyl morpholine, bisphenol A polyethoxydi(meth)acrylate , Tri-methylolpropane tri(meth)acrylate, pentaerythritol tetrakis (meth)acrylate, 2-hydroxyethyl Diluent of photopolymerizable monomer such as 2-hydroxyethyl acrylate, dipropylene glycol monomethyl ether or dipentaerythritol hexa (meth) acrylate Or a combination thereof.

Suitable as the epoxy curing agent containing at least two epoxy groups as the above (4), for example, Cresol Novolac Epoxy, Bisphenol-A Novolac Epoxy, Bisphenol-F Novolac Epoxy Or Phenol Novolac Epoxy, they can be used alone or in combination.

The above-mentioned (5) organic solvent may be an ether, an ester, an ether ester or an aromatic hydrocarbon, and each of the above organic solvents may be used singly or in combination.

In addition to the above (1) to (5), organic or inorganic fillers such as talc, barium sulfate, calcium carbonate, magnesium carbonate, barium titanate, and aluminum hydroxide may be added. Aluminum hydroxide), fillers such as alumina, ceria, silica, and clay; pigments such as phthalocyanine blue, phthalocyanine green, or titanium oxide; produced by AEROSIL Thixotropy auxiliaries; flat agents for bismuth and fluorine series and KS66 for sale by Shinetsu a foaming agent; or a polymerization inhibitor such as hudroquinone, hydroquinone monomethyl ether or the like.

Diol-based modified substance (T1) synthesis example

The tricyclo [5,2,1,0 ^2,6] decanedimethanol ^{(Tricyclo [5,2,1,0 2,6] decanedimethanol)} ( molecular weight 164 g / mole) 24.6g (0.15 mole), Pyromollic acid anhydride (molecular weight 218 g / mol) 130.8 g (0.6 mol), polytetramethylene glycol (PTMG) (weight average molecular weight 1000 g / mol) 300 g ( 0.3 mol of dimethyl alcohol and 125 g of carbitol acetate were placed in a reaction flask and heated to 100 ° C for 10 hours. Next, 2-hydroxyethyl acrylate (molecular weight 122 g/mole) 36.6 g (0.3 mol) and methyl hydroxyquinone 0.32 g were placed in the above reaction bottle. And reacting at 95 ° C for 6 hours to obtain a diol-based modified product (T1) having a weight average molecular weight of 8,000, an acid value of 105 mg KOH/g, and a solid content of about 80% with a carboxylic acid group and a double bond. Its structural formula is as follows:

Where R ₁ is or ; R ₂ is C ₁ -C ₂₀ alkyl: R ₃ is C ₁ -C ₄ alkyl or ; R ₄ is CH ₃ or hydrogen; m is an integer from 1 to 100; and n is an integer from 1 to 100.

Synthesis example of cresol epoxy resin modified substance (C1)

220 g of carbitol acetate, 220 g of light oil (naphtha 150) and 460 g of cresol novolak epoxy (softening point 92.5 ° C) were placed in a reaction flask and heated to 90 ° C. Next, 0.4 g of hydroquinone, 134 g of acrylic acid (1.84 g/mole) and 2.5 g of triphenylphosphine were added, stirred and heated to 110 ° C and at least 10 After an hour, tetrahydrophthalic anhydride (molecular weight 152 g/mole) 123.1 g (0.8 mol) was added, and reacted at 110 ° C for 8 hours to obtain a cresol ring having an acid value of 72.5 mg KOH/g. Oxygen resin modification (C1).

Synthesis example of bisphenol A epoxy resin modified substance (C2)

220 g of carbitol acetate, 220 g of light oil (naphtha 150) and 400 g of bisphenol A novolak epoxy (softening point 63.5 ° C) were placed in a reaction flask and heated to 90 ° C. . Next, adding 0.4 g of hydroquinone, 134 g (1.8 mol) of acrylic acid (molecular weight 74.4 g/mole) and 2.5 g of triphenylphosphine, stirring and heating to 110 ° C at least 10 After an hour, tetrahydrophthalic anhydride (molecular weight 152 g/mole) 123.1 g (0.8 mol) was added, and reacted at 110 ° C for 8 hours to obtain a bisphenol A ring having an acid value of 73.6 mg KOH/g. Oxygen resin modification (C2).

Phenolic epoxy resin modified substance (C3) synthesis example

220 g of carbitol acetate, 220 g of light oil (naphtha 150) and 360 g of phenol novolak epoxy (softening point below room temperature) were placed in a reaction flask and heated to 90 °C. Next, adding 0.4 g of hydroquinone, 134 g (1.8 mol) of acrylic acid (molecular weight 74.4 g/mole) and 2.5 g of triphenylphosphine, stirring and heating to 110 ° C at least After 10 hours, tetrahydrophthalic anhydrid (molecular weight 152 g/mole) 123.1 g (0.8 mol) was added, and reacted at 110 ° C for 8 hours to obtain a phenolic acid having an acid value of 74.3 mg KOH/g. Epoxy resin modification (C3).

