Cationic modified water-absorbing auxiliary, its preparation method and application

Abstract

The application relates to the technical field of paper auxiliaries, in particular to a cationic modified water-absorbing auxiliary and a preparation method and application thereof. The application discloses a cationic modified water-absorbing auxiliary, which comprises an amide intermediate and an epoxy modifier; the molar ratio of the amide intermediate to the epoxy modifier is the molar ratio of a secondary amide group in the amide intermediate to an epoxy group in the epoxy modifier, and the molar ratio is 1:0.1-2; and the epoxy modifier is a cationic epoxy modifier. The cationic modified water-absorbing auxiliary disclosed by the application is a functional polymer material with a hydrophilic group and a three-dimensional network structure, the cationic modified water-absorbing auxiliary swells between fibers, hinders the combination of hydrogen bonds between the fibers, plays a supporting and fluffy role, forms loose and porous paper, and thus improves the stiffness and water absorption of the paper.

Description

TECHNICAL FIELD

[0001] The application relates to the paper auxiliary technical field, in particular to a cationic modified water-absorbing auxiliary and a preparation method and application thereof. BACKGROUND

[0002] With the continuous improvement of people's quality of life, people's demand for toilet paper, napkin paper, facial tissue paper and the like is increasing, and the requirements for the paper are continuously improved, and it is necessary to improve the water absorption, hand feeling and surface softness of the paper. At present, the synthetic wet paper strength enhancer includes polyvinyl acid salt, polyvinyl alcohol and polyoxyethylene. However, these wet paper strength enhancers can only improve the water absorption of paper through water-absorbing groups, and cannot reduce the pulp consumption by changing the arrangement tightness of fibers, and there are problems of high production cost, adhesion into a group and gel blockage. In view of the current situation of shortage of wood resources, how to reduce the cost while ensuring the quality of paper has been the focus of the paper industry. SUMMARY

[0003] In order to overcome the shortcomings and deficiencies in the prior art, the cationic modified water-absorbing auxiliary provided in the application is a functional polymer material with hydrophilic groups and a three-dimensional network structure. By swelling between fibers, the combination of hydrogen bonds between fibers is hindered, and the effect of supporting and fluffing is achieved, forming a loose and porous paper, thereby improving the stiffness and water absorption of the paper. In addition, the water-absorbing auxiliary can make the paper soft and bulky, maintain the original quality and thickness of the paper while reducing the weight, reduce the use of pulp, reduce the environmental pollution load and transportation cost, and save energy.

[0004] The purpose of the application is achieved by the following technical solutions:

[0005] The first purpose of the application is to provide a cationic modified water-absorbing auxiliary, which comprises an amide intermediate and an epoxy modifier.

[0006] The molar ratio of the amide intermediate to the epoxy modifier is the molar ratio of the secondary amide group in the amide intermediate to the epoxy group in the epoxy modifier, which is 1:0.1-2.

[0007] The amide intermediate is obtained by reacting a polyamine with a secondary amine group with an unsaturated acid; the molar ratio of the polyamine with a secondary amine group to the unsaturated acid is the molar ratio of the secondary amine group in the polyamine with a secondary amine group to the monocarboxyl group in the unsaturated acid, which is 2:1.1.

[0008] The epoxy modifier is a cationic epoxy modifier.

[0009] Further, the cationic epoxy modifier is at least one of epichlorohydrin and epoxy propyl trimethyl ammonium chloride.

[0010] Further, the unsaturated acid is at least one of octadecanoic acid, lauric acid, cinnamic acid, oleic acid, succinic acid, glutaric acid, adipic acid.

[0011] Further, the polyamine having a secondary amine group is at least one of diethylenetriamine, triethylenetetramine, tetraethylenepentamine.

[0012] The second object of the present application provides a preparation method of the cationic modified water absorption aid, comprising the following steps:

[0013] The polyamine having a secondary amine group and the unsaturated acid are reacted to obtain an amide intermediate; then the amide intermediate is subjected to cationization reaction with an epoxy modifier, and finally a uniform emulsion is formed under the action of water.

[0014] Further, the process of reacting the polyamine having a secondary amine group and the unsaturated acid to obtain the amide intermediate is as follows:

[0015] The unsaturated acid and the polyamine having a secondary amine group are subjected to reflux reaction at 100℃ to 140℃ for 2h to obtain the polyamide intermediate.

