Anion modified low-foam dispersed rosin size as well as raw material composition, preparation method and application thereof

Abstract

The invention relates to anion modified low-foam dispersed rosin size as well as a raw material composition, a preparation method and application thereof, and belongs to the technical field of papermaking sizing agents. The low-temperature-resistant rosin resin comprises the following raw materials in parts by weight: 50-100 parts of rosin, 5-10 parts of maleic anhydride, 1.5-8 parts of sodium sulfite, 8-15 parts of a compound emulsifier, 0.1-0.5 part of a stabilizer, 50-100 parts of water and 0.1-0.5 part of a defoaming agent, the compound emulsifier comprises sodium dodecyl benzene sulfonate and fatty alcohol-polyoxyethylene ether sodium sulfate. According to the method, the anionic rosin size which is low in foam, short in cold water dispersion time and stable in long-term storage can be prepared by using a small amount of specific compound emulsifier.

Description

Technical Field

[0001] This invention belongs to the field of paper sizing agent technology, specifically relating to an anionic modified low-foaming dispersible rosin adhesive, its raw material composition, its preparation method, and its application. Background Technology

[0002] Sizing is a crucial process in papermaking. Among the many paper sizing agents, rosin sizing agents dominate, accounting for more than two-thirds of the total sizing volume. Rosin sizing agents include saponified rosin gum, reinforced rosin gum, and dispersible rosin gum. Dispersible rosin gum exhibits significantly higher sizing efficiency than other types, achieving a sizing rate up to four times that of saponified rosin gum and twice that of reinforced rosin gum. Furthermore, this type of gum effectively improves paper quality and helps reduce the amount of aluminum sulfate and brighteners required.

[0003] However, traditional anionic dispersed rosin adhesives have several significant drawbacks: First, achieving good emulsification typically requires the addition of large amounts of surfactants (often exceeding 150 parts), which not only increases costs but also easily leads to severe foaming problems (foam height often exceeding 10 cm), interfering with the production process and affecting paper quality. Second, due to the poor hydrophilicity of unmodified or insufficiently modified rosin, its dispersion speed in cold water is slow, often requiring more than 60 seconds for complete dispersion, making it difficult to meet the rapid application needs of production sites. Third, the product has poor storage stability; it exhibits stratification within four months of storage at room temperature, affecting its performance. Although existing technologies have attempted single-stage modification using maleic anhydride, the resulting products have low absolute Zeta potential values ​​(typically greater than -35 mV), leading to poor uniformity of adhesive adsorption on fibers and ultimately affecting the sizing effect. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide an anionic modified low-foaming dispersed rosin gum, its raw material composition, its preparation method, and its applications. This method can produce anionic dispersed rosin gum with low foaming, fast cold water dispersion time, and long-term storage stability using only a small amount of emulsifier.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] This invention provides a raw material composition for anionic modified low-foaming dispersible rosin gum, comprising the following raw materials in parts by weight: 50-100 parts rosin, 5-10 parts maleic anhydride, 1.5-8 parts sodium sulfite, 8-15 parts compound emulsifier, 0.1-0.5 parts stabilizer, 50-100 parts water, and 0.1-0.5 parts defoamer;

[0007] The compound emulsifier includes sodium dodecylbenzenesulfonate and sodium fatty alcohol polyoxyethylene ether sulfate.

[0008] Furthermore, the stabilizer includes at least one of sodium lignosulfonate and sodium carboxymethyl cellulose.

[0009] Furthermore, the defoamer includes at least one of silicone oil-based defoamers, higher alcohol complexes, and polyether-based defoamers;

[0010] Preferably, the silicone oil-based defoamer is polydimethylsiloxane or emulsified silicone oil.

[0011] Furthermore, the weight ratio of sodium dodecylbenzenesulfonate to sodium fatty alcohol polyoxyethylene ether sulfate is 1:0.5 to 1:2.

[0012] Furthermore, the amount of sodium sulfite used is 3-8% of the weight of the rosin.

