The process for purification of gallic acid eliminating minute metallic impurity
Technical field
The present invention relates to a kind of process for purification of gallic acid eliminating minute metallic impurity, through the ultra-clean washing composition of this method purified gallic acid mainly as electronics industry.
Background technology
Gallic acid mainly with in homemade Turkey-galls and Peru to produce that tower draws be that raw material makes, be a kind of important Fine Organic Chemical product, be widely used.American-European in recent years microelectronics already uses ultra-clean, high-purity gallic acid to wash unicircuit, makes clean-out system washing chip polymer raw material and etch residue with gallic acid.As everyone knows, metal ion has electric action, thereby the metallic impurity that contain in the clean-out system can cause defective increase, operating barrier in high density integrated circuit, computer hardware driving and the chip.Therefore, strict especially to specification of quality as the gallic acid of electronic cleaning agent purposes, especially require each metal ion species residual quantity such as Na, K, Fe, Ca to reach trace level respectively, promptly 5 * 10
-8The order of magnitude.
China's forest products aboundresources is one of major country of production of gallic acid.Metals content impurity is higher in the PREPARATION OF INDUSTRIAL GALLIC product at present, and various metallic impurity are all on the 500ppb level.Domestic Guizhou University of Technology journal relevant report that makes fresh water supply system ion exchange resin purification gallic acid in 2000, metals content impurity is also in the 100ppb level in the gallic acid finished product of its preparation, still can not satisfy photoresist material, the electronic-grade clean-out system requirements at the higher level to metals content impurity.Trace metal impurities becomes the gordian technique of producing qualified gallic acid microelectronics clean-out system in the removal gallic acid.
Summary of the invention
The process for purification that the purpose of this invention is to provide a kind of gallic acid eliminating minute metal ion, the ultra-clean gallic acid product with the electron gain level satisfies the requirement of electronics washing composition to the gallic acid metals content impurity.
The method following steps of eliminating minute metal ion of the present invention:
(1) the raw material gallic acid is made solution, with raw material gallic acid (refer to PREPARATION OF INDUSTRIAL GALLIC or through general method purified gallic acid), adds C
1-4The low-carbon (LC) organic polar solvent, stirring and dissolving under the 50-70 ℃ of temperature, the solution of making injects the solution basin;
(2) the solution basin is connected with the ion exchange resin column system by peristaltic pump, form the recycle system; Said ion exchange resin column system comprises strong cationic resin exchange column and male-female ion mixture iron exchange resin post, said strong cationic resin is analytical pure or the pure macropore vinylbenzene chelating type strong acidic ion resin of nuclear level, and said male-female ion hybrid resin is mixed by analytical pure or pure macropore vinylbenzene strongly basic anionic resin and the macropore vinylbenzene strong acidic ion resin of nuclear level;
(3) open peristaltic pump, solution was circulated 20 minutes to 2 hours between solution basin and pillar system.Required cycling time is according to the size of metal ion content in the raw material and difference.
(4) organic solvent is reclaimed in the solution decompression after above-mentioned column system circular treatment evaporation, separates out to the gallic acid crystallization, cross and filter out unnecessary solvent, crystallisate is in 70 ℃-80 ℃, and 0.08-0.09MPa vacuum-drying 4-6 hour gets ultra-clean purified electronic grade gallic acid product.
The present invention further method is the macropore vinylbenzene strong acidic ion resin post of also connecting after male-female hybrid resin post.
The present invention further method is, in the above recycle system, and microfiltration membrane of series connection before the ion exchange resin system, contained contaminant particles in the filtering gallic acid.The mean pore size of said microfiltration membrane is 0.1-0.5 μ m.
The blending ratio of the yin, yang ion exchange resin of said male-female hybrid resin post is 4: 6~6: 4.
Said chelating type strong acidic ion resin is the macropore phenylethylene resin series that contains amido oxalic acid or alpha-amino phosphonate functional group, and homemade D401, D402, D751 are all effective.
Said chelating type strong acidic ion resin adopts following method pre-treatment: be earlier the analytical pure ammonia scrubbing transition of 8%-18% with concentration, make resin transfer the ammonium salt type to from the Na type, use the following washed with de-ionized water of specific conductivity 0.5 μ s/cm again, wash that Na, Fe ion are lower than 30ppb and 20ppb respectively to the resin.
Said vinylbenzene strongly basic anionic resin is used washed with de-ionized water or/and the vinylbenzene strong acidic ion resin is first, and then uses C
1-4The low-carbon (LC) organic polar solvent clean to Na, Fe ion and be lower than 30ppb and 20ppb respectively.
The pre-treatment of above resin can be carried out in container, and resin is adorned post after carrying out washing treatment in the container; Washing process also can carry out in post, and promptly resin is adorned post earlier, links column system again after the washing then in post.
Said low-carbon (LC) polar organic solvent can be selected from C
1-4Alcohol, ketone or ether.
The ion exchange resin column system can singly organize to be provided with or to organize more in parallel or connect and be provided with.
Gallic acid after the inventive method is handled, metal ions such as its Na, K, Fe, Ca, Mg, Cu, Zn all reach the following trace level of 50ppb, and the gallic acid yield is up to more than 90%, product purity 〉=99.5%.
The present invention adopts water-soluble alcohol, ketone, low-carbon (LC) polar organic solvents such as ether, metallic impurity in the gallic acid are converted into the dissociable metal ion that dissolves in this organic solvent, and has the particularly ability of heavy metal ion of intensive adsorbing metal ions according to macropore vinylbenzene chelating ion exchange resin, and cinnamic strongly-acid, strong basicity, sun, the purity height of negative resin own, the characteristics that impurity is small, the resin post is connected with mixed type macroporous resin column (mixing bed), setting up constant filters, the absorption recirculation system makes metal ion in the gallic acid by carrying out ion-exchange with the resin column system and adsorption process is removed.Increase micro-filtration (MF) film in the system, other granulometric impurity of filtering in advance makes gallic acid purity higher, and quality is better, gallic acid behind present method purifying can be used for microelectronics safely and already make washing composition such as high density integrated circuit, chip, remarkable in economical benefits.
