CN114369099A - Method for preparing pyromellitic dianhydride by liquid-phase oxidation - Google Patents
Method for preparing pyromellitic dianhydride by liquid-phase oxidation Download PDFInfo
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- CN114369099A CN114369099A CN202111569691.3A CN202111569691A CN114369099A CN 114369099 A CN114369099 A CN 114369099A CN 202111569691 A CN202111569691 A CN 202111569691A CN 114369099 A CN114369099 A CN 114369099A
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- durene
- pyromellitic dianhydride
- acetate tetrahydrate
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- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D493/00—Heterocyclic compounds containing oxygen atoms as the only ring hetero atoms in the condensed system
- C07D493/02—Heterocyclic compounds containing oxygen atoms as the only ring hetero atoms in the condensed system in which the condensed system contains two hetero rings
- C07D493/04—Ortho-condensed systems
Abstract
The invention provides a method for preparing pyromellitic dianhydride by liquid-phase oxidation, which comprises the following steps: firstly, dissolving durene and a catalyst in acetic acid, feeding the mixture and air into a reactor for a first oxidation reaction, then adding a hydrogen peroxide solution as a co-oxidant of the air, carrying out a second oxidation reaction with the air, finally cooling and filtering a reaction product, collecting a filter cake, adding water for recrystallization to obtain the durene tetracarboxylic acid, and then heating in vacuum for dehydration and sublimation to obtain the durene tetracarboxylic dianhydride. The method has simple process, lower reaction temperature and pressure, no use of high-corrosivity bromide in the preparation process, high product quality and yield, and suitability for continuous industrial production of pyromellitic dianhydride.
Description
Technical Field
The invention belongs to the field of preparation of pyromellitic dianhydride, and particularly relates to a method for preparing pyromellitic dianhydride in high yield by air-liquid phase oxidation of durene in the presence of an oxidation promoter.
Background
Pyromellitic dianhydride, which is called 1,2,4, 5-benzoic dianhydride in chemical name, is called pyromellitic dianhydride for short, is called PMDA in English short, is white powder or needle crystal in appearance, has the melting point of 284-286 ℃ and the boiling point of 397-400 ℃, is one of the most important dianhydride monomers for synthesizing high-temperature-resistant insulating material polyimide, and is also an important curing agent for epoxy resin and polyester resin and an auxiliary agent for powder coating as well as a main raw material for a high-performance plasticizer.
The synthesis method of pyromellitic dianhydride comprises the following steps: (1) durene oxidation; (2) a partial trimethylbenzene alkylation-oxidation process; (3) a pseudocumene carbonylation-oxidation process; (4) xylene chloromethylation-oxidation method. At present, the industrial device basically adopts a durene oxidation method, and other methods cannot realize large-scale industrialization due to one or more of the reasons of large environmental pollution, high requirements on equipment, low technical maturity and the like.
Durene oxidation processes are classified into gas phase processes and liquid phase processes. As early as 1947, the research company California in the United states takes durene as raw material and vanadium pentoxide composite oxide as catalyst to synthesize the pyromellitic anhydride through gas phase oxidation; the DuPont company establishes an industrial device for preparing the pyromellitic anhydride by nitric acid liquid phase oxidation of durene in 1960 for the first time; the ancient river electric company of Japan established an industrial device for preparing the pyromellitic anhydride by nitric acid liquid phase oxidation and air liquid phase oxidation of durene in 1969; in 1970, the Federal Germany Wiba chemical company established an industrial plant for the gas-phase oxidation of durene to pyromellitic anhydride.
