Environment-friendly alkyd resin and preparation method thereof

Abstract

The present application relates to the field of resin, in particular to an environment-friendly alkyd resin and a preparation method thereof.The alkyd resin comprises the following components by weight fraction: 20-35 parts of vegetable oil, 10-20 parts of polyol, 15-25 parts of polyacid, 2-5 parts of functional monomer, 0.5-3 parts of catalyst, 0.1-0.5 parts of initiator, 0.1-1 parts of antioxidant, 3-8 parts of cosolvent, 2-4 parts of neutralizing agent and 40-60 parts of deionized water.The present application mainly uses renewable bio-based raw materials, combined with water-based treatment, and the final product uses water as the dispersion medium, the volatile organic compound content is controlled at a low level, the problem of organic solvent poisoning in the production, construction and application process of traditional solvent-based resin is solved, and the green environmental protection requirement is met.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of resin, in particular to an environment-friendly alkyd resin and a preparation method thereof. BACKGROUND

[0002] Alkyd resin is an important modified polyester resin prepared by polycondensation of polyol, polyacid and fatty acid. It has been widely used in the fields of paint, ink, adhesive and so on for a long time due to its excellent adhesion, high film fullness, good weather resistance and relatively low cost, and it is one of the main film-forming substances in solvent-based paint.

[0003] However, traditional alkyd resin usually relies on petrochemical raw materials such as phthalic anhydride, benzoic acid and various petroleum-based fatty acids. There are obvious environmental and health problems in its preparation and use process. In order to obtain suitable construction viscosity, a large amount of volatile organic compounds (VOCs) such as aromatic hydrocarbons, esters, ketones and other organic solvents are contained in traditional alkyd resin paint. Under this background, water-based alkyd resin emerges as the times require, which uses water as the main dispersion medium, can significantly reduce the use of organic solvents, reduce about 400 kg of organic solvents per ton of paint, greatly reduce the VOC content, and has the outstanding advantages of production and construction safety, easy cleaning of equipment, etc.

[0004] Although water-based alkyd resin has significant environmental advantages, there are still many problems in its practical application and performance: first, the drying speed is slow and the initial hardness is too low: the latent heat of evaporation of water is much higher than that of organic solvents, which leads to a significant extension of the paint film surface drying and real drying time, affecting the construction efficiency; second, poor water resistance and storage stability, which is the most core defect of water-based alkyd resin, the ester bond in the resin main chain is easy to hydrolyze in weak alkaline or aqueous environment, leading to the breakage of resin molecular chain.

[0005] Therefore, there is an urgent need for a new alkyd resin and its preparation method, which can fundamentally or significantly reduce the emission of VOCs, while overcoming the shortcomings of existing water-based alkyd resin in film performance (such as water resistance, drying speed, hardness), storage stability or preparation process complexity, and providing an alkyd resin solution that combines excellent environmental characteristics and practical performance. SUMMARY

[0006] In view of the problems in the prior art, the purpose of the present application is to provide an environment-friendly alkyd resin and a preparation method thereof.

[0007] The purpose of the present application is achieved by adopting the following technical solutions:

[0008] In a first aspect, the present application provides an environment-friendly alkyd resin, which comprises the following components in terms of weight fraction:

[0009] 20-35 parts of vegetable oil, 10-20 parts of polyol, 15-25 parts of polybasic acid, 2-5 parts of functional monomer, 0.5-3 parts of catalyst, 0.1-0.5 parts of initiator, 0.1-1 parts of antioxidant, 3-8 parts of cosolvent, 2-4 parts of neutralizing agent and 40-60 parts of deionized water.

[0010] Preferably, the vegetable oil is one or more of linseed oil, tung oil, soybean oil, castor oil.

[0011] Preferably, the polyol is one or more of sorbitol, glycerol, pentaerythritol.

[0012] Preferably, the polybasic acid is a mixture of isophthalic acid, trimellitic anhydride, bis(4-carboxyphenyl)phenyl phosphine oxide.

[0013] Preferably, the weight ratio of isophthalic acid, trimellitic anhydride, bis(4-carboxyphenyl)phenyl phosphine oxide is 5-8:2-4:2-4.

