JP5590988B2 - Low boiling point solvent-soluble resin, and ink material and ink using the resin - Google Patents

Description

  The present invention relates to a low boiling point solvent-soluble resin, an ink material using the resin, and an ink.

  In general, in a flexible printed circuit board, in order to protect a circuit, a cover lay film in which an adhesive is applied to a plastic film such as a polyimide film or a polyester film has been covered. However, the cover lay film has a complicated circuit because the part to be exposed of the circuit is punched or drilled, and then overlaid while being aligned on the circuit board and bonded together by heat and pressure. Then, it was difficult to drill and position the coverlay film. In addition, since the adhesive used for the coverlay film has poor heat resistance and insulation reliability, these characteristics as a circuit board are inevitably poor.

  In order to solve this problem, a so-called printing method in which a printing ink composition is applied to the substrate surface has been developed and widely used. For example, Patent Document 1 discloses an ink composition containing an exci resin having two or more epoxy groups in a soluble polyimide molecule having a repeating unit, a curing agent, a solvent, and a thixotropic agent. Recently, the environmental characteristics required for substrates have become increasingly severe, and high heat resistance has been demanded.

Japanese Patent Laid-Open No. 11-172181

  However, in Patent Document 1, when 40 parts by weight of the epoxy resin described in the examples is added, although there is a short time heat resistance such as solder heat resistance, a long time heat resistance, for example, 200 ° C. for 100 hours. In this case, it can be easily estimated that physical property deterioration occurs due to deterioration. There is a need to provide ink that does not have sufficient heat resistance and meets the required heat resistance requirements. Although described in Patent Document 1, a polyimide-based ink composition has also been developed with a focus on excellent bending resistance, both of which have been printed in the state of polyamic acid, which is a polyimide precursor. Since it is imidized, water generated when the polyamic acid is ring-closed may cause foaming of the coating or may remain in the inside as it is, leading to deterioration of characteristics.

  The present invention has been made in view of such problems, and is particularly excellent in heat resistance. For example, it can be used as a printing ink composition suitable as a protective coating material for a circuit of a flexible printed circuit board, etc. It is an object to provide a boiling-point solvent-soluble resin, an ink material having heat resistance using the resin, and an ink.

As a means for solving this problem, for example, an embodiment of the present invention according to the present invention has the following configuration.
That is, a low-boiling-point solvent-soluble resin characterized by being a polyamideimide synthesized from trimellitic acid chloride and bis [4- (3-aminophenoxy) phenyl] sulfone.

  For example, the ink material is an ink material in which an organic solvent that can be dissolved in the low-boiling-point solvent-soluble resin is added. Further, for example, the ink material is characterized by being an ink obtained by adding a desired pigment or dye (or a mixture thereof) to the ink material.

  For example, the soluble organic solvent includes 1-methyl-2-pyrrolidone, dihydrofuran-2 (3H) -one, cyclopentanone, bis (2-methoxyethyl) ether, 1,2-bis (2- Any one of (methoxyethoxy) ethane is used.

  Furthermore, for example, after adding dimethylacetamide and triethylamine to bis [4- (3-aminophenoxy) phenyl] sulfone and stirring, trimellitic acid chloride is slowly added and reacted at a predetermined temperature, and aniline is added after the reaction. A polyamide solution is synthesized by stirring and then imidized to obtain a low-boiling solvent-soluble resin.

In addition, for example, acetic anhydride and pyridine are added to the polyamide solution and stirred to perform imidization.
Alternatively, an ink material comprising an organic solvent that can be dissolved in a low-boiling-point solvent-soluble resin characterized by comprising the following structural formula:

  According to the present invention, it is possible to provide a low-boiling-point solvent-soluble resin having excellent heat resistance and high reliability, and a heat-resistant ink material and heat-resistant ink using the resin.

  Hereinafter, an embodiment of an invention according to the present invention will be described in detail. In this embodiment, a low-boiling-point solvent-soluble resin excellent in heat resistance and mechanical strength, a heat-resistant ink material and a heat-resistant ink using the resin will be described.

