Solvent Composition

Abstract

A solvent composition is provided, which may be a mixture of two or more components, wherein the molecules in the solvent contain a carbonyl group, an ether linkage, and a group selected from -OH and -NH2.

Description

[Technical Field]

[0001] Introduction Photosensitive materials are widely used, for example, in the electronics industry for the production of printed circuits. One useful class of photosensitive materials is the class of photosensitive polyimides. Polyimides are generally the reaction product of one or more dianhydride monomers and one or more diamine monomers. To form a photosensitive polyimide, one or more monomers typically have one or more substituents that can react with photons to form groups that initiate and / or participate in a crosslinking reaction.

[0002] In one common process for manufacturing printed circuits, a layer containing a photosensitive polyimide is present on a surface. Some portions of the layer are exposed to radiation (e.g., ultraviolet light), while other portions are not. The radiation-exposed portions undergo crosslinking, while the unexposed portions do not. In this process, the layer is then contacted with an alkaline solution, which decomposes the uncrosslinked polyimide to produce monomeric moieties. The layer is then washed with one or more solvents to dissolve the monomeric moieties, and then the layer is washed with water to remove the solvent along with the dissolved monomeric moieties.

[0003] US Patent Application Publication No. 2012 / 0276741 describes a cleaning process carried out using a liquid mixture containing at least two benign chemicals capable of forming a eutectic.

[0004] It is desirable to provide a solvent suitable for dissolving the monomer moieties produced in the processes described hereinabove. Desirable properties of such a solvent include one or more of the following: the relevant monomers have good solubility in the solvent; the solvent is relatively non-volatile; the solvent is not considered to be reproductively toxic; the solvent has a melting point of 65°C or less, the solvent is relatively easy to make, and the solvent has few or no halogen atoms. Furthermore, it is desirable for the solvent to have one or more of the following characteristics: the solvent is relatively inexpensive; and the solvent is biodegradable. Summary of the Invention

[0005] A first aspect is a solvent composition SC1 comprising one or more compounds C1, one or more compounds C2, and one or more compounds C3, a) each compound C1 comprises one or more chemical groups selected from the list consisting of -NH2 and -OH, where the -OH group, if present, may or may not be part of a carboxyl group; b) each compound C2 contains one or more ether bonds; c) each compound C3 contains one or more carbonyl groups which may or may not be part of a carboxyl group; d) a single compound can function as two or more of compound C1, compound C2, and compound C3; e) the melting point of the solvent composition SC1 is 65°C or less; f) solvent composition SC1 either has no halogen atoms or has halogen atoms in an amount of 0.1% by weight or less, based on the weight of solvent composition SC1; g) there is a temperature T1 greater than or equal to 15°C and less than or equal to 40°C, wherein solvent composition SC1 is liquid at temperature T1, and wherein at temperature T1 the solubility of monomer A in solvent composition SC1 is greater than or equal to 0.5 wt %, based on the weight of solvent composition SC1, and wherein monomer A has the structure

[0006] [ka] and h) At temperature T1, the solubility of monomer B in solvent composition SC1 is 0.5 wt. % or more, based on the weight of solvent composition SC1, and monomer B has the structure

[0007] [ka] It has.

[0008] A second embodiment is solvent composition SC2, which comprises a mixture of one or more compounds selected from the group consisting of: M1) A mixture consisting of urea, glycolic acid, and diethylene glycol n-butyl ether, wherein the weight percentages of urea, glycolic acid, and diethylene glycol n-butyl ether satisfy one of criterion A) or criterion B), all percentages being by weight based on the weight of mixture M1, pU is the percentage of urea, pGA is the percentage of glycolic acid, and pDBE is the percentage of diethylene glycol n-butyl ether, and criterion A) and criterion B) are defined as follows: Criterion A): pGA is 8% or more, pGA is less than 32%, pU is 0% or more, pU is 30% or less, pDBE = 100-(pU + pGA); Criterion B): A mixture of pGA 32% or more, pGA 50% or less, pU 10% or more, pU 30% or less, and pDBE = 100 - (pU + pGA). M2) a mixture of urea and diethylene glycol, wherein the molar ratio of urea to diethylene glycol is 0.1:1 to 0.3:1; M3) a mixture of glycolic acid and diethylene glycol, wherein the molar ratio of glycolic acid to diethylene glycol is 0.1:1 to 5:1; M4) A mixture consisting of urea and 2-phenoxyethanol, wherein the molar ratio of urea to 2-phenoxyethanol is 0.1:1 to 0.3:1. DETAILED DESCRIPTION OF THE INVENTION

