阅读说明：本技术 活泼亚甲基型除醛剂及其应用 (Active methylene type aldehyde remover and application thereof ) 是由 李少杰 高清 陈玉 赵立 赵俊飞 于 2020-12-11 设计创作，主要内容包括：本发明涉及一种活泼亚甲基型除醛剂及其应用,主要解决现有技术中存在的除醛剂制备中需要使用催化剂和溶剂,操作复杂的问题。本发明通过提供一种活泼亚甲基型除醛剂,其制备方法包括：在反应容器中按摩尔比1：1～3加入丙二酸二烷酯和多元醇,在与反应物呈惰性的气体保护和搅拌的条件下反应,反应温度为105～150℃,反应时间为2～8h,然后采用减压蒸馏脱除反应副产物和过量的丙二酸二烷酯,冷却至室温,得到活泼亚甲基型除醛剂及其应用的技术方案,较好地解决了该问题,可用于聚氨酯泡沫制品的工业生产中。(The invention relates to an active methylene type aldehyde remover and application thereof, and mainly solves the problems that in the prior art, a catalyst and a solvent are required to be used in the preparation of the aldehyde remover, and the operation is complex. The invention provides an active methylene type aldehyde remover, which comprises the following steps: in a reaction vessel, the molar ratio of 1: 1-3, adding dialkyl malonate and polyol, reacting under the protection of inert gas and stirring with reactants at the temperature of 105-150 ℃ for 2-8 hours, removing reaction byproducts and excessive dialkyl malonate by reduced pressure distillation, and cooling to room temperature to obtain the active methylene aldehyde remover and the application technical scheme thereof.)

1. An active methylene type aldehyde remover, which is structurally characterized by the general formula:

wherein: r is-CH₃Or H (O (CH)₂)_m)_n-O-

R' is-CH₃Or H (O (CH)₂)_m′)_n′-O-

m and (or) m 'are 1-3, n and (or) n' are 1-19;

the preparation method of the active methylene type aldehyde remover is characterized by comprising the following steps:

a. in a reaction vessel, the molar ratio of 1: 1-3, adding dialkyl malonate and polyhydric alcohol to obtain a material I;

b. reacting the material I under the conditions of inert gas protection and stirring with reactants, wherein the reaction temperature is 105-150 ℃, the reaction time is 2-8 h, and a by-product is separated by adopting an atmospheric distillation method in the reaction process to obtain a material II;

c. carrying out reduced pressure distillation on the material II to remove reaction byproducts and excessive dialkyl malonate to obtain a material III, wherein the pressure of the reduced pressure distillation is-0.080-0.105 Mpa, and the temperature is 105-150 ℃;

d. and cooling the material III to room temperature to obtain a viscous light yellow liquid, namely the active methylene type aldehyde remover to be prepared.

2. The active methylene-type aldehyde scavenger according to claim 1, characterized in that the dialkyl malonate in step a is selected from at least one of dimethyl malonate or diethyl malonate.

3. The active methylene aldehyde scavenger according to claim 1, wherein the polyol in step a is at least one selected from the group consisting of ethylene glycol and diethylene glycol.

4. The active methylene aldehyde scavenger according to claim 1, wherein the gas inert to the reactants is selected from at least one of nitrogen, helium or argon.

5. The active methylene aldehyde scavenger according to claim 1, wherein the reaction temperature is 130 to 150 ℃.

6. Use of the active methylene type aldehyde scavenger of claim 1 in polyurethane foams.

Technical Field

The invention relates to the field of aldehyde removing agents, in particular to an active methylene type aldehyde removing agent and application thereof in polyurethane foam.

Background

Formaldehyde is one of the main indoor Volatile Organic Compounds (VOCs), and is listed as the first carcinogen by the international agency for research on cancer (IARC) in 2004 as the second place on the priority control list of toxic chemicals in China, and a large amount of documents also describe that the influence of formaldehyde on human health is mainly reflected in aspects of abnormal smell, irritation, allergy, abnormal lung function, abnormal liver function, abnormal immune function and the like, and is easy to cause nasopharyngeal carcinoma, nasal cavity cancer and nasal poverty cancer of human beings, and can cause leukemia. Along with the improvement of living standard and the enhancement of environmental protection consciousness of people, the harm of formaldehyde released from materials closely related to the life of people, such as artificial boards, polyurethane foam materials, indoor decoration and the like, is more and more aroused attention of people, the research on formaldehyde removal is imperative, and an effective, simple and economic formaldehyde removal method is not only beneficial to the health of people, but also has important significance for improving the life quality and the environmental quality of people.

