CN104592138B - Method of increasing hydroxymethyl content of hexahydroxymethyl melamine - Google Patents
Method of increasing hydroxymethyl content of hexahydroxymethyl melamine Download PDFInfo
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- CN104592138B CN104592138B CN201510008949.0A CN201510008949A CN104592138B CN 104592138 B CN104592138 B CN 104592138B CN 201510008949 A CN201510008949 A CN 201510008949A CN 104592138 B CN104592138 B CN 104592138B
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- melamine
- formaldehyde
- cushioning liquid
- reaction system
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D251/00—Heterocyclic compounds containing 1,3,5-triazine rings
- C07D251/02—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings
- C07D251/12—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings having three double bonds between ring members or between ring members and non-ring members
- C07D251/26—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings having three double bonds between ring members or between ring members and non-ring members with only hetero atoms directly attached to ring carbon atoms
- C07D251/40—Nitrogen atoms
- C07D251/54—Three nitrogen atoms
- C07D251/64—Condensation products of melamine with aldehydes; Derivatives thereof
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Phenolic Resins Or Amino Resins (AREA)
Abstract
The invention relates to a method of increasing the hydroxymethyl content of hexahydroxymethyl melamine. The method concretely comprises the following steps: (1) according to the molar ratio of melamine, formaldehyde and water to be 1 to (6-7) to (30-35), adding the amount of the water into a reaction kettle, regulating the rotary speed of a stirrer of the reaction kettle to be 80-120rpm, adding the amount of the formaldehyde, raising the temperature, regulating the temperature to be 45-50 DEG C, adding the amount of the melamine, stirring for 10-30 minutes, keeping the temperature to be 55-60 DEG C, wherein in the whole process, a pH value of a reaction system to be 8.3-8.4 is kept by using a buffer liquid, and the buffer liquid is a sodium carbonate-sodium bicarbonate buffer liquid; (2) after the melamine in the reaction system is completely dissolved, lowering the stirring speed of the reaction kettle to 50-70rpm, and keeping reaction for 2-3h; and (3) stopping stirring, standing for crystallization for 1-1.5h, carrying out air pump filtration separation, removing a waste liquid, and drying to obtain the finished hexahydroxymethyl melamine. According to the method disclosed by the invention, the hydroxymethyl content of the hexahydroxymethyl melamine achieves 59-61 percent.
Description
Technical field
The invention belongs to the field of chemical synthesis, the methylol for relating to the use of chemical method raising hexamethylolmelamine contains
Amount method.
Background technology
The production method of Amino resin has one-step method and two step method.Wherein one-step method is production amino resins process
Middle hydroxymethylation and one step of etherificate are completed, and resin does not differentiate between alkalescence and acid two stages during the course of the reaction, and reaction is begun
Be in faintly acid eventually, have the advantages that it is with short production cycle, simple to operate, be easily controlled, but the resinite for producing in this way
Amount stability is poor, hardness of paint film is low, not easy to store.Therefore, domestic mostly to use two-step method, two-step method is methylolation and etherificate
Substep is completed, and methylolation is followed by the etherification stage under solutions of weak acidity in the basic conditions, and detailed process is as follows：(1)
Methylol reacts, the mixture that melamine is not waited with formaldehyde reaction generation number containing methylol；(2) etherification reaction, i.e. methylol
Compound reacts with alcohols, improves molecular polarity, forms new alkoxy.The group connected on triazine ring is different, then trimerization
The overall performance of melamine resin is also different.The present invention is directed the first step methylol reaction in two-step method.
The methylolation step that the A of patent CN 102010380 are related to is：Melamine is added in a kettle. with excess
Paraformaldehyde, paraformaldehyde should be greater than 10 with the mol ratio of melamine, and at ambient pressure, temperature control is in 30~35 DEG C, moisture
Control carries out hydroxymethylation between 5~15% by adding appropriate manganese dioxide-catalyst, generates intermediate product,
It is basically completed by hydroxymethylation after 3~4 hours, generates hexamethylolmelamine.
In the A of patent CN 1910162, melamine and formaldehyde are with 1:4~12 mol ratio is used, and formaldehyde is with 35-95
The form of weight % formalins is used, and wherein methylolation is carried out at a temperature of 120 DEG C, and hydroxymethylation carries out 2-
90 minutes, adjusted with 30% sodium hydroxide solution (being mixed with 0.73g boraxs) to the pH of 8.5-8.8, gained methylolation melamine
Amine has the methylolation degree of 4.0-6.0.