[0014] Preferably, the functional monomer is a mixture of allyl boronic pinacol ester and dodecafluoroheptyl methacrylate, and the weight ratio of allyl boronic pinacol ester and dodecafluoroheptyl methacrylate is 1:1.5-2.5.

[0015] Preferably, the catalyst is an organotin catalyst, specifically one or more of dibutyltin dilaurate (DBTDL), dioctyltin dilaurate (DOTDL), dibutyltin octoate (DBTO).

[0016] Preferably, the initiator is benzoyl peroxide (BPO) or azobisisobutyronitrile (AIBN).

[0017] Preferably, the antioxidant is a hindered phenolic antioxidant, specifically one or more of antioxidant 1010, antioxidant 1076, antioxidant 1098, antioxidant 1135.

[0018] Preferably, the cosolvent is one or more of propylene glycol methyl ether, dipropylene glycol methyl ether, ethylene glycol methyl ether, dipropylene glycol butyl ether.

[0019] Preferably, the neutralizing agent is ammonia or dimethyl ethanolamine.

[0020] In a second aspect, the present application provides a preparation method of an environmentally friendly alkyd resin, comprising the following steps:

[0021] Step 1, mix vegetable oil, polyol and catalyst, and perform alcoholysis reaction to obtain a mixed alcohol system;

[0022] Step 2, add all polybasic acids to the mixed alcohol system to start esterification polycondensation reaction to obtain an alkyd resin prepolymer;

[0023] Step 3, add a cosolvent to the alcohol acid resin prepolymer, dilute the system and cool it down, pre-mix the functional monomer and initiator uniformly, slowly add them to the reaction system, after the addition is completed, keep the reaction, and obtain the alkyd resin composite system;

[0024] Step 4, after the alkyd resin composite system is cooled down, add a neutralizing agent, stir it uniformly, add deionized water and shear stir, filter after cooling, and obtain the environmentally friendly alkyd resin.

[0025] Preferably, in step 1, the temperature of the alcoholysis reaction is 230-240℃, and the time is 1-2h.

[0026] Preferably, in step 2, the temperature of the esterification polycondensation reaction is 230-240℃, and the acid value is reduced to 15-20mg KOH / g before the heating is stopped.

[0027] Preferably, in step 3, the dropping time is 2-3h, and the reaction is kept for 1.5-2.5h after the dropping is completed.

[0028] Preferably, in step 4, the speed of the shear stirring is 800-1200 rpm, and the time is 30-40min.

[0029] The beneficial effects of the present application are:

[0030] 1, the present application mainly uses renewable bio-based raw materials, combined with water-based treatment, the final product uses water as the dispersion medium, the content of volatile organic compounds is controlled at a low level, the problem of organic solvent poisoning in the production, construction and application process of traditional solvent-based resin is solved, and the green and environmentally friendly requirements are met.

[0031] 2, the preparation method of the present application adopts a one-pot step-by-step process, which can be completed on the traditional alkyd resin synthesis equipment without complex post-treatment. The in-situ hybridization step of the functional monomer and the resin synthesis process can seamlessly connect, the process is simple and controllable, and is suitable for large-scale industrial production. By adjusting the ratio of polybasic acid and functional monomer, the performance of the final product can be easily adjusted to meet the application requirements in different fields from wood coating to industrial corrosion prevention.

[0032] 3、The application selects a plurality of environmentally friendly polyols, selects isophthalic acid to construct a resin main chain, and introduces bis(4-carboxyphenyl)phenyl phosphine oxide as a reactive phosphorus-containing polyacid, so that it is connected to the resin skeleton in the form of a chemical bond, gives the resin certain flame retardance, and also enhances the surface strength. DETAILED DESCRIPTION

[0033] The technical solutions of the present application are described below through specific examples. It should be understood that the one or more method steps mentioned in the present application do not exclude the existence of other method steps before and after the combination steps or the insertion of other method steps between the explicitly mentioned steps; it should also be understood that these examples are only used to illustrate the present application and not to limit the scope of the present application. Moreover, unless otherwise stated, the numbering of each method step is only a convenient tool to identify each method step, and is not a limitation on the arrangement order of each method step or a limitation on the scope of the present application. Changes or adjustments of the relative relationship, without substantial changes in technical content, are also considered as the scope of the present application.

