CN113999358A - Preparation method of urea formaldehyde pre-condensed liquid for producing shaving boards by formaldehyde - Google Patents
Preparation method of urea formaldehyde pre-condensed liquid for producing shaving boards by formaldehyde Download PDFInfo
- Publication number
- CN113999358A CN113999358A CN202111392162.0A CN202111392162A CN113999358A CN 113999358 A CN113999358 A CN 113999358A CN 202111392162 A CN202111392162 A CN 202111392162A CN 113999358 A CN113999358 A CN 113999358A
- Authority
- CN
- China
- Prior art keywords
- formaldehyde
- urea
- ufc
- preparing
- tail gas
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Links
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 title claims abstract description 124
- 229920001807 Urea-formaldehyde Polymers 0.000 title claims abstract description 33
- ODGAOXROABLFNM-UHFFFAOYSA-N polynoxylin Chemical compound O=C.NC(N)=O ODGAOXROABLFNM-UHFFFAOYSA-N 0.000 title claims abstract description 33
- 238000002360 preparation method Methods 0.000 title claims abstract description 16
- 239000007788 liquid Substances 0.000 title abstract description 19
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 claims abstract description 20
- 239000004202 carbamide Substances 0.000 claims abstract description 20
- 239000002245 particle Substances 0.000 claims abstract description 10
- 229920000877 Melamine resin Polymers 0.000 claims abstract description 9
- 238000010521 absorption reaction Methods 0.000 claims abstract description 9
- JDSHMPZPIAZGSV-UHFFFAOYSA-N melamine Chemical compound NC1=NC(N)=NC(N)=N1 JDSHMPZPIAZGSV-UHFFFAOYSA-N 0.000 claims abstract description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 3
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims description 24
- 238000000034 method Methods 0.000 claims description 10
- YNAVUWVOSKDBBP-UHFFFAOYSA-N Morpholine Chemical compound C1COCCN1 YNAVUWVOSKDBBP-UHFFFAOYSA-N 0.000 claims description 4
- NQRYJNQNLNOLGT-UHFFFAOYSA-N Piperidine Chemical compound C1CCNCC1 NQRYJNQNLNOLGT-UHFFFAOYSA-N 0.000 claims description 4
- JUJWROOIHBZHMG-UHFFFAOYSA-N Pyridine Chemical compound C1=CC=NC=C1 JUJWROOIHBZHMG-UHFFFAOYSA-N 0.000 claims description 4
- 150000007530 organic bases Chemical class 0.000 claims description 4
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 claims description 2
- 230000009471 action Effects 0.000 claims description 2
- 239000003054 catalyst Substances 0.000 claims description 2
- 238000001704 evaporation Methods 0.000 claims description 2
- 238000010438 heat treatment Methods 0.000 claims description 2
- 238000012432 intermediate storage Methods 0.000 claims description 2
- 239000000203 mixture Substances 0.000 claims description 2
- 239000007800 oxidant agent Substances 0.000 claims description 2
- UMJSCPRVCHMLSP-UHFFFAOYSA-N pyridine Natural products COC1=CC=CN=C1 UMJSCPRVCHMLSP-UHFFFAOYSA-N 0.000 claims description 2
- 229910052709 silver Inorganic materials 0.000 claims description 2
- 239000004332 silver Substances 0.000 claims description 2
- 238000003860 storage Methods 0.000 claims description 2
- 238000004519 manufacturing process Methods 0.000 claims 1
- 125000002485 formyl group Chemical class [H]C(*)=O 0.000 abstract description 16
- 238000006243 chemical reaction Methods 0.000 abstract description 10
- WSFSSNUMVMOOMR-NJFSPNSNSA-N methanone Chemical compound O=[14CH2] WSFSSNUMVMOOMR-NJFSPNSNSA-N 0.000 abstract description 5
- 230000007613 environmental effect Effects 0.000 abstract description 3
- 239000000126 substance Substances 0.000 abstract description 3
- 230000000052 comparative effect Effects 0.000 description 6
- 239000008098 formaldehyde solution Substances 0.000 description 6
- 239000003513 alkali Substances 0.000 description 4
- 230000008901 benefit Effects 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 239000003292 glue Substances 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G12/00—Condensation polymers of aldehydes or ketones with only compounds containing hydrogen attached to nitrogen
- C08G12/02—Condensation polymers of aldehydes or ketones with only compounds containing hydrogen attached to nitrogen of aldehydes