  In this embodiment, trimellitic acid chloride (hereinafter referred to as “TAC”) represented by Structural Formula 1 below and bis [4- (3-aminophenoxy) phenyl] sulfone (Structural Formula 2) are used as raw materials. (Hereinafter referred to as “BAPS-M”), and these are synthesized to produce a polyamideimide resin (developed product) represented by Structural Formula 3.

It was confirmed that the polyamide-imide resin of the present embodiment has solubility in various organic solvents shown below.
1-methyl-2-pyrrolidone, dihydrofuran-2 (3H) -one, cyclopentanone, bis (2-methoxyethyl) ether, 1,2-bis (2-methoxyethoxy) ethane

  In addition, it was confirmed that the polyamide-imide resin of the present embodiment shown in the structural formula 3 achieved an increase in transmittance in the visible light region and achieved a cutoff wavelength of 420 mm (general polyimide has a cutoff wavelength). About 530 mm).

Because it has such high transparency, using this embodiment as an ink material can produce various colors including white, which was impossible with general polyimide resin ink. I can do it.
Moreover, as a result of the measurement, high heat resistance capable of withstanding a high temperature of Tg-227 ° C. has been realized.

構造式１ ＴＡＣ（：本実施の形態例樹脂材料１）

Structural formula 1 TAC (: resin material 1 in this embodiment)

構造式２ ＢＡＰＳ−Ｍ（：本実施の形態例樹脂材料２）

Structural formula 2 BAPS-M (: Resin material 2 of this embodiment)

構造式３ 開発品（：本実施の形態例のポリアミドイミド樹脂）

Structural formula 3 New product (: Polyamideimide resin of this embodiment)

A method for synthesizing the polyamideimide resin of the present embodiment shown in the above structural formula 3 will be described below.
First, 261.23 g (0.604 mol) of BAPS-M was charged into a 2 L glass container equipped with a stirrer, a thermometer, and a nitrogen gas introduction tube, 1320 g of dimethylacetamide (hereinafter referred to as “DMAc”), and triethylamine. Add 61.12 g (0.604 mol) and stir to make a homogeneous solution.

  Next, 127.18 g (0.604 mol) of TAC is slowly added while cooling the solution with ice. After completion of the addition, the ice-cooling was stopped and the reaction was allowed to proceed at room temperature for about 2 hours. Then, 0.84 g (0.009 mol) of aniline was added and stirred for 30 minutes to obtain a polyamide solution having a viscosity of 30 ps. .

  To this solution, 112 mL of acetic anhydride and 52 mL of pyridine were added and stirred at 55 ° C. for 2 hours for imidization. The obtained reaction solution is added to a water / methanol mixed solution, and the resulting powder is washed with water and dried to obtain a polyamideimide powder (developed product of this embodiment).

Physical property evaluation of developed product of this embodiment 1. Molecular weight measurement
N, N-dimethylformamide (DMF) to which 3 mL of lithium bromide (LiBr) is added is dissolved in 3 mg of the obtained polyamideimide powder of the present embodiment and dissolved to obtain a 0.045 μm hydrophilic PTEF membrane filter card. What was filtered with Ridge (Nippon Millipore Millex-LH) was subjected to gel permeation chromatography to measure the molecular weight.

The measurement conditions are as follows.
Column: Tosoh TSK gel Super AWM-H
6.0mm (ID) x 150mm (L)
Mobile phase: DFM 10 mM LiBr added Flow rate: 0.6 mL / min
Detector: RI-101 differential refractometer (manufactured by Showa Denko)
Injection volume: 20 μL
Molecular weight calibration: monodisperse polystyrene
The measurement results are as shown in Table 1.

2. Solubility The developed polyamideimide powder of this embodiment was added to the organic solvent so as to be 20 W%, and the solubility was confirmed. The method was determined to be soluble by allowing the prepared solution to stand at room temperature for 15 days and then visually confirming that there was no insoluble matter and fluidity.
The results are shown in Table 2. As a comparison, the solubility of organic solvent-soluble polyamideimide (SOXR manufactured by Nippon Kogyo Paper Industries Co., Ltd.) having a general structure on the market is described.

