Use of a highly active reactive rosin organosilicon resin

Abstract

The present invention discloses the use of a highly active reactive rosin organosilicon resin, and its structural formula is: #imgabs0# wherein, R1 is rosin or its derivative; R2 is one of -O-, #imgabs1# or NH-(CH2)2-NH-(CH2)3-; R3 is at least one or a combination of -CH3, -OCH3, -OCH2CH3, -CH=CH2 or -OH. The present invention prepares a highly active reactive rosin organosilicon resin by reacting rosin or its derivative with a silane coupling agent, which can be added as a sizing agent to a pulp fiber suspension. A covalent bond can be formed between the alkoxy group in the structure of the rosin organosilicon resin and the hydroxyl group of cellulose, endowing the paper-based material with firm, durable and stable water resistance, so that the sized paper-based material shows great potential to replace plastic packaging.

Description

Technical Field

[0001] The present invention relates to the use of a highly active reactive rosin silicone resin, belonging to the field of new energy-saving and environmental protection materials. Background Art

[0002] Rosin is a characteristic forestry resource in China, with an annual output of more than 6 million tons, accounting for more than 60% of the world. Its products mainly focus on light-colored rosin, rosin tackifying resin, rosin modified printing ink resin and other series of products.

[0003] The irreplaceability of using forestry resources such as rosin to prepare bio-based chemicals and degradable materials has become increasingly obvious. Therefore, the current situation of deep processing of rosin resources in China urgently needs to be transformed and upgraded, and actively promote the research and development of high-value-added rosin deep processing products. In the paper-making field, rosin has a long history as a sizing agent, but the current rosin-based sizing agents have problems such as poor sizing effect, low retention rate, unstable water resistance, and there are still a large number of micropores in the paper-based materials after sizing, which makes it difficult to replace plastics in a humid environment. The emergence of reactive rosin sizing agents has solved the above problems to a certain extent, but the large steric hindrance of the hydrogenated phenanthrene ring in the rosin structure weakens its reactivity, which results in that the formation of covalent bonds between rosin and cellulose often requires a reaction at a high temperature of 130 °C for more than 12 h, and toxic chemicals (such as acetone, oxalyl chloride, toluene, etc.) will inevitably be used. At present, it is still a huge challenge to covalently graft rosin onto paper-based materials in a green, efficient and mild way. Summary of the Invention

[0004] In order to solve the problems of poor water resistance, low strength, poor sizing effect, etc. in the prior art of paper-based materials, the present invention provides the use of a highly active reactive rosin silicone resin.

[0005] In order to solve the above technical problems, the technical solutions adopted by the present invention are as follows:

[0006] The use of a highly active reactive rosin silicone resin as a sizing agent to enhance the water resistance and strength of paper-based materials, and the paper-based materials after sizing are used as degradable packaging materials; the structural formula of the highly active reactive rosin silicone resin is:

[0007] Among them, R1 is rosin or its derivative; R2 is -O-, or one of NH-(CH2)2-NH-(CH2)3-; R3 is at least one or a combination of -CH3, -OCH3, -OCH2CH3, -CH=CH2 or -OH.

[0008] The above high-activity reactive rosin organosilicon resin can form covalent bonds between the alkoxy groups in its structure and the hydroxyl groups of cellulose, endowing the paper-based material with strong, durable, and stable water resistance, so that the sized paper-based material can be used as a degradable alternative to plastic packaging.

[0009] Existing reactive rosin sizing agents mainly focus on surface sizing modification. The reactive rosin sizing agent prepared in this application can be used for both surface sizing and internal sizing. When used for internal sizing, the active groups in its structure can build a cross-linked network around cellulose, enhancing the structural compactness and significantly improving the water resistance and mechanical properties of cellulose-based materials, which is superior to surface sizing.

