A caprolactone-modified hybrid coating and methods of making and using the same

Abstract

The present application discloses a kind of caprolactone modified composite coating and its preparation and use method, including caprolactone modified epoxy resin coating used as primer coating and caprolactone modified polyurea topcoat used as top coating;The caprolactone modified epoxy resin coating includes A component and B component;The A component includes caprolactone modified epoxy resin and diluent;The B component is amine curing agent and first auxiliary agent;The caprolactone modified polyurea topcoat includes C component and D component;The C component is semi-prepolymer;D component includes caprolactone modified amino chain extender, color paste and second auxiliary agent.The present application improves the flexibility and adhesion of epoxy resin and epoxy primer, especially low temperature performance and makes polyurea coating completely cured with excellent adhesion and low temperature performance.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of high polymer materials, and particularly relates to a caprolactone modified composite coating and a preparation and use method thereof. BACKGROUND

[0002] In addition to poor adhesion to non-polar plastics such as polyolefins, the epoxy resin has excellent adhesion to various metal materials such as aluminum, iron and copper, non-metal materials such as glass, wood and concrete, and thermosetting plastics such as phenolic, amino and unsaturated polyester. The epoxy resin also has a small curing shrinkage, and the cured resin has excellent corrosion resistance and adhesion.

[0003] Polyurea belongs to the polyurethane system and is divided into semi-polyurea and pure polyurea. The semi-polyurea is obtained by reacting amino and hydroxyl as a chain extender with an isocyanate component; and the pure polyurea is obtained by reacting an amino-terminated polyether or a small molecular diamine as a chain extender with an isocyanate component. The polyurea curing does not require a catalyst and has a fast curing speed, and is not affected by temperature and humidity during construction. The cured coating has excellent physical and chemical properties.

[0004] However, the coating prepared from the epoxy resin has a large rigidity and poor toughness, especially in a low temperature environment, leading to cracking of the coating; and the use of polyurea results in a large shrinkage of the coating due to the fast curing speed, and poor interlayer adhesion, so that the coating is easily peeled off. SUMMARY

[0005] The purpose of the present application is to prepare a caprolactone modified composite coating, to modify the poor low-temperature flexibility of the epoxy and polyurea, to improve the compatibility between the epoxy and the polyurea and the interlayer adhesion of the coating by using the good compatibility of the caprolactone.

[0006] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0007] A caprolactone modified composite coating, characterized in that it comprises a caprolactone modified epoxy resin coating used as a base coating and a caprolactone modified polyurea top coating used as a top coating.

[0008] The caprolactone modified epoxy resin coating comprises an A component and a B component; the A component comprises a caprolactone modified epoxy resin and a diluent; and the B component is an amine curing agent and a first auxiliary agent.

[0009] The caprolactone modified polyurea top coating comprises a C component and a D component; the C component is a semi-prepolymer; and the D component comprises a caprolactone modified amino chain extender, a color paste and a second auxiliary agent.

[0010] Further improvement, the mass ratio of caprolactone modified epoxy resin, diluent and the first auxiliary agent in the A component is 400-510:20-55:1-5; the mass ratio of caprolactone modified epoxy resin and amine curing agent is 400-510:165-180;

[0011] The mass ratio of caprolactone modified amino chain extender, color paste and the second auxiliary agent is 450-570:5-10:0.5-1; the mass ratio of caprolactone modified amino chain extender and semi-prepolymer is 450-570:1150-1250.

[0012] Further improvement, the preparation method of the caprolactone modified epoxy resin is as follows:

[0013] Caprolactone is reacted with the hydroxyl group in E51 epoxy resin at 100-150 DEG C under the action of the first catalyst for 4-10 h to obtain the caprolactone modified epoxy resin.

[0014] Further improvement, the mass ratio of caprolactone and E51 epoxy resin is 16-80:380, and the epoxy equivalent of E51 epoxy resin is 190; the first catalyst is dibutyltin dilaurate, and the addition amount is 50-200 ppm.