The formaldehyde scavenger is also called formaldehyde scavenger, formaldehyde absorptive agent or formaldehyde trapping agent, and is an aqueous solution containing compounds which can chemically react with formaldehyde under certain conditions, such as amides, phenol hydrazines, organic amines, inorganic ammonium salts and the like, and a mixture thereof, and the substances can be combined with formaldehyde in a chemical bond form to generate another stable compound, so that the release amount of the formaldehyde is reduced; therefore, many researchers are dedicated to the research on the development, synthesis and application of formaldehyde scavengers, and at present, scholars at home and abroad have made much research work on the aspect of formaldehyde scavengers, and although various formaldehyde scavengers can reduce the formaldehyde emission, the formaldehyde scavengers have many defects at the same time.

For example, chinese patent CN88103032.5 discloses a water-soluble active methylene group used as a formaldehyde scavenger, which is prepared by transesterifying diethyl malonate or ethyl acetoacetate with a substituted or unsubstituted polyhydric alcohol to obtain a water-soluble active methylene compound, and is used for removing formaldehyde from fabrics and particle boards treated with a permanent setting finishing agent. In the prior art, catalysts and solvents are used in other processes for synthesizing the active methylene type aldehyde removing agent, so that the process is complex, the cost is high, and the environment is greatly influenced.

Disclosure of Invention

One of the technical problems to be solved by the invention is to provide an active methylene type aldehyde remover, which has the advantages of no need of using a catalyst and a solvent and simple operation.

The second technical problem to be solved by the invention is to provide the application of the active methylene aldehyde-removing agent corresponding to the first problem to the polyurethane foam, and the application has the advantage that the prepared polyurethane foam has low formaldehyde content.

In order to solve one of the above technical problems, the technical scheme adopted by the invention is as follows: an active methylene type aldehyde remover, which is structurally characterized by the general formula:

wherein: r is-CH₃Or H (O (CH)₂)_m)_n-O-

R' is-CH₃Or H (O (CH)₂)_m′)_n′-O-

m and (or) m 'are 1-3, n and (or) n' are 1-19;

the preparation method of the active methylene type aldehyde remover is characterized by comprising the following steps:

a. in a reaction vessel, the molar ratio of 1: 1-3, adding dialkyl malonate and polyhydric alcohol to obtain a material I;

b. reacting the material I under the conditions of inert gas protection and stirring with reactants, wherein the reaction temperature is 105-150 ℃, the reaction time is 2-8 h, and a by-product is separated by adopting an atmospheric distillation method in the reaction process to obtain a material II;

c. carrying out reduced pressure distillation on the material II to remove reaction byproducts and excessive dialkyl malonate to obtain a material III, wherein the pressure of the reduced pressure distillation is-0.080-0.105 Mpa, and the temperature is 105-150 ℃;

d. and cooling the material III to room temperature to obtain a viscous light yellow liquid, namely the active methylene type aldehyde remover to be prepared.

In the above technical solution, preferably, the dialkyl malonate in the step a is selected from at least one of dimethyl malonate and diethyl malonate.

In the above technical solution, preferably, the polyol in step a is at least one selected from ethylene glycol and diethylene glycol.

In the above technical solution, preferably, the gas inert to the reactant is selected from at least one of nitrogen, helium, and argon.

In the technical scheme, the reaction temperature is preferably 130-150 ℃.

In order to solve the second technical problem, the invention adopts the technical scheme that: the prepared active methylene type aldehyde removing agent is added into a foaming formula of polyurethane foam for foaming.

The invention provides an active methylene type aldehyde remover, the reaction is carried out under normal pressure in the preparation method of the aldehyde remover, the vacuum is not needed, the post-treatment is convenient, and the needed target product, namely the active methylene type aldehyde remover can be obtained only by removing reaction byproducts and excessive dialkyl malonate through reduced pressure distillation; the reaction is carried out at high temperature, and by utilizing the principle that dialkyl malonate is decomposed at high temperature to generate malonic acid and small molecular alcohol, the small molecular alcohol is volatile at high temperature, and the malonic acid and the polyol form a more stable ester bond at high temperature, so that a catalyst and an organic solvent are not needed in the process, the reaction steps are few, the operation is simple, and the environment-friendly effect is realized; when the active methylene type formaldehyde remover is added into a polyurethane foam formula to prepare polyurethane foam, the prepared polyurethane foam has low formaldehyde content and can obtain a good formaldehyde removing effect, for example, the formaldehyde removing agent with the mass fraction of 2.0 percent is added in example 5, the formaldehyde content of the obtained polyurethane foam can be reduced from 1.89ppm to 0.54ppm, and the formaldehyde removal rate can reach 71 percent; meanwhile, the acetaldehyde content is effectively removed, the acetaldehyde content is reduced from 0.41ppm to 0.22ppm, the acetaldehyde removal rate reaches 46 percent, and a better technical effect is achieved.

Detailed Description

[ example 1 ] blank

Polyurethane foams were prepared according to the formulations shown in Table 1, and the performance index data of the resulting polyurethane foams are shown in Table 3.