[0010] The method for using the above high-activity reactive rosin organosilicon resin as a sizing agent includes the following steps:

[0011] (1) Drop the high-activity reactive rosin organosilicon resin into deionized water containing a compound emulsifier, and quickly stir and emulsify to obtain an emulsion. The compound emulsifier is composed of a non-ionic emulsifier and a cationic emulsifier. Among them, the non-ionic emulsifier is at least one of polyoxyethylene sorbitan fatty acid ester, sorbitan fatty acid ester, fatty alcohol polyoxyethylene ether, fatty acid polyoxyethylene ester, or alkylphenol polyoxyethylene ether; the cationic emulsifier is at least one of cationic starch, cetyltrimethylammonium bromide, cetyltrimethylammonium chloride, or cationic polyacrylamide; the mass ratio of the non-ionic emulsifier to the cationic emulsifier is 1:1 - 2;

[0012] (2) Adjust the pH of the emulsion to 5.5 - 8.5;

[0013] (3) Add the emulsion to the pulp fiber suspension, quickly stir and disperse, and obtain waterproof paper through papermaking and hot pressing.

[0014] The compounding of the non-ionic emulsifier and the cationic emulsifier above can improve the retention rate of the sizing agent in the fiber, and then enhance the mechanical properties and water resistance of the waterproof paper.

[0015] Preferably, the non-ionic emulsifier is alkylphenol polyoxyethylene ether, and the cationic emulsifier is cationic starch, cetyltrimethylammonium chloride, or cationic polyacrylamide. The cationic emulsifier is further preferably cationic starch or cetyltrimethylammonium chloride, and more preferably cationic starch. The most preferred compound emulsifier in this application is a mixture of OP-10 emulsifier and cationic starch with a mass ratio of 1:(1 - 1.3), and at this time, the mechanical properties and water resistance of the obtained waterproof paper are the best.

[0016] In the above step (2), at least one of ammonia water, sodium bicarbonate or sodium hydroxide is used to adjust the pH. The selection of the pH value is relatively important. Being too acidic will cause hydrolysis of cellulose and affect the strength of the sized paper; being too alkaline will cause hydrolysis and self-polymerization of rosin silicone, forming oligomers, which is not conducive to sizing; at the same time, being too acidic or too alkaline will affect the emulsifying effect of the emulsifier.

[0017] In the above step (3), the cationic emulsifier makes the sizing agent carry a positive charge and can be adsorbed on the surface of negatively charged fibers through electrostatic neutralization without compounding other components.

[0018] To improve the product yield, in step (1), the dropping rate is 1 drop per 2 - 5 s, the emulsifier is alkylphenol polyoxyethylene ether, the stirring speed is 800 - 1500 r / min, and the stirring time is 2 - 10 min; in step (3), the stirring speed is 500 - 1200 r / min, the stirring time is 5 - 10 min, the hot pressing temperature is 60 - 100 °C, the hot pressing pressure is 5 - 15 MPa, and the hot pressing time is 0.5 - 1.5 h.

[0019] To improve the emulsion stability and sizing effect, the mass ratio of the highly active reactive rosin silicone resin, deionized water, and emulsifier is 100:400 - 900:2 - 5. In step (1), the solid content should not be too high, otherwise it will cause self-polymerization of the highly active reactive rosin silicone resin, resulting in a significant reduction in emulsion stability.

[0020] To improve the reaction efficiency, the solid content of the pulp fiber suspension is 1.2 - 2.4%; the mass ratio of the emulsion to the pulp fiber suspension is 1:8 - 15. With less emulsion used, the sizing effect is good.

[0021] The preparation method of the above highly active reactive rosin silicone resin is obtained by reacting rosin or its derivatives with a silane coupling agent. Among them, rosin or its derivatives are at least one of rosin, hydrogenated rosin, polymerized rosin, disproportionated rosin, maleic rosin, dehydroabietic acid, abienylacrylic acid or pimaropimaric acid. Preferably, it is fully hydrogenated rosin.

[0022] To ensure the smooth progress of the reaction, the silane coupling agent is at least one of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, methylvinyldiethoxysilane, dimethylethoxyvinylsilane, vinyltris(2-methoxyethoxy)silane, dimethyldiethoxysilane, methyldiethoxysilane, tetramethoxysilane, tetraethoxysilane, 3-(2-aminoethylamino)propyltriethoxysilane, N-aminoethyl-3-aminopropylmethyldimethoxysilane, [3-[(2-aminoethyl)amino]propyl]silanetriol. Preferably, it is 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane.