[0013] This invention also provides a method for preparing anionicly modified low-foaming dispersion rosin gum, wherein the raw materials for the anionicly modified low-foaming dispersion rosin gum include the above-mentioned raw material composition for anionicly modified low-foaming dispersion rosin gum, and the preparation method includes the following steps:

[0014] Step 1) The rosin and maleic anhydride are mixed and subjected to a diene addition reaction to obtain product A;

[0015] Step 2) Add the sodium sulfite to product A to carry out a sulfonation reaction to obtain anionic modified rosin;

[0016] Step 3) Add the compound emulsifier and water to the anionic modified rosin, pre-emulsify and homogenize under high pressure using an emulsification pump, and cool down to obtain the anionic modified low-foaming dispersion rosin gum.

[0017] Preferably, in step 1), the diene addition reaction temperature is 170-185℃ and the reaction time is 2-4h;

[0018] In step 2), the sulfonation reaction temperature is 110-120℃, and the reaction time is 1-2 hours;

[0019] In step 3), the pre-emulsification temperature is 170-180℃, and the high-pressure homogenization pressure is 20-25MPa;

[0020] In step 3), the cooling process also includes adding defoamer and stabilizer to adjust the solid content.

[0021] The present invention also provides an anionic modified low-foaming dispersion rosin gum, which is prepared by the preparation method of the anionic modified low-foaming dispersion rosin gum described above.

[0022] Furthermore, the anionic modified low-foaming dispersed rosin gum has a solid content of 30-40% and a Zeta potential ≤-45mV.

[0023] This invention also provides the application of anionic modified low-foaming dispersible rosin gum as a sizing agent in papermaking.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] (1) The present invention utilizes a specific compound emulsifier system—sodium dodecylbenzenesulfonate and sodium fatty alcohol polyoxyethylene ether sulfate—to work synergistically. At extremely low dosages, it not only reduces interfacial tension and achieves effective emulsification, but also allows sodium fatty alcohol polyoxyethylene ether sulfate to form a dense liquid film, significantly inhibiting foam generation and controlling the foam height to below 4 cm.

[0026] (2) This invention introduces carboxyl groups through a two-stage chemical modification—a diene addition reaction and a sulfonation reaction—which greatly enhances the hydrophilicity of rosin molecules, enabling them to disperse rapidly in cold water within 20 seconds. Furthermore, the high degree of anionization (Zeta potential ≤ -45mV) results in strong electrostatic repulsion between the particles. Combined with the action of a stabilizer, this ensures that the product remains stable for 6 months at room temperature without stratification or precipitation.

[0027] (3) The product obtained by the present invention has excellent dispersibility, which makes the adhesive more evenly distributed on the fibers, and the product has less foam, does not cause fiber flocculation, and does not affect the paper forming. Detailed Implementation

[0028] The present invention is further illustrated below by way of examples, but these examples do not limit the invention to the scope of the embodiments described. Experimental methods in the following examples, unless otherwise specified, were performed according to conventional methods and conditions, or as selected in the product instructions. Furthermore, unless otherwise specified, all reagents and raw materials used in the present invention are commercially available products.

[0029] Example 1

[0030] Step 1: Weigh out 50 parts of rosin and 5 parts of maleic anhydride, mix them, and keep them at 180℃ for 2 hours;

[0031] Step 2: Cool to 110℃, add 1.5 parts of sodium sulfite, keep warm for 1 hour, and obtain anionic modified rosin;

[0032] Step 3: Add 2.67 parts of sodium dodecylbenzenesulfonate, 1.33 parts of sodium fatty alcohol polyoxyethylene ether sulfate, and 36 parts of water to the anionic modified rosin, heat to 170°C, and then homogenize through a high-speed shearing pump for 10 minutes and a high-pressure homogenizer at 20 MPa.

[0033] Step 4: After cooling to below 40°C, add 0.1 parts of sodium lignosulfonate and 0.1 parts of polydimethylsiloxane, and add water to adjust the solid content to 40% to obtain anionic modified low-foaming dispersion rosin gum.

