Polymer elastomer resin as well as preparation method and application thereof

Abstract

The invention relates to the technical field of coating preparation, particularly discloses polymer elastomer resin as well as a preparation method and application thereof, and aims to solve the problem that a polymer film layer is in a crack state due to film shrinkage in an ultralow-temperature state. The polymer elastomer resin with a low-polarity and high-confusion-degree structure is prepared, so that the condition that a film is not broken due to film shrinkage in an ultralow-temperature state of a polymer is ensured, and the integrity of a coating film in an ultralow-temperature environment is ensured; the prepared polymer elastomer resin, isocyanate and a catalyst are mixed and react to prepare the coating, and the coating not only has good ultralow temperature resistance, hydrophobicity and ultraviolet resistance, but also has excellent adhesiveness on the surfaces of low-surface-tension metals such as stainless steel and aluminum alloy.

Description

Technical Field

[0001] The present invention relates to the technical field of coating preparation, and particularly relates to a polymer elastomer resin, a preparation method thereof and an application thereof. Background Art

[0002] At present, at home and abroad, for metal protection in ultra-low temperature environments and under strong ultraviolet irradiation, almost all use fluorine-containing polyurethane coatings. To solve the adhesion problem, generally, a macromolecular acrylate polymer is used as the bottom layer. However, in the prior art, for fluorine-containing polymer coatings and polyacrylate film formers, at lower temperatures, their degree of crystallization in the condensed state is lower than that of the traditional polyurethane system. However, due to the regularity of the structure, the fluorine-containing polymer coatings or polyacrylate films still have an overall crystal structure arrangement. For many years, the research on organic polymers at home and abroad has mainly focused on the energy and morphological changes during the conversion between the viscoelastic state and the glassy state at normal temperature or lower temperatures, while the research on organic polymer polymers in the ultra-low temperature state is almost blank in the real environment.

[0003] Due to the properties of monomers and the similarity of structures during the synthesis of organic polymers, they generally exhibit a crystalline state in the solid state due to the similarity of structures. When the proportion of the crystalline state exceeds a certain amount, the polymer film will form a glassy state, resulting in fracture due to excessive shrinkage, which is more likely to occur in thin films. The degree of crystallization of a polymer is related to the polarity or surface tension of the polymer. The lower the surface tension, the lower the degree of crystallization, the higher the degree of disorder, and the better the cold resistance. This is one of the reasons why fluorocarbon polymer coatings can be used for material protection at low temperatures. However, the existing fluorocarbon resins have the problem of too regular structures, and they are prone to crystallization even when the temperature is slightly reduced, resulting in cracks in the coating. Therefore, reducing the degree of disorder of the polymer material structure has also become the main idea for low-temperature protective resins.

[0004] Chinese patent document CN104987467A discloses a low infrared emissivity acrylate-modified hydroxyl-terminated polybutadiene resin and a preparation method thereof, which is obtained by free radical copolymerization of hydroxyl-terminated polybutadiene with acrylate monomers and / or methacrylate monomers. The obtained low infrared emissivity acrylate-modified hydroxyl-terminated polybutadiene resin has a solid content of 40wt% - 60wt%. The prepared acrylate-modified hydroxyl-terminated polybutadiene resin has low gloss and good weather resistance, and can be used to prepare two-component infrared stealth coatings for coating military equipment, machinery, engineering, barracks and other sites to achieve the purpose of stealth, but its cold resistance still needs to be further improved. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a polymer elastomer resin, a preparation method thereof and an application thereof.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a method for preparing a polymer elastomer resin, comprising the following steps: adding hydroxyl-terminated polybutadiene, hydroxyl-terminated polysiloxane and a part of the solvent into a reactor, stirring evenly, heating to 100-135 °C, then dropping an acrylate monomer and a part of the initiator, after the dropping is completed, maintaining the temperature for reaction for 50-70 min, then adding the remaining solvent and the remaining initiator, continuing to maintain the temperature for reaction for 3.5-4 h, after the reaction is completed, cooling to 50-60 °C, and filtering to obtain the polymer elastomer resin.

[0008] In the technical solution of the present invention, based on the mass fraction of the raw materials for preparing the polymer elastomer resin, it includes: 5-15 parts of hydroxyl-terminated polybutadiene, 0.5-2 parts of hydroxyl-terminated polysiloxane, 35-45 parts of acrylate monomer, 0.5-2 parts of initiator, and 40-50 parts of solvent.

[0009] In the technical solution of the present invention, the acrylate monomer is selected from at least two of acrylic acid, hydroxypropyl acrylate, hydroxybutyl acrylate, butyl acrylate, isooctyl acrylate, cyclohexyl acrylate, lauryl acrylate.