  A general organic solvent-soluble polyamideimide is soluble only in NMP. As shown below, NMP is somewhat difficult to handle. That is, it easily absorbs moisture and has a high boiling point. If the moisture is absorbed, the ink surface becomes cloudy and then loses fluidity. For example, when coating by screen printing, it is known that the ink loses fluidity on the plate and becomes unprintable.

  For this reason, when using ink using NMP, there are many problems such as requiring a high-temperature drying furnace under strict humidity control (40% or less). In addition, since the boiling point is as high as 202 ° C. and drying requires a high temperature and a long time, productivity is poor, and expensive equipment corresponding to the high temperature is required.

  However, as shown in Table 2, the developed product can use a solvent other than NMP that does not have the above-mentioned drawbacks. Therefore, when the developed product is used as an ink for screen printing, it is dissolved in various solvents. And an ink material that can be printed and dried more easily than a general product to form a polyamideimide film.

3. Measurement of light transmittance Production of film for light transmittance measurement Ink was prepared by dissolving 30 w% of the developed product in DG. Using a blade coater, this ink is coated on a glass whose surface has been peeled off. After drying this at 120 ° C. for about 15 minutes, the coating film was peeled off from the glass, and this was dried at 200 ° C. for 40 minutes to obtain a measurement film having a thickness of 25 μm.

Measurement result of light transmittance The light transmittance of 200-700 nm was measured for the produced film using a U-4100 type spectrophotometer manufactured by Hitachi High-Tech. Table 3 shows the measurement results. In Table 3, as compared with the developed product, light transmittance was similarly measured for a film using SOXR manufactured by Nippon Kogyo Paper Industry Co., Ltd. and Kapton manufactured by Toray DuPont, which is a typical polyimide film.

  The cut-off wavelength of Kapton is 530 nm, the cut-off wavelength of SOXR is 470 nm, and the appearance is also yellow to dark brown. In contrast, in the developed product, the cut-off wavelength is shifted to a short wavelength of 420 nm, and the appearance is light yellow.

  As a result, the transparency is greatly improved, and it becomes possible to obtain an ink of a desired color by mixing a pigment or a dye. For example, white ink can be obtained by mixing a white pigment.

4). Measurement of other physical property values For measurement of physical property values, three types of 25 μm-thick films were prepared in the same manner as the measurement film in the above-described light transmission measurement test, and used as measurement samples.
-Measurement of tensile strength, elastic modulus, and elongation rate As a measuring device, STRROPH E-L made by Toyo Seiki Seisakusho was used. The measurement conditions are as follows.
Sample size: 10mm x 130mm
Tensile speed: 100 mm / min

Measurement of glass transition temperature and thermal expansion coefficient Thermo Plus TMA8310 manufactured by Rigaku was used as a measuring device. The measurement conditions are as follows.
Sample size: 5mm x 15mm
Measurement method: TMA method Measurement range: Room temperature to 300 ° C
Temperature increase rate: 10 ° C / min

-Measurement of dielectric constant As a measuring device, a network analyzer manufactured by Agilent Technologies was used. The measurement conditions are as follows.
Sample size: 3mm x 15mm
Test method: Cavity resonator perturbation method Test frequency: 1 GHz
Physical property value measurement results Table 4 shows the physical property value measurement results.

表４から明かなように本実施の形態例開発品によれば、ポリアミドイミド樹脂が本来持つ高いガラス転移温度を有する耐熱性の高いインクが提供できる。

As is apparent from Table 4, according to the developed product of this embodiment, it is possible to provide a highly heat-resistant ink having a high glass transition temperature inherent to the polyamide-imide resin.

5. Synthesis and Evaluation of Ink Material Using Other Raw Materials (1) Synthesis of Ink Material The solubility and light transmittance of various polyamideimides synthesized until the discovery of the developed product of this embodiment is shown below.

(Comparative product 1)
The same conditions as in the developed product except that 120.9 g (0.604 mol) of 4.4-oxydianiline (hereinafter referred to as “4.4-ODA”) shown in Structural Formula 4 is used instead of BAPS-M. It carried out in.