[0034] Example 2

[0035] Step 1: Weigh 100 parts of rosin and 10 parts of maleic anhydride, mix them, and keep them at 185℃ for 4 hours;

[0036] Step 2: After cooling to 120℃, add 8 parts of sodium sulfite and keep warm for 2 hours to obtain anionic modified rosin;

[0037] Step 3: Add 3.33 parts of sodium dodecylbenzenesulfonate, 6.67 parts of sodium fatty alcohol polyoxyethylene ether sulfate, and 90 parts of water to the anionic modified rosin, heat to 170°C, and then homogenize through a high-speed shearing pump for 10 minutes and a high-pressure homogenizer at 25 MPa.

[0038] Step 4: After cooling to below 40°C, add 0.1 parts of sodium carboxymethyl cellulose and 0.5 parts of polydimethylsiloxane, and add water to adjust the solid content to 40% to obtain anionic modified low-foaming dispersion rosin gum.

[0039] Example 3

[0040] Step 1: Weigh out 80 parts of rosin and 6.4 parts of maleic anhydride, mix them, and keep warm at 182℃ for 3 hours;

[0041] Step 2: After cooling to 115℃, add 4.8 parts of sodium sulfite and keep warm for 1.5h to obtain anionic modified rosin;

[0042] Step 3: Add 4 parts sodium dodecylbenzenesulfonate, 4 parts sodium fatty alcohol polyoxyethylene ether sulfate, and 85 parts water to the anionic modified rosin, heat to 176°C, and then homogenize through a high-pressure homogenizer at 22 MPa after high-speed shearing by an emulsifying pump for 10 minutes.

[0043] Step 4: After cooling to below 40°C, add 0.1 parts of sodium lignosulfonate and 0.2 parts of polydimethylsiloxane, and add water to adjust the solid content to 40% to obtain anionic modified low-foaming dispersion rosin gum.

[0044] Example 4

[0045] Step 1: Weigh out 50 parts of rosin and 4 parts of maleic anhydride, mix them, and keep warm at 170℃ for 2 hours;

[0046] Step 2: After cooling to 110℃, add 1.5 parts of sodium sulfite and keep warm for 1 hour to obtain anionic modified rosin;

[0047] Step 3: Add 2.67 parts of sodium dodecylbenzenesulfonate, 1.33 parts of sodium fatty alcohol polyoxyethylene ether sulfate, and 36 parts of water to the anionic modified rosin, heat to 180°C, and then homogenize through a high-speed shearing pump for 10 minutes and a high-pressure homogenizer at 20 MPa.

[0048] Step 4: After cooling to below 40°C, add 0.1 parts of sodium lignosulfonate and 0.3 parts of polydimethylsiloxane, and add water to adjust the solid content to 36% to obtain anionic modified low-foaming dispersion rosin gum.

[0049] Example 5

[0050] Step 1: Weigh 100 parts of rosin and 10 parts of maleic anhydride, mix them, and keep them at 185℃ for 4 hours;

[0051] Step 2: After cooling to 120℃, add 4 parts of sodium sulfite and keep warm for 2 hours to obtain anionic modified rosin;

[0052] Step 3: Add 3.33 parts of sodium dodecylbenzenesulfonate, 6.67 parts of sodium fatty alcohol polyoxyethylene ether sulfate, and 90 parts of water to the anionic modified rosin, heat to 170°C, and then homogenize through a high-speed shearing pump for 10 minutes and a high-pressure homogenizer at 25 MPa.

[0053] Step 4: After cooling to below 40°C, add 0.1 parts of sodium carboxymethyl cellulose and 0.5 parts of higher alcohol defoamer, and add water to adjust the solid content to 40% to obtain anionic modified low-foaming dispersion rosin gum.

[0054] Comparative Example 1 (Unmodified Rosin)

[0055] Step 1: Weigh 80 parts of rosin, 4 parts of sodium dodecylbenzenesulfonate, and 4 parts of sodium fatty alcohol polyoxyethylene ether sulfate, mix them evenly, heat to 170℃, and then pass them through a high-speed shearing pump for 10 minutes before homogenizing them through a high-pressure homogenizer at 22MPa.

