CN114230708B

CN114230708B - Carbomer and preparation method thereof

Info

Publication number: CN114230708B
Application number: CN202111612996.8A
Authority: CN
Inventors: 王中喜; 王安琪; 肖磊
Original assignee: Hubei Xindesheng Material Technology Co ltd
Current assignee: Hubei Xindesheng Material Technology Co ltd
Priority date: 2021-12-27
Filing date: 2021-12-27
Publication date: 2023-01-03
Anticipated expiration: 2041-12-27
Also published as: CN114230708A

Abstract

The invention relates to the technical field of thickening agents, and particularly relates to carbomer and a preparation method thereof. The carbomer is prepared from the following raw materials in parts by mass: 100 parts of acrylic monomer, 5.0-8.0 parts of acrylamide, 0.5-2.0 parts of hydroxyethyl acrylate, 0.4-0.6 part of initiator, 0.6-1.4 parts of cross-linking agent, 0.4-1.0 part of stabilizer and 800-1000 parts of mixed solvent. The method comprises the following steps: uniformly mixing the mixed solvent, adding the mixed solvent into a reaction kettle, starting stirring, and heating to 80-85 ℃; then uniformly mixing the mixed monomer, the cross-linking agent, the initiator and the stabilizer, adding into a reaction kettle, and dropwise adding for 2-2.5h; after the dropwise addition, the reaction is continued for 3 to 5 hours under the condition of heat preservation; and filtering, washing and drying the obtained product to obtain the catalyst. The carbomer prepared by the invention is prepared into an aqueous solution with the mass fraction of 0.5%, the wetting time is only 55-178s, the pH value is adjusted to 6.8-7.5 by using a NaOH solution with the mass fraction of 15%, the viscosity is 5000-80000mPa & s, and the carbomer can swell in an ethanol aqueous solution with the volume fraction of 80%.

Description

Carbomer and preparation method thereof

Technical Field

The invention relates to the technical field of thickening agents, and particularly relates to carbomer and a preparation method thereof.

Background

Carbomer is an important high molecular polymer thickener, which is polymerized by homopolymerization or copolymerization high polymer taking acrylic acid or acrylic ester as monomers and allyl sucrose ether or pentaerythritol allyl ether as a cross-linking agent. The appearance of the product is white loose powder, and the molecular structure contains 52-68% of acid group, so that the product has certain acidity, hydrophilic property, and can be dissolved in water, glycerol, ethanol and the like.

The carbomer has two main thickening principles, namely neutralization thickening and hydrogen bond thickening. The neutralization thickening refers to alkali neutralized carbomer, the carboxyl of which is ionized, and the coiled molecular chain stretches into a greatly expanded state due to the mutual repulsion of negative charges, so that the original volume is increased to about 1000 times, and the thickening effect is achieved. The neutralizing agents commonly used are sodium hydroxide, potassium bicarbonate, triethanolamine, and the like. Hydrogen bonding thickening refers to thickening by the carbomer molecule acting as a carboxyl donor, capable of binding to one or more than two hydroxyl groups to form hydrogen bonds, a reaction mechanism which takes time. As the hydroxyl donor, a nonionic surfactant, a polyhydric alcohol and the like are usually used.

Carbomer is widely used in the fields of medicine and cosmetics because of its good thickening, suspension stabilizing and emulsifying effects. The required thickening effect can be achieved by only using a small amount of carbomer, and the common amount is 0.10-0.50% of mass fraction. The carbomer with different crosslinking degrees and molecular weights can be used for preparing emulsion, cream and gel products with wider viscosity range and different rheological properties. Nowadays, people pay more and more attention to the health of the body, so that the requirements on cosmetics and medical health care products are increasing day by day, and the preparation and application of carbomer have wide prospects.

However, most carbomers on the market today are added to deionized water, which has a slow wetting rate, requiring several tens of minutes to several hours for wetting in 0.5% by mass of aqueous carbomer solutions with different cross-linking degrees and molecular weights, whereas higher mass fractions of aqueous carbomer solutions require longer wetting times, and traditional carbomers such as 940 can only swell in ethanol aqueous solutions below 70v/v% (more than 12 hours for complete swelling under these conditions). Thus, extremely long wetting times lead to less efficient production of further products and swelling conditions limit the use of conventional carbomers.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides carbomer and a preparation method thereof. The method is simple to prepare, and the prepared carbomer is 0.5 percent in mass fraction: the viscosity is 5000-80000 mPas, the wetting time is within 5 minutes, and the water-soluble polymer can swell in 80% volume fraction ethanol water solution.