[0034] In order to better understand the above technical solutions, the exemplary embodiments of the present application are described in more detail below. Although exemplary embodiments of the present application are shown, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present application and to fully convey the scope of the present application to those skilled in the art.

[0035] The present application is further described below in conjunction with the following examples.

[0036] Example 1

[0037] An environmentally friendly alkyd resin, according to the weight fraction, includes the components as shown in Table 1:

[0038]

[0039] The preparation method of the above-mentioned environmentally friendly alkyd resin includes the following steps:

[0040] Step 1: weigh 25 parts of linseed oil, 15 parts of glycerol and 1.5 parts of DBTDL, add them into a reaction kettle with stirrer, thermometer and condenser, heat to 235℃ under nitrogen protection, keep alcoholysis reaction for 1.5h, take sample to detect the transparency of alcoholysis liquid (no stratification, clear), and obtain a mixed alcohol system;

[0041] Step 2: 20 parts of polybasic acid (10 parts of isophthalic acid, 5 parts of trimellitic anhydride, and 5 parts of bis(4-carboxyphenyl)phenyl phosphine oxide) were added to the mixed alcohol system, and esterification polycondensation reaction was carried out at 235°C, and the acid value was detected every 30 min, and the heating was stopped when the acid value was reduced to 18 mgKOH / g, to obtain an alkyd resin prepolymer;

[0042] Step 3: 5 parts of propylene glycol methyl ether were added to the alkyd resin prepolymer, and stirring and dilution were performed and the temperature was reduced to 120°C, 3 parts of functional monomer (1 part of allyl borate pinacol ester and 2 parts of methyl methacrylate dodecafluoroheptyl ester) were mixed and dissolved with 0.3 parts of BPO in advance, and were slowly added to the reaction system through a constant pressure dropping funnel, the dropping time was 2.5 h, and after the dropping was completed, the reaction was maintained at 120°C for 2 h, to obtain an alkyd resin composite system;

[0043] Step 4: The alkyd resin composite system was cooled to 60°C, 3 parts of ammonia water were added, stirring was performed for 15 min until the system was uniform, then 50 parts of deionized water were added, the stirring speed was adjusted to 1000 rpm, and continuous stirring was performed for 35 min, and after cooling to room temperature, the system was filtered through a 200 mesh filter cloth, to obtain an environmentally friendly alkyd resin emulsion.

[0044] Example 2

[0045] An environmentally friendly alkyd resin, according to weight parts, includes the components as shown in Table 2:

[0046]

[0047] The preparation method of the above-mentioned environmentally friendly alkyd resin includes the following steps:

[0048] Step 1: 15 parts of soybean oil, 15 parts of castor oil, 6 parts of sorbitol, 6 parts of pentaerythritol, and 0.8 parts of DOTDL were weighed and added to a reaction kettle, and the temperature was raised to 232°C under nitrogen protection, alcoholysis reaction was performed for 1.2 h, and the alcoholysis liquid was detected to be free of stratification, to obtain a mixed alcohol system;

[0049] Step 2: 22 parts of polybasic acid (12.83 parts of isophthalic acid, 3.67 parts of trimellitic anhydride, and 5.5 parts of bis(4-carboxyphenyl)phenyl phosphine oxide) were added, esterification polycondensation reaction was carried out at 232°C, and the heating was stopped when the acid value was reduced to 16 mgKOH / g, to obtain an alkyd resin prepolymer;

[0050] Step 3: 6 parts of dipropylene glycol methyl ether were added for dilution and the temperature was reduced to 115°C, 4 parts of functional monomer (1.6 parts of allyl borate pinacol ester and 2.4 parts of methyl methacrylate dodecafluoroheptyl ester) were mixed and dissolved with 0.2 parts of AIBN, the dropping time was 2 h, and after the dropping was completed, the reaction was maintained at 115°C for 1.5 h, to obtain an alkyd resin composite system;

[0051] Step 4: cool down to 55℃, add 2.5 parts of dimethyl ethanolamine and stir evenly, add 45 parts of deionized water, shear stirring at 800 rpm for 40 min, cool down and filter to obtain the environmentally friendly alkyd resin emulsion.