[0009] The following terms are defined herein as follows:

[0010] As used herein, an ether bond is a chemical group in which an oxygen atom is linked by a single bond to two carbon atoms, each of which is in turn bonded only to either a hydrogen atom or another carbon atom.

[0011] As used herein, a carbonyl group is a group in which a carbon atom is attached to an oxygen atom by a double bond, and that carbon atom is attached to two other atoms by single bonds, which may be atoms of any type.

[0012] As used herein, the melting point of a composition is the onset temperature of the melting transition as measured by differential scanning calorimetry (DSC) at 10° C. / min. If more than one transition is detected, the melting point of the composition is determined as the onset temperature of the transition occurring at the lowest temperature of all transitions.

[0013] As used herein, a polyimide is a polymer having the following structure (I):

[0014] [ka] In structure (I), the ovals represent chemical groups, R is a chemical group, and n is 10 or greater.

[0015] Ratios presented herein are characterized as follows. For example, when a ratio is said to be 3:1 or greater, the ratio can be 3:1, or 5:1, or 100:1, but cannot be 2:1. This characterization can be generally described as follows: When a ratio is said to be X:1 or greater herein, it means that the ratio is Y:1, where Y is X or greater. As another example, when a ratio is said to be 15:1 or less, it can be 15:1, or 10:1, or 0.1:1, but cannot be 20:1. Generally, when a ratio is said to be W:1 or less herein, it means that the ratio is Z:1, where Z is W or less.

[0016] The present invention includes solvent compositions, herein labeled SC1, that contain one or more compounds of the type herein labeled C1, one or more compounds of the type herein labeled C2, and one or more compounds of the type herein labeled C3. In some embodiments, there are one or more compounds that have characteristics that cause the compound to belong to more than one of the C1, C2, and / or C3 types.

[0017] Compound C1 contains one or more chemical groups selected from -NH2 and -OH in the molecule. Compounds containing an -OH group are considered to be C1 compounds herein, regardless of whether the -OH group is attached to a carbon atom that is also attached to an oxygen or nitrogen atom. For example, compounds containing an -OH group are considered to be C1 compounds herein, regardless of whether the -OH group is part of a carboxyl group. Preferred compounds C1 contain two or more -NH2 groups or two or more -OH groups. Preferred compounds C1 have five or fewer carbon atoms, more preferably four or fewer, more preferably three or fewer, and more preferably two or fewer. Preferred compounds C1 are urea, glycolic acid, 2-phenoxyethanol, glycerin, lactic acid, ethylene glycol, diethylene glycol, glucose, sorbitol, diethylene glycol n-butyl ether, and mixtures thereof. Urea, glycolic acid, lactic acid, glucose, and mixtures thereof are more preferred, and urea, glycolic acid, and mixtures thereof are more preferred.

[0018] Compound C2 contains one or more ether bonds. Preferred compounds C2 have 4 or more carbon atoms, more preferably 6 or more carbon atoms, and more preferably 8 or more carbon atoms. Preferred compounds C2 have 12 or less carbon atoms, more preferably 10 or less carbon atoms, and more preferably 8 or less carbon atoms. Preferred compounds C2 are 2-phenoxyethanol, diethylene glycol, and diethylene glycol n-butyl ether.