In the A of patent CN 101333198, hydroxymethylation is then anti-by paraformaldehyde, melamine and methyl alcohol input
Kettle is answered, pH value 7.5~9.5 is adjusted with NaOH, controlling reaction temperature obtains hexamethylol melamine at 60 DEG C~70 DEG C
Amine, after precipitation to be crystallized, insulation is lowered the temperature for 2~3 hours again.
In the A of patent CN 103554044, melamine and methyl alcohol or formalin or methyl alcohol and formalin are mixed
Liquid is 1 in mass ratio:L-3 is beaten, and obtains component A；Configuration quality percentage composition is 25-65% formalins, obtains B component；Will
The component of A, B two is 1 in mass ratio:1-5 is continuously added in reactor, and controlling reaction temperature is 45-85 DEG C, is adjusted by triethylamine
PH to 7.5-10.0, control reaction time 10-90 minute, obtain dihydroxymethyl melamine, trihydroxy methyl melamine and
Tetra methylol melamine mixture.
In the A of patent CN 102010380 and the A of CN 101045711, methylolated catalyst is manganese dioxide,
Regulation pH to 8-9；In the A of patent CN 101333198, the catalyst for using is NaOH, regulation pH value to 7.5~9.5；
In patent CN 1910162A, methylolation catalyst be 30% sodium hydroxide solution (being mixed with 0.73g boraxs) adjust pH to
8.5-8.8；The catalyst used in the A of patent CN 103554044 is triethylamine, adjusts pH to 7.5-10.0.
Because during hydroxymethylation, the pH value of system is reduced and then influences methylolation process, makes synthesis
The methylol group content of hexamethylolmelamine is only 55~56%, it is difficult to reach 62%.
The content of the invention
The methylol group content of the hexamethylolmelamine prepared for prior synthesizing method is only 55~56% deficiency,
The present invention proposes using sodium carbonate-bicarbonate buffer system as methylolated catalyst, suppresses pH value in reaction and change, makes anti-
System pH is more stablized during answering, further to improve the methylol group content of hexamethylolmelamine.
Realizing the technical scheme of the object of the invention is：A kind of method for improving hexamethylolmelamine methylol group content,
It is first raw material with the melamine that measures, formaldehyde, water, adds sodium carbonate-bicarbonate cushioning liquid catalyst, the suitable temperature of selection
Degree, pH value, reaction ratio, time, so as to obtain methylol group content hexamethylolmelamine high.Its specific method step is such as
Under：
(1) by melamine：Formaldehyde：Water mol ratio is 1:(6~7):(30~35), to putting into above-mentioned metering in reactor
Water, adjust reactor agitator 80~120rpm of rotating speed, add the formaldehyde of above-mentioned metering, the regulation temperature that heats up is 45~50
DEG C, the melamine of above-mentioned metering is added, maintained the temperature between 55~60 DEG C after 10~30min of stirring；Used in whole process
It is 8.3~8.4 that cushioning liquid keeps the pH value of reaction system；Wherein described cushioning liquid is sodium carbonate-bicarbonate buffer solution；
(2) melamine is completely dissolved in question response system, reduces reactor mixing speed to 50~70rpm, keeps anti-
Answer 2~3h；The crystallization that reactor mixing speed is conducive to product hexamethylolmelamine is reduced in this step；
(3) stop stirring, stand 1~1.5h of crystallization, suction filtration is separated, and sloughs waste liquid, drying finished product hexamethylol three
Poly cyanamid.
Under preferable case, the sodium carbonate-bicarbonate buffer solution is with Preparation Method：By same molar ratio
Na2CO3The aqueous solution and NaHCO3The aqueous solution is mixed by a certain percentage, and the cushioning liquid for obtaining pH value at 20 DEG C is 9-10.
In the case of more preferably, using the Na of 0.1mol/L2CO3The NaHCO of the aqueous solution and 0.1mol/L3The aqueous solution presses 4:6 volume ratio is entered
Row mixing, cushioning liquid pH value at 20 DEG C is 9.78, is 9.50 at 37 DEG C.
Under preferable case, the addition of cushioning liquid is divided into two steps wherein in step (1), and the first step is added in melamine
Cushioning liquid is first added before reaction system, the pH value in reaction system is adjusted to 7.9~8.1；Second step is in melamine
Amine is added after reaction system, then adds cushioning liquid, and the pH value in reaction system is adjusted into 8.3~8.4.By two-step method
Cushioning liquid is added, reaction system can be made more to stablize, react more balanced, so as to obtain final products hexamethylol trimerization
Cyanamide methylol group content is higher.