[0015] Further improvement, the preparation method of the caprolactone modified amino chain extender is as follows:

[0016] The binary amino chain extender is reacted with caprolactone at 120-150 DEG C under the action of the second catalyst to obtain the caprolactone modified amino chain extender.

[0017] The semi-prepolymer is prepared by reacting polycaprolactone polyol with polyisocyanate at 60-90 DEG C for 2-3 h.

[0018] Further improvement, the mass ratio of the binary amino chain extender and caprolactone is 396:57-171; the second catalyst is stannous octoate, and the addition amount of stannous octoate is 10-200 ppm; the binary amino chain extender is 4,4-diaminodiphenyl methane; and the polycaprolactone polyol is PCL-2044 of Hunan Poly New Material Co., Ltd.

[0019] Further improvement, the diluent is propylene glycol methyl ether; the first auxiliary agent is curing accelerator DMP-30, and the amine curing agent is isophorone diamine.

[0020] Further improvement, the color paste is polyurea special Longhui black color paste BT-508 black; and the second auxiliary agent is defoaming agent, and the defoaming agent is BYK-066N of Germany BYK company.

[0021] A preparation method of the caprolactone modified composite coating, comprising the following steps:

[0022] Step one, preparing the primer coating:

[0023] 1.1) preparing the caprolactone modified epoxy resin:

[0024] The caprolactone is reacted with the hydroxyl group in the E51 epoxy resin at 100-150 DEG C for 4-10 h in the presence of a first catalyst to obtain the caprolactone modified epoxy resin;

[0025] 1.2) mixing the caprolactone modified epoxy resin and diluent to form the A component;

[0026] 1.3) mixing the amine curing agent and first additive to form the B component; the A component and the B component are separately stored to form the primer coating;

[0027] Step two, preparing the top coating:

[0028] 2.1) preparing the semi-prepolymer:

[0029] The polycaprolactone polyol is reacted with the polyisocyanate at 60-90 DEG C for 2-3 h to obtain the semi-prepolymer as the C component;

[0030] 2.2) preparing the caprolactone modified amino chain extender:

[0031] The di-amino chain extender is reacted with the caprolactone at 120-150 DEG C in the presence of a second catalyst to obtain the caprolactone modified amino chain extender;

[0032] 2.2) mixing the caprolactone modified amino chain extender, color paste and second additive to form the D component; the C component and the D component are separately stored to form the top coating.

[0033] A method for preparing and using the caprolactone modified composite coating, comprising the following steps:

[0034] S1: mixing the A component and the B component to form the primer coating, which is sprayed to form the primer layer; the thickness of the primer layer is 80-120 um;

[0035] S2: mixing the C component and the B component to form the top coating, which is sprayed onto the not completely cured primer layer, and then waiting for curing to form the caprolactone modified composite coating; the thickness of the top coating is 0.5 mm-2 mm.

[0036] The present application has the following advantages:

[0037] 1. The present application modifies the epoxy resin with caprolactone, which improves the flexibility and adhesion of the epoxy resin and the epoxy primer, especially the low temperature performance.

[0038] 2. The present application regulates the curing speed of the polyurea coating by the amount of caprolactone added to the raw material of the polyurea coating, i.e. the di-amino chain extender MDA, so that the polyurea coating has a suitable curing time after construction, thereby ensuring that the polyurea coating has excellent adhesion after complete curing.

[0039] 3. The composite coating of the present application has a caprolactone segment, which improves the compatibility between the epoxy and the polyurea and the interlayer adhesion of the coating by virtue of the good compatibility of caprolactone.

[0040] 4. The construction method of the present application is to start spraying the polyurea coating after the epoxy primer is tack-free, so that the incompletely cured epoxy coating can chemically react with and link to the polyurea coating, thereby further improving the compatibility and interlayer adhesion. DETAILED DESCRIPTION

[0041] Example 1

[0042] I. Preparation of the caprolactone-modified epoxy primer:

[0043] The components of the caprolactone-modified epoxy primer include 412 parts of caprolactone-modified epoxy resin, 50 parts of propylene glycol methyl ether, 5 parts of curing accelerator DMP-30, and 170 parts of amine curing agent isophorone diamine.