The raw materials used in table 1 are as follows:

1) CHE-828: polyether polyol with a hydroxyl value of 26-30 mgKOH/g, a molecular weight of 6000 and a functionality of 3, and is produced by Changhua chemical technology, Inc.;

2) CHK-350D: polyether polyol with a hydroxyl value of 31-35 mgKOH/g, a molecular weight of 7500, a functionality of 4, and a manufacturer of Changhua chemical science and technology, Inc.;

3) DEOA: diethanolamine, amine catalyst, basf, manufacturer;

4) ZF-10: 2- [ [2- [2- (dimethylamino) ethoxyethyl ] methylamino ] -ethanol, an amine catalyst, the manufacturer is Hensman;

5) desmodur 3133: 4, 4' -diphenylmethane-diisocyanate (MDI) and mixtures of polyisocyanates of its isomers and homologues, from a manufacturer of Korsakochun.

TABLE 1 parts by mass of polyurethane foaming formulations in blank example 1, examples 1 to 5 and comparative example 1

[ example 1 ]

a. Adding 1mol of diethyl malonate and 2mol of ethylene glycol into a reaction container to obtain a material I;

b. reacting the material I under the conditions of nitrogen protection and stirring, wherein the reaction temperature is 135 ℃, the reaction time is 4 hours, and a by-product is separated by adopting a normal pressure distillation method in the reaction process to obtain a material II;

c. carrying out reduced pressure distillation on the material II to remove reaction byproducts and excessive diethyl malonate to obtain a material III, wherein the pressure of the reduced pressure distillation is-0.089 Mpa, and the temperature is 135 ℃;

d. cooling the material III to room temperature to obtain a viscous light yellow liquid which is the active methylene aldehyde removing agent S to be prepared₁。

The obtained active methylene type aldehyde removing agent S₁The performance index data for the polyurethane foams obtained when the polyurethane foams were added to the polyurethane foam formulations in the amounts shown in Table 1 are shown in Table 3.

[ examples 2 to 5 ]

The steps in the embodiment 2 to 5 are carried out according to the steps in the embodiment 1, the only difference is that the reaction raw materials, the raw material proportion, the reaction time and the reaction temperature are different, and the specific difference is shown in a table 2; the prepared active methylene aldehyde-removing agent is added into a foaming formula of the polyurethane foam according to the adding amount shown in the table 1 for foaming, and the performance index data of the prepared polyurethane foam is shown in the table 3.

TABLE 2 moles of raw materials and reaction conditions used in preparation of aldehyde-removing agents of examples 1-5

[ COMPARATIVE EXAMPLE 1 ]

Referring to patent CN88103032.5, under anhydrous condition, adding 1mol of diethyl malonate, 2.2mol of diethylene glycol and 0.2mL of concentrated sulfuric acid with the mass concentration of 99% into a 1L reaction kettle, vacuumizing, starting stirring and heating, controlling the reaction temperature at 98 +/-2 ℃, carrying out ester exchange reaction for 6 +/-0.2 hours, removing by-product ethanol in vacuum during the reaction process, and cooling to room temperature to obtain the aldehyde removing agent product S.

The resulting aldehyde scavenger S was added to the polyurethane foam formulation in the amounts shown in Table 1, and the resulting polyurethane foam had performance index data shown in Table 3.

TABLE 3 Performance index data for polyurethane foams of blank example 1, examples 1 to 5 and comparative example 1

As can be seen from the preparation processes of the embodiments 1 to 5, the preparation of the active methylene type aldehyde remover disclosed by the invention does not need to use a catalyst or a chemical solvent, the reaction is carried out under normal pressure, the operation is simple, and the preparation method is environment-friendly; as can be seen from the aldehyde content test data in table 3, the aldehyde removing agents prepared in examples 1 to 5 and comparative example 1 are respectively added to the formula of the blank example 1, so that the aldehyde content in the foam, particularly the content of formaldehyde and acetaldehyde, can be effectively reduced, the formaldehyde removal rate in example 1 is 47%, and the acetaldehyde removal rate is 17%; in example 2, the formaldehyde removal rate was 61% and the acetaldehyde removal rate was 32%; in example 3, the formaldehyde removal rate was 48% and the acetaldehyde removal rate was 24%; in example 4, the formaldehyde removal rate was 67% and the acetaldehyde removal rate was 39%; in example 5, the formaldehyde removal rate was 71% and the acetaldehyde removal rate was 46%; while the formaldehyde removal rate was 58% and the acetaldehyde removal rate was 34% in comparative example 1; it can be seen that, in the cases of the aldehyde removing agents in the examples 1 to 5 being added in an amount of 0.1 to 2.0% by mass, the removal rate of formaldehyde in polyurethane foam can reach 71%, the removal rate of acetaldehyde can reach 46%, and the aldehyde removing effect of the examples 1 to 5 is similar to that of the comparative example 1, but the preparation process is simpler, a catalyst and a solvent are not needed, the reaction is carried out under normal pressure, and the operation is simple.