[0052] Example 3

[0053] An environmentally friendly alkyd resin, according to weight parts, includes the ingredients as shown in Table 3:

[0054]

[0055] The preparation method of the above-mentioned environmentally friendly alkyd resin includes the following steps:

[0056] Step 1: weigh 22 parts of tung oil, 12 parts of glycerol, 6 parts of sorbitol and 2 parts of DBTO, and heat to 238℃ in a reaction kettle under nitrogen protection, alcoholysis reaction for 1.8h to obtain a mixed alcohol system;

[0057] Step 2: add 18 parts of polybasic acid (6.92 parts of isophthalic acid, 5.54 parts of trimellitic anhydride, and 5.54 parts of bis(4-carboxyphenyl)phenyl phosphine oxide), esterification polycondensation reaction at 238℃ until the acid value is 17 mgKOH / g, stop heating;

[0058] Step 3: add 4 parts of ethylene glycol methyl ether to dilute and cool down to 125℃, mix 2.5 parts of functional monomer (0.71 parts of allyl borate pinacol ester, 1.79 parts of methyl methacrylate dodecafluoroheptyl ester) with 0.4 parts of BPO, drop for 3h, and keep at 125℃ for 2.5h after dropping;

[0059] Step 4: cool down to 65℃, add 3.5 parts of ammonia water and stir, add 55 parts of deionized water, shear stirring at 1200 rpm for 30 min, cool down and filter to obtain the product.

[0060] Example 4

[0061] An environmentally friendly alkyd resin, according to weight parts, includes the ingredients as shown in Table 4:

[0062]

[0063] The preparation method of the above-mentioned environmentally friendly alkyd resin includes the following steps:

[0064] Step 1: weigh 19.8 parts of linseed oil, 13.2 parts of soybean oil, 14 parts of pentaerythritol and 1 part of composite catalyst (0.5 parts of dibutyltin dilaurate + 0.5 parts of dioctyltin dilaurate), add to the reaction kettle, heat to 235℃ under nitrogen protection, and keep alcoholysis reaction for 1.5h to obtain a mixed alcohol system;

[0065] Step 2: Add 24 parts of polybasic acid (isophthalic acid 13.72 parts, trimellitic anhydride 5.14 parts, bis(4-carboxyphenyl)phenyl phosphine oxide 5.14 parts) to the mixed alcohol system, maintain 235°C for esterification polycondensation reaction, periodically test the acid value, stop heating when the acid value is reduced to 19 mgKOH / g, obtain the alkyd resin prepolymer;

[0066] Step 3: Add 7 parts of dipropylene glycol butyl ether, stir and dilute, and cool to 120°C, 4.5 parts of functional monomer (allyl borate pinacol ester 1.5 parts, methyl methacrylate dodecafluoroheptyl ester 3 parts) is pre-mixed and dissolved with 0.3 parts of AIBN, slowly drop through a constant pressure dropping funnel, the drop time is 2.5h, after the drop is completed, maintain 120°C for 2h, obtain the alkyd resin composite system;

[0067] Step 4: Cool the system to 60°C, add 2 parts of dimethyl ethanolamine, stir for 20 min to uniform, add 48 parts of deionized water, adjust the shear stirring speed to 1000 rpm, continue stirring for 35 min, cool to room temperature, filter with 200 mesh filter cloth, obtain the environmentally friendly alkyd resin emulsion.

[0068] Comparative Example 1

[0069] An environmentally friendly alkyd resin, according to weight fraction, includes the components as shown in Table 5:

[0070]

[0071] The preparation method of the above environmentally friendly alkyd resin is completely consistent with Example 1 (only no functional monomer is added in step 3, and the rest of the process parameters are unchanged).

[0072] Comparative Example 2

[0073] An environmentally friendly alkyd resin, according to weight fraction, includes the components as shown in Table 6:

[0074]

[0075] The preparation method of the above environmentally friendly alkyd resin is completely consistent with Example 1 (only the polybasic acid component is adjusted, and the rest of the process parameters are unchanged).

[0076] Comparative Example 3

[0077] An environmentally friendly alkyd resin, according to weight fraction, includes the components as shown in Table 7:

[0078]

[0079] The preparation method of the above environmentally friendly alkyd resin is completely consistent with Example 1 (the polybasic acid component is adjusted, and there is no functional monomer drop step, and the rest of the process parameters are unchanged).