The invention is realized by the following technical scheme.

Carbomer is prepared from the following raw materials: the acrylic acid monomer, acrylamide, hydroxyethyl acrylate, an initiator, a cross-linking agent, a stabilizer and a mixed solvent, wherein the mass portions are respectively as follows: 100 parts of acrylic monomer, 5.0-8.0 parts of acrylamide, 0.5-2.0 parts of hydroxyethyl acrylate, 0.4-0.6 part of initiator, 0.6-1.4 parts of cross-linking agent, 0.4-1.0 part of stabilizer and 800-1000 parts of mixed solvent; preferably, the feed is prepared from the following raw materials in parts by mass: 100 parts of acrylic monomer, 5.0-8.0 parts of acrylamide, 0.5-2.0 parts of hydroxyethyl acrylate, 0.4-0.6 part of initiator, 0.6-1.0 part of cross-linking agent, 0.4-1.0 part of stabilizer and 800-1000 parts of mixed solvent.

Further, the acrylic monomer is one or two of acrylic acid and methacrylic acid.

Further, the initiator is one of azobisisobutyronitrile, azobisisoheptonitrile and benzoyl peroxide;

further, the stabilizer is one of Hypermer B246 and polysiloxane high-molecular surfactant;

further, the mixed solvent is a mixture of an ester solvent and a hydrocarbon solvent, the ester solvent is one of propyl formate and ethyl acetate, and the hydrocarbon solvent is one of cyclohexane and n-hexane.

Further, the mass ratio of the ester solvent to the hydrocarbon solvent is 100 to 100; preferably, the mass ratio of the ester solvent to the hydrocarbon solvent is 100.

Further, the cross-linking agent is one of allyl sucrose ether and pentaerythritol allyl ether, the viscosity of the prepared carbomer is 5500-40000mPa & s, and the wetting time is 67-189s;

furthermore, the cross-linking agent is one of triallyl cyanurate and trimethylolpropane trimethacrylate, so that the high-viscosity carbomer can be prepared, the viscosity is 5000-80000mPa & s, and the wetting time is 55-178s.

The preparation method of the carbomer is designed according to the proportion, and comprises the following steps:

(1) Weighing the mixed solvent, uniformly mixing, adding into a reaction kettle, starting electric stirring, heating the reaction kettle to 80-85 ℃, and keeping the temperature in the temperature range;

(2) Uniformly mixing mixed monomers (acrylic monomers, acrylamide and hydroxyethyl acrylate), a cross-linking agent, an initiator and a stabilizer to obtain a solution A, arranging a high-level tank on a reaction kettle, adding the solution A, and dropwise adding the solution A into the reaction kettle for 2-2.5 hours;

(3) After the dropwise addition is finished, continuously carrying out heat preservation reaction for 3-5 hours to obtain a solution-like product;

(4) And (4) filtering, washing and drying the product obtained in the step (3) to obtain white and fluffy carbomer powder.

If the hydrophilic monomer acrylamide or hydroxyethyl acrylate selected by the invention is used alone to be copolymerized with acrylic acid or methacrylic acid, the effect is not ideal. When acrylamide alone is copolymerized with acrylic or methacrylic acid, the resulting carbomer has a wetting time of over 20min. When hydroxyethyl acrylate alone is copolymerized with acrylic acid or methacrylic acid, the hydroxyethyl acrylate, which has a too high polarity, is precipitated from the solvent in advance and fails to complete the polymerization. Only when acrylamide and hydroxyethyl acrylate are copolymerized with acrylic acid or methacrylic acid at the same time, the resulting carbomer can achieve a shorter wetting time.

Compared with the prior art, the invention has the advantages and beneficial effects that:

acrylamide and hydroxyethyl acrylate are used as hydrophilic monomers to perform hydrophilic modification on the synthesized carbomer, and the carbomer hydrogel with different viscosities and mass fractions of 0.5 percent can be prepared by adjusting the proportion of the acrylic monomers, the acrylamide and the hydroxyethyl acrylate and the dosage of the cross-linking agent.

The mass ratio of acrylamide to hydroxyethyl acrylate was gradually increased from 2.5. When hydrophilic monomers of acrylamide and hydroxyethyl acrylate are used and allyl sucrose ether or pentaerythritol allyl ether is used as a cross-linking agent for polymerization, only carbomer (5500-40000 mPas) with medium viscosity can be obtained, and when triallyl cyanurate or trimethylolpropane trimethacrylate is selected as the cross-linking agent for polymerization, carbomer (5000-80000 mPas) with high viscosity can be obtained.