The production process of the pyromellitic dianhydride gas phase oxidation method does not need to use highly corrosive bromides, and the requirement on a device is low, so the method becomes the mainstream process of the current industrial production, but the molar yield of the gas phase oxidation method is usually lower than 60 percent, the atom utilization rate is low, and a large amount of organic residues generated in the production pollute the environment. The liquid phase oxidation method of the sym-tetramethylbenzene has the product yield far higher than that of the gas phase oxidation method, but catalyst systems all contain halide with high corrosivity, so the requirements on equipment materials are high, and further the wide application of the liquid phase method is limited. US 5041633 discloses a method for preparing pyromellitic dianhydride by air oxidation of durene in the presence of a cobalt-manganese-zirconium bromide composite catalyst through two-stage reaction, wherein the catalyst is added in stages, and water is added to promote the dissolution of the catalyst and further promote the reaction, and the molar yield of the pyromellitic acid reaches 84%. CN 110746435 discloses that pyromellitic dianhydride is prepared by continuous liquid phase oxidation of durene in an acetic acid solvent at the temperature of 200-300 ℃ and the pressure of 0.5-3 MPa with Co-Mn-Br-Zr-guanidine as a catalyst, wherein the purity of the pyromellitic dianhydride is 98-99%, the conversion rate is 94-98%, and the product selectivity is not mentioned. The catalyst system is complex, the reaction temperature is high, and the requirement on equipment is high.
Comprehensively, the existing durene oxidation process mainly has the problems of long process flow of a liquid phase method, high equipment requirement, poor selectivity of a gas phase method and low product quality and yield.
Disclosure of Invention
Aiming at the defects of the prior art, the invention aims to provide a method for preparing pyromellitic dianhydride by oxidizing durene in a liquid phase with hydrogen peroxide assisted air, which has a simple preparation process and is suitable for industrial application.
The method comprises the steps of taking durene as a raw material, taking acetic acid as a solvent, taking cobalt acetate tetrahydrate and manganese acetate tetrahydrate as catalysts, taking air as an oxidant to perform a first-stage low-temperature oxidation reaction in a tubular reactor, then adding hydrogen peroxide solution as a co-oxidant of oxygen, heating, performing a second-stage high-temperature oxidation reaction in the tubular reactor, collecting precipitates after the reaction, recrystallizing in hot water to obtain high-purity durene tetracarboxylic acid, and further performing vacuum dehydration and sublimation to obtain the durene tetracarboxylic dianhydride. The specific technical scheme is as follows:
the invention relates to a method for preparing pyromellitic dianhydride by liquid-phase oxidation, which comprises the following steps:
1) sequentially adding acetic acid, durene, cobalt acetate tetrahydrate and manganese acetate tetrahydrate into a reactor, heating to 60-100 ℃, continuously introducing a certain amount of air, and keeping at 0.5-1.0 MPa for carrying out a first-stage oxidation reaction for 0.1-2 h; the mass ratio of acetic acid to durene is 2: 1-10: 1, the molar ratio of cobalt acetate tetrahydrate to manganese acetate tetrahydrate is 1: 1-4: 1, the molar ratio of cobalt acetate tetrahydrate to durene is 1: 1000-1: 20, and the preferred molar ratio of air introduced in the first stage of reaction to durene is 20: 1-50: 1;
2) then heating to 100-180 ℃, continuously introducing air and hydrogen peroxide solution, and keeping at 1.0-2.0 MPa to perform a second-stage oxidation reaction for 0.1-2 hours; the mol ratio of the air introduced into the second-stage oxidation reaction to the durene is preferably 20: 1-100: 1, the concentration of the hydrogen peroxide introduced into the second-stage oxidation reaction is 5% -80%, and the mol ratio of the added hydrogen peroxide to the durene is 0.01: 1-0.5: 1;
3) and after the reaction is finished, cooling the obtained slurry, carrying out solid-liquid separation, washing with deionized water, drying and crushing to obtain a powdery crude product, recrystallizing with hot water, drying and crushing to obtain pyromellitic acid without impurities, transferring the obtained pyromellitic acid into a sublimation bottle, and carrying out vacuum dehydration and sublimation to obtain pyromellitic dianhydride.
In the method, the cooling temperature of the slurry in the step 3) is preferably 5-20 ℃.
Preferably, the mass ratio of the water consumption for recrystallization to the powdery crude product is 2: 1-10: 1.
Preferably, the absolute pressure of dehydration and sublimation is 1-10 KPa, the dehydration temperature is 180-230 ℃, the dehydration time is 0.1-2 h, the temperature rise is 220-260 ℃, and the sublimation time is 0.5-2 h.