[0080] Experimental performance test:

[0081] The waterborne alkyd resins prepared in Examples 1-4 and Comparative Examples 1-3 were subjected to performance testing, and the performance indexes and test methods are shown in Table 8:

[0082]

[0083] The results of the test are shown in Table 9:

[0084]

[0085] From the data of Example 1 and Comparative Example 1 in Table 9, it can be seen that the water resistance, adhesion, and surface hardness of Example 1 are obviously superior to those of Comparative Example 1; from the data of Example 1 and Comparative Example 2, it can be seen that the surface hardness and storage stability of Example 1 are obviously superior to those of Comparative Example 2; and from the data of Comparative Example 3, it can be seen that the introduction of the polyacid bis(4-carboxyphenyl)phenyl phosphine oxide and the functional monomer is not simply additive for performance improvement, thereby further confirming the synergistic effect of the two in functional complementation.

[0086] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the illustrative description of the above terms should not be understood as necessarily referring to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate different embodiments or examples described in this specification.

[0087] Although the embodiments of the present application have been shown and described above, it should be understood that the above-described embodiments are exemplary and should not be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above-described embodiments within the scope of the present application.

Claims

1. An environmentally friendly alkyd resin, characterized in that, The raw materials, calculated by weight, include the following components: 20-35 parts vegetable oil, 10-20 parts polyol, 15-25 parts polyacid, 2-5 parts functional monomer, 0.5-3 parts catalyst, 0.1-0.5 parts initiator, 0.1-1 part antioxidant, 3-8 parts solubilizer, 2-4 parts neutralizer and 40-60 parts deionized water; The polybasic acid is a mixture of isophthalic acid, trimellitic anhydride, and bis(4-carboxyphenyl)phenylphosphine oxide; the functional monomer is a mixture of allyl borate pinacol ester and dodecafluoroheptyl methacrylate. The vegetable oil is one or more of linseed oil, tung oil, soybean oil, and castor oil; The polybasic acid is isophthalic acid, trimellitic anhydride, and bis(4-carboxyphenyl)phenylphosphine oxide in a weight ratio of 5-8:2-4:2-4; The weight ratio of allyl borate pinacol ester and dodecafluoroheptyl methacrylate is 1:1.5-2.

5.

2. The environmentally friendly alkyd resin according to claim 1, characterized in that, The polyol is one or more of sorbitol, glycerol, and pentaerythritol.

3. The environmentally friendly alkyd resin according to claim 1, characterized in that, The catalyst is one or more of dibutyltin dilaurate, dioctyltin dilaurate, and dibutyltin dioctanoate.

4. The environmentally friendly alkyd resin according to claim 1, characterized in that, The initiator is benzoyl peroxide or azobisisobutyronitrile.

5. The environmentally friendly alkyd resin according to claim 1, characterized in that, The antioxidant is one or more of antioxidant 1010, antioxidant 1076, antioxidant 1098, and antioxidant 1135.

6. The environmentally friendly alkyd resin according to claim 1, characterized in that, The cosolvent is one or more of propylene glycol methyl ether, dipropylene glycol methyl ether, ethylene glycol methyl ether, and dipropylene glycol butyl ether; the neutralizing agent is ammonia or dimethylethanolamine.

7. A method for preparing the environmentally friendly alkyd resin according to claim 1, characterized in that, Includes the following steps: Step 1: Weigh out vegetable oil, polyol and catalyst, mix them, and carry out alcoholysis reaction to obtain a mixed alcohol system; Step 2: Add all the polybasic acids into the mixed alcohol system to start the esterification polycondensation reaction and obtain the alkyd resin prepolymer. Step 3: Add a co-solvent to the alkyd resin prepolymer, dilute the system and cool it down. Mix the functional monomer and initiator evenly beforehand and slowly add them dropwise to the reaction system. After the addition is complete, keep the reaction at the temperature to obtain the alkyd resin composite system. Step 4: After cooling the alkyd resin composite system, add a neutralizing agent, stir evenly, add deionized water and shear stir, cool and filter to obtain environmentally friendly alkyd resin.

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