[0010] In the technical solution of the present invention, the hydroxyl value of the hydroxyl-terminated polybutadiene is 0.7-0.8%, and the number average molecular weight is 2.70×10 3 -3.30×10 3 .

[0011] In the technical solution of the present invention, the number average molecular weight of the hydroxyl-terminated polysiloxane is 2.0×10 4 -3.0×10 4 .

[0012] In the technical solution of the present invention, the initiator is selected from at least one of benzoyl peroxide, tert-butyl perbenzoate, di-tert-butyl peroxide, di-tert-amyl peroxide.

[0013] In the technical solution of the present invention, the solvent is selected from hydrocarbon solvents, ketone solvents, ester solvents or ether solvents.

[0014] In the technical solution of the present invention, the amount of the initiator added for the first time accounts for 70-90% of the total amount of the initiator. For example, 70%, 75%, 80%, 85%, 90% can be selected, but it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0015] In the technical solution of the present invention, the amount of the solvent added for the first time accounts for 75-90% of the total amount of the solvent. For example, 75%, 80%, 85%, 90% can be selected, but it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0016] In the second aspect, the present invention provides a polymer elastomer resin prepared by the above preparation method.

[0017] In the third aspect, the present invention further provides the application of the above polymer elastomer resin in the field of coatings.

[0018] In the technical solution of the present invention, the coating components include the above polymer elastomer resin, isocyanate elastomer and catalyst.

[0019] In the technical solution of the present invention, the cyano group in the isocyanate elastomer and the hydroxyl group in the polymer elastomer resin are proportioned according to the molar ratio NCO / OH = 1.0-1.05:1.

[0020] In the technical solution of the present invention, the catalyst is selected from dibutyltin dilaurate.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) For the polymer elastomer resin provided by the present invention, firstly, under the induction of an initiator, through the in-situ polymerization reaction of the double bond in linear hydroxyl-terminated polybutadiene and acrylic monomers, a polybutadiene-grafted hydroxyacrylate polymer elastomer is formed; and the acrylate monomers can also copolymerize to form a hydroxyacrylate polymer; at the same time, there is also the in-situ polymerization of acrylic monomers in the hydroxyl-terminated polybutadiene and hydroxyl-terminated polydimethylsiloxane solutions to form a low-polarity linear polymer polybutadiene-silicone-polyacrylate elastomer resin with an interpenetrating structure; due to the good compatibility of the polybutadiene-grafted hydroxyacrylate polymer elastomer, hydroxyacrylate polymer and polybutadiene-silicone-polyacrylate elastomer resin, the extremely low surface tension enables the polymer chain segments to have excellent flexibility, cold resistance and anti-sticking property at room temperature, which can meet the surface coating protection requirements of aluminum alloy and stainless steel at a specific ultra-low temperature state, and also has good ultraviolet resistance.

[0023] (2) To solve the problem that the polymer film layer cracks due to film shrinkage at ultra-low temperatures, the present invention considers aspects such as the polarity of polymer chain segments and the irregularity of polymer structures, and prepares a polymer elastomer resin with low polarity and high degree of disorder structure, ensuring that the polymer does not break even due to film shrinkage at ultra-low temperatures, thus ensuring the integrity of the coating film in an ultra-low temperature environment; the present invention mixes and reacts the prepared polymer elastomer resin with isocyanate and a catalyst to prepare a coating, which not only has good ultra-low temperature resistance, hydrophobicity and ultraviolet resistance, but also has excellent adhesion on low surface tension metals such as stainless steel and aluminum alloy. Detailed implementation mode

[0024] The following further details the present invention through specific preferred embodiments, but the present invention is not limited to the following embodiments.

[0025] It should be noted that unless otherwise specified, the chemical reagents involved in the present invention are all purchased through commercial channels.

[0026] The hydroxyl-terminated polybutadiene used in the present invention is purchased from Shenzhen Hongyuan Chemical New Material Technology Co., Ltd.; the hydroxyl-terminated polysiloxane is purchased from Hubei Peizi Pharmaceutical Technology Co., Ltd.; the brand of the isocyanate elastomer is: N3800;

[0027] The compositions of each material in Examples 1-5 and Comparative Examples 1-3 of the present invention are shown in Table 1 below. Compared with Example 1, Comparative Example 1 does not add hydroxyl-terminated polybutadiene and hydroxyl-terminated polysiloxane; compared with Example 1, Comparative Example 2 does not add hydroxyl-terminated polybutadiene; compared with Example 1, Comparative Example 3 does not add hydroxyl-terminated polysiloxane.