The carbomer prepared by the invention is prepared into a carbomer aqueous solution with the mass fraction of 0.5%, after the pH value is adjusted to 6.8-7.5 by using a NaOH solution with the mass fraction of 15%, the viscosity is 5000-80000mPa & s, the wetting time is only 55-178s, and the carbomer can swell in an ethanol aqueous solution with the volume fraction of 80%, and the traditional carbomer such as 940 can only swell in an ethanol aqueous solution with the volume fraction of below 70%, so that the satisfactory effect is obtained, and the carbomer meeting various viscosity requirements can be produced.

Detailed Description

The present invention is further described in the following examples, which are not intended to limit the scope of the invention as claimed.

In the following examples: the viscosity of carbomer was measured using the rotational viscometer method of the third method of the general guidelines 0633, pharmacopoeia of the people's republic of China, 2020 edition.

The carbomer wetting time is determined according to the luobu official wetting time test method, and the operation process is as follows: a0.5% mass fraction aqueous solution of carbomer was prepared by sprinkling 2.5g of the powder into 500ml of deionized water in a 800ml beaker and observing and recording the time to complete wetting of all the powder.

Swelling carbomer in 80% volume fraction ethanol aqueous solution: 1.0g of carbomer was weighed into 200.0g of 80v/v% aqueous ethanol and swelling of the carbomer was observed.

Example 1

Carbomer, the raw material formula composition of which is shown in table 1:

TABLE 1

Starting materials	Dosage (parts by mass)
		Acrylic Acid (AA)	100
Acrylamide (ACA)	5.0
		Acrylic acid hydroxy ethyl ester	2.0
Benzoyl peroxide	0.6
		Triallyl cyanurate	0.6
HypermerB246	0.4
		Propyl formate	429
N-hexane	571

The method for preparing the carbomer by combining the carbomer raw materials comprises the following steps:

(1) Weighing 1g of mixed solvent in parts by mass, uniformly mixing, adding into a reaction kettle, starting electric stirring, heating the reaction kettle to 80-85 ℃, and preserving heat;

(2) Uniformly mixing mixed monomers (acrylic monomers, acrylamide and hydroxyethyl acrylate), a cross-linking agent, an initiator and a stabilizer to obtain a solution A, wherein a high-level tank is arranged on a reaction kettle, the solution A is added into the high-level tank, and the solution A is dropwise added into the reaction kettle for 2 hours;

(3) After the dropwise addition is finished, continuously carrying out heat preservation reaction for 5 hours to obtain a solution-like product;

(4) And (3) cooling the product obtained in the step, filtering, washing with a solvent (any one of the raw material formula solvents), and drying under reduced pressure at 90 ℃ to obtain white and fluffy carbomer powder.

And (3) adding 2.5g of the carbomer powder prepared in the step (4) into 500mL of deionized water to prepare 0.5% by mass of carbomer aqueous solution, observing the time for completely wetting all the powder, recording the wetting time to be 178s, adjusting the pH value of the 0.5% carbomer aqueous solution to be 6.8-7.5 by using 15% by mass of NaOH solution, and measuring the viscosity to be 5000 mPas.

1.0g of the carbomer powder prepared in step (4) was weighed into 200.0g of an 80v/v% aqueous ethanol solution, swelling of the carbomer was observed, and after 6 hours, total swelling was observed.

Example 2

Carbomer, the raw material formulation composition of which is shown in table 2:

TABLE 2

Raw materials	Dosage (parts by mass)
		Acrylic Acid (AA)	100
Acrylamide	5.0
		Acrylic acid hydroxy ethyl ester	2.0
Benzoyl peroxide	0.6
		Allyl sucrose ether	0.6
HypermerB246	0.4
		Propyl formate	429
N-hexane	571

The procedure of compounding the carbomer with the carbomer raw material was the same as in example 1.

The prepared carbomer is prepared into a carbomer aqueous solution with the mass fraction of 0.5%, the wetting time is 189 seconds, and then the pH value of the carbomer aqueous solution with the mass fraction of 0.5% is adjusted to 6.8-7.5 by using a NaOH solution with the mass fraction of 15%, so that the viscosity is 5500mPa & s.

1.0g of the carbomer prepared in this example was weighed into 200.0g of an 80v/v% aqueous ethanol solution, swelling of the carbomer was observed, and after 6 hours, total swelling was observed.