[0023] The preparation method of the above high-activity reactive rosin organosilicon resin includes the following steps:

[0024] (1) Grind rosin or its derivative into powder, add it to a three-necked flask containing a silane coupling agent while stirring under dry conditions, and introduce nitrogen for protection;

[0025] (2) Heat the three-necked flask in step (1) until the rosin or its derivative powder melts, and stir rapidly for dispersion;

[0026] (3) Add a catalyst to the three-necked flask in step (2), and further raise the temperature for reaction;

[0027] (4) Remove low-boiling impurities from the product obtained in step (3) by rotary evaporation to obtain a light yellow high-activity reactive rosin organosilicon resin.

[0028] For convenient operation and to improve the product yield, in step (1), the dry condition is that the air humidity is 20% - 40%, and the nitrogen purity is at least 99.5%; in step (2), the melting temperature of rosin or its derivative is 80°C, the stirring speed is 500 - 800 r / min, and the stirring time is 20 - 40 min; in step (3), the catalyst is benzyltriethylammonium chloride, the reaction temperature is 100 - 150°C, and the reaction time is 3 - 6 h; in step (4), the rotary evaporation vacuum degree is 50 - 100 bar, and the rotary evaporation temperature is 40 - 80°C.

[0029] In step (1), if the humidity is too high, it will cause the silane coupling agent to hydrolyze and self-polymerize rapidly, generating oligomers and affecting the product yield. Therefore, the reaction should be carried out in a relatively dry environment.

[0030] To improve the reaction efficiency, the mass ratio of rosin or its derivative, silane coupling agent, and catalyst is 100:80 - 300:0.5 - 1.

[0031] The waterproof paper prepared in this application can be recycled. The recycling method of the waterproof paper is as follows: The waste waterproof paper is used to recover the pulp fiber suspension through alkali cooking, and then, after sizing and hot pressing (the same as the above sizing and hot pressing methods), the waterproof paper is obtained.

[0032] For technologies not mentioned in the present invention, reference is made to the prior art.

[0033] The beneficial effects of the present invention are as follows:

[0034] 1. Compared with commercially available rosin sizing agents, the reactive rosin organosilicon resin prepared in the present invention has the advantages of simple preparation process, short operation process, high stability, strong water resistance, and outstanding strengthening performance. After realizing industrial large-scale production, it can promote the development and upgrading of similar products in the market, which is conducive to improving the utilization efficiency of forestry resources such as rosin. The paper-based material sized with the highly active reactive rosin organosilicon resin prepared in this application can be used as an excellent degradable packaging material.

[0035] 2. The products developed in the present invention basically achieve full utilization of quality, and no organic solvents are used in the preparation process, realizing low three-waste emissions. In addition, all raw materials and products can be recycled and degraded, which conforms to the concept of global green ecological development.

[0036] 3. Currently, commonly used plastic packaging substitutes, such as polylactic acid, polycaprolactone and other degradable plastics, although having excellent performance in various aspects, have high prices and problems such as competing with people for food and requiring specific conditions for degradation, resulting in their inability to be widely promoted and used on a large scale. The paper-based material prepared in the present invention has the advantages of easy availability of raw materials, stable performance, and low price, and can be used as a new generation of degradable packaging material to replace degradable plastics such as polylactic acid and promote the development of the market economy. Description of the Drawings

[0037] Figure 1 It is the infrared spectrum of the highly active reactive rosin organosilicon resin prepared in Example 1.

[0038] Figure 2 It is the proton nuclear magnetic resonance spectrum of the highly active reactive rosin organosilicon resin prepared in Example 1.

[0039] Figure 3 It is the particle size distribution and stability of the rosin organosilicon resin emulsion prepared in Example 2.

[0040] Figure 4 It is the microscopic morphology of the surface and cross-section of the paper-based material before and after sizing in Example 2.

[0041] Figure 5 It is the water resistance of the paper-based material before and after sizing in Example 2.

[0042] Figure 6is the abrasion resistance of the paper-based material after sizing in Example 2.

[0043] Figure 7 are the mechanical properties of the paper-based material before and after sizing in Example 2.