[0044] ① Preparation of the caprolactone-modified epoxy resin: After dehydration of 32 parts of caprolactone monomer and 380 parts of E51 epoxy resin, the mixture is reacted at 140°C for 5h in the presence of dibutyltin dilaurate catalyst to obtain the caprolactone-modified epoxy resin.

[0045] ② 50 parts of propylene glycol methyl ether diluent are added to 412 parts of the caprolactone-modified epoxy resin, and then stirred and mixed uniformly to obtain component A.

[0046] ③ 170 parts of amine curing agent isophorone diamine and 5 parts of curing accelerator DMP-30 are mixed as component B with component A, and then coated onto the corresponding substrate to obtain the caprolactone-modified epoxy primer.

[0047] II. Preparation of the caprolactone-modified polyurea coating:

[0048] The components of the caprolactone-modified polyurea coating include 1150 parts of semi-prepolymer component, 0.5 parts of defoaming agent BYK-066N, 453 parts of caprolactone-modified amino chain extender component, and 8 parts of black color paste BT-508 black for polyurea.

[0049] ① Preparation of the caprolactone-modified amino chain extender: 396 parts of di-amino chain extender and 57 parts of caprolactone are reacted at 130°C in the presence of stannous octoate catalyst to obtain the caprolactone-modified amino chain extender.

[0050] (ii) Preparation of the semi-prepolymer component: a semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0051] (iii) Mixing 453 parts of caprolactone-modified amino chain extender, 8 parts of color paste, and 0.5 parts of defoaming agent BYK-066N to obtain component D.

[0052] (iv) When the caprolactone-modified epoxy primer is not completely cured, the C component and the D component are mixed and sprayed on the epoxy primer using a spraying device specially used for spraying polyurea coatings to obtain a caprolactone-modified polyurea coating.

[0053] (v) After the caprolactone-modified epoxy primer and the caprolactone-modified polyurea coating are completely cured, a caprolactone-modified composite coating is obtained.

[0054] Example 2

[0055] I. Preparation of the caprolactone-modified epoxy primer:

[0056] The components of the caprolactone-modified epoxy primer include 412 parts of caprolactone-modified epoxy resin, 50 parts of propylene glycol methyl ether, 5 parts of curing accelerator DMP-30, and 170 parts of amine curing agent isophorone diamine.

[0057] (i) Preparation of the caprolactone-modified epoxy resin: 32 parts of caprolactone monomer and 380 parts of E51 epoxy resin are dehydrated and then reacted at 140°C for 5 h in the presence of dibutyltin dilaurate catalyst to obtain a caprolactone-modified epoxy resin.

[0058] (ii) 50 parts of propylene glycol methyl ether diluent are added to 412 parts of the caprolactone-modified epoxy resin, and then uniformly mixed by stirring to obtain component A.

[0059] (iii) 170 parts of isophorone diamine and 5 parts of curing accelerator DMP-30 are mixed as component B and component A, and then coated on the corresponding substrate to obtain a caprolactone-modified epoxy primer.

[0060] II. Preparation of the caprolactone-modified polyurea coating:

[0061] The components of the caprolactone-modified polyurea coating include 1150 parts of semi-prepolymer component, 0.5 parts of defoaming agent BYK-066N as an auxiliary component, 510 parts of caprolactone-modified amino chain extender component, and 8 parts of black color paste BT-508 black specially used for polyurea.

[0062] (i) Preparation of the caprolactone-modified amino chain extender: 396 parts of di-amino chain extender and 114 parts of caprolactone are reacted at 130°C in the presence of stannous octoate catalyst to obtain a caprolactone-modified amino chain extender.

[0063] Preparation of semi-prepolymer component: semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0064] Preparation of semi-prepolymer component: semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0065] Preparation of semi-prepolymer component: semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0066] Preparation of semi-prepolymer component: semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0067] Example 3

[0068] Preparation of semi-prepolymer component: semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0069] Preparation of semi-prepolymer component: semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0070] Preparation of semi-prepolymer component: semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0071] Preparation of semi-prepolymer component: semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0072] Preparation of semi-prepolymer component: semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0073] Preparation of semi-prepolymer component: semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0074] Preparation of semi-prepolymer component: semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0075] Preparation of semi-prepolymer component: semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0076] ii. Preparation of the semi-prepolymer component: a semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0077] iii. Mixing 567 parts of caprolactone-modified amino chain extender, 8 parts of color paste, and 0.5 parts of defoaming agent BYK-066N to obtain component D.