- C08G12/26—Condensation polymers of aldehydes or ketones with only compounds containing hydrogen attached to nitrogen of aldehydes with heterocyclic compounds
- C08G12/34—Condensation polymers of aldehydes or ketones with only compounds containing hydrogen attached to nitrogen of aldehydes with heterocyclic compounds and acyclic or carbocyclic compounds
- C08G12/36—Ureas; Thioureas
- C08G12/38—Ureas; Thioureas and melamines
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J161/00—Adhesives based on condensation polymers of aldehydes or ketones; Adhesives based on derivatives of such polymers
- C09J161/20—Condensation polymers of aldehydes or ketones with only compounds containing hydrogen attached to nitrogen
- C09J161/30—Condensation polymers of aldehydes or ketones with only compounds containing hydrogen attached to nitrogen of aldehydes with heterocyclic and acyclic or carbocyclic compounds
Abstract
The invention discloses a preparation method of urea formaldehyde pre-condensed liquid for producing a particle board by formaldehyde, belonging to the technical field of chemical preparation and comprising the following steps: absorbing the mixed gas containing formaldehyde in an absorption tower in an alkaline environment through urea solution to prepare UFC; the formaldehyde gas which is not completely absorbed enters an absorption tower II and is absorbed by water; part of the produced tail gas enters a reactor through a mixer, and the rest is introduced into a tail gas processor; on one hand, the proper alkalinity of the system is kept in the preparation process of the urea formaldehyde pre-condensed liquid, so that the conversion rate of UFC can be improved by more than 15%; on the other hand, the free aldehyde in the UFC can be reduced by more than 30% by adding a proper amount of melamine into the urea solution, and when the urea solution is used for preparing the shaving board, the environmental protection performance of the prepared shaving board can reach E0 level; in addition, tail gas is recycled, and the pressure for treating the tail gas and the pressure for protecting the environment are reduced.
Description
Technical Field
The invention relates to the technical field of chemical preparation, in particular to a preparation method of urea formaldehyde pre-condensed liquid for producing a shaving board by formaldehyde.
Background
The urea formaldehyde precondensate (UFC) is the main raw material for producing urea formaldehyde glue, is an environment-friendly chemical product, and is most widely applied to the glue making process of artificial boards. The preparation of the urea formaldehyde precondensate solution well solves the problems of storing and transporting formaldehyde in cold winter.
There are many reports on the preparation of urea-formaldehyde precondensate, and the preparation method is generally to absorb mixed gas containing formaldehyde and solution containing urea.
The prior method for preparing the urea formaldehyde precondensate generally has the following problems: 1. the conversion rate of the urea formaldehyde pre-condensed liquid is lower, and is generally about 75 percent; 2. the content of free aldehyde in the urea formaldehyde pre-condensed liquid is higher, and is generally about 5 percent.
Disclosure of Invention
The invention aims to provide a preparation method of urea formaldehyde pre-condensed liquid for producing a particle board by formaldehyde, which aims to solve the problems.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows: a preparation method of urea formaldehyde precondensate for producing particle boards by formaldehyde comprises the following steps:
(1) absorbing the mixed gas containing formaldehyde in an absorption tower in an alkaline environment through urea solution to prepare UFC;
(2) the formaldehyde gas which is not completely absorbed in the step (1) enters an absorption tower II and is absorbed by water;
(3) and (3) feeding part of the tail gas produced in the step (2) into the reactor through the mixer, and feeding the rest into a tail gas processor.
A large number of experiments prove that the proper alkalinity of the system is maintained in the preparation process of the urea formaldehyde pre-condensed liquid, and the conversion rate of UFC can be remarkably improved.