[0044] Figure 8 are the long-term water resistance of the paper-based material before and after sizing in Example 2.

[0045] Figure 9 is the degradability and recyclability of the paper-based material after sizing in Example 2. Detailed implementation manners

[0046] To better understand the present invention, the content of the present invention will be further clarified below in conjunction with embodiments. However, the content of the present invention is not limited to the following embodiments only.

[0047] Example 1

[0048] 100 g of fully hydrogenated rosin was ground into powder, which was added to a three-necked flask containing 100 g of 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, and nitrogen was introduced. During the reaction, the air humidity was maintained at 30%. Then the three-necked flask was heated to 80 °C and stirred for 30 min at a stirring speed of 500 r / min. After that, 0.5 g of benzyltriethylammonium chloride was added to the three-necked flask, and the temperature was raised to 120 °C and reacted for 4 h. Finally, the product was rotary evaporated to remove low-boiling impurities under the conditions of 80 bar and 70 °C to obtain a light yellow highly active reactive rosin organosilicon resin.

[0049] The infrared spectrum of the highly active reactive rosin organosilicon resin is as Figure 1 shown: The characteristic absorption peaks of the epoxy group and the Si-O-C bond in 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane are clearly observed at 910 cm -1 and 957 cm -1 respectively. After the ring-opening reaction, the characteristic absorption peak of the epoxy group in the infrared spectrum of the highly active reactive rosin organosilicon resin disappears (the green area in the figure), and a characteristic absorption peak of the Si-O-C bond appears at 957 cm -1 . At the same time, the infrared spectrum of the highly active reactive rosin organosilicon resin has a broad -OH absorption peak at 3420 cm -1 . Compared with the infrared spectrum of fully hydrogenated rosin, due to the formation of the ester group, the C=O stretching vibration peak in the infrared spectrum of the highly active reactive rosin organosilicon resin moves from 1690 cm -1 to 1720 cm -1 . The above results prove the successful synthesis of the highly active reactive rosin organosilicon resin.

[0050] The nuclear magnetic hydrogen spectrum of the highly active reactive rosin organosilicon resin is asFigure 2 As shown, chemical shift peaks can be clearly observed at 1.21 ppm (attributed to -CH3 in ethoxy) and 3.83 ppm (attributed to -CH2- in ethoxy). Meanwhile, the chemical shift peaks at 0.62, 1.42, 3.4, and 4.2 ppm are attributed to the hydrogens on the alkyl chain in 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane. The chemical shift peaks from 1.2 ppm to 2 ppm are attributed to the hydrogens on perhydrogenated rosin. The chemical shift peak at 12.08 ppm is attributed to the hydrogen on the carboxyl group of perhydrogenated rosin. It should be noted that in the 1 1H NMR of the highly reactive reactive rosin organosilicon resin, the chemical shift peak at 12.08 ppm disappears. Meanwhile, the chemical shift peak at 5.48 ppm is attributed to the hydrogen on the hydroxyl group generated by the ring-opening reaction. The above results further prove the successful preparation of the highly reactive reactive rosin organosilicon resin, and its structure is:

[0051] Example 2

[0052] Dissolve 2 g of OP-10 emulsifier and 3 g of cetyltrimethylammonium bromide in 900 g of deionized water, and then slowly dropwise add (20 drops / min) 100 g of the highly reactive reactive rosin organosilicon resin (prepared in Example 1) while stirring, control the stirring speed at 1500 r / min, and stir for 5 min. Then, adjust the pH to 7 with ammonia water to obtain a rosin organosilicon resin emulsion with a solid content of 10%. As Figure 3 shown, the average particle size of the emulsion reaches 265.6 nm, and the emulsion remains stable without stratification after standing for one month, and the average particle size increases slightly. Next, beat the bagasse to obtain a bagasse pulp fiber suspension with a solid content of 2.4%. Take 10 g of the freshly prepared emulsion and add it to 90 g of the fiber suspension, and stir at a speed of 500 r / min for 10 min. Finally, hot press for 1 h under the conditions of a pressure of 10 MPa and a temperature of 80 °C to obtain a waterproof paper with a thickness of 0.2 mm.