[0078] iv. When the caprolactone-modified epoxy primer is not completely cured, the C component and the D component are mixed and sprayed on the epoxy primer using a spraying device specially used for spraying polyurea coatings to obtain a caprolactone-modified polyurea coating.

[0079] v. After the caprolactone-modified epoxy primer and the caprolactone-modified polyurea coating are completely cured, a caprolactone-modified composite coating is obtained.

[0080] Example 4

[0081] I. Preparation of the caprolactone-modified epoxy primer:

[0082] The components of the caprolactone-modified epoxy primer include 460 parts of caprolactone-modified epoxy resin, 50 parts of propylene glycol methyl ether, 5 parts of curing accelerator DMP-30, and 170 parts of amine curing agent isophorone diamine.

[0083] i. Preparation of the caprolactone-modified epoxy resin: 80 parts of caprolactone monomer and 380 parts of E51 epoxy resin are dehydrated and then reacted at 140°C for 5 h in the presence of dibutyltin dilaurate catalyst to obtain a caprolactone-modified epoxy resin.

[0084] ii. Adding 50 parts of propylene glycol methyl ether diluent to 460 parts of caprolactone-modified epoxy resin, and then stirring and mixing uniformly to obtain component A.

[0085] iii. Mixing 170 parts of isophorone diamine and 5 parts of curing accelerator DMP-30 as component B with component A, and then coating on the corresponding substrate to obtain a caprolactone-modified epoxy primer.

[0086] II. Preparation of the caprolactone-modified polyurea coating:

[0087] The components of the caprolactone-modified polyurea coating include 1150 parts of semi-prepolymer component, 0.5 parts of defoaming agent BYK-066N as auxiliary component, 453 parts of caprolactone-modified amino chain extender component, and 8 parts of black color paste BT-508 black as color paste specially used for polyurea.

[0088] i. Preparation of the caprolactone-modified amino chain extender: 396 parts of di-amino chain extender and 57 parts of caprolactone are reacted at 130°C in the presence of stannous octoate catalyst to obtain a caprolactone-modified amino chain extender.

[0089] Preparation of semi-prepolymer component: semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0090] Preparation of semi-prepolymer component: semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0091] Preparation of semi-prepolymer component: semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0092] Preparation of semi-prepolymer component: semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0093] Example 5

[0094] Preparation of semi-prepolymer component: semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0095] Preparation of semi-prepolymer component: semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0096] Preparation of semi-prepolymer component: semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0097] Preparation of semi-prepolymer component: semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0098] Preparation of semi-prepolymer component: semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0099] Preparation of semi-prepolymer component: semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0100] Preparation of semi-prepolymer component: semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0101] Preparation of semi-prepolymer component: semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0102] ii. Preparation of the semi-prepolymer component: a semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0103] iii. Mixing 510 parts of caprolactone-modified amino chain extender, 8 parts of color paste, and 0.5 parts of defoaming agent BYK-066N to obtain component D.

[0104] iv. When the caprolactone-modified epoxy primer is not completely cured, the C component and the D component are mixed and sprayed on the epoxy primer using a spraying device specially used for spraying polyurea coatings to obtain a caprolactone-modified polyurea coating.

[0105] v. After the caprolactone-modified epoxy primer and the caprolactone-modified polyurea coating are completely cured, a caprolactone-modified composite coating is obtained.

[0106] Example 6

[0107] I. Preparation of the caprolactone-modified epoxy primer:

[0108] The components of the caprolactone-modified epoxy primer include 460 parts of caprolactone-modified epoxy resin, 50 parts of propylene glycol methyl ether, 5 parts of curing accelerator DMP-30, and 170 parts of amine curing agent isophorone diamine.

