Acid and alkali resistant polyacrylate emulsion and preparation method thereof

Abstract

The invention relates to an acid and alkali resistant polyacrylate emulsion and a preparation method thereof, and belongs to the technical field of polyacrylate emulsion. The polyacrylate emulsion is prepared from the following raw materials: a compound emulsifier, methyl methacrylate, butyl acrylate, 2-ethylhexyl acrylate, acrylic acid, an initiator, a reducing agent, vinyltriethoxysilane, epoxy resin, dodecafluoroheptyl methacrylate, a phosphate functional monomer and deionized water. A specific reaction process is designed, and the acid and alkali resistance of a polyacrylate emulsion finished product is improved from the aspects of reducing the surface tension of a system, shielding a polymer main chain, strengthening the chemical bond effect and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of polyacrylate emulsions, and in particular relates to an acid- and alkali-resistant polyacrylate emulsion and a preparation method thereof. Background Art

[0002] In today's field of materials science and engineering, polyacrylate emulsions are widely used in many industries such as coatings, adhesives, inks, and textile finishing agents due to their good film-forming properties, adhesion, and environmental friendliness. However, with the development of related industries, especially in application scenarios involving contact with acids and alkalis, such as lead-acid batteries, glass cutting and cleaning, and semiconductor etching, ordinary polyacrylate emulsions have exposed serious performance defects. In acid-base environments, the coating or membrane structure formed by traditional polyacrylate emulsions is easily corroded by acids and alkalis. This is mainly due to the high surface energy of polyacrylate emulsions, which makes it easy for acid and alkali ions to penetrate into the emulsion system, thereby destroying the cohesion and structural integrity of the emulsion, resulting in blistering, peeling, and loss of adhesion of the coating, which seriously affects the service life and performance stability of polyacrylate emulsions in these specific fields. In order to solve this problem, some studies are committed to reducing the surface energy of the system by adding low-surface energy substances through physical blending, but this method often has problems such as poor compatibility, limited addition, and easy phase separation, and cannot effectively maintain acid-base resistance for a long time. Therefore, there is an urgent need to develop a highly acid- and alkali-resistant polyacrylate emulsion to meet the practical needs of the growing number of high-performance materials in application scenarios involving contact with acids and alkalis. Summary of the invention

[0003] The purpose of the present invention is to provide an acid- and alkali-resistant polyacrylate emulsion and a preparation method thereof, so as to solve the problem that the polyacrylate emulsion in the prior art is weak in acid and alkali resistance.

[0004] The purpose of the present invention can be achieved through the following technical solutions:

[0005] A method for preparing an acid- and alkali-resistant polyacrylate emulsion specifically comprises the following steps:

[0006] S1. Mix the composite emulsifier and deionized water, add methyl methacrylate, butyl acrylate, isooctyl acrylate and acrylic acid, and stir to obtain a mixture A for standby use; mix the initiator and deionized water to obtain a mixture B for standby use; mix the reducing agent and deionized water to obtain a mixture C for standby use;

[0007] S2. Add mixture B, vinyl triethoxysilane, epoxy resin, dodecafluoroheptyl methacrylate, phosphate functional monomer and mixture C to mixture A in sequence, control the temperature and stir evenly, keep the temperature, then cool down, adjust the pH, and discharge the mixture to obtain a polyacrylate emulsion.

[0008] As a preferred technical solution of the present invention, in the mixed material A of step S1, the composite emulsifier is 0.8-1 parts by weight, deionized water is 12-16 parts by weight, methyl methacrylate is 18-23 parts by weight, butyl acrylate is 13-25 parts by weight, isooctyl acrylate is 12-24 parts by weight, and acrylic acid is 1-2 parts by weight; the initiator in the mixed material B is 0.6-1 parts by weight, and deionized water is 8-12 parts by weight; the reducing agent in the mixed material C is 0.3-0.5 parts by weight, and deionized water is 3-5 parts by weight.

[0009] Furthermore, the composite emulsifier comprises an anionic surfactant and a nonionic surfactant in a mass ratio of 1-1.2:2, the initiator comprises ammonium persulfate, and the reducing agent comprises sodium sulfite.