[0053] Effect evaluation

[0054] The internal structure changes of the paper-based material before and after sizing (the thickness of the paper-based material before and after sizing is 0.2 mm) were observed by scanning electron microscopy. As Figure 4As shown, the shape and contour of the fibers can be clearly observed on the surface of the paper-based material before sizing, and its surface is rough with many micropores between the fibers. At the same time, the loose porous structure of the paper-based material before sizing can be clearly observed from the cross-section, and the water contact angle is almost 0°, which proves that the paper-based material before sizing has high hydrophilicity. The internal structure of the sized paper-based material (the waterproof paper prepared in Example 2) is denser, and the micropores between the fibers are filled, thus weakening its capillary action and blocking the diffusion and penetration of water, and the water contact angle reaches 130°. The above results prove that the sized paper-based material prepared in Example 2 belongs to a waterproof material.

[0055] The water resistance of the paper-based material before and after sizing was evaluated by measuring the water absorption rate. As Figure 5 shown, the paper-based material before sizing is extremely unstable in water, and the water absorption rate reaches 196.3% after being immersed in water at 25°C for 1 h, while the sized paper-based material (waterproof paper) has very excellent water resistance, and the water absorption rate is only 10.2% after being immersed in water at 25°C for 1 h; when the paper-based materials before and after sizing are respectively immersed in hot water at 90°C for 1 h, the sized paper-based material still maintains a low water absorption rate (13.2%), while the water absorption rate of the paper-based material before sizing increases further significantly (252.7%). Even if the sized paper-based material is worn on P320 type sandpaper for 50 cm, it still maintains excellent water resistance. As Figure 6 shown, when a pressure of 500 g is applied to wear the surface of the sized paper-based material on P320 type sandpaper, the water absorption rates of the paper-based material before and after wear when immersed in water at 25°C for 1 h are both about 10%, and show a similar change trend. This result proves that rosin organosilicon resin endows the paper-based material with strong water resistance. The above results prove that the water resistance of the sized paper-based material prepared in Example 2 is greatly enhanced.

[0056] The mechanical properties of the paper-based material before and after sizing were measured by a universal tensile machine. As Figure 7 shown, the tensile strength of the sized paper-based material is 47.9 MPa, which is 11 times that of the paper-based material before sizing (4.5 MPa). Even after being immersed in water at 25°C for 1 h, the tensile strength of the sized paper-based material also reaches 34.3 MPa, far superior to the wet tensile strength (0.9 MPa) of the paper-based material before sizing. The above results prove that the sized paper-based material prepared in Example 2 has excellent mechanical properties. When the paper-based materials before and after sizing are stored in an environment with a humidity of 80% for one month, observe the change of their mechanical properties. As Figure 8 shown, the hydrogen bond network of the paper-based material before sizing is broken due to the penetration of water molecules, and its tensile strength gradually decreases, while the excellent water resistance of the sized paper-based material blocks the invasion of water molecules in the air, and its tensile strength remains basically unchanged, indicating that rosin organosilicon resin endows the paper-based material with durable water resistance.

[0057] The environmental impact of the waterproof paper (prepared in Example 2) was evaluated through degradation experiments and recycling experiments. As Figure 9 shown, the polyethylene plastic film and the waterproof paper were buried 5 cm underground. After 60 days, the waterproof paper was completely degraded while the polyethylene plastic film remained intact. In addition, the waste waterproof paper was used to recover the pulp fiber suspension through alkali cooking, and after sizing and hot pressing again (refer to Example 2), waterproof paper could be obtained again. Its mechanical properties and water resistance attenuated by less than 5% compared with those before being discarded. The above results prove that the waterproof paper is recyclable and degradable and belongs to an environmentally friendly material.

[0058] Comparative Example 1

[0059] The difference from Example 2 was that the pH adjustment step was omitted. At this time, the pH of the rosin organosilicon resin emulsion was 4.0, and the rest were all referred to Example 2 to prepare a waterproof paper with a thickness of 0.2 mm.

