Silicon-based modified organic phosphorus functional monomer and method for preparing bulk flame-retardant copolymer from silicon-based modified organic phosphorus functional monomer

Abstract

The invention provides a silicon-based modified organophosphorus functional monomer and a method for preparing a bulk flame-retardant copolymer by using the same, and relates to the field of fireproof coatings. The silicon-based modified organophosphorus functional monomer is prepared from PAM100 and KH560 through a polymerization reaction, and the silicon-based modified organophosphorus functional monomer, an olefinic bond-containing monomer, a cross-linking material, an emulsifier, a PH buffer agent, an initiator and other raw materials can be used for preparing the bulk flame-retardant copolymer. According to the invention, the defects in the prior art are overcome, a core-shell emulsion polymerization mode is adopted, and the main silicon-based modified phosphate monomer and the monomer with carboxyl are used for preparing the shell layer, so that a better protection effect is formed on the surface of a polymer film through phosphorus, nitrogen and silicon, and the flame-retardant characteristic is achieved.

Description

Technical Field

[0001] The invention relates to the field of fireproof coatings, and in particular to a silicon-based modified organic phosphorus functional monomer and a method for preparing a bulk flame-retardant copolymer thereof. Background Art

[0002] Acrylic emulsion uses water as a dispersion medium and is used in the fields of coatings, adhesives, etc. It has the advantages of low cost, simple production process, easy use, non-toxic and safe, and no pollution to the environment. However, when used in the field of flame retardancy, it is often necessary to add flame retardants to acrylic emulsions. Additive flame retardants are physically dispersed in the substrate to make the material flame retardant. Additive flame retardants must be added in large amounts to achieve flame retardant effects, which will seriously affect the stability of acrylic emulsions, reduce the mechanical properties of the resin, and also cause problems such as poor compatibility and poor appearance.

[0003] The reactive flame retardant is grafted into the resin to form an effective bulk flame-retardant copolymer, which is the development direction of flame-retardant copolymers. In existing studies, the comparative document CN 117050451 A emulsifies nitrogen-containing phenolic resin, zirconium phosphate and other substances in the system during the synthesis of acrylic emulsion to form a flame-retardant resin, which still belongs to a physical mixing method to improve the flame retardant effect of acrylic emulsion. The comparative document CN 10185567B adds phosphate monomer PAM300 to acrylic polymer and forms a pressure-sensitive adhesive with flame retardant effect by solution polymerization with acrylic ester. It was found through experiments that it is difficult to achieve a high addition amount of PAM300 in emulsion polymerization, thereby achieving an effective flame retardant effect. The comparative document CN109232785A prepares a resin with bulk flame retardancy by emulsion polymerization of polyhydroxyphosphonic acid and acrylic ester monomers.

[0004] Therefore, the preparation of reactive flame-retardant acrylates has great development prospects. It can achieve high flame-retardant effects with very small addition amounts and is a technology that is urgently needed in the current market. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides a silicon-modified organic phosphorus functional monomer and a method for preparing a bulk flame-retardant copolymer thereof, which can provide a bulk flame-retardant acrylate copolymer with high stability and high environmental protection.

[0006] To achieve the above objectives, the technical solution of the present invention is implemented through the following technical solutions:

[0007] A silicon-modified organic phosphorus functional monomer, wherein the silicon-modified organic phosphorus functional monomer has the following structural formula:

[0008]

[0009] Wherein, R1 is H, Any one of .

[0010] Preferably, the method for preparing the silicon-modified organophosphorus functional monomer comprises the following steps:

[0011] S1. Weigh PAM100:KH560 in a molar ratio of 1:2.1 to 2:1 for later use;

[0012] S2. PAM100 and KH560 are added into the reactor and nitrogen is introduced, and the temperature is raised to 60° C. for reaction for 3 h to obtain silicon-modified organophosphorus functional monomer.

[0013] The bulk flame retardant copolymer is prepared by using silicon-modified organic phosphorus functional monomers, and the specific preparation method includes the following steps:

[0014] (1) Prepare the following materials in parts by weight: 4.5-15 parts of silicon-modified organophosphorus functional monomer, 20.0-42.3 parts of other olefinic monomers, 0.3-7.5 parts of crosslinking material, 0.2-5 parts of emulsifier, 0.05-2.5 parts of pH buffer, 0.15-3 parts of initiator, and the balance is deionized water, and the solid content is controlled at 20-60%;

[0015] (2) Preparation of seed emulsion: 20% to 40% of deionized water and 10% to 15% of emulsifier are added to the reactor, stirred evenly, and then 1% to 10% of olefin-containing monomers are added to the reaction bottle, the temperature is gradually raised to 60 to 75° C., and then 3 to 10% of initiator is added to prepare seed emulsion;