[0056] Step 2: After cooling down, add 0.1 parts of sodium carboxymethyl cellulose and 0.1 parts of polydimethylsiloxane, and add water to adjust the solid content to 40% to obtain anionic dispersed rosin gum.

[0057] Comparative Example 2 (Single-stage modification)

[0058] The only difference from Example 3 is that step 2 is removed.

[0059] Comparative Example 3 (using other anionic emulsifiers instead of the compound emulsifier)

[0060] The only difference from Example 2 is that in step 3, “sodium dodecylbenzenesulfonate 3.33 parts and sodium fatty alcohol polyoxyethylene ether sulfate 6.67 parts” is replaced with “sodium stearate 3.33 parts and sulfonic acid type epoxy alkyl propyl polyether 6.67 parts”.

[0061] Comparative Example 4 (using maleic anhydride instead of maleic anhydride)

[0062] The only difference from Example 2 is that "10 parts of maleic anhydride" in step 1 is replaced with "10 parts of maleic acid".

[0063] Comparative Example 5 (Sodium dodecylbenzenesulfonate only)

[0064] The only difference from Example 2 is that in step 3, “sodium dodecylbenzenesulfonate 3.33 parts and sodium fatty alcohol polyoxyethylene ether sulfate 6.67 parts” is replaced with “sodium dodecylbenzenesulfonate 10 parts”.

[0065] Comparative Example 6 (Proportion of changing the compound emulsifier)

[0066] The only difference from Example 2 is that in step 3, “sodium dodecylbenzenesulfonate 3.33 parts and sodium fatty alcohol polyoxyethylene ether sulfate 6.67 parts” is replaced with “sodium dodecylbenzenesulfonate 3.33 parts and sodium fatty alcohol polyoxyethylene ether sulfate 8.33 parts”.

[0067] Comparative Example 7 (Adjusting Process Parameters)

[0068] The only difference from Example 5 is that the reaction temperature in step 1 is adjusted to 190°C and the reaction time is adjusted to 5 hours; the sulfonation reaction temperature in step 2 is adjusted to 90°C and the reaction time is adjusted to 3 hours.

[0069] Effect Example

[0070] The properties of the rosin gum prepared in the above examples and comparative examples were tested using the following methods or standards.

[0071] I. Solid content determination: 2g sample, dried at 150℃ for 30min;

[0072] II. Application degree: TAPPI T530

[0073] III. Storage stability: GB / T 11543-2008 (40℃ accelerated test)

[0074] IV. Cold Water Dispersibility Test: QB / T 1237-2019

[0075] Instruments: 250mL stoppered graduated cylinder, constant temperature water bath (25±0.5℃)

[0076] Steps: Add 200mL of deionized water to a graduated cylinder and keep the temperature constant at 25℃; quickly add 1.0g of rosin gum emulsion (accurate to 0.01g); immediately invert the graduated cylinder 10 times (2 seconds each time); let it stand and observe, and record the time (in seconds) when the emulsion is completely dispersed and there are no visible particles.

[0077] V. Foam Height Test: GB / T 13173-2021

[0078] Instrument: Roche foam analyzer

[0079] Procedure: Prepare 200 mL of 0.5% rosin gum aqueous solution and maintain the temperature at 40℃; the solution flows into a graduated cylinder from a height of 450 mm, causing foam to form; after standing for 5 minutes, measure the height of the foam layer (cm).

[0080] VI. Zeta potential: The particle charge analyzer, model PCD-05, manufactured by BTG, was used for measurement.

[0081] Test results

[0082] The performance of the samples from Examples 1-5 and Comparative Examples 1-7 was measured, and the results are shown in Table 1.