And (4) extracting the finished UFC from a tower kettle, feeding the UFC into an intermediate storage tank, analyzing to obtain a qualified UFC product, uniformly mixing, and feeding into a finished product storage tank.
As a preferable technical solution, in the step (1), the method for preparing the mixed gas containing formaldehyde comprises the following steps:
s1: introducing methanol and air into an evaporator;
s3: mixing and evaporating methanol and air and introducing into a superheater;
s3: mixing and heating methanol, air and steam in a superheater and introducing the mixture into a filter;
s4: the methanol, the air, the tail gas and the steam which are filtered by the filter enter a reactor through a mixer;
s5: the mixed gas is oxidized in an oxidizer under the action of a silver catalyst to generate the mixed gas containing formaldehyde.
As a preferable technical scheme, in the step (1), the alkaline environment means that the pH of the system is kept between 7.8 and 9.5.
As a further preferred solution, the alkaline environment is formed by the addition of an organic base.
By adopting the organic alkali, the corrosion of the alkalinity to the equipment seal is reduced while the appropriate alkalinity of the system is maintained, the risk of accidental leakage is reduced, and the service life of the equipment is prolonged.
As a further preferable embodiment, the organic base is at least one selected from piperidine, morpholine, and pyridine.
As a preferable technical scheme, in the step (1), 1-3wt% of melamine is added into the urea solution based on the content of formaldehyde.
The inventor of this application proves through a large amount of experiments that in urea-formaldehyde precondensate liquid preparation process, add appropriate amount melamine in urea solution, can show especially aldehyde content in the UFC product to do benefit to its environmental protection nature when being used for producing the shaving board more.
Compared with the prior art, the invention has the advantages that: on one hand, the proper alkalinity of the system is kept in the urea formaldehyde pre-condensed liquid preparation process, so that the conversion rate of UFC can be improved to 93%; on the other hand, the free aldehyde in the UFC can be reduced to 1.5% from the conventional 5% by adding a proper amount of melamine into the urea solution, and when the urea solution is used for preparing the shaving board, the environmental protection performance of the prepared shaving board can reach E0 level (the formaldehyde emission of E0 is less than or equal to 0.5mg/L, the formaldehyde emission of E1 is 0.5 mg/I-1.5 mg/L, and the formaldehyde emission of E2 is more than 1.5 mg/L); in addition, tail gas is recycled, and the pressure for treating the tail gas and the pressure for protecting the environment are reduced.
Detailed Description
The present invention will be further described with reference to the following examples.
Example 1:
controlling the yield of the formaldehyde device at 120t/d, collecting dilute aldehyde in the second tower into a dilute aldehyde tank (used for preparing urea solution and solving the dilute aldehyde balance problem of the system), increasing the concentration of the formaldehyde online product to 53 percent, and adding dilute alkali liquor (20 wt%) to the middle section and the lower section of the absorption first tower to adjust the pH value of the formaldehyde solution to 9.3; the urea solution is added with 2wt% of melamine based on the content of formaldehyde, 65wt% of prepared urea solution is injected into the upper section of a tower to react with the formaldehyde solution, the temperature of the tower bottom is controlled at 83-85 ℃, the urea-formaldehyde pre-condensed liquid (UFC) is prepared after 8 hours of operation, the total content of the UFC is about 74.5%, the conversion rate of the UFC is 93%, the content of free aldehyde is 1.5%, and the product is colorless, clear and transparent in appearance.
Example 2:
controlling the yield of the formaldehyde device at 120t/d, collecting the dilute aldehyde in the second tower into a dilute aldehyde tank (used for preparing urea solution and solving the dilute aldehyde balance problem of the system), increasing the concentration of the formaldehyde online product to 53 percent, and adding dilute alkali liquor (20 wt%) to the middle section and the lower section of the absorption first tower to adjust the pH value of the formaldehyde solution to 8.7; the urea solution is added with 2wt% of melamine based on the content of formaldehyde, 65wt% of prepared urea solution is injected into the upper section of a tower to react with the formaldehyde solution, the temperature of the tower bottom is controlled at 83-85 ℃, the urea-formaldehyde pre-condensed liquid (UFC) is prepared after 8 hours of operation, the total content of the UFC is about 74.3%, the conversion rate of the UFC is 92.8%, the content of free aldehyde is 1.5%, and the product is colorless, clear and transparent in appearance.