Example 3

Carbomer, the formulation of which is shown in table 3:

TABLE 3

The prepared carbomer is prepared into 0.5 mass percent of carbomer aqueous solution, the wetting time is 152s, then the pH value of the 0.5 mass percent of carbomer aqueous solution is adjusted to 6.8-7.5 by using 15 mass percent of NaOH solution, and the viscosity is determined to be 25000mPa & s.

Example 4

Carbomer, the raw material formulation composition of which is as shown in table 4:

TABLE 4

Starting materials	Dosage (parts by mass)
		Acrylic Acid (AA)	70
Methacrylic acid	30
		Acrylamide	6.0
Acrylic acid hydroxyethyl ester	1.0
		Benzoyl peroxide	0.5
Triallyl cyanurate	0.8
		HypermerB246	0.6
Ethyl acetate	286
		N-hexane	514

The prepared carbomer is prepared into a carbomer aqueous solution with the mass fraction of 0.5%, the wetting time is 133s, then the pH value of the carbomer aqueous solution with the mass fraction of 0.5% is adjusted to 6.8-7.5 by using a NaOH solution with the mass fraction of 15%, and the viscosity is 36000 mPas.

Example 5

Carbomer, having the raw material formulation composition as given in table 5:

TABLE 5

The prepared carbomer is prepared into a carbomer aqueous solution with the mass fraction of 0.5%, the wetting time is 118s, and then the pH value of the 0.5% carbomer aqueous solution is adjusted to 6.8-7.5 by using a NaOH solution with the mass fraction of 15%, so that the viscosity is 48000mPa & s.

Example 6

Carbomer, having the raw material formulation composition as given in table 6:

TABLE 6

Starting materials	Dosage (parts by mass)
		Acrylic Acid (AA)	20
Methacrylic acid (MAA)	80
		Acrylamide	8.0
Acrylic acid hydroxy ethyl ester	0.8
		Benzoyl peroxide	0.5
Trimethylolpropane trimethacrylate	1.0
		HypermerB246	0.8
Ethyl acetate	386
		Cyclohexane	514

The prepared carbomer is prepared into a carbomer aqueous solution with the mass fraction of 0.5%, the wetting time is 87s, then the pH value of the carbomer aqueous solution with the mass fraction of 0.5% is adjusted to 6.8-7.5 by using a NaOH solution with the mass fraction of 15%, and the viscosity is 66000mPa & s.

Example 7

Carbomer with the formula shown in Table 7

TABLE 7

The prepared carbomer is prepared into a carbomer aqueous solution with the mass fraction of 0.5%, the wetting time is 67s, and then the pH value of the 0.5% carbomer aqueous solution is adjusted to 6.8-7.5 by using a NaOH solution with the mass fraction of 15%, so that the viscosity is 40000 mPas.

Example 8

Carbomer having the raw material formulation composition shown in table 8:

TABLE 8

Raw materials	Dosage (parts by mass)
		Methacrylic acid (MAA)	100
Acrylamide (ACA)	8.0
		Acrylic acid hydroxy ethyl ester	0.5
Benzoyl peroxide	0.5
		Trimethylolpropane trimethacrylate	1.0
HypermerB246	1.0
		Ethyl acetate	343
Cyclohexane	457

The prepared carbomer is prepared into 0.5 mass percent of carbomer aqueous solution, the wetting time is 55s, then 15 mass percent of NaOH solution is used for adjusting the pH value of the 0.5 mass percent of carbomer aqueous solution to 6.8-7.5, and the viscosity is 80000 mPas.

Example 9

Carbomer having the raw material formulation composition shown in table 9:

TABLE 9

The prepared carbomer is prepared into 0.5 mass percent of carbomer aqueous solution, the wetting time is 90s, and then the pH value of the 0.5 mass percent of carbomer aqueous solution is adjusted to 6.8-7.5 by using 15 mass percent of NaOH solution, so that the viscosity is 64000mPa & s.

Example 10

Carbomer having the raw material formulation composition shown in table 10:

watch 10

Starting materials	Dosage (parts by mass)
		Methacrylic acid	100
Acrylamide	8.0
		Acrylic acid hydroxy ethyl ester	0.5
Benzoyl peroxide	0.5
		Trimethylolpropane trimethacrylate	1.0
HypermerB246	1.0
		Ethyl acetate	500
Cyclohexane	300

The prepared carbomer is prepared into 0.5 mass percent of carbomer aqueous solution, the wetting time is 64s, and then the pH value of the 0.5 mass percent of carbomer aqueous solution is adjusted to 6.8-7.5 by using 15 mass percent of NaOH solution, so that the viscosity is 68000 mPas.