[0016] Further, the process of subjecting the amide intermediate to cationization reaction with the epoxy modifier is as follows: the epoxy modifier and the amide intermediate are mixed and reacted at 80℃ for 2 to 3h.

[0017] Further, the process of finally forming a uniform emulsion under the action of water is as follows: after the amide intermediate is subjected to cationization reaction with the epoxy modifier, water is added to form an emulsion with a solid content of 10% to 20%.

[0018] The third object of the present application provides the application of the cationic modified water absorption aid described above. The cationic modified water absorption aid is used as an additive in the papermaking process.

[0019] Further, the water absorption aid can be added in any process in the papermaking process. For example, it can be added before or after beating, in the blending process of adding chemicals, or before papermaking. The use amount of the water absorption aid of the present application is not particularly limited, and generally, 0.01 to 5 parts by weight, more preferably 0.1 to 2 parts by weight, is used with respect to 100 parts by weight of the pulp. The cationic modified water absorption aid of the present application can be used together with various known additives commonly used in papermaking. As the additives, for example, sizing agents, wet paper strength enhancers, dry paper strength enhancers, resin control agents, slurry control agents, defoaming agents, fillers, pigments can be listed.

[0020] The present application has the following beneficial effects:

[0021] 1. The water absorption aid of the present application expands the two-dimensional nitrogen atoms into three dimensions by opening the ring reaction of the nitrogen in the amide intermediate with the epoxy modifier, and at the same time, by cationizing the amide polymer, it is absorbed onto the fiber, weakening the formation of hydrogen bonds between the fibers, thereby exhibiting a porous effect. In addition, the water absorption aid is a self-emulsifying system, and has good stability by itself, and can form a stable emulsion without the addition of an emulsifier.

[0022] 2. The water absorption aid prepared in the present application, when used as an additive in the papermaking process, mainly swells between the fibers and reduces the formation of hydrogen bonds between the fibers, plays a supporting and bulking role, and improves the stiffness of the paper sheet. At the same time, in order to make the water absorption aid better fixed on the fiber, the cationic water absorption aid is adsorbed on the pulp fiber, and due to the repulsion of the charges, the distance between the fibers is far away, preventing the interweaving of the fine fibers during drying and dehydration, and achieving the purpose of bulkiness and porosity, and improving the water absorption capacity. DETAILED DESCRIPTION

[0023] In order to facilitate the understanding of those skilled in the art, the present application will be further described below in conjunction with examples, and the content mentioned in the embodiments is not a limitation of the present application.

[0024] As used herein, "and / or" includes the term "and" and / or the term "or", and any and all combinations of one or more of the associated listed items. The terms used herein are only used to describe specific embodiments, and are not intended to limit the present application. As used herein, the singular forms "a", "an" and "the" are also intended to include the plural forms, unless the context clearly indicates otherwise. It is further understood that "comprising" is used in the present specification to specify the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or combinations thereof.

[0025] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It is further understood that terms such as defined in a commonly used dictionary, are interpreted as having a meaning that is consistent with their meaning in the context of the relevant art, and are not interpreted in an idealized or overly formal sense, unless expressly so defined herein.

[0026] The exemplary applications described herein can suitably lack any one or more of the optional elements described herein, and thus the terms "comprise", "include", "contain", and the like, are to be construed in an open, inclusive and non-limiting sense. Furthermore, the terms "comprise", "comprising", "include", "including" and the like, as used herein, are specifically intended to be read as "including but not limited to". The terms "comprise", "comprising", "include", "including" and the like, as used herein, are specifically intended to be read as "including but not limited to", "concluding, uncluding but not limited to", or "encompassing, uncompassing but not limited to". It will be appreciated that variations to the details of the exemplary applications described herein will occur to persons skilled in the art. Such variations are contemplated and can be carried out without departing from the scope of the present application. Accordingly, the application is not limited to only the described embodiments.

[0027] The raw materials or reagents used in the examples and comparative examples of the present application are purchased from mainstream manufacturers in the market. If the manufacturer is not specified or the concentration is not specified, it is an analytical pure raw material or reagent that can be obtained conventionally, and there is no particular limitation as long as it can play the expected role. The instruments and equipment involved in the reaction, mixing and the like in the examples are purchased from major manufacturers in the market, and there is no particular limitation as long as they can play the expected role. If the specific technology or condition is not specified in the examples, it is carried out according to the technology or condition described in the literature in the art or according to the product instruction.