[0016] (3) Emulsion core layer: 60% to 85% of olefinic monomer, 1% to 30% of silicon-modified organophosphorus functional monomer, 80% to 90% of emulsifier and 30% to 58% of deionized water are mixed to prepare a pre-emulsion, and then 60% to 80% of initiator and pH buffer are added to prepare a mixed solution, and then the mixed solution is gradually added dropwise to the above seed emulsion, and the reaction temperature is controlled to be 75 to 85° C. to prepare a core layer emulsion;

[0017] (4) Emulsion shell layer: the remaining olefinic monomers, silicon-modified organic phosphorus functional monomers and initiators, and deionized water are added dropwise to the core layer emulsion of the above step (3). After the addition is completed, the mixture is kept at 75-85° C. for 30-60 minutes to obtain a bulk flame-retardant copolymer emulsion. The cross-linking material is then added and stirred evenly to obtain a bulk flame-retardant copolymer.

[0018] Preferably, the other olefinic monomers are at least one of monomers containing acrylic functional groups, monomers containing vinyl functional groups, and cross-linking materials other than silicon-modified organic phosphorus functional monomers.

[0019] Preferably, the monomer containing an acrylic functional group is at least one of acrylic acid, methacrylic acid, itaconic acid, (meth)acrylonitrile, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, tert-butyl (meth)acrylate, isooctyl (meth)acrylate, lauryl (meth)acrylate, nonyl (meth)acrylate, polyethylene glycol di(meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, and β-hydroxyethyl acrylate; the monomer containing a vinyl functional group is at least one of vinyl acetate, styrene, and divinylbenzene.

[0020] Preferably, the cross-linking material is at least one of acrylamide, N-hydroxymethyl acrylamide, N,N-methylenebisacrylamide, pentaerythritol triacrylate, pentaerythritol tetraacrylate, and melamine resin cross-linking agent.

[0021] Preferably, the emulsifier is at least one of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, sodium isotridecyl ether sulfate, fatty alcohol polyoxyethylene ether, phosphate ester of fatty alcohol ethoxylate, allyloxy isomeric alcohol ether sulfate ammonium salt, and XR-10.

[0022] Preferably, the initiator is at least one of potassium sulfate, ammonium persulfate, sodium persulfate, sodium bisulfite, vitamin C, and FF6M.

[0023] Preferably, the pH buffer is at least one of sodium bicarbonate, sodium acetate, disodium hydrogen phosphate, and sodium hydrogen phosphate.

[0024] The bulk flame-retardant copolymer prepared as above can be used to prepare fire-retardant coatings.

[0025] The present invention provides a silicon-modified organic phosphorus functional monomer and a method for preparing a bulk flame-retardant copolymer thereof, which has the following advantages over the prior art:

[0026] (1) In the process of preparing the copolymer of the present invention, core-shell emulsion polymerization is adopted, and the main silicon-modified phosphate monomer and the monomer with carboxyl group are used for the preparation of the shell layer, so that phosphorus, nitrogen and silicon form a good protective effect on the surface of the polymer film, which plays a role in flame retardancy; the bulk flame-retardant copolymer is designed and synthesized according to the molecular structure, and has good adhesion to a variety of textiles, and has high flame retardant efficiency and durable phosphate flame retardant molecular structure with halogen-free, impregnated or intumescent flame retardant, and overcomes the shortcomings of general flame retardant glues containing halogen, salting out, white frosting, and poor water resistance; the present invention has the characteristics of high adhesion to the substrate, effectively reducing the addition of flame retardant powder, improving the textile to obtain good washability, excellent hand feel, etc. The highest flame retardant level can reach V0 or self-extinguishing level; the bulk flame-retardant polyacrylate emulsion prepared by the present invention is obtained by connecting the halogen-free flame retardant monomer and acrylic ester by chemical bonds, so it has good adhesion and good durability;

[0027] (2) The bulk flame-retardant copolymer prepared by the present invention has a synergistic flame-retardant effect formed by phosphorus, silicon and nitrogen, and has bulk flame-retardant properties; and does not contain the addition of halogen-related harmful substances, and is an environmentally friendly bulk flame-retardant polymer;

[0028] (3) The bulk flame-retardant copolymer prepared by the present invention has a simple and easy synthesis method for the functional monomer, which is conducive to the industrialization of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Thermogravimetric curve of the comparative example of the present invention;

[0030] Figure 2 The thermogravimetric curve of Example 1 of the present invention;

[0031] Figure 3 This is the thermogravimetric curve of Example 2 of the present invention;

[0032] Figure 4 It is the infrared spectra of Example 1 of the present invention and the comparative example. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention is clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are 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.