Example 11

Carbomer having the raw material formulation composition shown in table 11:

TABLE 11

The prepared carbomer is prepared into a carbomer aqueous solution with the mass fraction of 0.5%, the wetting time is 193s, then the pH value of the carbomer aqueous solution with the mass fraction of 0.5% is adjusted to 6.8-7.5 by using a NaOH solution with the mass fraction of 15%, and the viscosity is 3600mPa & s.

Table 12 shows the comprehensive performance test tables of the carbomers prepared in examples 1 to 11.

TABLE 12

Carbomer	0.5wt% viscosity (mPas)	Wetting time(s)
			Example 1	5000	178
Example 2	5500	189
			Example 3	25000	152
Example 4	36000	133
			Example 5	48000	118
Example 6	66000	87
			Example 7	40000	67
Example 8	80000	55
			Example 9	64000	90
Example 10	68000	64
			Example 11	3600	193

From the above test results, it was found that when polymerization is carried out using allyl sucrose ether or pentaerythritol allyl ether as a crosslinking agent after using hydrophilic monomers of acrylamide and hydroxyethyl acrylate, only carbomer of moderate viscosity (5500 to 40000mPa · s) can be obtained, and when polymerization is carried out using triallyl cyanurate or trimethylolpropane trimethacrylate as a crosslinking agent, carbomer of high viscosity (5000 to 80000mPa · s) can be obtained. When the amount of the crosslinking agent used exceeds 1.0 part by mass, the viscosity of the carbomer synthesized using the same raw material ratio as in example 8 is reduced to 64000 mPas, see example 9. When the ratio of the ester solvent is greater than that of the hydrocarbon solvent, the viscosity of the carbomer synthesized using the same material formulation as in example 8 will decrease to 68000 mPa-s, see example 10. When the mass ratio of acrylamide to hydroxyethyl acrylate is 2: the viscosity of carbomer synthesized using the same material formulation as in example 1 was reduced to 3600mPa · s, see example 11.

Claims

1. The carbomer is characterized by being prepared from the following raw materials in parts by mass: 100 parts of acrylic monomer, 5.0-8.0 parts of acrylamide, 0.5-2.0 parts of hydroxyethyl acrylate, 0.4-0.6 part of initiator, 0.6-1.4 parts of cross-linking agent, 0.4-1.0 part of stabilizer and 800-1000 parts of mixed solvent;

the acrylic monomer is one or the combination of two of acrylic acid and methacrylic acid;

the initiator is one of azobisisobutyronitrile, azobisisoheptonitrile and benzoyl peroxide;

the cross-linking agent is one of triallyl cyanurate and trimethylolpropane trimethacrylate;

the stabilizer is one of Hypermer B246 and polysiloxane high molecular surfactant;

the mixed solvent is a mixture of an ester solvent and a hydrocarbon solvent, the ester solvent is one of propyl formate and ethyl acetate, and the hydrocarbon solvent is one of cyclohexane and n-hexane.

2. The carbomer of claim 1, wherein said cross-linking agent is one of allyl sucrose ether and allyl ether of pentaerythritol.

3. Carbomer according to claim 1 or 2, prepared from the following raw materials in parts by mass: 100 parts of acrylic monomer, 5.0-8.0 parts of acrylamide, 0.5-2.0 parts of hydroxyethyl acrylate, 0.4-0.6 part of initiator, 0.6-1.0 part of cross-linking agent, 0.4-1.0 part of stabilizer and 800-1000 parts of mixed solvent.

4. Carbomer according to claim 1 or 2, wherein the mass ratio of ester solvent to hydrocarbon solvent is from 100.

5. Carbomer according to claim 1 or 2, wherein the mass ratio of said ester solvent to hydrocarbon solvent is from 100.

6. A method of preparing a carbomer according to any one of claims 1 to 5, comprising the steps of:

(1) Weighing the mixed solvent, uniformly mixing, adding the mixed solvent into a reaction kettle, starting electric stirring, and heating the reaction kettle to 80-85 ℃;

(2) Uniformly mixing an acrylic monomer, acrylamide, hydroxyethyl acrylate, a cross-linking agent, an initiator and a stabilizer, and then dropwise adding into the reaction kettle in the step (1), wherein the dropwise adding time is 2-2.5 hours;

(3) After the dropwise addition is finished, continuously preserving the heat and reacting for 3-5h to obtain a solution-shaped product;

(4) And (4) filtering, washing and drying the product obtained in the step (3) to obtain white fluffy powdery carbomer.