Exchange column equipment is processed by the ion exchange column pattern by plastic pipe, plates such as polypropylene, poly-maples.
Description of drawings
Fig. 1 and Fig. 2 are respectively two embodiment schematic flow sheets that the present invention removes the gallic acid trace metal impurities.
Accompanying drawing is represented: 1-peristaltic pump, 2-polypropylene micro-filtration membrane module, 3-cation exchange resin column, 4-male-female hybrid ionic resin-column, 5-cation exchange resin column, 6-gallic acid solution storage tank, 7-thief hole.
Embodiment
Concentration that following examples relate to or content value are all measured by weight.
Embodiment 1 (flow process is seen accompanying drawing 1)
(1) resin pre-treatment
One, polypropylene or the poly-maple plastics tubing with Φ 80mm is ion exchange column, and wherein, the D401 type of packing in the post 3 (commercially available) macropore vinylbenzene chelating resin 500g is the chemical pure ammonia soln washing of 8%-18% with concentration, makes resin transfer the ammonium salt type to from the Na type; Use the following washed with de-ionized water of specific conductivity 0.5 μ s/cm again, washing Na, Fe ion to the ion exchange resin of two posts are lower than 30ppb and 20ppb respectively.
Two, mix pure SIPI-DG-20NG type (commercially available) macropore strong acid vinylbenzene resin cation (R.C.) and each 250g of SIPI-DA-20NG type (commercially available) macroporous strong basic resin anion(R.A) of nuclear level that pack in the post 4, make the male-female mixed bed.This mixed bed use earlier washed with de-ionized water, and then with water-soluble organic polar solvent ethanol or acetone cleaning, is lower than 30ppb and 20ppb respectively to Na, Fe ion.
(2) solution basin 6 is composed in series closed circuit circulatory system with peristaltic pump 1, polypropylene micro-filtration (MF) membrane module 2, cation exchange resin column 3, male-female hybrid ionic resin-column 4 successively.Wherein the membrane pore size of micro-filtration (MF) film is 0.2 μ m.
(3) get refining (refer to general refining) gallic acid powder raw material 2000g, add among the solution basin 6 after adding 8500g methyl alcohol stirring and dissolving.
(4) start peristaltic pump 1, control flow velocity 150mL/min, solution circulates in closed-circuit system, and when reaching 40min, 60min, 80min cycling time, respectively in the exit sampling, filtering the back call number is sample 1, sample 2,3 three samples of sample.
(5) with three samples respectively underpressure distillation reclaim methyl alcohol to there being crystallization to separate out, remove the crystallization of must wetting of unnecessary methyl alcohol through vacuum filtration again, in 80 ℃, 0.09MPa dry 4 hours down, gallic acid sample after three purifications, total recovery 92%.
In this example, gallic acid is forward and backward in purifying treatment respectively, and with its metal ion content of aas determination, metal ion content changes and sees Table 1 before and after handling.
Table 1
By table 1 as seen, gallic acid after the inventive method purifying treatment, control suitable cycling time, Na ion that wherein content is the highest and Ca ion can be reduced to 50ppb and lower level by the above ppb of original 1000-2000, other former content just all reaches level below the 50ppb during then at circulation 40min at the metal ion of 100-900ppb.
Embodiment 2 (flow process is seen accompanying drawing 2)
(1) the D402 type macropore vinylbenzene chelating resin 500g that packs in the cationic exchange coloum 3, the nuclear level of packing in the zwitterion mixing column 4 pure (or analytical pure) SIPI-C-10NG type gel-type strong acid positive resin 200g, SIPI-A-10NG type gel type strong base negative resin 300g, form mixed bed, the pure SIPI-DC-20NG type macropore vinylbenzene strong acid positive resin 500g of the nuclear level of packing in the cation seperation column 5.The resin pre-treatment of this routine post 3 and post 4 is with embodiment 1, and the resin pre-treatment of post 5 is with post 4.By 3,4,5 and MF microfiltration membrane posts 2 of three ion exchange resin columns as accompanying drawing 2 and pump 1 and the storage tank 6 special loop systems that is in series.
(2) get technical grade gallic acid 2000g, be dissolved in the 6600g acetone, make metallic impurity in the gallic acid become the solution of dissolved ions state.
(3) control flow velocity with peristaltic pump, solution stream is through column system, and reaches the constant circulation state.Flow rate control 120mL/min, and reach the constant circulation state; In the exit of column system sampling, be numbered sample 4, sample 5, sample 6 three solution when reaching 30min, 60min, 100min respectively cycling time;
(4) with the underpressure distillation respectively of sample 4, sample 5, sample 6 solution, recovery part acetone is to there being crystallization to separate out, and removes the acetone crystallization of must wetting through vacuum filtration again, in 80 ℃, 0.09MPa vacuum-drying 4 hours, gallic acid sample after three purifications, total amount 460g.
Use Atomic Absorption Spectrometry, before and after handling in the gallic acid metal ion contain to change and see Table 2.
Table 2
As seen table 2 is raw material with the technical grade gallic acid, after column system purifying treatment of the present invention
Get the ultra-clean gallic acid, metal ion Na, K, Ca, Fe, Al, Zn, Cu equal size are respectively all in the 50ppb scope.
This routine gained gallic acid purity 〉=99.5%, yield 92%.