[0028] In one aspect, the present application provides a cationic modified water-absorbing adjuvant, comprising an amide intermediate and an epoxy modifier.

[0029] The molar ratio of the amide intermediate to the epoxy modifier is the molar ratio of the secondary amide group in the amide intermediate to the epoxy group in the epoxy modifier, which is 1:0.1-2.

[0030] The amide intermediate is obtained by reacting a polyamine with a secondary amine group with an unsaturated acid; the molar ratio of the polyamine with a secondary amine group to the unsaturated acid is the molar ratio of the secondary amine group in the polyamine with a secondary amine group to the monocarboxyl group in the unsaturated acid, which is 2:1.1.

[0031] The epoxy modifier is a cationic epoxy modifier.

[0032] In one embodiment, the molar ratio of the secondary amide group in the amide intermediate to the epoxy group in the epoxy modifier is 1:0.1-2, which can be any one of 1:0.1, 1:0.2, 1:0.4, 1:0.8, 1:1.1, 1:1.2, 1:1.7, 1:1.8, 1:2.0, as long as it meets the requirement of 1:0.1-2.

[0033] In another aspect, the present application provides a preparation method of a cationic modified water-absorbing adjuvant, comprising the following steps:

[0034] The polyamine having a secondary amine group and the unsaturated acid are reacted to obtain an amide intermediate, and the process is as follows: the unsaturated acid and the polyamine having a secondary amine group are reacted at 100-140°C for 2h to obtain a polyamide intermediate.

[0035] The amide intermediate and the epoxy modifier are subjected to cationization reaction, and the process is as follows: the epoxy modifier and the amide intermediate are mixed and reacted at 80°C for 2-3h.

[0036] Finally, a uniform emulsion is formed in the presence of water, and the process is as follows: the amide intermediate and the epoxy modifier are subjected to cationization reaction, and then water is added to form an emulsion with a solid content of 10-20%.

[0037] The cationic modified water-absorbing aid described in the present application is further illustrated by the following examples, comparative examples, and commercial examples.

[0038] Example 1

[0039] A method for preparing a cationic modified water-absorbing aid, comprising the following steps:

[0040] 1) A reaction vessel provided with a stirrer, a dehydration tube, a cooling tube, and a thermometer is charged with 1 mol of oleic acid, and then 0.55 mol of diethylenetriamine is added when the temperature is heated to 100°C. After refluxing at 140°C for 2h, the reaction is condensed at 160°C for 4-6h, and the water generated in the reaction is removed from the system. When no water flows out, heating is stopped, and the temperature is lowered to 80°C;

[0041] 2) 0.11 mol of epoxypropyltrimethylammonium chloride is added, and the reaction is carried out for 2h;

[0042] 3) Deionized water is added to form a suspension, and the suspension is stirred at room temperature for about 2-4h, and then discharged to obtain a cationic modified water-absorbing aid.

[0043] Example 2

[0044] A method for preparing a cationic modified water-absorbing aid, comprising the following steps:

[0045] In step 2), 0.22 mol of epoxypropyltrimethylammonium chloride is added, and the reaction is carried out for 2h;

[0046] The other conditions are the same as in Example 1.

[0047] Example 3

[0048] A method for preparing a cationic modified water-absorbing aid, comprising the following steps:

[0049] In step 2), 0.33 mol of epoxypropyltrimethylammonium chloride is added, and the reaction is carried out for 2h;

[0050] Other conditions are the same as in Example 1.

[0051] Example 4

[0052] A method for preparing a cationic modified water-absorbing aid, comprising the following steps:

[0053] 1) A reaction vessel equipped with a stirrer, a dehydration tube, a cooling tube, and a thermometer is charged with 1 mol of oleic acid, and heated to 100°C. Then 0.55 mol of diethylenetriamine is added. After refluxing at 140°C for 2 h, the reaction is condensed at 160°C for 4-6 h. The water generated in the reaction is removed from the system. When no water flows out, heating is stopped, and the temperature is lowered to 80°C;

[0054] 2) 0.11 mol of epichlorohydrin is added, and the reaction is carried out for 2 h;

[0055] 3) Deionized water is added to form a suspension. After stirring the suspension at room temperature for about 2-4 h, the product is discharged, and a cationic modified water-absorbing aid is obtained.