[0060] The water contact angle of the waterproof paper was 110°; the water absorption rate of the waterproof paper after being immersed in water at 25°C for 1 h was 15.5%, and the water absorption rate after being immersed in water at 90°C for 1 h was 25.8%. The tensile strength of the waterproof paper was 27.3 MPa. The reasons for the performance decline of the waterproof paper were that on the one hand, the acidic conditions would inactivate the emulsifier, resulting in the precipitation of rosin organosilicon resin in water and reducing the retention rate; on the other hand, the acidic conditions would cause cellulose hydrolysis, resulting in a significant attenuation of the mechanical properties of the paper-based material.

[0061] Comparative Example 2

[0062] A commercially available maleic rosin-based reinforced rosin size was used as the sizing agent, and the rest were all referred to Example 2 to prepare a waterproof paper with a thickness of 0.2 mm.

[0063] The water contact angle of the comparative waterproof paper was 92°; the water absorption rate of the comparative waterproof paper after being immersed in water at 25°C for 1 h was 52.8%, and the water absorption rate after being immersed in water at 90°C for 1 h was 79.2%. The tensile strength of the comparative waterproof paper was 10.8 MPa. The conventional rosin sizing agent had a low retention rate, resulting in poor water resistance and mechanical properties of the comparative waterproof paper. In the rosin organosilicon resin prepared in this application, the silalkoxy groups hydrolyze to generate Si-OH. In addition to the electrostatic neutralization effect, it can also be adsorbed on the fiber surface through hydrogen bonds, significantly improving the retention rate of the sizing agent, and the performance is also better than that of the paper-based material after conventional sizing.

[0064] Example 3

[0065] Dissolve 1 g of OP-10 emulsifier and 1 g of cationic starch in 500 g of deionized water. Then, while slowly (20 drops / min) adding 100 g of highly active reactive rosin organosilicon resin (prepared in Example 1) dropwise, stir at a stirring speed of 1200 r / min for 3 min. Then, adjust the pH to 6.5 with ammonia water to obtain a rosin organosilicon resin emulsion. Next, beat the bagasse to obtain a bagasse pulp fiber suspension with a solid content of 1.2%. Take 20 g of the emulsion and add it to 100 g of the fiber suspension, and stir at a speed of 600 r / min for 15 min. Finally, hot press for 0.5 h under the conditions of a pressure of 5 MPa and a temperature of 100 °C to obtain waterproof paper with a thickness of 0.2 mm.

[0066] The water contact angle of the waterproof paper is 138°; the water absorption rate of the waterproof paper after being immersed in water at 25 °C for 1 h is 6.5%, and the water absorption rate after being immersed in water at 90 °C for 1 h is 9.2%. The tensile strength of the waterproof paper is 53.9 MPa.

[0067] Example 4

[0068] Dissolve 1.5 g of OP-10 emulsifier and 2.5 g of cationic polyacrylamide in 700 g of deionized water. Then, while slowly (20 drops / min) adding 100 g of reactive rosin organosilicon resin dropwise, stir at a stirring speed of 1400 r / min for 4 min. Then, adjust the pH to 7.5 with ammonia water to obtain a rosin organosilicon resin emulsion. Next, beat the bagasse to obtain a bagasse pulp fiber suspension with a solid content of 2%. Take 15 g of the emulsion and add it to 120 g of the fiber suspension, and stir at a speed of 800 r / min for 12 min. Finally, hot press for 1.5 h under the conditions of a pressure of 15 MPa and a temperature of 110 °C to obtain waterproof paper with a thickness of 0.2 mm.

[0069] The water contact angle of the waterproof paper is 125°; the water absorption rate of the waterproof paper after being immersed in water at 25 °C for 1 h is 11.1%, and the water absorption rate after being immersed in water at 90 °C for 1 h is 13.4%. The tensile strength of the waterproof paper is 47.2 MPa.