[0034] Embodiment 1:

[0035] Preparation of bulk flame retardant copolymers:

[0036] (1) Preparation of silicon-modified organophosphorus functional monomer: 22.8 g PAM100 and 23.6 g KH560 were weighed into a reaction bottle, and then nitrogen was introduced into the reactor, and the temperature was gradually raised to 60° C. for reaction for 3 h to obtain silicon-modified organophosphorus functional monomer;

[0037] (2) Preparation of seed emulsion: 45 g of deionized water, 0.05 g of emulsifier K12 (sodium dodecyl sulfate) and 0.05 g of emulsifier AEO-9 (fatty alcohol polyoxyethylene ether) were added to the reactor and stirred evenly. Then, 2 g of methyl acrylate and 3 g of butyl acrylate were added to the reaction bottle for emulsification. The temperature was gradually raised to 60° C., and then 0.018 g of potassium persulfate and 0.009 g of FF6M were added to the reaction system to initiate polymerization to form a seed emulsion.

[0038] (3) Emulsion core layer: 41 g butyl acrylate, 32 g ethyl acrylate, 10 g acrylonitrile, 4 g hydroxypropyl acrylate, 10 g isooctyl acrylate, 4 g acrylamide, 6 g silicon-modified organophosphorus functional monomer, 0.3 g emulsifier K-12 and 0.3 g emulsifier AEO-9 and 140 g deionized water were prepared into a pre-emulsion, and then 0.4 g potassium persulfate and 0.2 g sodium acetate were added and stirred evenly, and then the pre-emulsion was added dropwise into the seed emulsion. The reaction temperature was controlled to 84° C. to prepare a core layer emulsion;

[0039] (4) Emulsion shell layer: 2g methyl methacrylate, 12g silicon-modified organic phosphorus functional monomer, 0.15g potassium persulfate and 20g deionized water are added dropwise to the reaction system in step (3). After the reaction is completed, the mixture is kept warm for 30 minutes. The flame-retardant copolymer emulsion is obtained. The solid content of the obtained emulsion is 33%. Finally, 6g melamine resin crosslinking agent is added to the emulsion when it is used, and the mixture is stirred evenly to obtain the flame-retardant copolymer.

[0040] Embodiment 2:

[0041] The silicon-modified phosphate monomer in Example 1 was replaced with the following materials, and the rest was the same as in Example 1.

[0042] (1) Preparation of silicon-modified organophosphorus functional monomer: 22.8 g of PAM100 and 47.2 g of KH560 were weighed into a reaction bottle, and then nitrogen was introduced into the reactor, and the temperature was gradually raised to 60° C. for reaction for 3 h to obtain a silicon-modified organophosphorus functional monomer.

[0043] Embodiment 3:

[0044] Preparation of bulk flame retardant copolymers:

[0045] (1) Preparation of silicon-modified organophosphorus functional monomer: 45.6 g PAM100 and 23.6 g KH560 were weighed into a reaction bottle, and then nitrogen was introduced into the reactor, and the temperature was gradually raised to 60° C. for reaction for 3 h to obtain silicon-modified organophosphorus functional monomer;

[0046] (2) Preparation of seed emulsion: 120 g of deionized water and 0.7 g of emulsifier SR-10 were added to the reactor and stirred evenly. Then, 6 g of ethyl acrylate and 3 g of itaconic acid ethylenic monomer were added to the reaction bottle. The temperature was gradually raised to 75° C., and then 0.1 g of ammonium persulfate was added to prepare the seed emulsion.

[0047] (3) Emulsion core layer: 100 g of isooctyl acrylate, 40 g of tert-butyl acrylate, 40 g of styrene, 20 g of hydroxyethyl acrylate, 20 g of acrylamide, 28 g of silicon-modified organophosphorus functional monomer, 15 g of emulsifier SR-10 and 150 g of deionized water were used to prepare a pre-emulsion, and then 1.44 g of ammonium persulfate and 4 g of sodium bicarbonate were added, and then gradually added dropwise to the seed emulsion. The reaction temperature was controlled to 80°C to prepare a core layer emulsion.

[0048] (4) Emulsion shell layer: 11 g of methacrylic acid, 62 g of silicon-modified organic phosphorus functional monomer, 0.5 g of ammonium persulfate and 20 g of deionized water are added dropwise to the reaction system in step (3). After the reaction is completed, the system is kept warm for 60 min to obtain a flame-retardant copolymer emulsion. The solid content of the obtained emulsion is 49.8%.