The pyromellitic dianhydride obtained by the method has the mass yield of 110-125 percent relative to durene and the purity of 98.5-99.5 percent.
The method adopts hydrogen peroxide as a co-oxidant, hydrogen peroxide is an excellent oxidant, the hydrogen peroxide is non-toxic and odorless, a reduction byproduct is only water, the hydrogen peroxide is widely applied to organic synthesis, and bromide with high corrosivity is not needed, so that the defects of the prior art are overcome, the preparation process is simple, and industrial production is easy to carry out.
Detailed Description
The technical scheme of the method is further explained by combining specific examples.
Example 1
Adding 50g of acetic acid, 12g of durene, 22mg of manganese acetate tetrahydrate and 23mg of cobalt acetate tetrahydrate into a 100mL reaction kettle in sequence, then heating to 90 ℃, continuously introducing air at the speed of 0.80L/min, controlling the pressure in the kettle to be 1.0MPa by using an outlet back pressure valve, and reacting for 2 hours; then stopping introducing air, heating to 150 ℃, continuously introducing air at the speed of 1.67L/min, continuously introducing 5% hydrogen peroxide solution at the speed of 0.25ml/min, controlling the pressure in the kettle to be 2.0MPa by using an outlet back pressure valve, and reacting for 2 hours; after the reaction is finished, releasing pressure and reducing temperature, cooling the obtained slurry to 5 ℃, carrying out solid-liquid separation, washing a filter cake by using a small amount of deionized water, carrying out vacuum drying at 80 ℃, crushing to obtain a powdery crude product, adding 77g of water for recrystallization, carrying out vacuum drying at 80 ℃, crushing to obtain pyromellitic acid without impurities, transferring the obtained pyromellitic acid into a sublimation bottle, dehydrating for 1h under the conditions that the pressure is 1KPa and the temperature is 200 ℃, then heating to 230 ℃, and sublimating for 1h to obtain 13.8g of pyromellitic dianhydride with the purity of 98.5%.
Example 2
Adding 50g of acetic acid, 5g of durene, 18mg of manganese acetate tetrahydrate and 74mg of cobalt acetate tetrahydrate into a 100mL reaction kettle in sequence, then heating to 90 ℃, continuously introducing air at the speed of 0.70L/min, controlling the pressure in the kettle to be 0.6MPa by using an outlet back pressure valve, and reacting for 0.5 h; then stopping introducing air, heating to 180 ℃, continuously introducing air at the speed of 0.70L/min, continuously introducing 5% hydrogen peroxide solution at the speed of 0.10ml/min, controlling the pressure in the kettle to be 2.0MPa by using an outlet back pressure valve, and reacting for 2 hours; after the reaction is finished, releasing pressure and reducing temperature, cooling the obtained slurry to 10 ℃, carrying out solid-liquid separation, washing a filter cake by using a small amount of deionized water, carrying out vacuum drying at 80 ℃, crushing to obtain a powdery crude product, adding 23g of water for recrystallization, carrying out vacuum drying at 80 ℃, crushing to obtain pyromellitic acid without impurities, transferring the obtained pyromellitic acid into a sublimation bottle, dehydrating for 0.1h under the conditions that the pressure is 8KPa and the temperature is 230 ℃, then heating to 260 ℃, and sublimating for 0.5h to obtain 5.6g of pyromellitic dianhydride with the purity of 98.9%.