[0070] Example 5

[0071] Grind 50 g of rosin into powder, add it to a three-necked flask containing 60 g of tetraethoxysilane, and introduce nitrogen, and keep the air humidity at 20% during the reaction. Then heat the three-necked flask to 85 °C, stir for 20 min, and the stirring speed is 800 r / min. Then, add 0.4 g of benzyltriethylammonium chloride to the three-necked flask, raise the temperature to 140 °C, and react for 3 h. Finally, rotary evaporate the product under the conditions of 50 bar and 80 °C to remove low-boiling impurities to obtain a light yellow highly active reactive rosin organosilicon resin, and its structure is:

[0072] Dissolve 1 g of OP-10 emulsifier and 1 g of cationic starch in 500 g of deionized water. Then, while slowly (20 drops / min) dropping 100 g of highly active reactive rosin organosilicon resin (prepared in Example 5) with stirring, control the stirring speed at 1200 r / min and stir for 3 min. Then, adjust the pH to 6.5 with ammonia water to obtain a rosin organosilicon resin emulsion. Next, beat the bagasse to obtain a bagasse pulp fiber suspension with a solid content of 1.2%. Take 20 g of the emulsion and add it to 100 g of the fiber suspension, and stir at a speed of 600 r / min for 15 min. Finally, hot press for 0.5 h under the conditions of a pressure of 5 MPa and a temperature of 100 °C to obtain waterproof paper with a thickness of 0.2 mm.

[0073] The water contact angle of the waterproof paper is 135°; the water absorption rate of the waterproof paper after being immersed in water at 25 °C for 1 h is 8.5%, and the water absorption rate after being immersed in water at 90 °C for 1 h is 11.2%. The tensile strength of the waterproof paper is 50.9 MPa.

[0074] Example 6

[0075] Grind 80 g of dehydroabietic acid into powder, add it to a three-necked flask containing 150 g of 3-(2-aminoethylamino)propyltriethoxysilane, and introduce nitrogen. Keep the air humidity at 25% during the reaction. Then heat the three-necked flask to 80 °C and stir for 40 min with a stirring speed of 1200 r / min. After that, add 0.6 g of benzyltriethylammonium chloride to the three-necked flask, raise the temperature to 150 °C, and react for 6 h. Finally, rotary evaporate to remove low-boiling impurities under the conditions of 60 bar and 70 °C to obtain a light yellow highly active reactive rosin organosilicon resin, and its structure is:

[0076] Dissolve 1.5 g of OP-10 emulsifier and 2.5 g of cationic polyacrylamide in 700 g of deionized water. Then, while slowly (20 drops / min) dropping 100 g of reactive rosin organosilicon resin (prepared in Example 6) with stirring, control the stirring speed at 1400 r / min and stir for 4 min. Then, adjust the pH to 7.5 with ammonia water to obtain a rosin organosilicon resin emulsion. Next, beat the bagasse to obtain a bagasse pulp fiber suspension with a solid content of 2%. Take 15 g of the emulsion and add it to 120 g of the fiber suspension, and stir at a speed of 800 r / min for 12 min. Finally, hot press for 1.5 h under the conditions of a pressure of 15 MPa and a temperature of 110 °C to obtain waterproof paper with a thickness of 0.2 mm.

[0077] The water contact angle of the waterproof paper is 124°; the water absorption rate of the waterproof paper after being immersed in water at 25°C for 1 h is 13.1%, and the water absorption rate after being immersed in water at 90°C for 1 h is 16.4%. The tensile strength of the waterproof paper is 46.2 MPa.

Claims

1. Use of a highly active reactive rosin organosilicon resin, characterized in that: As a sizing agent, it enhances the water resistance and strength of paper-based materials, and the sized paper-based materials are used as degradable packaging materials; the structural formula of the highly active reactive rosin organosilicon resin is: Among them, R1 is rosin or its derivative; R2 is one of -O-, or NH-(CH2)2-NH-(CH2)3-; R3 is at least one or a combination of multiple ones among -CH3, -OCH3, -OCH2CH3, -CH=CH2 or -OH.

2. Use of the highly active reactive rosin organosilicon resin according to claim 1, characterized in that: Usage method, including the following steps: (1) Drop the highly active reactive rosin organosilicon resin into deionized water containing a compound emulsifier, and quickly stir and emulsify to obtain an emulsion. The compound emulsifier is composed of a non-ionic emulsifier and a cationic emulsifier with a mass ratio of 1:(1-2). Among them, the non-ionic emulsifier is at least one of polyoxyethylene sorbitan fatty acid ester, sorbitan fatty acid ester, fatty alcohol polyoxyethylene ether, fatty acid polyoxyethylene ester or alkylphenol polyoxyethylene ether; the cationic emulsifier is at least one of cationic starch, cetyltrimethylammonium bromide, cetyltrimethylammonium chloride or cationic polyacrylamide; (2) Adjust the pH of the emulsion to 5.5-8.5; (3) Add the emulsion to the pulp fiber suspension, quickly stir and disperse, and obtain waterproof paper through papermaking and hot pressing.