[0049] Before use, 30 g of melamine resin cross-linking agent was added to the bulk flame-retardant acrylic emulsion, and the mixture was mixed and stirred evenly to obtain a bulk flame-retardant copolymer.

[0050] Example 4

[0051] The silicon-modified phosphate monomer in Example 3 was replaced with the following materials, and the rest was the same as in Example 3:

[0052] (1) Preparation of silicon-modified organophosphorus functional monomer: 22.8 g of PAM100 and 47.2 g of KH560 were weighed into a reaction bottle, and then nitrogen was introduced into the reactor, and the temperature was gradually raised to 60° C. for reaction for 3 h to obtain a silicon-modified organophosphorus functional monomer.

[0053] Embodiment 5:

[0054] Preparation of bulk flame retardant copolymers:

[0055] (1) Preparation of silicon-modified organophosphorus functional monomer: 45.6 g PAM100 and 47.2 g KH560 were weighed into a reaction bottle, and then nitrogen was introduced into the reactor, and the temperature was gradually raised to 60° C. for reaction for 3 h to obtain a silicon-modified organophosphorus functional monomer.

[0056] (2) Preparation of seed emulsion: 162 g of deionized water and 1.8 g of sodium dodecyl sulfate, an emulsifier, were added to the reactor and stirred evenly. Then, 13.8 g of N-hydroxymethyl acrylamide and 15 g of cyclohexyl acrylate were added to the reaction bottle, and the temperature was gradually raised to 70° C. Then, 1.8 g of H2O2 and 0.9 g of NaHSO3 as an initiator were added to prepare the seed emulsion;

[0057] (3) Emulsion core layer: 60 g of lauryl acrylate, 60 g of nonyl acrylate, 24 g of hydroxyethyl acrylate, 102 g of ethyl acrylate, 21 g of silicon-modified organophosphorus functional monomer, 12 g of sodium dodecyl sulfonate, 4.2 g of phosphate ester of fatty alcohol ethoxylate and 270 g of deionized water were used to prepare a pre-emulsion, and then 6.9 g of sodium persulfate and 9 g of sodium dihydrogen phosphate were added, and then gradually added dropwise to the seed emulsion, and the reaction temperature was controlled to 80° C. to prepare a core layer emulsion;

[0058] (4) Emulsion shell layer: 16.2 g acrylic acid, 9 g butyl acrylate, 57 g silicon-modified organophosphorus functional monomer, 6.3 g sodium persulfate and 108 g deionized water are added dropwise to the reaction system in step (3). After the reaction is completed, the mixture is kept warm for 30 min to obtain a bulk flame-retardant copolymer emulsion.

[0059] Before use, 72 g of melamine resin cross-linking agent was added to the bulk flame-retardant copolymer to obtain the bulk flame-retardant copolymer.

[0060] Embodiment 6:

[0061] The silicon-modified phosphate monomer in Example 5 was replaced with the following materials, and the rest was the same as in Example 5:

[0062] (1) Preparation of silicon-modified organophosphorus functional monomer: 44.6 g PAM100 and 23.6 g KH560 were weighed into a reaction bottle, and then nitrogen was introduced into the reactor, and the temperature was gradually raised to 60° C. for reaction for 3 h to obtain a silicon-modified organophosphorus functional monomer.

[0063] Comparative Example:

[0064] The preparation method of Example 1 is referred to, except that no silicon-modified organic phosphorus functional monomer is added for synthesis, and all the synthesis steps are the same as those of Example 1.

[0065] Detection:

[0066] The performance of the bulk flame-retardant copolymers prepared in the above Examples 1-6 and Comparative Examples was tested, and the specific results are shown in the following table:

[0067]

[0068] It can be seen from the above table that the copolymer with a multi-level structure prepared by silicon-modified organic phosphorus functional monomers has good flame retardant properties.

[0069] At the same time, the thermogravimetric test results of the comparative example, embodiment 1 and embodiment 2 are as follows Figure 1 , Figure 2 , Figure 3 As shown, it can be seen that the decomposition temperature of the comparative example is 405°C, and the remaining components are 5.57% at 600°C; the pyrolysis temperature of Example 1 is 407.33°C, and the remaining components are 10.373% at 600°C; the pyrolysis temperature of Example 2 is 408.3°C, and the remaining components account for 14.590% at 600°C. Therefore, the multi-level structure copolymer prepared by silicon-modified organic phosphorus functional monomer has good heat resistance.