Example 3
Adding 50g of acetic acid, 22g of durene, 804mg of manganese acetate tetrahydrate and 1635mg of cobalt acetate tetrahydrate into a 100mL reaction kettle in sequence, then heating to 65 ℃, continuously introducing air at the speed of 1.53L/min, controlling the pressure in the kettle to be 1.0MPa by using an outlet back pressure valve, and reacting for 2 hours; then stopping introducing air, heating to 160 ℃, continuously introducing air at the speed of 2.76L/min, continuously introducing 10% hydrogen peroxide solution at the speed of 0.05ml/min, controlling the pressure in the kettle to be 2.0MPa by using an outlet back pressure valve, and reacting for 2 hours; after the reaction is finished, releasing pressure and reducing temperature, cooling the obtained slurry to 20 ℃, carrying out solid-liquid separation, washing a filter cake by using a small amount of deionized water, carrying out vacuum drying at 80 ℃, crushing to obtain a powdery crude product, adding 112g of water for recrystallization, carrying out vacuum drying at 80 ℃, crushing to obtain pyromellitic acid without impurities, transferring the obtained pyromellitic acid into a sublimation bottle, dehydrating for 2 hours under the conditions that the pressure is 1KPa and the temperature is 180 ℃, then heating to 220 ℃, and sublimating for 2 hours to obtain 26.8g of the product, namely the pyromellitic anhydride, and the purity is 99.5%.
Example 4
Adding 50g of acetic acid, 22g of durene, 201mg of manganese acetate tetrahydrate and 818mg of cobalt acetate tetrahydrate into a 100mL reaction kettle in sequence, then heating to 90 ℃, continuously introducing air at the speed of 1.22L/min, controlling the pressure in the kettle to be 1.0MPa by using an outlet back pressure valve, and reacting for 1 h; then stopping introducing air, heating to 120 ℃, continuously introducing air at the speed of 5.52L/min, continuously introducing 20% hydrogen peroxide solution at the speed of 0.23ml/min, controlling the pressure in the kettle to be 2.0MPa by using an outlet back pressure valve, and reacting for 1 h; after the reaction is finished, releasing pressure and reducing temperature, cooling the obtained slurry to 5 ℃, carrying out solid-liquid separation, washing a filter cake by using a small amount of deionized water, carrying out vacuum drying at 80 ℃, crushing to obtain a powdery crude product, adding 119g of water for recrystallization, carrying out vacuum drying at 80 ℃, crushing to obtain pyromellitic acid without impurities, transferring the obtained pyromellitic acid into a sublimation bottle, dehydrating for 2 hours under the conditions that the pressure is 2KPa and the temperature is 190 ℃, then heating to 220 ℃, and sublimating for 2 hours to obtain 27.5g of pyromellitic dianhydride with the purity of 98.8%.
Example 5
Adding 1000g of acetic acid, 460g of durene, 4.20g of manganese acetate tetrahydrate and 8.55g of cobalt acetate tetrahydrate into a 2L reaction kettle in sequence, then heating to 100 ℃, continuously introducing air at the speed of 25.6L/min, controlling the pressure in the kettle to be 1.0MPa by using an outlet back pressure valve, and reacting for 2 hours; then stopping introducing air, heating to 160 ℃, continuously introducing air at the speed of 38.4L/min, continuously introducing 80% hydrogen peroxide solution at the speed of 0.36ml/min, controlling the pressure in the kettle to be 2.0MPa by using an outlet back pressure valve, and reacting for 2 hours; after the reaction is finished, releasing pressure and reducing temperature, cooling the obtained slurry to 5 ℃, carrying out solid-liquid separation, washing a filter cake by using a small amount of deionized water, carrying out vacuum drying at 80 ℃, crushing to obtain a powdery crude product, adding 2504g of water for recrystallization, carrying out vacuum drying at 80 ℃, crushing to obtain pyromellitic acid without impurities, transferring the obtained pyromellitic acid into a sublimation bottle, dehydrating for 2 hours under the conditions that the pressure is 2KPa and the temperature is 180 ℃, then heating to 225 ℃, and sublimating for 2 hours to obtain pyromellitic dianhydride with the purity of 99.1 g.