Under preferable case, formaldehyde used is the formalin of mass fraction 37%.When using formalin, step
(1) water in proportion scale is also comprising the water in formalin.
GB/T5543-2006 " the total formaldehyde of resin finishing agent is used to method of the present invention synthesis hexamethylolmelamine
The measure of content, free formaldehyde content and hydroxymethyl formaldehyde content " is measured to methylol group content, as a result shows the hydroxyl of product six
Methyl melamine methylol group content reaches 59~61%.
This method is simple to operate, and process conditions are gentle, and catalyst is convenient source, and low production cost, product methylol contains
Amount is high.
This method can be applied to the industrialized production of the hexamethylolmelamine of high methylol group content.Give birth in this way
The hexamethylolmelamine that output is come can further carry out etherification reaction production amino resins.
Specific embodiment
With reference to concrete example, the present invention is further illustrated, but the present invention is not limited solely to following examples.
Embodiment 1
One kind improves hexamethylolmelamine methylol group content method, comprises the following steps that：
(1) by melamine: formaldehyde: water mol ratio is for 1: 6: 30 to the water that above-mentioned metering is put into reactor, and regulation is anti-
Kettle agitator speed 120rpm is answered, the formaldehyde of above-mentioned metering is added, formaldehyde used is the formalin of mass fraction 37%, first
Plus sodium carbonate-bicarbonate cushioning liquid catalyst adjusts pH value to 8.0, regulation temperature is heated up to add above-mentioned metering after 50 DEG C
Melamine, stirring 30min after be incubated at 55 DEG C, then add sodium carbonate-bicarbonate cushioning liquid catalyst keep pH value about
It is 8.4.Wherein sodium carbonate-bicarbonate cushioning liquid is using the Na of 0.1mol/L2CO3The aqueous solution is with 0.1mol/L's
NaHCO3The aqueous solution presses 4:6 volume ratio is mixed.
(2) treat that melamine is completely dissolved, reduce reactor mixing speed, adjust reactor agitator rotating speed 50rpm, protect
Hold reaction 2h.
(3) stop stirring, stand crystallization 1h, suction filtration is separated, and sloughs waste liquid, is drying to obtain finished product hexamethylolmelamine
White granular solid.
Hexamethylolmelamine finished product sampling to obtaining, carries out methylol group content measure, and its content is 60%.
Embodiment 2
One kind improves hexamethylolmelamine methylol group content method, comprises the following steps that：
(1) by melamine: formaldehyde: water mol ratio is 1: 6.5: 33 to the water that above-mentioned metering is put into reactor, regulation
Reactor agitator rotating speed 90rpm, adds the formaldehyde of above-mentioned metering, and formaldehyde used is the formalin of mass fraction 37%,
First plus sodium carbonate-bicarbonate cushioning liquid catalyst adjusts pH value to 8.1, the regulation temperature that heats up is to add above-mentioned meter after 50 DEG C
The melamine of amount, is incubated at 55 DEG C after stirring 20min, then adds sodium carbonate-bicarbonate cushioning liquid catalyst to keep pH value
About 8.3.Wherein sodium carbonate-bicarbonate cushioning liquid is using the Na of 0.1mol/L2CO3The aqueous solution is with 0.1mol/L's
NaHCO3The aqueous solution presses 4:6 volume ratio is mixed.
(2) treat that melamine is completely dissolved, reduce reactor mixing speed, adjust reactor agitator rotating speed 60rpm, protect
Hold reaction 2.5h.
(3) stop stirring, stand crystallization 1.5h, suction filtration is separated, and sloughs waste liquid, is drying to obtain finished product hexamethylol melamine
Amine white granular solid.
Hexamethylolmelamine finished product sampling to obtaining, carries out methylol group content measure, and its content is 59%.
Embodiment 3
One kind improves hexamethylolmelamine methylol group content method, comprises the following steps that：
(1) by melamine: formaldehyde: water mol ratio is for 1: 7: 35 to the water that above-mentioned metering is put into reactor, and regulation is anti-
Kettle agitator speed 80rpm is answered, the formaldehyde of above-mentioned metering is added, formaldehyde used is the formalin of mass fraction 37%, first
Plus sodium carbonate-bicarbonate cushioning liquid catalyst adjusts pH value to 7.9, regulation temperature is heated up to add above-mentioned metering after 45 DEG C
Melamine, stirring 10min after be incubated at 60 DEG C, then add sodium carbonate-bicarbonate cushioning liquid catalyst keep pH value about
It is 8.3.Wherein sodium carbonate-bicarbonate cushioning liquid is using the Na of 0.1mol/L2CO3The aqueous solution is with 0.1mol/L's
NaHCO3The aqueous solution presses 4:6 volume ratio is mixed.
