A preparation method of alkenyl succinic anhydride

Abstract

The present invention discloses a kind of preparation method of alkenyl succinic anhydride, raw material internal olefin is pumped into synthesis reactor by metering pump, nitrogen protection is passed through, catalyst and antioxidant are added, stirring is opened and is warming up to 180 ℃ 220 ℃;Maleic anhydride is put into hot melt kettle, steam is passed through and is warming up to 70 ℃, until material is completely melted, stirring is standby;Step 2 is added dropwise into synthesis reactor) maleic anhydride after melting, and dropping temperature is 180 ℃ 220 ℃;After completion of dropwise addition, react at reaction temperature 180 ℃ 250 ℃;The reaction product of is put into short-range molecular still, removes light component and is used as raw material recovery, and remaining fraction is alkenyl succinic anhydride.A kind of preparation method of alkenyl succinic anhydride of the present invention, by the selection of catalyst, the selection and proportioning of raw material and introducing short-range molecular still, can effectively simplify process, save synthesis and purification time, improve product yield and product sizing effect, improve production efficiency, reduce production cost.

Description

Technical Field

[0001] The present invention relates to the technical field of organic synthesis, and in particular to a method for preparing alkenyl succinic anhydride. Background Art

[0002] Alkenyl succinic anhydride, abbreviated as ASA, is a general term for unsaturated hydrocarbons with succinic anhydride groups. It is an oily amber liquid at room temperature and is a highly effective internal sizing agent for paper pulp. ASA's molecular structure contains hydrophobic groups and reactive anhydride groups. The hydrophobic groups coat the conical pores on the cellulose surface, acting as a water repellent. The reactive anhydride groups constitute the reactive groups in the sizing agent, forming covalent bonds with the hydroxyl groups on the cellulose, thereby providing a fixative. Compared to traditional rosin sizing agents, ASA sizing agents offer advantages such as a wide pH range, good compatibility with alkaline fillers and pigments, superior paper strength, and strong resistance to penetration by acidic and alkaline liquids.

[0003] In the prior art, ASA is prepared from C13-C14 internal olefins and maleic anhydride. However, due to the low carbon number of the olefins used, their use as a sizing agent is not ideal. In addition, the purification method is usually distillation in a distillation tower, which consumes a lot of energy and is time-consuming. As a result, the product cokes during the purification process and is difficult to handle, affecting the product yield and quality, resulting in high production costs. Summary of the Invention

[0004] In view of the above-mentioned defects in the prior art, the purpose of the present invention is to provide a method for preparing alkenyl succinic anhydride, which can improve the product yield and product sizing effect, improve production efficiency and reduce production costs.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] A method for preparing alkenyl succinic anhydride, comprising the following steps:

[0007] Step 1) The raw material internal olefin is pumped into the synthesis reactor through a metering pump, nitrogen is introduced for protection, a catalyst and an antioxidant are added, stirring is started, and the temperature is raised to 180° C.-220° C.;

[0008] Step 2) maleic anhydride is added to a hot melt kettle, steam is introduced, and the temperature is raised to 70°C. After the material is completely melted, stirring is performed for later use;

[0009] Step 3) adding the melted maleic anhydride from step 2) dropwise to the synthesis reaction kettle at a temperature of 180° C. to 220° C.;

[0010] Step 4) After the dropwise addition is completed, the reaction is carried out at a reaction temperature of 180°C-250°C;

[0011] Step 5) putting the reaction product of step 4) into a short-path molecular distiller to remove light components and recycle them as raw materials, and the remaining fraction is alkenyl succinic anhydride;

[0012] Wherein, the catalyst is any one or more of concentrated sulfuric acid, fuming sulfuric acid, and solid phosphoric acid.

[0013] Furthermore, in step 1), the internal olefin is a linear internal olefin of C16, C18, or C20 with a purity of more than 95%, and the mass ratio of C16, C18, and C20 is 1-2:1:0.1-0.4.

[0014] Furthermore, in step 1), the amount of the catalyst added is 0.3%-1.5% of the mass of the internal olefin.

[0015] Furthermore, in step 1), the amount of the antioxidant added is 1%-2% of the mass of the internal olefin.

[0016] Furthermore, in step 1), the antioxidant is any one or more of hydroquinone, phenothiazine, triester phosphite, and 2,6-di-tert-butylcresol.

[0017] Furthermore, in step 3), the molar ratio of maleic anhydride to internal olefin is 1:1-2.

[0018] Furthermore, in step 3), the dropping time is 1 h-4 h.

[0019] Furthermore, in step 4), the reaction time is 3h-8h.

[0020] Furthermore, in step 5), the pressure of the short-range molecular distillation for purification is 1Pa-100Pa, and the temperature is 100°C-150°C.

[0021] Alkenyl succinic anhydride prepared by any one of the above methods for preparing alkenyl succinic anhydride.

[0022] The outstanding effects of the present invention are:

[0023] The preparation method of alkenylsuccinic anhydride of the present invention can effectively simplify the process, save synthesis and purification time, improve product yield and product sizing effect, enhance production efficiency, and reduce production costs through the selection of catalysts, selection and proportioning of raw materials, and introduction of a short-path molecular distillation device.