[0019] Compound C3 contains one or more carbonyl groups. Preferred compounds C3 are glucose, lactic acid, glycolic acid, and urea. More preferably, glycolic acid and urea. Preferred compounds C3 have 5 or less carbon atoms, more preferably 4 or less, more preferably 3 or less, and more preferably 2 or less carbon atoms. Preferred compounds C3 are also eligible as compound C1. Preferably, all compounds C3 present are also eligible as compound C1.

[0020] In some embodiments, solvent composition SC1 may contain one or more "other" compounds, defined herein as compounds that do not qualify as Compound C1, Compound C2, or Compound C3. In preferred embodiments, the amount of "other" compounds in solvent composition SC1 is relatively low or zero. That is, the sum of all "other" compounds is preferably 0% to 20% by weight, based on the weight of solvent composition SC1. More preferably, it is 0% to 5% by weight. More preferably, it is 0% to 1% by weight. More preferably, it is 0% to 0.2% by weight. More preferably, it is 0% to 0.05% by weight. More preferably, it is 0% to 0.01% by weight. In some embodiments, the amount of "other" compounds in solvent composition SC1 is zero.

[0021] The solvent composition SC1 has a melting point of preferably 65°C or less, more preferably 55°C or less, more preferably 40°C or less, more preferably 35°C or less, more preferably 30°C or less.

[0022] Preferably, in the practice of the present invention, one or more compounds C1 have a melting point. The melting point of solvent composition SC1 is preferably lower than the melting point of one or more compounds C1. Similarly, one or more compounds C2 preferably have a melting point, and the melting point of solvent composition SC1 is preferably lower than the melting point of one or more compounds C2. Furthermore, one or more compounds C3 preferably have a melting point, and the melting point of solvent composition SC1 is preferably lower than the melting point of one or more compounds C3. Preferably, the melting point of solvent composition SC1 is lower than all of the melting points of all compounds C1, all compounds C2, and all compounds C3.

[0023] As an illustrative, non-limiting example of these preferred melting point comparisons, it is useful to consider an embodiment in which solvent composition SC1 contains two compounds: one compound (X) qualifies only as compounds C1 and C3, and the other compound (Y) qualifies only as compound C2. In this preferred embodiment, the melting point of solvent composition SC1 is lower than both the melting point of compound X and the melting point of compound Y.

[0024] Halogen atoms are not present in solvent composition SC1 at all, or if present, are present in a limited amount. The amount of halogen atoms in solvent composition SC1 is 0 to 0.1 wt % based on the weight of solvent composition SC1. More preferably, it is 0 to 0.03 wt %, more preferably 0 to 0.01 wt %, more preferably 0.003%, and more preferably 0 to 0.001 wt %.

[0025] Solvent composition SC1 is liquid over a temperature range, the range including at least one temperature T1 at which solvent composition SC1 is liquid, T1 being equal to or greater than 15° C. and T1 being equal to or less than 65° C. Preferably, there is a T1 of equal to or greater than 20° C. Preferably, there is a T1 of equal to or less than 30° C.

[0026] Solvent composition SC1 is desirably capable of dissolving monomer moieties produced in the decomposition of photosensitive polyimides. To evaluate this property, Monomer A and Monomer B (defined hereinabove) are used. Many of the monomers used in producing photosensitive polyimides have strong similarities to (or are identical to) Monomer A or Monomer B. Because solvent composition SC1 can effectively dissolve high concentrations of Monomer A and Monomer B, it is expected that solvent composition SC1 will also be able to effectively dissolve high concentrations of any monomer moieties produced in the decomposition of photosensitive polyimides.

[0027] There exists a temperature T1, as defined above, at which the solubility of monomer A in solvent composition SC1 is 0.5% by weight or more, based on the weight of solvent composition SC1. Preferably, it is 1% by weight or more, more preferably 2% by weight or more, and more preferably 5% by weight or more. At that same temperature T1, the solubility of monomer B in solvent composition SC1 is 0.5% by weight or more, based on the weight of solvent composition SC1. Preferably, it is 1% by weight or more, more preferably 2% by weight or more, and more preferably 5% by weight or more.