[0028] Table 1 Compositions of each material (unit: g)

[0029]

[0030]

[0031] Example 1

[0032] Add each material according to the formula in Example 1 in Table 1. The preparation method of the polymer elastomer resin is as follows:

[0033] Add hydroxyl-terminated polybutadiene, hydroxyl-terminated polysiloxane and 40 g of the solvent xylene into the reactor, stir evenly, heat up to 130 °C, then dropwise add acrylate monomer and 0.8 g of initiator, finish the dropwise addition in 3 h. After the dropwise addition is completed, keep the temperature at 130 °C for heat preservation reaction for 60 min. Subsequently, add the remaining solvent and the remaining initiator, continue the heat preservation reaction at 130 °C for 4 h. After the reaction is completed, cool down to 60 °C and filter to obtain the polymer elastomer resin.

[0034] Example 2

[0035] Add each material according to the formula in Example 2 in Table 1. The preparation method of the polymer elastomer resin is as follows:

[0036] Add hydroxyl-terminated polybutadiene, hydroxyl-terminated polysiloxane and 40 g of the solvent xylene into the reactor, stir evenly, heat up to 130 °C, then dropwise add acrylate monomer and 0.8 g of initiator, finish the dropwise addition in 3 h. After the dropwise addition is completed, keep the temperature at 130 °C for heat preservation reaction for 60 min. Subsequently, add the remaining solvent and the remaining initiator, continue the heat preservation reaction at 130 °C for 4 h. After the reaction is completed, cool down to 60 °C and filter to obtain the polymer elastomer resin.

[0037] Example 3

[0038] Add each material according to the formula in Example 3 in Table 1. The preparation method of the polymer elastomer resin is as follows:

[0039] Add hydroxyl-terminated polybutadiene, hydroxyl-terminated polysiloxane and 40 g of the solvent xylene into the reactor, stir evenly, heat up to 130 °C, then dropwise add acrylate monomer and 1.0 g of initiator, finish the dropwise addition in 3 h. After the dropwise addition is completed, keep the temperature at 130 °C for heat preservation reaction for 60 min. Subsequently, add the remaining solvent and the remaining initiator, continue the heat preservation reaction at 130 °C for 4 h. After the reaction is completed, cool down to 60 °C and filter to obtain the polymer elastomer resin.

[0040] Example 4

[0041] Add each material according to the formula in Example 4 in Table 1. The preparation method of the polymer elastomer resin is as follows:

[0042] Add hydroxyl-terminated polybutadiene, hydroxyl-terminated polysiloxane and 40 g of the solvent xylene into the reactor, stir evenly, heat up to 130 °C, then dropwise add acrylate monomer and 1.2 g of initiator, finish the dropwise addition in 3 h. After the dropwise addition is completed, keep the temperature at 130 °C for heat preservation reaction for 60 min. Subsequently, add the remaining solvent and the remaining initiator, continue the heat preservation reaction at 130 °C for 4 h. After the reaction is completed, cool down to 60 °C and filter to obtain the polymer elastomer resin.

[0043] Example 5

[0044] Add each material according to the formulation in Example 5 of Table 1. The preparation method of the polymer elastomer resin is as follows:

[0045] Add hydroxyl-terminated polybutadiene, hydroxyl-terminated polysiloxane and 40 g of xylene solvent to the reactor, stir evenly, heat up to 130 °C, then dropwise add acrylate monomer and 0.8 g of initiator, and finish dropping in 3 h. After the dropping is completed, keep the temperature at 130 °C for heat preservation reaction for 60 min. Subsequently, add the remaining solvent and the remaining initiator, continue the heat preservation reaction at 130 °C for 4 h. After the reaction is completed, cool down to 60 °C and filter to obtain the polymer elastomer resin.

[0046] Comparative Example 1

[0047] Add each material according to the formulation in Comparative Example 1 of Table 1. The preparation method of the polymer elastomer resin is as follows:

[0048] Add 40 g of xylene solvent to the reactor, heat up to 130 °C, then dropwise add acrylate monomer and 0.8 g of initiator, and finish dropping in 3 h. After the dropping is completed, keep the temperature at 130 °C for heat preservation reaction for 60 min. Subsequently, add the remaining solvent and the remaining initiator, continue the heat preservation reaction at 130 °C for 4 h. After the reaction is completed, cool down to 60 °C and filter to obtain the polymer elastomer resin.