[0024] The specific implementation methods of the present invention are further described below in conjunction with embodiments to make the technical solutions of the present invention easier to understand and grasp. DETAILED DESCRIPTION

[0025] The method of the present invention is described below by means of specific examples, but the present invention is not limited thereto. The experimental methods described in the following examples are conventional methods unless otherwise specified; the reagents and materials described are all commercially available unless otherwise specified.

[0026] Example 1

[0027] The preparation method of alkenyl succinic anhydride of this embodiment specifically comprises the following steps:

[0028] Step 1) C16, C18, and C20 linear internal olefins with a purity of more than 95% and a mass ratio of 2:1:0.4 are pumped into a synthesis reactor through a metering pump, nitrogen is introduced for protection, solid phosphoric acid as a catalyst and hydroquinone as an antioxidant are added, stirring is started, and the temperature is raised to 180° C.; the amount of catalyst added is 1% of the mass of the internal olefin, and the amount of antioxidant added is 1% of the mass of the internal olefin;

[0029] Step 2) maleic anhydride is added to a hot melt kettle, steam is introduced, and the temperature is raised to 70°C. After the material is completely melted, stirring is performed for later use;

[0030] Step 3) adding the melted maleic anhydride prepared in step 2) dropwise to the synthesis reaction vessel, wherein the molar ratio of maleic anhydride to internal olefin is 1:1, the dropping temperature is 180° C., and the dropping time is 1 h;

[0031] Step 4) After the dropwise addition is completed, the reaction is carried out at a reaction temperature of 180° C. for 8 hours;

[0032] Step 5) The reaction product of step 4) is put into a short-path molecular distiller and purified at a pressure of 1 Pa and a temperature of 100° C. The light components are removed and recycled as raw materials. The remaining fraction is an oily amber liquid, i.e., alkenyl succinic anhydride, with a yield of 68%.

[0033] Example 2

[0034] The preparation method of alkenyl succinic anhydride of this embodiment specifically comprises the following steps:

[0035] Step 1) C16, C18, and C20 linear internal olefins with a purity of more than 95% and a mass ratio of 2:1:0.4 are pumped into a synthesis reactor through a metering pump, nitrogen is introduced for protection, concentrated sulfuric acid as a catalyst, and 2,6-di-tert-butylcresol as an antioxidant are added, stirring is started, and the temperature is raised to 220° C. The amount of catalyst added is 0.5% of the mass of the internal olefin, and the amount of antioxidant added is 2% of the mass of the internal olefin;

[0036] Step 2) maleic anhydride is added to a hot melt kettle, steam is introduced, and the temperature is raised to 70°C. After the material is completely melted, stirring is performed for later use;

[0037] Step 3) adding the melted maleic anhydride prepared in step 2) dropwise to the synthesis reaction vessel, wherein the molar ratio of maleic anhydride to internal olefin is 1:2, the dropping temperature is 220° C., and the dropping time is 3 h;

[0038] Step 4) After the dropwise addition is completed, the reaction is carried out at a reaction temperature of 250° C. for 3 hours;

[0039] Step 5) The reaction product of step 4) is put into a short-path molecular distiller and purified at a pressure of 100 Pa and a temperature of 150° C. The light components are removed and recycled as raw materials. The remaining fraction is an oily amber liquid, i.e., alkenyl succinic anhydride, with a yield of 77%.

[0040] Example 3

[0041] The preparation method of alkenyl succinic anhydride of this embodiment specifically comprises the following steps:

[0042] Step 1) C16, C18, and C20 linear internal olefins with a purity of more than 95% and a mass ratio of 1:1:0.1 are pumped into a synthesis reactor through a metering pump, nitrogen is introduced for protection, solid phosphoric acid as a catalyst and phenothiazine as an antioxidant are added, stirring is started, and the temperature is raised to 200° C.; the amount of catalyst added is 0.3% of the mass of the internal olefin, and the amount of antioxidant added is 1.5% of the mass of the internal olefin;

[0043] Step 2) maleic anhydride is added to a hot melt kettle, steam is introduced, and the temperature is raised to 70°C. After the material is completely melted, stirring is performed for later use;

[0044] Step 3) adding the melted maleic anhydride from step 2) dropwise to the synthesis reaction kettle, wherein the molar ratio of maleic anhydride to internal olefin is 1:1.3, the dropping temperature is 200° C., and the dropping time is 2 h;

[0045] Step 4) After the dropwise addition is completed, the reaction is carried out at a reaction temperature of 245° C. for 4.5 hours;

[0046] Step 5) The reaction product of step 4) is put into a short-path molecular distiller and purified at a pressure of 50 Pa and a temperature of 130° C. The light components are removed and recycled as raw materials. The remaining fraction is an oily amber liquid, i.e., alkenyl succinic anhydride, with a yield of 88%.