Example 3
Controlling the yield of the formaldehyde device at 120t/d, collecting dilute aldehyde in the second tower into a dilute aldehyde tank (used for preparing urea solution and solving the dilute aldehyde balance problem of the system), increasing the concentration of the formaldehyde online product to 53 percent, and adding dilute alkali liquor (20 wt%) to the middle section and the lower section of the absorption first tower to adjust the pH value of the formaldehyde solution to 9.3; the urea solution is added with 1wt% of melamine based on the content of formaldehyde, 65wt% of prepared urea solution is injected into the upper section of a tower to react with the formaldehyde solution, the temperature of the tower bottom is controlled at 83-85 ℃, the urea-formaldehyde precondensate (UFC) is prepared after 8 hours of operation, the total content of the UFC is about 74.3%, the conversion rate of the UFC is 92.8%, the content of free aldehyde is 1.6%, and the product is colorless, clear and transparent in appearance.
Comparative example 1:
the comparative example was conducted in the same manner as in example 1 except that the pH of the formalin was adjusted from 9.3 to 7.5 as compared with example 1, and the results were as follows: after 8 hours of operation, the total content of the urea formaldehyde pre-condensed liquid (UFC) is about 65 percent, the conversion rate of the UFC is 80 percent, the free formaldehyde content of the urea formaldehyde pre-condensed liquid (UFC) is 1.9 percent, and the appearance of the product is colorless.
Comparative example 2:
the comparative example was conducted in the same manner as in example 1 except that the pH of the formalin was adjusted from 9.3 to 10 as compared with example 1, and the results were as follows: after 8 hours of operation, the total content of the urea formaldehyde pre-condensed liquid (UFC) is about 71.5 percent, the conversion rate of the UFC is 89.1 percent, the free formaldehyde content of the urea formaldehyde pre-condensed liquid (UFC) is 1.6 percent, and the appearance of the product is yellowish.
Comparative example 3
This comparative example is identical to example 1, except that no melamine was added, as compared to example 1, with the result that: after 8 hours of operation, the total content of the urea formaldehyde pre-condensed liquid (UFC) is about 73.5 percent, the conversion rate of the UFC is 91 percent, and the free formaldehyde content of the urea formaldehyde pre-condensed liquid (UFC) is 6.5 percent.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.
Claims (7)
1. A preparation method of urea formaldehyde precondensate for producing particle boards by formaldehyde is characterized by comprising the following steps:
(1) absorbing the mixed gas containing formaldehyde in an absorption tower in an alkaline environment through urea solution to prepare UFC;
(2) the formaldehyde gas which is not completely absorbed in the step (1) enters an absorption tower II and is absorbed by water;
(3) and (3) feeding part of the tail gas produced in the step (2) into the reactor through the mixer, and feeding the rest into a tail gas processor.
2. The method for preparing the urea formaldehyde precondensate solution for the formaldehyde particle board in the formaldehyde production according to claim 1, further comprising the step (4) of collecting the finished UFC from a tower kettle, feeding the collected UFC into an intermediate storage tank, uniformly mixing the UFC after the UFC is analyzed to be qualified, and feeding the UFC into a finished product storage tank.
3. The method for preparing the urea formaldehyde precondensate for the formaldehyde particle board according to claim 1, wherein the method for preparing the formaldehyde-containing mixed gas in the step (1) comprises the following steps:
s1: introducing methanol and air into an evaporator;
s3: mixing and evaporating methanol and air and introducing into a superheater;
s3: mixing and heating methanol, air and steam in a superheater and introducing the mixture into a filter;
s4: the methanol, the air, the tail gas and the steam which are filtered by the filter enter a reactor through a mixer;
s5: the mixed gas is oxidized in an oxidizer under the action of a silver catalyst to generate the mixed gas containing formaldehyde.