[0083]

[0084]

[0085] The results above show that the anionic modified low-foaming rosin dispersible adhesive disclosed in this invention has a Zeta potential ≤ -45mV, foam height ≤ 4cm (GB / T 13173), cold water dispersion time ≤ 20 seconds, and no stratification or precipitation after 6 months of storage at room temperature. It has better storage stability and superior performance than the comparative product.

[0086] The results show that, compared with existing products, the anionic modified low-foaming dispersion rosin adhesive prepared in Example 2 has a more ideal sizing effect, and the paper products prepared with it have better surface strength, water resistance, smoothness and other properties.

[0087] Finally, it should be noted that in this invention, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0088] Although this disclosure has been described above through specific embodiments, it should be understood that those skilled in the art can devise various modifications, improvements, or equivalents to this disclosure within the spirit and scope of the appended solutions. Such modifications, improvements, or equivalents should also be considered to be included within the scope of protection claimed in this disclosure.

Claims

1. A raw material composition for anionic modified low-foaming dispersible rosin gum, characterized in that, The raw materials contain the following parts by weight: 50-100 parts rosin, 5-10 parts maleic anhydride, 1.5-8 parts sodium sulfite, 8-15 parts compound emulsifier, 0.1-0.5 parts stabilizer, 50-100 parts water, and 0.1-0.5 parts defoamer. The compound emulsifier includes sodium dodecylbenzenesulfonate and sodium fatty alcohol polyoxyethylene ether sulfate.

2. The raw material composition of the anionic modified low-foaming dispersible rosin gum according to claim 1, characterized in that, The stabilizer includes at least one of sodium lignosulfonate and sodium carboxymethyl cellulose.

3. The raw material composition of the anionic modified low-foaming dispersible rosin gum according to claim 1, characterized in that, The defoamer includes at least one of silicone oil-based defoamers, higher alcohol complexes, and polyether defoamers; Preferably, the silicone oil-based defoamer is polydimethylsiloxane or emulsified silicone oil.

4. The raw material composition of the anionic modified low-foaming dispersible rosin gum according to claim 1, characterized in that, The weight ratio of sodium dodecylbenzenesulfonate to sodium fatty alcohol polyoxyethylene ether sulfate is 1:0.5 to 1:

2.

5. The raw material composition of the anionic modified low-foaming dispersible rosin gum according to claim 1, characterized in that, The amount of sodium sulfite used is 3-8% of the weight of the rosin.

6. A method for preparing anionic modified low-foaming dispersible rosin gum, characterized in that, The raw materials include the raw material composition of anionic modified low-foaming dispersible rosin gum as described in any one of claims 1 to 5, and the preparation method includes the following steps: Step 1) The rosin and maleic anhydride are mixed and subjected to a diene addition reaction to obtain product A; Step 2) Add the sodium sulfite to product A to carry out a sulfonation reaction to obtain anionic modified rosin; Step 3) Add the compound emulsifier and water to the anionic modified rosin, pre-emulsify and homogenize under high pressure using an emulsification pump, and cool down to obtain the anionic modified low-foaming dispersion rosin adhesive.

7. The preparation method of anionic modified low-foaming dispersible rosin gum according to claim 6, characterized in that, The preparation method satisfies at least one of the following conditions: In step 1), the diene addition reaction temperature is 170-185℃, and the reaction time is 2-4h; In step 2), the sulfonation reaction temperature is 110-120℃, and the reaction time is 1-2 hours; In step 3), the pre-emulsification temperature is 170-180℃, and the high-pressure homogenization pressure is 20-25MPa; In step 3), the cooling process also includes adding defoamer and stabilizer to adjust the solid content.

8. An anionic modified low-foaming dispersion rosin gum, characterized in that, It is prepared by the method of any one of claims 6 to 7 for preparing anionic modified low-foaming dispersed rosin gum.

9. The anionic modified low-foaming dispersion rosin gum according to claim 8, characterized in that, The anionic modified low-foaming dispersed rosin gum has a solid content of 30-40% and a Zeta potential ≤-45mV.

10. The application of anionic modified low-foaming dispersible rosin gum as described in claim 8 or 9 as a sizing agent in papermaking.

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