(Comparative product 2)
The same as the developed product except that 120.9 g (0.604 mol) of 3.4-oxydianiline (hereinafter referred to as “3.4-ODA”) shown in Structural Formula 5 is used instead of BAPS-M. Conducted under conditions.

(Comparative product 3)
The test was carried out under the same conditions as the developed product, except that 130.6 g (0.604 mol) of 4,4-thiodianiline (hereinafter referred to as “ASD”) represented by Structural Formula 6 was used instead of BAPS-M.

(Comparative product 4)
Instead of BAPS-M, 312.2 g (0.604 mol) of 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane (hereinafter referred to as “HFBAPP”) represented by Structural Formula 7 was used. Except for the above, the conditions were the same as for the developed product.

(Comparative product 5)
A bis [4- (4-aminophenoxy) phenyl] sulfone (hereinafter referred to as “BAPS”) represented by Structural Formula 8 instead of BAPS-M, except that 261.2 g (0.604 mol) was used, It carried out on the same conditions.

(Comparative product 6)
The same conditions as in the developed product were used except that 115.1 g (0.604 mol) of m-tolidine (hereinafter referred to as “m-TB”) represented by Structural Formula 9 was used instead of BAPS-M.

(Comparative product 7)
Development was performed except that 193.4 g (0.604 mol) of 2,2-bis (trifluoromethyl-4,4-diaminobiphenyl (hereinafter referred to as “TFMB”) shown in Structural Formula 10 was used instead of BAPS-M. The same conditions as the product were carried out.

(Comparative product 8)
Development was performed except that 127.0 g of BAPS-M (0.604 mol) (0.604 mol) was used instead of BAPS-M, and 4,4-diaminodicyclohexylmethane (hereinafter referred to as “DCHM”) represented by Structural Formula 11 was used. The synthesis was attempted under the same conditions as the product, but during the addition of TAC, the reaction solution lost fluidity, making stirring difficult, and the desired polyamideimide could not be obtained.

(2) Measurement result of physical property value Measurement of solubility of developed product and comparative product in organic solvent and light transmittance at 420 nm.
The measurement method was the same as the method shown for the developed product. However, when preparing a sample film for light transmittance measurement, those that are insoluble in DG are dissolved in NMP to form an ink material, and then the film is prepared by applying the same method and conditions. did.

Table 5 shows the measurement results of the solubility in organic solvents and the light transmittance at 420 nm.

(2) Measurement results of physical property values Comparative products 1 to 6 are polyamideimide resins that are soluble in organic solvents other than NMP, but the solvent to be dissolved is limited, and various solubility properties such as the developed product are exhibited. There is nothing to show. Furthermore, since the light transmittance is low, the ink itself has a specific color, and even if it is a light color, especially a white ink, a color peculiar to the ink will appear, so the expressed color There were major restrictions.
Moreover, in the comparative product 7, although the light transmittance is equivalent to the developed product, it does not dissolve in organic solvents other than the NMP solvent.

  As described above, according to the developed product of this embodiment example, since the light transmission is high, when the developed product is used as an ink material, it does not become a specific color. For example, a white pigment or dye is used. If mixed, white ink can be obtained.

Since white ink can be provided, it is a matter of course that inks of various colors can be provided by mixing pigments and dyes of other colors with respect to other colors.
Table 6 shows examples of dyes used when creating ink materials. All dyes shown in Table 6 were dyes made by Kiwa Chemical.

  As described above, according to the present embodiment, white ink can be provided, and by first applying a background treatment with white ink, each color ink is applied thereon to realize vivid color development. Furthermore, it is possible to provide a yellow ink by mixing a yellow dye, a red ink if a red dye is mixed, and a blue ink if a blue dye is mixed. Any color expression is possible by adjusting the mixing ratio.

6). Application example of this embodiment Application example of use as low-temperature dry coverlay ink Solvents other than NMP, especially low boiling point solvents as shown in Table 4 can be used, so that the ink can be easily screen-printed. It can be used as a coverlay ink for printed circuit boards that can be dried at low temperatures.
The reliability test data when the developed product is used as a printed circuit board coverlay ink is described below.