4. The method for preparing the urea-formaldehyde precondensate for the formaldehyde particle board according to claim 1, wherein in the step (1), the alkaline environment means that the pH of the system is maintained between 7.8 and 9.5.
5. The method for preparing the urea-formaldehyde precondensate for the formaldehyde particle board as claimed in claim 4, wherein the alkaline environment is formed by adding an organic base.
6. The method for preparing the urea-formaldehyde precondensate for the formaldehyde particle board according to claim 5, wherein the organic base is at least one selected from piperidine, morpholine and pyridine.
7. The method for preparing the urea-formaldehyde precondensate for the particle board produced by formaldehyde according to claim 1, wherein in the step (1), 1-3wt% of melamine is added based on the content of formaldehyde in the urea solution.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111392162.0A CN113999358B (en) | 2021-11-23 | 2021-11-23 | Preparation method of urea formaldehyde pre-shrinking liquid for formaldehyde production chipboard |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111392162.0A CN113999358B (en) | 2021-11-23 | 2021-11-23 | Preparation method of urea formaldehyde pre-shrinking liquid for formaldehyde production chipboard |
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| Publication Number | Publication Date |
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| CN113999358A true CN113999358A (en) | 2022-02-01 |
| CN113999358B CN113999358B (en) | 2024-02-06 |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108689817A (en) * | 2018-08-01 | 2018-10-23 | 江苏道尔顿石化科技有限公司 | A kind of device and method of iron molybdenum method production formaldehyde coproduction UFC |
| CN117126357A (en) * | 2023-08-09 | 2023-11-28 | 山东联亿新能源科技股份有限公司 | Continuous high-quality ammonia aldehyde copolymer liquid production method and application |
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|---|---|---|---|---|
| GB906120A (en) * | 1957-10-30 | 1962-09-19 | Montedison Spa | Improvements relating to concentrated urea-formaldehyde solutions |
| EP0017206A1 (en) * | 1979-04-07 | 1980-10-15 | BASF Aktiengesellschaft | Process for the simultaneous preparation of concentrated aqueous formaldehyde-urea solutions and formaldehyde solutions |
| CN105348465A (en) * | 2015-12-04 | 2016-02-24 | 广西南宁德源胶粘剂有限公司 | Preparation method of E0-grade melamine modified urea formaldehyde resin |
| CN107522604A (en) * | 2017-09-01 | 2017-12-29 | 赵达扬 | The method of ultra-large production formaldehyde and ureaformaldehyde preshrunk liquid |
| CN108689817A (en) * | 2018-08-01 | 2018-10-23 | 江苏道尔顿石化科技有限公司 | A kind of device and method of iron molybdenum method production formaldehyde coproduction UFC |
| CN110563903A (en) * | 2019-09-06 | 2019-12-13 | 无锡市华立石化工程有限公司 | preparation system and preparation process of urea formaldehyde pre-condensed liquid |
-
2021
- 2021-11-23 CN CN202111392162.0A patent/CN113999358B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB906120A (en) * | 1957-10-30 | 1962-09-19 | Montedison Spa | Improvements relating to concentrated urea-formaldehyde solutions |
| US3067177A (en) * | 1957-10-30 | 1962-12-04 | Montedison Spa | Process for producing concentrated urea-formaldehyde solutions by absorbing gaseous formaldehyde in aqueous urea solutions |
| EP0017206A1 (en) * | 1979-04-07 | 1980-10-15 | BASF Aktiengesellschaft | Process for the simultaneous preparation of concentrated aqueous formaldehyde-urea solutions and formaldehyde solutions |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN108689817A (en) * | 2018-08-01 | 2018-10-23 | 江苏道尔顿石化科技有限公司 | A kind of device and method of iron molybdenum method production formaldehyde coproduction UFC |
| CN117126357A (en) * | 2023-08-09 | 2023-11-28 | 山东联亿新能源科技股份有限公司 | Continuous high-quality ammonia aldehyde copolymer liquid production method and application |
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| CN113999358B (en) | 2024-02-06 |
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