Example 1-7: Preparation of photosensitive resin composition

Mixing the above diol-based modified substance (T1), cresol epoxy modified substance (C1), bisphenol A epoxy modified substance (C2), and phenolic epoxy modified substance (C3) according to Table 1 Mix and mix in proportions.

Next, the photoinitiator was separately added: 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinepropan-1-one (2-methyl-1-4-(methylthio)) Phenyl)-2-morpholinopropane-1-one; Irgacure 907, produced by Ciba) 40 g, 2-isopropylthioxanthone (ITX; 2-isopropylthioxanthone) 10 g, photosensitive monomer (pentaerythritol hexaacrylate) 50 g, defoamer (KS-66, produced by Shinetsu Co., Ltd.) 10 g, catalyst: 10 g of melamine (Melamine) and 1 g of (dicyandiamide), and an additive: barium sulfate (B30, manufactured by Sakai Co., Ltd.) 31.4 g, 40 g of cerium oxide (R-972, manufactured by Degusa Co., Ltd.) and 3 g of a green coloring material (phthalocyanine green) were placed in a three-roll mill to uniformly disperse the photosensitive resin composition. Finally, an appropriate amount of dipropylene glycol monomethyl ether is added to prepare a photosensitive resin composition having a viscosity of 200 to 250 ps to become a main component.

On the other hand, 28 g of bisphenol F novolak epoxy (BEF-170) manufactured by Changchun Co., Ltd., and a phenolic ring containing 20% of carbitol acetate manufactured by Changchun Co., Ltd. 80g of phenol novolak epoxy (PNE-177) and 20% of carbitol acetate manufactured by Changchun Company The bisphenol A novolak epoxy (BNE-200) 42g was mixed and stirred to become a hardener.

Comparative Example 1-3: Preparation of photosensitive resin composition

The photosensitive resin composition of Comparative Example 1-3 was prepared in the same manner as in Example 1-3, according to the chemicals and the amounts shown in Tables 1 and 2. It is to be noted that the composition of Comparative Example 1-3 was not added with the diol-based modified product (T1).

Photosensitive resin composition evaluation

The main agent and the hardener shown in Table 2 were mixed and stirred at a ratio of 850 to 150, and then coated on a copper foil substrate using a 100 mesh screen, placed in a closed oven, and baked at 80 ° C. The film was dried in a minute to form a photosensitive resin composition having a film thickness of 25 to 30 μm. Next, the line pattern on the mask negative was transferred to the photosensitive resin composition at an exposure energy of 500 mJ/cm ² using an exposure machine manufactured by C SUN Co., Ltd. of 5 KW power, and a photohardening reaction was performed. Subsequently, the copper foil substrate coated with the photosensitive resin composition described above was placed in a developing machine at a concentration of 1% sodium carbonate (Na ₂ CO ₃ ) at a temperature of 30 ° C and a spray pressure of 1.5 to 2 kg/cm ² . Development under process conditions for 60 seconds. Next, the copper foil substrate was placed in a closed oven, baked at 150 ° C for 60 minutes, subjected to a thermosetting reaction, and tested for developability, tin-repellent resistance, buckling resistance, resolution, and chemical resistance. . The results are shown in Table 3. The criteria for the determination of each of the tests are as follows: (1) Developability: After development, the residual state of the photosensitive resin composition in the developed region was visually observed, and no residue was recorded as ○, and if it remained, it was recorded as ×.

(2) Resistance to soldering tin: Coating rosin-based flux (Tianlong 8650N type) on the above-mentioned thermosetting copper foil substrate, placed in a soldering furnace at 280 ° C for 10 seconds, and then peeling test with tape, visual observation In the peeled state of the photosensitive resin composition formed on the copper foil substrate, no peeling was recorded as ○, and when peeled off, it was recorded as ×.

(3) Buck resistance: The copper foil substrate was bent by 180 degrees, and the cracked or peeled state of the curved region was observed. No crack was recorded as ○, slight crack was recorded as Δ, and peeling was recorded as ×.

(4) Resolution: After development, the line width/line distance of the line pattern is visually observed, and the line pattern of 50 μm can be analyzed as ○, and the line pattern of 50 to 100 μm can be recorded as △, if 100 μm If the above line pattern still cannot be resolved, it will be recorded as ×.

(5) Chemical resistance: The above-mentioned hardened copper foil substrate was immersed in a sulfuric acid solution having a volume percentage of 10% for 20 minutes, and then rinsed with water and dried to remove moisture. Then, the peeling test was carried out with a tape, and the peeling state of the photosensitive resin composition formed on the copper foil substrate was visually observed, and the peeling-free recording was ○, the slight peeling recording was Δ, and the peeling was marked as ×.

From the results of the physical property test of Table 3, it was found that the photosensitive resin composition of Example 1-7 to which the diol-based modified product (T1) was added had good developability and solder-repellent resistance as compared with Comparative Example 1-3. Resistance to buckling, resolution, and chemical resistance; on the contrary, the photosensitive resin composition of Comparative Example 1-3 in which the diol-based modified product (T1) was not added had good developability and resistance to drifting tin Sexuality and resolution, but its resistance to flexion is not good. In particular, in Comparative Example 1, in addition to poor buckling resistance, chemical resistance was not good.