Insulation reliability A pattern of L / S = 0.07 μm / 0.07 μm was etched on one side of Nippon Steel Chemical's double-sided copper-clad laminate (ESPANEX MB12-12-12REG, copper foil 12 μm, PI layer 12 μm) The developed product ink dissolved in bis (2-methoxyethyl) ether was applied to both sides by screen printing and dried at 80 ° C for 5 minutes and 140 ° C for 60 minutes. The insulation resistance value between lines was measured.

環境負荷前後とも、１０¹²Ω以上の抵抗値があり、カバーレイインクとして十分使用できる。 The insulation resistance between the lines was measured after applying a voltage of 100 V for 1 minute using 4329A HIGH RESISTANCE METER manufactured by Yokogawa-Hewelett-Packard.
Table 7 shows the measurement results.

There is a resistance value of 10 ¹² Ω or more before and after environmental load, and it can be used sufficiently as a coverlay ink.

-White polyamideimide ink With conventional polyimide and polyamideimide, the material is yellow to dark brown, so it was possible to make a white polyamideimide ink that could not be achieved. By using this, a heat-resistant white coating film can be easily produced.

  For LED lighting that requires a white coating that is resistant to heat near 260 ° C in the mounting process and heat emitted from the LED, LED mounting boards for LED backlights, and printed circuit boards on which other light emitting elements are mounted Use as a coverlay ink or silk printing ink is expected.

Experimental data is shown below.
-White ink production 100 parts by weight of the developed product, 100 parts by weight of titanium oxide (JR-701 manufactured by Teika) and 230 parts by weight of dihydrofuran-2 (3H) -one as white pigments were used in a general kneader. Mix well.

-Preparation of sample for evaluation The above ink was applied on a copper foil by screen printing and dried at 120 ° C for 5 minutes and 250 ° C for 15 minutes to form a white coating film having a thickness of 10 µm.

・ Results of heat resistance test The following table 8 shows the results of evaluation using a difference meter (Σ90 COLOR MEASURING SYSTEM manufactured by Nippon Denshoku Industries Co., Ltd.) for discoloration when the above sample was left in an environment of 160 ° C and 200 ° C. And in Table 9. Table 8 shows the result of measuring the discoloration when the sample is left in an environment of 160 ° C. Table 9 shows the result of the measurement of discoloration when the sample is left in an environment of 200 ° C.

As is apparent from the measurement results, it can be used for 1000 hours or longer at 160 ° C. and 120 hours or longer at 200 ° C. without discoloration. If white polyamideimide ink using the ink material of this embodiment is used, a white coating can be formed on the substrate arbitrarily and easily by screen printing, and the increase in substrate thickness and weight is also minimized. It can be suppressed.
Further, as described above, colors other than white can be freely produced, and a heat-resistant colored coating film can be formed with vivid color.

Claims (6)

To polyamideimide synthesized from trimellitic acid chloride and bis [4- (3-aminophenoxy) phenyl] sulfone,
An ink material characterized by adding a soluble organic solvent. Examples of the soluble organic solvent include 1-methyl-2-pyrrolidone, dihydrofuran-2 (3H) -one, cyclopentanone, bis (2-methoxyethyl) ether, 1,2-bis (2-methoxyethoxy). The ink material according to claim 1, wherein any one of ethane is contained. The polyamidoimide is prepared by adding dimethylacetamide and triethylamine to bis-4- (3-aminophenoxy) phenyl] sulfone and stirring, and then slowly adding trimellitic acid chloride at a predetermined temperature to react, and adding aniline after the reaction. The ink material according to claim 1 or 2 , wherein the polyamide solution is synthesized by stirring and then imidized. The ink material according to claim 3 , wherein acetic anhydride and pyridine are added to the polyamide solution and stirred to perform imidization. An ink material comprising an organic solvent that is soluble in a low-boiling-point solvent-soluble resin, characterized by comprising the following structural formula:

An ink comprising a desired pigment, dye or a mixture thereof added to the ink material according to any one of claims 1 to 5 .