[0047] Example 4

[0048] The preparation method of alkenyl succinic anhydride of this embodiment specifically comprises the following steps:

[0049] Step 1) C16, C18, and C20 linear internal olefins with a purity of more than 95% and a mass ratio of 1.5:1:0.3 are pumped into a synthesis reactor through a metering pump, nitrogen is introduced, concentrated sulfuric acid as a catalyst and triester phosphite as an antioxidant are added, stirring is started, and the temperature is raised to 220° C. The amount of catalyst added is 1.5% of the mass of the internal olefin, and the amount of antioxidant added is 1% of the mass of the internal olefin;

[0050] Step 2) maleic anhydride is added to a hot melt kettle, steam is introduced, and the temperature is raised to 70°C. After the material is completely melted, stirring is performed for later use;

[0051] Step 3) adding the melted maleic anhydride prepared in step 2) dropwise to the synthesis reaction vessel, wherein the molar ratio of maleic anhydride to internal olefin is 1:1.5, the dropping temperature is 220° C., and the dropping time is 4 h;

[0052] Step 4) After the dropwise addition is completed, the reaction is carried out at a reaction temperature of 220° C. for 6 hours;

[0053] Step 5) The reaction product of step 4) is put into a short-path molecular distiller and purified at a pressure of 100 Pa and a temperature of 150° C. The light components are removed and recycled as raw materials. The remaining fraction is an oily amber liquid, i.e., alkenyl succinic anhydride, with a yield of 84%.

[0054] Performance test example

[0055] Handwritten sheet adding comparative application experiment

[0056] Experimental instruments:

[0057] Hamilton Beach HMD200 mixer (3 speed gears: 1st gear 13000r / min, 2nd gear 16000r / min, 3rd gear 18000r / min), LABTECH73-62 semi-automatic paper sheet former, electronic balance, Cobb surface absorption weight tester, paper sheet quick dryer and other equipment.

[0058] Experimental methods:

[0059] Papermaking weight 80g / m 2

[0060] Slurry (65%) + cationic starch + ASA emulsion + filler (mixed calcium 35%) + CPAM (100ppm) + microparticles 200ppm

[0061] ASA addition amount: 1.2Kg / t paper, 1.5Kg / t paper (added as ASA stock solution)

[0062] According to the above process, the slurry was weighed, and cationic starch, ASA emulsion, mixed calcium, CPAM and microparticles were added in turn and stirred for 1 min each to mix evenly. The prepared slurry was removed, and sheets were made using a 73-62 semi-automatic paper sheet former. After being pressed using a 73-50 standard paper sheet press, the paper samples were dried on a glazing machine, and the 1-min Cobb value was tested.

[0063] Table 1

[0064]

[0065] From the water absorption value of the hand-sheet paper samples, compared with the blank experiment without adding ASA, the application effects of adding ASA in Examples 1-4 are all higher than the paper samples without adding ASA.

[0066] There are many implementation methods of the present invention, and all technical solutions formed by equivalent transformation or equivalent transformation fall within the protection scope of the present invention.

Claims

1. A method for preparing alkenyl succinic anhydride, characterized in that The specific steps include: Step 1) pumping the raw internal olefin into a synthesis reactor through a metering pump, introducing nitrogen protection, adding a catalyst and an antioxidant, starting stirring and heating to 180° C.-220° C., wherein the internal olefin is a linear internal olefin of C16, C18, or C20 with a purity of more than 95%, and the mass ratio of C16, C18, and C20 is 1-2:1:0.1-0.4; Step 2) maleic anhydride is added to a hot melt kettle, steam is introduced, and the temperature is raised to 70°C. After the material is completely melted, stirring is performed for later use; Step 3) adding the melted maleic anhydride from step 2) dropwise to the synthesis reaction kettle at a temperature of 180° C. to 220° C. for 1 h to 4 h; Step 4) After the dropwise addition is completed, the reaction is carried out at a reaction temperature of 180°C-250°C; Step 5) putting the reaction product of step 4) into a short-path molecular distillation device for purification at a pressure of 1 Pa-100 Pa and a temperature of 100° C.-150° C. to remove light components and recycle them as raw materials. The remaining fraction is alkenyl succinic anhydride; Wherein, the catalyst is any one or more of concentrated sulfuric acid, fuming sulfuric acid, and solid phosphoric acid.

2. The method for preparing alkenyl succinic anhydride according to claim 1, wherein: In step 1), the amount of the catalyst added is 0.3%-1.5% of the mass of the internal olefin.

3. The method for preparing alkenyl succinic anhydride according to claim 1, wherein: In step 1), the amount of the antioxidant added is 1%-2% of the mass of the internal olefin.

4. The method for preparing alkenyl succinic anhydride according to claim 1, wherein: In step 1), the antioxidant is any one or more of hydroquinone, phenothiazine, triester phosphite, and 2,6-di-tert-butylcresol.

5. The method for preparing alkenyl succinic anhydride according to claim 1, wherein: In step 3), the molar ratio of maleic anhydride to internal olefin is 1:1-2.

6. The method for preparing alkenyl succinic anhydride according to claim 1, wherein: In step 4), the reaction time is 3h-8h.

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