Claims (6)
1. A method for preparing pyromellitic dianhydride by liquid-phase oxidation is characterized in that: the method comprises the following steps:
1) sequentially adding acetic acid, durene, cobalt acetate tetrahydrate and manganese acetate tetrahydrate into a reactor, heating to 60-100 ℃, continuously introducing air, and keeping at 0.5-1.0 MPa for carrying out a first-stage oxidation reaction for 0.1-2 hours; wherein the mass ratio of the acetic acid to the durene is 2: 1-10: 1, the molar ratio of the cobalt acetate tetrahydrate to the manganese acetate tetrahydrate is 1: 1-4: 1, and the molar ratio of the cobalt acetate tetrahydrate to the durene is 1: 1000-1: 20;
2) then heating to 100-180 ℃, continuously introducing air and hydrogen peroxide solution, and keeping at 1.0-2.0 MPa to perform a second-stage oxidation reaction for 0.1-2 hours; wherein the concentration of the hydrogen peroxide introduced in the second-stage oxidation reaction is 5-80%, and the molar ratio of the added hydrogen peroxide to the durene is 0.01: 1-0.5: 1;
3) and after the reaction is finished, cooling the obtained slurry, performing solid-liquid separation, washing a filter cake with deionized water, drying and crushing to obtain a powdery crude product, recrystallizing the powdery crude product with hot water, drying and crushing to obtain impurity-removed pyromellitic acid, transferring the obtained pyromellitic acid into a sublimation bottle, and performing vacuum dehydration and sublimation to obtain pyromellitic dianhydride.
2. The method according to claim 1, wherein the molar ratio of air introduced into the first-stage oxidation reaction to durene is 20: 1-50: 1; the molar ratio of the air introduced into the second-stage oxidation reaction to the durene is 20: 1-100: 1.
3. The method according to claim 1, wherein the slurry cooling temperature in the step 3) is 5-20 ℃.
4. The method according to claim 1, wherein the mass ratio of the water consumption for recrystallization to the powdery crude product is 2:1 to 10: 1.
5. The method according to claim 1, wherein the absolute pressure of dehydration and sublimation in step 3) is 1 to 10KPa, the dehydration temperature is 180 to 230 ℃, the dehydration time is 0.1 to 2 hours, the temperature rise is 220 to 260 ℃, and the sublimation time is 0.5 to 2 hours.
6. The method according to claim 1, wherein the pyromellitic dianhydride is obtained in a mass yield of 110 to 125% and a purity of 98.5 to 99.5% with respect to durene.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115010592A (en) * | 2022-07-07 | 2022-09-06 | 浙江大学 | Preparation method of 4-bromophthalic acid |
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|---|---|---|---|---|
| US20040143135A1 (en) * | 2003-01-16 | 2004-07-22 | Tatsuyuki Kumano | Production method of pyromellitic acid and pyromellitic anhydride |
| CN108218686A (en) * | 2018-03-08 | 2018-06-29 | 上海应用技术大学 | A kind of method that Anderson heteropoly acid catalysis oxidation prepares Pyromellitic Acid |
| CN110746435A (en) * | 2019-10-31 | 2020-02-04 | 曹正国 | Method for producing pyromellitic dianhydride by low-temperature liquid-phase continuous oxidation of durene |
| CN113583014A (en) * | 2021-08-17 | 2021-11-02 | 江苏正丹化学工业股份有限公司 | Method for synthesizing pyromellitic dianhydride by liquid-phase continuous oxygen-enriched precise oxidation of durene |
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040143135A1 (en) * | 2003-01-16 | 2004-07-22 | Tatsuyuki Kumano | Production method of pyromellitic acid and pyromellitic anhydride |
| CN108218686A (en) * | 2018-03-08 | 2018-06-29 | 上海应用技术大学 | A kind of method that Anderson heteropoly acid catalysis oxidation prepares Pyromellitic Acid |
| CN110746435A (en) * | 2019-10-31 | 2020-02-04 | 曹正国 | Method for producing pyromellitic dianhydride by low-temperature liquid-phase continuous oxidation of durene |
| CN113583014A (en) * | 2021-08-17 | 2021-11-02 | 江苏正丹化学工业股份有限公司 | Method for synthesizing pyromellitic dianhydride by liquid-phase continuous oxygen-enriched precise oxidation of durene |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115010592A (en) * | 2022-07-07 | 2022-09-06 | 浙江大学 | Preparation method of 4-bromophthalic acid |
| CN115010592B (en) * | 2022-07-07 | 2023-06-27 | 浙江大学 | Preparation method of 4-bromophthalic acid |
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