(2) treat that melamine is completely dissolved, reduce reactor mixing speed, adjust reactor agitator rotating speed 70rpm, protect
Hold reaction 3h.
(3) stop stirring, stand crystallization 1.2h, suction filtration is separated, and sloughs waste liquid, is drying to obtain finished product hexamethylol melamine
Amine white granular solid.
Hexamethylolmelamine finished product sampling to obtaining, carries out methylol group content measure, and its content is 61%.
Embodiment 4
One kind improves hexamethylolmelamine methylol group content method, comprises the following steps that：
(1) by melamine: formaldehyde: water mol ratio is for 1: 7: 35 to the water that above-mentioned metering is put into reactor, and regulation is anti-
Kettle agitator speed 80rpm is answered, the formaldehyde of above-mentioned metering is added, formaldehyde used is the formalin of mass fraction 37%, plus
Enter sodium carbonate-bicarbonate cushioning liquid catalyst and adjust pH value to 8.3, heat up regulation temperature to add above-mentioned metering after 45 DEG C
Melamine, stirring 10min after be incubated at 60 DEG C.Wherein sodium carbonate-bicarbonate cushioning liquid is using 0.1mol/L
Na2CO3The NaHCO of the aqueous solution and 0.1mol/L3The aqueous solution presses 4:6 volume ratio is mixed.
(2) treat that melamine is completely dissolved, reduce reactor mixing speed, adjust reactor agitator rotating speed 70rpm, protect
Hold reaction 3h.
(3) stop stirring, stand crystallization 1.2h, suction filtration is separated, and sloughs waste liquid, is drying to obtain finished product hexamethylol melamine
Amine white granular solid.
Hexamethylolmelamine finished product sampling to obtaining, carries out methylol group content measure, and its content is 59%.
Claims (2)
1. it is a kind of improve hexamethylolmelamine methylol group content method, it is comprised the following steps that：
(1) by melamine：Formaldehyde：Water mol ratio is 1:(6~7):(30~35), to putting into above-mentioned metering in reactor
Water, adjusts reactor agitator 80~120rpm of rotating speed, adds the formaldehyde of above-mentioned metering, and the regulation temperature that heats up is 45~50 DEG C,
The melamine of above-mentioned metering is added, is maintained the temperature between 55~60 DEG C after 10~30min of stirring；Wherein described cushioning liquid
It is sodium carbonate-bicarbonate buffer solution；
(2) melamine is completely dissolved in question response system, reduction reactor mixing speed to 50~70rpm, and holding reaction 2~
3h；
(3) stop stirring, stand 1~1.5h of crystallization, suction filtration is separated, and sloughs waste liquid, drying finished product hexamethylol melamine
Amine；
The sodium carbonate-bicarbonate buffer solution is with Preparation Method：By the Na of same molar ratio2CO3The aqueous solution and NaHCO3
The aqueous solution is mixed, and the cushioning liquid for obtaining pH value at 20 DEG C is 9-10；
The addition of cushioning liquid is divided into two steps wherein in step (1), and the first step is first before melamine adds reaction system
Cushioning liquid is added, the pH value in reaction system is adjusted to 7.9~8.1；Second step is to add reaction system in melamine
Afterwards, then cushioning liquid is added, the pH value in reaction system is adjusted to 8.3~8.4.
2. it is according to claim 1 improve hexamethylolmelamine methylol group content method, formaldehyde used be quality
The formalin of fraction 37%.
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| CN201510008949.0A CN104592138B (en) | 2015-01-08 | 2015-01-08 | Method of increasing hydroxymethyl content of hexahydroxymethyl melamine |
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| CN201510008949.0A CN104592138B (en) | 2015-01-08 | 2015-01-08 | Method of increasing hydroxymethyl content of hexahydroxymethyl melamine |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN106349175B (en) * | 2016-08-01 | 2019-08-27 | 重庆派昂科技发展有限公司 | Inorganic hybridization melamine methylol phosphate and preparation method thereof |
| CN108610298A (en) * | 2018-04-11 | 2018-10-02 | 重庆建峰浩康化工有限公司 | The environmental protection production of hexamethylolmelamine |
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| WO2014070155A1 (en) * | 2012-10-31 | 2014-05-08 | Empire Technology Development Llc | Multifunctional melamine epoxy resins, methylols and amines |
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| TW201435011A (en) * | 2013-01-30 | 2014-09-16 | 湛新智財有限公司 | One pack low temperature cure coating compositions |
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