[0010] Furthermore, the anionic surfactant includes sodium dodecyl sulfate or sodium dodecylbenzene sulfonate; the nonionic surfactant includes any one of isodecanol polyoxyethylene ether, secondary alcohol polyoxyethylene ether, and fatty alcohol polyoxyethylene ether.

[0011] As a preferred technical solution of the present invention, the stirring time in step S1 is 20-30 minutes.

[0012] Furthermore, in step S2, the vinyl triethoxysilane is 2-4 parts by weight, the epoxy resin is 5-6 parts by weight, the dodecafluoroheptyl methacrylate is 9-10 parts by weight, and the phosphate functional monomer is 3-4 parts by weight.

[0013] Furthermore, the phosphate functional monomer is POLONI RPM 2060, purchased from Shanghai Xiaogeng New Material Technology Co., Ltd.; POLONI RPM 2060 is an active phosphate methyl acrylate monomer that can be used in emulsion polymers to improve adhesion and bonding strength.

[0014] As a preferred technical solution of the present invention, the temperature for temperature control and uniform stirring in step S2 is 80-85°C; the insulation time is 1-2h; the cooling is to cool to 30-45°C; and the pH is adjusted by adding ammonia water to adjust the pH to 7.

[0015] As a preferred technical solution of the present invention, the present invention also provides a polyacrylate emulsion prepared by the above method for preparing the acid- and alkali-resistant polyacrylate emulsion.

[0016] Beneficial effects of the present invention:

[0017] The invention adds dodecafluoroheptyl methacrylate, introduces fluorine element and reduces the surface tension of the system; adds vinyl triethoxysilane, shields the polymer main chain with silicon-oxygen bonds with high bond energy and large bond angle, and further assists dodecafluoroheptyl methacrylate in reducing the low surface energy of the system; at the same time, adds epoxy resin so that the organic silicon and the main chain in the system are connected in the form of covalent bonds, so that the emulsion is difficult to be corroded by chemical solvents; adds POLONI RPM2060 to strengthen the chemical bond effect of the system, reduce the penetration of chemical solvents, and thus improve the acid and alkali resistance of the finished emulsion. DETAILED DESCRIPTION

[0018] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] The phosphate functional monomer used in the embodiment of the present invention is POLONI RPM 2060, purchased from Shanghai Xiaogeng New Material Technology Co., Ltd.; the isodecanol polyoxyethylene ether used, item number: P874992, purchased from Shanghai McLean Biochemical Technology Co., Ltd.; the secondary alcohol polyoxyethylene ether used, item number: S-90, purchased from Jiangsu Haolong Chemical Co., Ltd.; the fatty alcohol polyoxyethylene ether used, item number: AEO-25, purchased from Guangzhou Junxin Chemical Technology Co., Ltd.; the epoxy resin used, item number: CYDW-112W50, purchased from Shanghai Yueyi Chemical Co., Ltd.; the above will not be repeated later.

[0020] Example 1

[0021] A method for preparing an acid- and alkali-resistant polyacrylate emulsion specifically comprises the following steps:

[0022] S1. Mix 0.9 parts by weight of composite emulsifier and 12 parts by weight of deionized water, add 18 parts by weight of methyl methacrylate, 19 parts by weight of butyl acrylate, 12 parts by weight of isooctyl acrylate and 1.5 parts by weight of acrylic acid, and stir for 20 minutes to obtain a mixture A for standby use; mix 0.6 parts by weight of ammonium persulfate and 10 parts by weight of deionized water to obtain a mixture B for standby use; mix 0.3 parts by weight of sodium sulfite and 3 parts by weight of deionized water to obtain a mixture C for standby use;

[0023] In the mixture A, the composite emulsifier includes sodium lauryl sulfate and isodecanol polyoxyethylene ether in a mass ratio of 1:2;

[0024] S2. Add the above-mentioned mixed material B, 2 parts by weight of vinyl triethoxysilane, 5.5 parts by weight of epoxy resin, 9 parts by weight of dodecafluoroheptyl methacrylate, 3 parts by weight of POLONI RPM 2060 and the above-mentioned mixed material C to the mixed material A in sequence, control the temperature to 80°C and stir evenly, keep the temperature for 1 hour, then cool to 30°C, add ammonia water to adjust the emulsion pH to 7, and discharge the material to obtain a polyacrylate emulsion.