[0049] Comparative Example 2

[0050] Add each material according to the formulation in Comparative Example 2 of Table 1. The preparation method of the polymer elastomer resin is as follows:

[0051] Add hydroxyl-terminated polysiloxane and 40 g of xylene solvent to the reactor, stir evenly, heat up to 130 °C, then dropwise add acrylate monomer and 0.8 g of initiator, and finish dropping in 3 h. After the dropping is completed, keep the temperature at 130 °C for heat preservation reaction for 60 min. Subsequently, add the remaining solvent and the remaining initiator, continue the heat preservation reaction at 130 °C for 4 h. After the reaction is completed, cool down to 60 °C and filter to obtain the polymer elastomer resin.

[0052] Comparative Example 3

[0053] Add each material according to the formulation in Comparative Example 3 of Table 1. The preparation method of the polymer elastomer resin is as follows:

[0054] Add hydroxyl-terminated polybutadiene and 40 g of xylene solvent to the reactor, stir evenly, heat up to 130 °C, then dropwise add acrylate monomer and 0.8 g of initiator, and finish dropping in 3 h. After the dropping is completed, keep the temperature at 130 °C for heat preservation reaction for 60 min. Subsequently, add the remaining solvent and the remaining initiator, continue the heat preservation reaction at 130 °C for 4 h. After the reaction is completed, cool down to 60 °C and filter to obtain the polymer elastomer resin.

[0055] The polymer elastomer resins prepared in Examples 1-5 and Comparative Examples 1-3 were subjected to performance tests. The specific steps are as follows:

[0056] The polymer elastomer resins prepared in Examples 1-5 and Comparative Examples 1-3 were weighed separately and mixed evenly with dibutyltin dilaurate to obtain a mixture. The mass fraction of the polymer elastomer resin in the mixture was 99.94%, and the mass fraction of dibutyltin dilaurate was 0.06%. Then, the mixture was mixed with an isocyanate elastomer, and the ratio was adjusted according to the molar ratio of the cyano group in the isocyanate elastomer to the hydroxyl group in the polymer elastomer resin NCO / OH = 1.05:1 to obtain a coating. The coating was then applied to the surface of a 304 stainless steel plate to form a coating film with a thickness of 40 μm, and the performance of the coating film was tested. The results are shown in Table 2.

[0057] Table 2 Performance test results of the coating film

[0058]

[0059] Finally, it should be noted that the above examples do not limit the present invention in any form. For those skilled in the art, based on the present invention, some modifications and improvements can be made. Therefore, any modification or improvement made without departing from the spirit of the present invention falls within the scope of protection required by the present invention.

Claims

1. A method for preparing a polymer elastomer resin, characterized in that: The method comprises the following steps: adding terminal hydroxyl polybutadiene, terminal hydroxyl polysiloxane and part of solvent into a reactor, stirring evenly, heating to 100-135°C, then dripping acrylate monomer and part of initiator, keeping warm for reaction for 50-70 minutes after the dripping is completed, then adding the remaining solvent and the remaining initiator, continuing the keeping warm for reaction for 3.5-4 hours, cooling to 50-60°C after the reaction is completed, filtering, and obtaining the polymer elastomer resin.

2. The preparation method according to claim 1, characterized in that: The polymer elastomer resin comprises, based on the mass fraction of the raw materials for preparing the polymer elastomer resin, 5-15 parts of terminal hydroxyl polybutadiene, 0.5-2 parts of terminal hydroxyl polysiloxane, 35-45 parts of acrylate monomer, 0.5-2 parts of initiator and 40-50 parts of solvent.

3. The preparation method according to claim 1, characterized in that: The acrylic acid ester monomers are selected from at least two of butyl methacrylate, acrylic acid, hydroxypropyl acrylate, hydroxybutyl acrylate, butyl acrylate, isooctyl acrylate, cyclohexyl acrylate, and isobornyl acrylate.

4. The preparation method according to claim 1, characterized in that: The hydroxyl value of the hydroxyl-terminated polybutadiene is 0.7-0.8%, and the number average molecular weight is 2.70×10 3 -3.30×10 3 .

5. The preparation method according to claim 1, characterized in that: The number average molecular weight of the terminal hydroxyl polysiloxane is 2.0×10 4 -3.0×10 4 .

6. The preparation method according to claim 1, characterized in that: The initiator is selected from at least one of benzoyl peroxide, tert-butyl perbenzoate, di-tert-butyl peroxide and di-tert-amyl peroxide.

7. The preparation method according to claim 1, characterized in that: The solvent is selected from hydrocarbon solvents, ketone solvents, ester solvents or ether solvents.

8. The preparation method according to claim 1, characterized in that: The amount of the initiator added dropwise for the first time accounts for 70-90% of the total amount of the initiator used; the amount of the solvent added for the first time accounts for 75-90% of the total amount of the solvent used.

9. The polymer elastomer resin prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the polymer elastomer resin according to claim 9 in the field of coatings.

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