[0028] Solvent composition SC1 is preferably soluble in water at 25° C. Specifically, the preferred amount of solvent composition SC1 that dissolves in water at 25° C. is 1% by weight or more, more preferably 2% by weight or more, more preferably 5% by weight or more, and more preferably 10% by weight or more, based on the weight of water.

[0029] Preferably, solvent composition SC1 does not cause teratogenic effects when tested in laboratory animals, and preferably does not need to be labeled as "reproductively toxic" under the criteria of the 2012 publication "Hazard Communication Standard" issued by the U.S. Administration of Occupational Health and Safety in U.S. Publication of Federal Regulations 29 CFR 1910.1200.

[0030] It is useful to contemplate four specific mixtures that are embodiments of the present invention. These mixtures are labeled herein as M1, M2, M3, and M4 (defined below). A solvent composition containing one or more of these mixtures is labeled herein as "solvent composition SC2," although solvent composition SC2 may also qualify as solvent composition SC1, as defined above.

[0031] Mixture M1 consists of a mixture of urea, glycolic acid, and diethylene glycol n-butyl ether. Mixture M1 is conveniently described by using weight percentages, based on the weight of solvent mixture SC2. The weight percentages of urea, glycolic acid, and diethylene glycol n-butyl ether are referred to herein as pU, PGA, and pDEGE, respectively. Mixture M1 meets either Criterion A or Criterion B, as described below. Criterion A: pGA is 8% or more. pGA is less than 32%. pU is greater than 0%. pU is 30% or less, and pDEGE = 100 - (pGA + pU). Criterion B: pGA is 32% or more. pGA is 50% or less. pU is 10% or more. pU is 30% or less, and pDEGE is 100-(pGA+pU).

[0032] Mixtures M2, M3, and M4 are most conveniently described using molar ratios.

[0033] The mixture M2 is a mixture of urea and diethylene glycol, where the molar ratio of urea to diethylene glycol is 0.1:1 to 0.3:1.

[0034] Mixture M3 is a mixture of glycolic acid and diethylene glycol, with the molar ratio of glycolic acid to diethylene glycol being 0.1:1 to 5:1.

[0035] Mixture M4 consists of a mixture of urea and 2-phenoxyethanol, with the molar ratio of urea to 2-phenoxyethanol being 0.1:1 to 0.3:1.

[0036] Embodiments of the present invention contemplate that solvent composition SC2 contains exactly one of mixtures M1, M2, M3, or M4. Also contemplated are embodiments in which solvent composition SC2 contains two or more of mixtures M1, M2, M3, and M4.

[0037] Preferably, the total amount of all of the mixtures M1, M2, M3, and M4 is 80% by weight to 100% by weight, more preferably 90% by weight or 100% by weight, more preferably 95% to 100% by weight, based on the weight of the solvent composition SC2.

[0038] Preferably, halogen atoms are not present at all in solvent composition SC2, or if present, are present in a limited amount. The amount of halogen atoms in solvent composition SC2 is preferably 0 to 0.1 wt %, more preferably 0 to 0.03 wt %, more preferably 0 to 0.01 wt %, more preferably 0.003 wt %, more preferably 0 to 0.001 wt %, based on the weight of solvent composition SC1.

[0039] In one aspect of the present invention, a solution is formed using solvent composition SC1 or solvent composition SC2 as a solvent, and the solute comprises a decomposition product of a photosensitive polyimide. In a preferred embodiment, the solute comprises one or more compounds selected from the list consisting of a compound having the structure of monomer A and optionally having a substituent, a compound having the structure of monomer B and optionally having a substituent, and a mixture thereof.

[0040] The following are examples of the present invention. Unless otherwise stated, operations were carried out at room temperature (about 23° C.).

[0041] The materials used were as follows: All materials were obtained from Sinopharm. The water solubility values ​​given (literature values ​​published on Wikipedia) are at 25°C.