[0056] Example 5

[0057] A method for preparing a cationic modified water-absorbing aid, comprising the following steps:

[0058] In step 2), 0.22 mol of epichlorohydrin is added, and the reaction is carried out for 2 h;

[0059] Other conditions are the same as in Example 4.

[0060] Example 6

[0061] A method for preparing a cationic modified water-absorbing aid, comprising the following steps:

[0062] In step 2), 0.33 mol of epichlorohydrin is added, and the reaction is carried out for 2 h;

[0063] Other conditions are the same as in Example 4.

[0064] Test analysis and evaluation:

[0065] 1. Water absorption test of different amounts of epoxy modifier

[0066] The pulp used is bleached broadleaf wood pulp-chemi pulp, wherein 80 parts of bleached broadleaf wood pulp, 20 parts of chemi pulp, are mixed and beaten to a beating degree of 35°SR. The wet strength agent is added in an amount of 20 kg / t. The liquid absorption aid is used in an amount of 10 kg / t (Example 1). After adding the liquid absorption aid prepared in each of Examples 1-6 above and stirring for 5-10 min, the wet paper sheet is formed by using a Sheet Former 200S intermittent fiber-based wet forming device according to the national standard method for papermaking, and is transferred to a FFiberP-Dry01 paper sheet flat drying device for drying. After complete curing for 30 min, a circular paper sheet with a diameter of 0.2 m is obtained, and the basis weight of the paper is 80 g / m 2 The liquid absorption height of the liquid absorption aid is detected according to GBT 461.1-2002, the wet tensile of the liquid absorption aid is detected according to GBT 20808-2022, the wet tensile strength is detected according to GBT 24328.4-2009, and the bulk and tightness are detected according to GBT 24328.2-2020. The detection results are summarized in Table 1.

[0067] Table 1 Water absorption test results of different epoxy modifier dosage cases

[0068]

[0069] As can be seen from the data in Table 1, by using the water absorption aid of the present application, Example 5 significantly improves the liquid absorption height and water retention rate of the paper compared with the comparative example without reducing the strength of the paper, which shows that the water absorption aid of the present application has excellent water absorption performance. At the same time, the bulk of the paper of Example 5 is increased by a maximum of 70% compared with the comparative example, which shows that the water absorption aid of the present application can better increase the volume and thickness of the paper.

[0070] 2. Basic property test of polymer solution

[0071] The cationic modified water absorption aid of Examples 1-5 was stored at room temperature to investigate its stability. The PCD detection used a standard anion reagent PVSK, and the basic property test results are shown in Table 2:

[0072] Table 2 Basic property test results of cationic modified water absorption aid

[0073] No. Stability (60 d) Charge density (μeq / L) Color Example 1 Uniform 952 Light yellow Example 2 Uniform 1310 Light yellow Example 3 Uniform 1688 Light yellow Example 4 Uniform 878 Light yellow Example 5 Uniform 1023 Light yellow Example 6 Uniform 1477 Light yellow

[0074] 3. Water absorption test of different water absorption aid dosage cases

[0075] The pulp used was bleached hardwood pulp-chemi pulp, 80 parts of bleached hardwood pulp, 20 parts of chemi pulp, mixed beating, beating degree 35°SR. The wet strength agent was added in an amount of 20 kg / t. The amount of cationic modified water absorption aid used in Example 5: 1 kg / t (Example 7), 2 kg / t (Example 8), 4 kg / t (Example 9), 8 kg / t (Example 10), 0 kg / t (comparative example). The amount of commercially available water absorption aid used: 1 kg / t (commercial example 1), 2 kg / t (commercial example 2), 4 kg / t (commercial example 3), 8 kg / t (commercial example 4).

[0076] After adding the water absorption aid in each of the above examples, stirring for 5-10 min, according to the national standard method for papermaking, using Sheet Former 200S type intermittent fiber-based wet former to form a wet paper sheet, transferred to FFiberP-Dry01 type paper sheet flat dryer for drying, and after complete curing for 30 min, a circular paper sheet with a diameter of 0.2 m was obtained, the paper basis weight was 50 g / m2, the water absorption height of the water absorption aid was detected according to GBT461.1-2002, the wet tensile of the water absorption aid was detected according to GBT20808-2022, and the bulk was detected according to GBT24328.2-2020. The data is shown in Table 3.