[0025] Example 2

[0026] A method for preparing an acid- and alkali-resistant polyacrylate emulsion specifically comprises the following steps:

[0027] S1. Mix 0.8 parts by weight of composite emulsifier and 16 parts by weight of deionized water, add 23 parts by weight of methyl methacrylate, 13 parts by weight of butyl acrylate, 24 parts by weight of isooctyl acrylate and 2 parts by weight of acrylic acid, and stir for 30 minutes to obtain a mixture A for standby use; mix 1 part by weight of ammonium persulfate and 8 parts by weight of deionized water to obtain a mixture B for standby use; mix 0.5 parts by weight of sodium sulfite and 4 parts by weight of deionized water to obtain a mixture C for standby use;

[0028] In the mixture A, the composite emulsifier comprises sodium dodecylbenzene sulfonate and secondary alcohol polyoxyethylene ether in a mass ratio of 1.2:2;

[0029] S2. Add the above-mentioned mixed material B, 4 parts by weight of vinyl triethoxysilane, 5 parts by weight of epoxy resin, 10 parts by weight of dodecafluoroheptyl methacrylate, 3.5 parts by weight of POLONI RPM 2060 and the above-mentioned mixed material C to the mixed material A in sequence, control the temperature to 82.5°C and stir evenly, keep the temperature for 2 hours, then cool to 45°C, add ammonia water to adjust the emulsion pH to 7, and discharge the material to obtain a polyacrylate emulsion.

[0030] Example 3

[0031] A method for preparing an acid- and alkali-resistant polyacrylate emulsion specifically comprises the following steps:

[0032] S1. Mix 1 part by weight of a composite emulsifier and 14 parts by weight of deionized water, add 21 parts by weight of methyl methacrylate, 25 parts by weight of butyl acrylate, 18 parts by weight of isooctyl acrylate and 1 part by weight of acrylic acid, and stir for 25 minutes to obtain a mixture A for standby use; mix 0.8 parts by weight of ammonium persulfate and 12 parts by weight of deionized water to obtain a mixture B for standby use; mix 0.4 parts by weight of sodium sulfite and 5 parts by weight of deionized water to obtain a mixture C for standby use;

[0033] In the mixture A, the composite emulsifier includes sodium lauryl sulfate and fatty alcohol polyoxyethylene ether in a mass ratio of 1.1:2;

[0034] S2. Add the above-mentioned mixed material B, 3 parts by weight of vinyl triethoxysilane, 6 parts by weight of epoxy resin, 9.5 parts by weight of dodecafluoroheptyl methacrylate, 4 parts by weight of POLONI RPM 2060 and the above-mentioned mixed material C to the mixed material A in sequence, control the temperature to 85°C and stir evenly, keep the temperature for 1.5 hours, then cool to 28°C, add ammonia water to adjust the emulsion pH to 7, discharge the material, and obtain a polyacrylate emulsion.

[0035] Comparative Example 1

[0036] Compared with Example 2, the difference in Comparative Example 1 is that dodecafluoroheptyl methacrylate is not added, and the other operating steps and parameters remain unchanged.

[0037] Comparative Example 2

[0038] Compared with Example 2, the difference of Comparative Example 2 is that no vinyltriethoxysilane is added, and the other operating steps and parameters remain unchanged.

[0039] Comparative Example 3

[0040] Compared with Example 2, the difference in Comparative Example 3 is that no epoxy resin is added, and the other operating steps and parameters remain unchanged.

[0041] Comparative Example 4

[0042] Compared with Example 2, the difference in Comparative Example 4 is that POLONI RPM 2060 is not added, and the other operating steps and parameters remain unchanged.