[0109] i. Preparation of the caprolactone-modified epoxy resin: 80 parts of caprolactone monomer and 380 parts of E51 epoxy resin are dehydrated and then reacted at 140°C for 5 h in the presence of dibutyltin dilaurate catalyst to obtain a caprolactone-modified epoxy resin.

[0110] ii. Adding 50 parts of propylene glycol methyl ether diluent to 460 parts of caprolactone-modified epoxy resin, and then uniformly mixing and stirring to obtain component A.

[0111] iii. Mixing 170 parts of isophorone diamine and 5 parts of curing accelerator DMP-30 as component B with component A, and then coating on the corresponding substrate to obtain a caprolactone-modified epoxy primer.

[0112] II. Preparation of the caprolactone-modified polyurea coating:

[0113] The components of the caprolactone-modified polyurea coating include 1150 parts of semi-prepolymer component, 0.5 parts of defoaming agent BYK-066N as auxiliary component, 567 parts of caprolactone-modified amino chain extender component, and 8 parts of black color paste BT-508 black as color paste specially used for polyurea.

[0114] i. Preparation of the caprolactone-modified amino chain extender: 396 parts of di-amino chain extender and 171 parts of caprolactone are reacted at 130°C in the presence of stannous octoate catalyst to obtain a caprolactone-modified amino chain extender.

[0115] Preparation of semi-prepolymer component: semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0116] Preparation of semi-prepolymer component: semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0117] Preparation of semi-prepolymer component: semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0118] Preparation of semi-prepolymer component: semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0119] Example 7

[0120] Preparation of semi-prepolymer component: semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0121] Preparation of semi-prepolymer component: semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0122] Preparation of semi-prepolymer component: semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0123] Preparation of semi-prepolymer component: semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0124] Preparation of semi-prepolymer component: semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0125] Preparation of semi-prepolymer component: semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0126] Preparation of semi-prepolymer component: semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0127] Preparation of semi-prepolymer component: semi-prepolymer prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0128] Preparation of the semi-prepolymer component: a semi-prepolymer was prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0129] Preparation of the semi-prepolymer component: a semi-prepolymer was prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0130] Preparation of the semi-prepolymer component: a semi-prepolymer was prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0131] Preparation of the semi-prepolymer component: a semi-prepolymer was prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0132] Example 8

[0133] Preparation of the semi-prepolymer component: a semi-prepolymer was prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0134] The components of the caprolactone-modified epoxy resin primer include 508 parts of caprolactone-modified epoxy resin, 50 parts of propylene glycol methyl ether, 5 parts of curing accelerator DMP-30, and 170 parts of amine curing agent isophorone diamine.

[0135] Preparation of the semi-prepolymer component: a semi-prepolymer was prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0136] Preparation of the semi-prepolymer component: a semi-prepolymer was prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0137] Preparation of the semi-prepolymer component: a semi-prepolymer was prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0138] Preparation of the semi-prepolymer component: a semi-prepolymer was prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0139] The components of the caprolactone-modified epoxy resin primer include 508 parts of caprolactone-modified epoxy resin, 50 parts of propylene glycol methyl ether, 5 parts of curing accelerator DMP-30, and 170 parts of amine curing agent isophorone diamine.

[0140] Preparation of the semi-prepolymer component: a semi-prepolymer was prepared by reacting 400 parts of polycaprolactone polyol PCL-2044 with 750 parts of MDI at 75°C for 2.5 h to obtain component C.

[0141] ② Preparation of semi-prepolymer component: The semi-prepolymer obtained by reacting 400 parts of polycaprolactone polyol PCL-2044 and 750 parts of MDI at 75℃ for 2.5h is component C.

[0142] ③ Mix 510 parts of caprolactone-modified amino chain extender, 8 parts of color paste and 0.5 parts of defoamer BYK-066N evenly to obtain component D.