[0070] The infrared spectra of Example 1 and the comparative example are as follows: Figure 4 As shown in the figure, it can be seen that in the range of 1100 to 1000 cm -1 The main characteristic stretching vibration peaks are Si-O-Si and Si-OC, which are significantly enhanced compared with the control sample, 1668.93cm -1 The peak at the center is O=P-OH, indicating that the silicon-modified phosphate monomer has been successfully reacted into the polymer system.

[0071] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A silicon-modified organophosphorus functional monomer, characterized in that: The silicon-modified organic phosphorus functional monomer has the following structural formula: Wherein, R1 is H, Any one of .

2. The silicon-modified organic phosphorus functional monomer according to claim 1, characterized in that: The preparation method of the silicon-modified organic phosphorus functional monomer comprises the following steps: S1. Weigh PAM100:KH560 in a molar ratio of 1:2.1 to 2:1 for later use; S2. PAM100 and KH560 are added into the reactor and nitrogen is introduced, and the temperature is raised to 60° C. for reaction for 3 h to obtain silicon-modified organophosphorus functional monomer.

3. A method for preparing a bulk flame-retardant copolymer, characterized in that: The bulk flame-retardant copolymer is prepared by using the silicon-modified organic phosphorus functional monomer described in any one of claims 1 to 2, and the specific preparation method comprises the following steps: (1) Prepare the following materials in parts by weight: 4.5-15 parts of silicon-modified organophosphorus functional monomer, 20.0-42.3 parts of other olefinic monomers, 0.3-7.5 parts of crosslinking material, 0.2-5 parts of emulsifier, 0.05-2.5 parts of pH buffer, 0.15-3 parts of initiator, and the balance is deionized water, and the solid content is controlled at 20-60%; (2) Preparation of seed emulsion: 20% to 40% of deionized water and 10% to 15% of emulsifier are added to the reactor, stirred evenly, and then 1% to 10% of olefin-containing monomers are added to the reaction bottle, the temperature is gradually raised to 60 to 75° C., and then 3 to 10% of initiator is added to prepare seed emulsion; (3) Emulsion core layer: 60% to 85% of olefinic monomer, 1% to 30% of silicon-modified organophosphorus functional monomer, 80% to 90% of emulsifier and 30% to 58% of deionized water are mixed to prepare a pre-emulsion, and then 60% to 80% of initiator and pH buffer are added to prepare a mixed solution, and then the mixed solution is gradually added dropwise to the above seed emulsion, and the reaction temperature is controlled to be 75 to 85° C. to prepare a core layer emulsion; (4) Emulsion shell layer: the remaining olefinic monomers, silicon-modified organic phosphorus functional monomers and initiators, and deionized water are added dropwise to the core layer emulsion of the above step (3). After the addition is completed, the mixture is kept at 75-85° C. for 30-60 minutes to obtain a bulk flame-retardant copolymer emulsion. The cross-linking material is then added and stirred evenly to obtain a bulk flame-retardant copolymer.

4. The preparation method according to claim 3, characterized in that: The other olefinic monomers are at least one of monomers containing acrylic functional groups, monomers containing vinyl functional groups, and cross-linking materials other than silicon-modified organic phosphorus functional monomers.

5. The preparation method according to claim 4, characterized in that: The monomer containing an acrylic functional group is at least one of acrylic acid, methacrylic acid, itaconic acid, (meth)acrylonitrile, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, tert-butyl (meth)acrylate, isooctyl (meth)acrylate, lauryl (meth)acrylate, nonyl (meth)acrylate, polyethylene glycol di(meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, and β-hydroxyethyl acrylate; the monomer containing a vinyl functional group is at least one of vinyl acetate, styrene, and divinylbenzene.

6. The preparation method according to claim 4, characterized in that: The cross-linking material is at least one of acrylamide, N-hydroxymethyl acrylamide, N,N-methylenebisacrylamide, pentaerythritol triacrylate, pentaerythritol tetraacrylate, and melamine resin cross-linking agent.

7. The preparation method according to claim 3, characterized in that: The emulsifier is at least one of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, sodium isotridecyl ether sulfate, fatty alcohol polyoxyethylene ether, phosphate ester of fatty alcohol ethoxylate, ammonium salt of allyloxy isomeric alcohol ether sulfate, and XR-10.

8. The preparation method according to claim 3, characterized in that: The initiator is at least one of potassium sulfate, ammonium persulfate, sodium persulfate, sodium bisulfite, vitamin C, and FF6M.

9. The preparation method according to claim 3, characterized in that: The pH buffer is at least one of sodium bicarbonate, sodium acetate, disodium hydrogen phosphate and sodium hydrogen phosphate.

10. Use of the bulk flame-retardant copolymer prepared by the preparation method according to claims 1 to 9 in fire-retardant coatings.

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