[0077] Table 3 Water absorption test results of different water absorption aid dosage cases

[0078]

[0079] As can be seen from Table 3, using the water absorption aid of the present application, Example 7 and Example 8, compared with the comparative example, significantly improve the water absorption height and water retention rate of the paper, which shows that the water absorption aid of the present application has excellent water absorption performance and can be applied to the papermaking wet end chemical process as a water absorption aid.

[0080] 4. Bulk test of different proportion of chemi pulp cases

[0081] The pulp used was bleached hardwood pulp-chemi pulp, 100 parts of bleached hardwood pulp, 90 parts of bleached hardwood-10 parts of chemi pulp, 80 parts of bleached hardwood-20 parts of chemi pulp, 70 parts of bleached hardwood-30 parts of chemi pulp, mixed beating, beating degree 35°SR. The wet strength agent was added in an amount of 20 kg / t. The amount of water absorption aid used in Example 5 was 10 kg / t. After adding the water absorption aid in each of the above examples, stirring for 5-10 min, according to the national standard method for papermaking, using Sheet Former 200S type intermittent fiber-based wet former to form a wet paper sheet, transferred to FFiberP-Dry01 type paper sheet flat dryer for drying, and after complete curing for 30 min, a circular paper sheet with a diameter of 0.2 m was obtained, the paper basis weight was 50 g / m 2The bulk of the absorption aid was detected by GBT24328.2-2020, and the data are shown in Table 4.

[0082] Table 4: Bulk test results of different proportions of chemi-mechanical pulp cases

[0083]

[0084] As can be seen from Table 4, using the water absorption aid of Example 5 of the present application, the bulk of 100 parts of bleached broadleaf wood is equivalent to that of 90 parts of bleached broadleaf wood-10 parts of chemi-mechanical pulp, which shows that Example 5 can replace 10% of the amount of chemi-mechanical pulp, reduce the amount of chemi-mechanical pulp, and reduce the production cost.

[0085] The above examples are the preferred implementation schemes of the present application, in addition to this, the present application can also be implemented in other ways, any obvious replacement without departing from the concept of the present application is within the protection scope of the present application.

Claims

1. A cationically modified water-absorbing aid, characterized in that The preparation raw materials include an amide intermediate and an epoxy modifier; The amide intermediate is obtained by reacting a polyamine with a secondary amine group and an unsaturated acid; the molar ratio of the polyamine with a secondary amine group to the carboxyl group in the unsaturated acid is 1.1:2; the polyamine with a secondary amine group is diethylenetriamine; and the unsaturated acid is oleic acid; The epoxy modifier is a cationic epoxy modifier; and the cationic epoxy modifier is epichlorohydrin; The molar ratio of the amide intermediate to the epoxy modifier is 1:0.

4. The preparation method of the cationic modified water absorption aid includes the following steps: The amide intermediate and the epoxy modifier are subjected to cationization reaction, and finally form a uniform emulsion under the action of water.

2. The method for preparing a cationic modified water-absorbing adjuvant according to claim 1, characterized in that, The method includes the following steps: The polyamine with a secondary amine group and the unsaturated acid are reacted to obtain the amide intermediate; then the amide intermediate and the epoxy modifier are subjected to cationization reaction, and finally form a uniform emulsion under the action of water.

3. The preparation method according to claim 2, characterized in that, The process of reacting the polyamine with a secondary amine group and the unsaturated acid to obtain the amide intermediate is as follows: The unsaturated acid and the polyamine with a secondary amine group are subjected to reaction reflux at 100 ℃ to 140 ℃ for 2 h to obtain the polyamide intermediate.

4. The production method according to claim 2, characterized by, The process of cationization reaction of the amide intermediate and the epoxy modifier is as follows: the epoxy modifier and the amide intermediate are mixed and reacted at 80 ℃ for 2 to 3 h.

5. The preparation method according to claim 2, characterized in that, The process of finally forming a uniform emulsion under the action of water is as follows: the amide intermediate and the epoxy modifier are subjected to cationization reaction, and after the reaction is completed, water is added to form an emulsion with a solid content of 10% to 20%.

6. Use of a cationically modified water-absorbing aid, characterized in that The cationic modified water absorption aid of claim 1 or the cationic modified water absorption aid prepared by the preparation method of any one of claims 2 to 5 is applied as an additive in a papermaking process.

7. Use according to claim 6, characterized in that, The additive further includes any one or any combination of a sizing agent, a wet paper strength enhancer, a dry paper strength enhancer, a resin control agent, a slurry control agent, a defoaming agent, a filler, and a pigment.

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