3. Use of the highly active reactive rosin organosilicon resin according to claim 2, characterized in that: In step (1), the mass ratio of the highly active reactive rosin organosilicon resin, deionized water and the compound emulsifier is 100:400-900:2-5.

4. Use of the highly active reactive rosin organosilicon resin according to claim 2 or 3, characterized in that: In step (1), the dropping rate of the highly active reactive rosin organosilicon resin is 1 drop / 2-5 s, the stirring speed is 800-1500 r / min, and the stirring time is 2-10 min; In step (3), the stirring speed is 500-1200 r / min, the stirring time is 5-10 min, the hot pressing temperature is 60-100 °C, the hot pressing pressure is 5-15 MPa, and the hot pressing time is 0.5-1.5 h.

5. Use of the highly active reactive rosin organosilicon resin according to claim 2 or 3, characterized in that: In step (3), the solid content of the pulp fiber suspension is 1.2-2.4%; the mass ratio of the emulsion to the pulp fiber suspension is 1:8-15.

6. Use of the highly active reactive rosin organosilicon resin according to any one of claims 1-3, characterized in that: The highly active reactive rosin organosilicon resin is prepared by reacting rosin or its derivatives with a silane coupling agent. Among them, rosin or its derivatives are at least one of rosin, hydrogenated rosin, polymerized rosin, disproportionated rosin, maleic rosin, dehydroabietic acid, propenylpimaric acid or fumaropimaric acid; The silane coupling agent is at least one of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, methyldiethoxyvinylsilane, dimethylethoxyvinylsilane, vinyltris(2-methoxyethoxy)silane, dimethyldiethoxysilane, methyldiethoxysilane, tetramethoxysilane, tetraethoxysilane, 3-(2-aminoethylamino)propyltrimethoxysilane, N-aminoethyl-3-aminopropylmethyldimethoxysilane, [3-[(2-aminoethyl)amino]propyl]silane triol.

7. Use of the highly active reactive rosin organosilicon resin according to claim 6, characterized in that: Preparation method of the highly active reactive rosin organosilicon resin, including the following steps: (1) Grind rosin or its derivatives into powder, and while stirring under dry conditions, add it to a three-necked flask containing a silane coupling agent, and introduce nitrogen for protection; (2) Heat the three-necked flask in step (1) until the rosin or its derivative powder melts, and stir and disperse; (3) Add the catalyst into the three-necked flask in step (2), and further raise the temperature for reaction; (4) Remove the low-boiling impurities from the product obtained in step (3) by rotary evaporation to obtain a pale yellow highly active reactive rosin organosilicon resin.

8. Use of the highly active reactive rosin organosilicon resin according to claim 7, characterized in that: In step (1), the drying conditions are air humidity of 20% - 40% and nitrogen purity of at least 99.5%; in step (2), the melting temperature of rosin or its derivative is 80 ± 5 °C, the stirring speed is 500 - 1500 r / min, and the stirring time is 20 - 40 min; in step (3), the catalyst is benzyltriethylammonium chloride, the reaction temperature is 100 - 150 °C, and the reaction time is 3 - 6 h; in step (4), the rotary evaporation vacuum degree is 50 - 100 bar, and the rotary evaporation temperature is 40 - 80 °C.

9. Use of the highly active reactive rosin organosilicon resin according to claim 7, characterized in that: The mass ratio of rosin or its derivative, silane coupling agent, and catalyst is 100:80 - 300:0.5 - 1.

10. Use of the highly active reactive rosin organosilicon resin according to claim 2 or 3, characterized in that: The regeneration method of waterproof paper is as follows: Recover the pulp fiber suspension from the waste waterproof paper by alkali cooking, and then obtain the waterproof paper after sizing and hot pressing again.

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