[0042] [Table 1]

[0043] To create the test mixtures, the desired amount of each component was added to a clear vial. The sample was heated and shaken in a 70°C oven for 1 hour, then removed and allowed to return to room temperature (approximately 23°C). The vial was then photographed using a Phase Identification and Characterization Apparatus (PICA-II), an instrument built by Dow for imaging and analysis of research samples. As shown in Table 2A, various binary mixtures (i.e., mixtures of exactly two compounds) were formed. In Table 2A, "Com" means component, "op" means opaque, and "nt" means not tested. Binary mixtures are characterized herein by their molar ratios.

[0044] [Table 2]

[0045] Several samples from Table 2 were selected for further testing and given the following designations. The molar ratios indicated are Com 1:Com 2. Melting points were determined by DSC as described above.

[0046] [Table 3]

[0047] Ternary mixtures of urea, GA, and DBE were also formed as shown in Table 3. The amounts shown are weight percents based on the weight of the ternary mixture.

[0048] [Table 4]

[0049] [Table 5]

[0050] A mixture labeled "IE1" herein was also formed having 7.8 wt% urea, 29.4 wt% GA, and 62.8% DBE, and was also clear. Sample IE1 had a 1:1:1 molar ratio of urea:GA:DBE. Sample IE1 had a melting point below -80°C.

[0051] The samples in Table 2B and sample IE1 were all liquid at room temperature (about 23°C).

[0052] The individual components, the samples in Table 2B, and sample IE1 were all examined by FTIR (Fourier Transform Infrared) analysis. FTIR spectra were obtained using a Thermo Scientific Nicolet 5700 FTIR spectrometer in ATR mode with a diamond crystal at 4 cm -1 Resolution of 4000-5000 cm -1 The area was scanned 32 times.

[0053] The FTIR spectrum of each mixture was compared with the FTIR spectrum of each component of that mixture. For each mixture, the FTIR spectrum was the sum of the FTIR spectra of the components of that mixture. This result is intended to demonstrate that the components in each mixture did not undergo any chemical reactions.

[0054] The samples in Table 2B, Sample IE1, and NMF were tested to determine whether each was a good solvent for Monomer A and Monomer B. To perform these tests, 0.125 g of Monomer A, 0.125 g of Monomer B, and 2.5 g of sample solvent were placed in vials and photographed with a PICA-II instrument. For each sample, the height of the monomer mixture in the vial was 4 mm. The vials were placed in a 54°C oven for 13 hours without stirring. The vials were returned to room temperature and photographed again with the PICA-II instrument. The height of the solid residue was observed. The residue, if present, was believed to be undissolved Monomer A, undissolved Monomer B, or a mixture thereof. The % solvency of each solvent composition was determined as follows: Solvent Power % = 100*(1-[(final height of monomer) / (initial height of monomer)])

[0055] [Table 6]

[0056] Based on the results in Table 4, inventive solvent compositions IE1, IE2, IE3, and IE4 are excellent solvents for monomer A and monomer B, while comparative solvent compositions CE2, CE3, CE4, and CE5 are poor solvents for monomer A and monomer B. Although solvent NMF is a good solvent for monomer A and monomer B, NMF has other undesirable properties that place it outside the scope of the present invention. It is observed that in each of the 100% solvency samples, the concentration of monomer A in the final solution was 5 wt % based on the weight of the solvent composition, and the concentration of monomer B in the final solution was 5 wt % based on the weight of the solvent composition.

[0057] In interpreting the results, it is important to note that inventive Examples IE1, IE2, IE3, and IE4 have molecules with all three required functional groups: (1) —NH or —OH, (2) a carbonyl group, and (3) an ether linkage, and all are good solvents for Monomer A and Monomer B. In contrast, comparative examples CE2, CE3, CE4, and CE5 each lack an ether linkage entirely, and all are poor solvents for Monomer A and Monomer B.

[0058] It should be noted that all of the components used in the inventive mixtures IE1, IE2, IE3, and IE4 have a solubility in water of 1% by weight or more at 25° C. Therefore, it is believed that these inventive mixtures also have a solubility in water at 25° C. of 1% by weight or more.