[0043] Test Case

[0044] According to GB / T 1763-1979, the polyacrylate emulsions prepared in Examples 1-3 and Comparative Examples 1-4 were tested for resistance to 3% NaCl, 3% NaOH, 3% H 2 SO 4 The test results are shown in Table 1.

[0045] Table 1

[0046] Resistant to 3% NaCl / h Resistant to 3% NaOH / h <![CDATA[Resistant to 3% H 2 SO 4 / h]]> Example 1 480 96 96 Example 2 480 96 96 Example 3 480 96 96 Comparative Example 1 432 72 72 Comparative Example 2 432 72 72 Comparative Example 3 432 72 48 Comparative Example 4 408 72 48

[0047] It can be seen from Table 1 that the polyacrylate emulsion prepared in the present invention has excellent acid and alkali resistance.

[0048] In the description of the specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0049] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A method for preparing an acid- and alkali-resistant polyacrylate emulsion, characterized in that: The steps include: S1. Mix the composite emulsifier and deionized water, add methyl methacrylate, butyl acrylate, isooctyl acrylate and acrylic acid, and stir to obtain a mixture A for standby use; mix the initiator and deionized water to obtain a mixture B for standby use; mix the reducing agent and deionized water to obtain a mixture C for standby use; S2. Add mixture B, vinyl triethoxysilane, epoxy resin, dodecafluoroheptyl methacrylate, phosphate functional monomer and mixture C to mixture A in sequence, control the temperature and stir evenly, keep the temperature, then cool down, adjust the pH, and discharge the mixture to obtain a polyacrylate emulsion.

2. The method for preparing the acid- and alkali-resistant polyacrylate emulsion according to claim 1, characterized in that: In the mixed material A of step S1, the composite emulsifier is 0.8-1 parts by weight, deionized water is 12-16 parts by weight, methyl methacrylate is 18-23 parts by weight, butyl acrylate is 13-25 parts by weight, isooctyl acrylate is 12-24 parts by weight, and acrylic acid is 1-2 parts by weight; in the mixed material B, the initiator is 0.6-1 parts by weight, and deionized water is 8-12 parts by weight; in the mixed material C, the reducing agent is 0.3-0.5 parts by weight, and deionized water is 3-5 parts by weight.

3. The method for preparing the acid- and alkali-resistant polyacrylate emulsion according to claim 2, characterized in that: The composite emulsifier comprises an anionic surfactant and a nonionic surfactant in a mass ratio of 1-1.2:2, the initiator comprises ammonium persulfate, and the reducing agent comprises sodium sulfite.

4. The method for preparing the acid- and alkali-resistant polyacrylate emulsion according to claim 3, characterized in that: The anionic surfactant includes sodium dodecyl sulfate or sodium dodecylbenzene sulfonate; the nonionic surfactant includes any one of isodecanol polyoxyethylene ether, secondary alcohol polyoxyethylene ether, and fatty alcohol polyoxyethylene ether.

5. The method for preparing the acid- and alkali-resistant polyacrylate emulsion according to claim 1, characterized in that: The stirring time in step S1 is 20-30 min.

6. The method for preparing the acid- and alkali-resistant polyacrylate emulsion according to claim 1, characterized in that: In step S2, the vinyl triethoxysilane is 2-4 parts by weight, the epoxy resin is 5-6 parts by weight, the dodecafluoroheptyl methacrylate is 9-10 parts by weight, and the phosphate functional monomer is 3-4 parts by weight.

7. The method for preparing the acid- and alkali-resistant polyacrylate emulsion according to claim 6, characterized in that: The phosphate functional monomer is POLONI RPM 2060.

8. The method for preparing the acid- and alkali-resistant polyacrylate emulsion according to claim 1, characterized in that: In step S2, the temperature for temperature control and uniform stirring is 80-85°C; the insulation time is 1-2h; the cooling is to cool to 30-45°C; and the pH is adjusted by adding ammonia water to adjust the pH to 7.

9. A polyacrylate emulsion prepared by the method for preparing the acid- and alkali-resistant polyacrylate emulsion according to any one of claims 1 to 8.