It is worth noting that since the diol-based modified material (T1) can form a linear aliphatic group and a heterocyclic structure having better heat resistance after addition polymerization, the diol-based modified substance (T1) has a higher benzene ratio. The soft structure of the ring structure. Therefore, the use of the photosensitive resin composition containing the diol-based modified material (T1) as the solder resist ink of the flexible printed circuit board can improve the buckling resistance in addition to the preferable heat resistance.

Although the present invention has been disclosed in the above preferred embodiments, it is not intended to limit the present invention, and the present invention can be modified and retouched without departing from the spirit and scope of the present invention. The scope of protection is subject to the definition of the scope of the patent application attached.

Claims (13)

A high molecular oligomer consisting of a product obtained by reacting a diol compound, a polyol compound, an acid dianhydride, and a double bond compound having an alcohol group, wherein the alcohol compound bis (diol compound) of tricyclo [5,2,1,0 ^2,6] decanedimethanol ^{(tricyclo [5,2,1,0 2,6] decanedimethanol)} . The polymer oligomer according to claim 1, wherein the polyol compound is an ethylene oxide selected from the group consisting of at least one polytetramethylene glycol and bisphenol A. Ethylene oxide additament, propylene oxide additament of bisphenol-A, copolymer of methacrylic acid ester (meth), methacrylic acid Polyol (meth) acrylic polyol copolymer, polybutadiene polyol, and alkyl alcohol at both ends of dimethyl polysiloxane contain phenol A group of phenolic molecules or a combination thereof. The polymer oligomer according to claim 1, wherein the bis-anhydride compound is selected from the group consisting of at least one pyromellitic dianhydride, benzophenone tetracarboxylic dianhydride, and Biphenyl tetracarboxylic dianhydride, diphenyl sulfo tetracarboxylic dianhydride, butan tetracarboxylic dianhydride, and ethylene glycol dibenzoate A group consisting of ethylene glycol bis (anhydro-trimellitate) or a combination thereof. The high molecular oligomer according to claim 1, wherein the double bond compound having an alcohol group is selected from the group consisting of at least one 2-hydroxy ethyl acrylate, 2-hydroxyl - 2-hydroxy ethyl (meth)acrylate, 2-hydroxyl propyl (meth)acrylate, glycidyl dimethacrylate (glycidoldi (meth) Acetate), and a group consisting of pentaerythritol tri(meth)acrylate or a combination thereof. The high molecular oligomer according to claim 1, wherein the high molecular oligomer is a random copolymer (Randam copolymer). The polymer oligomer according to claim 1, wherein the polymer oligomer has an acid value of 10 to 200 mg KOH/g. The polymer oligomer according to claim 1, wherein the polymer oligomer has a weight average molecular weight of 1,000 to 100,000 g/mol. A thermosetting photosensitive resin composition comprising: the high molecular oligomer according to claim 1 of the patent application, as a first resin main body; a photoinitiator; a photopolymerizable photosensitive monomer and/or Or a photosensitive oligomer; an epoxy hardener containing at least 2 epoxy groups; and an organic solvent. The thermosetting photosensitive resin composition according to claim 8 of the patent application, further comprising a cresol epoxy modified substance, a bisphenol epoxy modified substance or a phenolic epoxy modified substance as a second Resin body. The thermosetting photosensitive resin composition according to claim 9, wherein the content of the first resin body is 10 to 50 by weight; and the content of the second resin body is 5 to 40 by weight; The photoinitiator is contained in an amount of from 1 to 10 by weight; the photopolymerizable photosensitive monomer and/or photosensitive oligomer is contained in an amount of from 1 to 10 by weight; and an epoxy hardener containing at least two epoxy groups is used. The content is 3 to 20 by weight; the content of the organic solvent is 10 to 40 by weight. The thermosetting photosensitive resin composition according to claim 8, wherein the photosensitive initiator is at least one selected from the group consisting of acetophenone, Benzoquinone, and ton Tyoxanthone, ketal, benzophenone, phosphine oxide, metallocene, hydroxyketones, phenylglycolic acid Phenylglyoxylate or Oxime, which may be used singly or in combination of two or more. The thermosetting photosensitive resin composition according to claim 8, wherein the photopolymerizable photosensitive monomer and/or photosensitive oligomer is selected from at least one diethylene glycol diethyl ether (methyl) ) carbitol (meth) acrylate, carbitol acetate, phenoxy ethyl (meth) acrylate, acryloyl morpholine , bisphenol A polyethoxydi(meth)acrylate, trishydroxyl Tri-methylolpropane tri(meth)acrylate, pentaerythritol tetrakis (meth)acrylate, 2-hydroxyethyl acrylate (2) a group consisting of -hydroxyethyl acrylate), dipropylene glycol monomethyl ether, and dipentaerythritol hexa (meth) acrylate, or a combination thereof. The thermosetting photosensitive resin composition according to claim 8, wherein the epoxy hardener containing at least two epoxy groups is selected from at least one bisphenol F phenolic epoxy resin (bisphenol F novolak) Epoxy), Phenol Novolac Epoxy, and Bisphenol A Novolak Epoxy, or a combination thereof.