[0143] ④ Before the caprolactone-modified epoxy primer is fully cured, use a special spraying equipment for spraying polyurea coatings to mix components C and D and then spray them onto the epoxy primer to obtain a caprolactone-modified polyurea coating.

[0144] ⑤ After the caprolactone-modified epoxy resin primer and the caprolactone-modified polyurea coating have been completely cured, a caprolactone-modified composite coating is obtained.

[0145] Example 9

[0146] I. Preparation of caprolactone-modified epoxy resin primer:

[0147] The components of the caprolactone-modified epoxy resin primer include 508 parts caprolactone-modified epoxy resin, 50 parts propylene glycol methyl ether, 5 parts curing accelerator DMP-30, and 170 parts amine curing agent isophorone diamine.

[0148] ① Preparation of caprolactone-modified epoxy resin: 128 parts of caprolactone monomer and 380 parts of E51 epoxy resin were dehydrated and then reacted at 140℃ for 5 h under the action of dibutyltin dilaurate catalyst to obtain caprolactone-modified epoxy resin.

[0149] ② Add 50 parts of propylene glycol methyl ether diluent to 508 parts of caprolactone-modified epoxy resin, and then stir evenly to obtain component A.

[0150] ③ Mix 170 parts of isophorone diamine and 5 parts of curing accelerator DMP-30 as component B and component A, and then apply the mixture to the corresponding substrate to obtain caprolactone modified epoxy resin primer.

[0151] II. Preparation of caprolactone-modified polyurea coating:

[0152] The components of the caprolactone-modified polyurea coating include 1150 parts of semi-prepolymer component, 0.5 parts of auxiliary component, defoamer BYK-066N, 567 parts of caprolactone-modified amino chain extender component, and 8 parts of polyurea-specific color paste, black color paste BT-508 black.

[0153] ① Preparation of caprolactone-modified amino chain extender: 396 parts of diamino chain extender and 171 parts of caprolactone were reacted at 130℃ in the presence of stannous octoate catalyst to prepare caprolactone-modified amino chain extender.

[0154] Preparation of the epoxy primer: 380 parts of epoxy resin, 50 parts of propylene glycol methyl ether, 5 parts of curing accelerator DMP-30 and 170 parts of amine curing agent isophorone diamine were mixed to obtain the epoxy primer.

[0155] Preparation of the polyurea coating: 1150 parts of semi-prepolymer component, 0.5 parts of defoaming agent BYK-066N, 396 parts of amino chain extender component and 8 parts of black colorant BT-508 black were mixed to obtain the polyurea coating.

[0156] Preparation of the polyurea coating: 1150 parts of semi-prepolymer component, 0.5 parts of defoaming agent BYK-066N, 396 parts of amino chain extender component and 8 parts of black colorant BT-508 black were mixed to obtain the polyurea coating.

[0157] Preparation of the polyurea coating: 1150 parts of semi-prepolymer component, 0.5 parts of defoaming agent BYK-066N, 396 parts of amino chain extender component and 8 parts of black colorant BT-508 black were mixed to obtain the polyurea coating.

[0158] Preparation of the polyurea coating: 1150 parts of semi-prepolymer component, 0.5 parts of defoaming agent BYK-066N, 396 parts of amino chain extender component and 8 parts of black colorant BT-508 black were mixed to obtain the polyurea coating.

[0159] Preparation of the epoxy primer: 380 parts of epoxy resin, 50 parts of propylene glycol methyl ether, 5 parts of curing accelerator DMP-30 and 170 parts of amine curing agent isophorone diamine were mixed to obtain the epoxy primer.

[0160] Preparation of the epoxy primer: 380 parts of epoxy resin, 50 parts of propylene glycol methyl ether, 5 parts of curing accelerator DMP-30 and 170 parts of amine curing agent isophorone diamine were mixed to obtain the epoxy primer.

[0161] Preparation of the epoxy primer: 380 parts of epoxy resin, 50 parts of propylene glycol methyl ether, 5 parts of curing accelerator DMP-30 and 170 parts of amine curing agent isophorone diamine were mixed to obtain the epoxy primer.