[0059] It should also be noted that the mixtures IE1, IE2, IE3 and IE4 of the present invention are mixtures of widely available components without chemical reactions, and therefore, these mixtures are believed to be relatively easy and relatively inexpensive to prepare.

Claims

1. A solvent composition SC1 comprising one or more compounds C1, one or more compounds C2, and one or more compounds C3, a) Each compound C1 is —NH ２ and -OH, said -OH group, if present, may or may not be part of a carboxyl group; b) each compound C2 contains one or more ether bonds; c) each compound C3 contains one or more carbonyl groups which may or may not be part of a carboxyl group; d) a single compound can function as two or more of Compound C1, Compound C2, and Compound C3; e) the melting point of the solvent composition SC1 is 65°C or less; f) the solvent composition SC1 either has no halogen atoms or has halogen atoms in an amount of 0.1 wt. % or less, based on the weight of the solvent composition SC1; g) there is a temperature T1 greater than or equal to 15°C and less than or equal to 40°C, wherein said solvent composition SC1 is liquid at temperature T1, and wherein at said temperature T1, the solubility of monomer A in said solvent composition SC1 is greater than or equal to 0.5 wt%, based on the weight of said solvent composition SC1, and wherein monomer A has the structure 【Chemistry 1】 and h) at the temperature T1, the solubility of the monomer B in the solvent composition SC1 is 0.5 wt % or more, based on the weight of the solvent composition SC1, and the monomer B has the structure 【Chemistry 2】 Solvent composition SC1 having:

2. 10. The solvent composition SC1 of claim 1, wherein said solvent composition SC1 is non-reproductively toxic.

3. 2. The solvent composition SC1 of claim 1, wherein the solubility of the solvent composition SC1 in water at 25°C is 1% by weight or more, based on the weight of the water.

4. 2. The solvent composition SC1 of claim 1, wherein the total amount of all compounds not qualifying as either Compound C1, Compound C2, or Compound C3 is 0% by weight or less than 20% by weight, based on the total weight of the solvent composition SC1.

5. The solvent composition SC1 has two or more —OH groups or two or more —NH groups in each molecule. ２ 2. The solvent composition SC1 of claim 1, comprising one or more compounds C1 having a group.

6. 6. The solvent composition SC1 of claim 5, comprising one or more compounds C1 comprising urea, glycolic acid, or a mixture thereof.

7. 2. The solvent composition SC1 of claim 1, wherein the melting point of the solvent composition SC1 is lower than the melting point of one or more of the compounds C1.

8. M1) a mixture consisting of urea, glycolic acid, and diethylene glycol n-butyl ether, wherein the weight percentages of urea, glycolic acid, and diethylene glycol n-butyl ether satisfy one of criterion A) or criterion B), all percentages being by weight based on the weight of mixture M1, pU being the percentage of urea, pGA being the percentage of glycolic acid, and pDBE being the percentage of diethylene glycol n-butyl ether, and wherein criterion A) and criterion B) are defined as follows: Criterion A): pGA is 8% or more, pGA is less than 32%, pU is 0% or more, pU is 30% or less, pDBE=100-(pU+pGA); Criterion B): pGA is 32% or more, pGA is 50% or less, pU is 10% or more, pU is 30% or less, pDBE=100-(pU+pGA); M2) a mixture of urea and diethylene glycol, wherein the molar ratio of urea to diethylene glycol is from 0.1:1 to 0.3:1; M3) a mixture of glycolic acid and diethylene glycol, wherein the molar ratio of glycolic acid to diethylene glycol is 0.1:1 to 5:1; M4) Solvent composition SC2 comprising a mixture of one or more compounds selected from the group consisting of a mixture of urea and 2-phenoxyethanol, wherein the molar ratio of urea to 2-phenoxyethanol is 0.1:1 to 0.3:

1.

9. 8. The solvent composition SC2 of claim 7, wherein the total amount of all mixtures M1, M2, M3, and M4 is 80% to 100% by weight, based on the weight of the composition SC2.

Images