[0162] Preparation of the epoxy primer: 380 parts of epoxy resin, 50 parts of propylene glycol methyl ether, 5 parts of curing accelerator DMP-30 and 170 parts of amine curing agent isophorone diamine were mixed to obtain the epoxy primer.

[0163] Preparation of the polyurea coating: 1150 parts of semi-prepolymer component, 0.5 parts of defoaming agent BYK-066N, 396 parts of amino chain extender component and 8 parts of black colorant BT-508 black were mixed to obtain the polyurea coating.

[0164] Preparation of the polyurea coating: 1150 parts of semi-prepolymer component, 0.5 parts of defoaming agent BYK-066N, 396 parts of amino chain extender component and 8 parts of black colorant BT-508 black were mixed to obtain the polyurea coating.

[0165] Preparation of the epoxy primer: 380 parts of epoxy resin, 50 parts of propylene glycol methyl ether, 5 parts of curing accelerator DMP-30 and 170 parts of amine curing agent isophorone diamine were mixed to obtain the epoxy primer.

[0166] Preparation of the epoxy primer: 380 parts of epoxy resin, 50 parts of propylene glycol methyl ether, 5 parts of curing accelerator DMP-30 and 170 parts of amine curing agent isophorone diamine were mixed to obtain the epoxy primer.

[0167] Preparation of the polyurea coating: 1150 parts of semi-prepolymer component, 0.5 parts of defoaming agent BYK-066N, 396 parts of amino chain extender component and 8 parts of black colorant BT-508 black were mixed to obtain the polyurea coating.

[0168] IV. The epoxy primer and the caprolactone-modified polyurea coating are completely cured to obtain the composite coating.

[0169] Comparative Example 2

[0170] I. Preparation of the epoxy primer:

[0171] The components of the epoxy primer include 380 parts of epoxy resin, 50 parts of propylene glycol methyl ether, 5 parts of curing accelerator DMP-30, and 170 parts of amine curing agent isophorone diamine.

[0172] I. Preparation of the epoxy primer:

[0173] II. Preparation of the caprolactone-modified polyurea coating:

[0174] I. Preparation of the epoxy primer:

[0175] The components of the caprolactone-modified polyurea coating include 1150 parts of semi-prepolymer component, 0.5 parts of defoaming agent BYK-066N, 510 parts of caprolactone-modified amino chain extender component, and 8 parts of black color paste BT-508 black for polyurea.

[0176] I. Preparation of the epoxy primer:

[0177] II. Preparation of the caprolactone-modified polyurea coating:

[0178] III. Preparation of the caprolactone-modified amino chain extender:

[0179] IV. The epoxy primer and the caprolactone-modified polyurea coating are completely cured to obtain the composite coating.

[0180] IV. The epoxy primer and the caprolactone-modified polyurea coating are completely cured to obtain the composite coating.

[0181] Performance test method:

[0182]

[0183]

[0184]

[0185] The performance test results are as follows:

[0186]

[0187]

[0188] As can be seen from Examples 1-3 or Examples 4-6 or Examples 7-9, in the caprolactone modified polyurea coating, the more the caprolactone added in the caprolactone and amino chain extender, the more the interlayer adhesion of the polyurea coating and the epoxy coating can be increased, which is mainly because the caprolactone modifies the amino chain extender, converts part of the amino group into hydroxyl group, reduces the reaction speed, allows the polyurea coating to be better cured, thereby improving the adhesion of itself, but the hardness of the coating will also show a downward trend.

[0189] As can be seen from Examples 1, Examples 4, Examples 7, Comparative Example 1 and Comparative Example 2, in the epoxy primer, increasing the addition amount of caprolactone monomer can also increase the adhesion and low-temperature flexibility of the epoxy primer, especially from no addition of caprolactone to addition of a small amount of caprolactone, the adhesion increases obviously. However, with the increase of the addition amount of caprolactone monomer, the hardness will also show a downward trend.

[0190] As can be seen from Examples 1, Examples 4 and Examples 7 and Comparative Example 1, with the increase of the caprolactone segment in the epoxy coating, the interlayer adhesion of the polyurea coating and the epoxy resin will also increase accordingly, which should be that the polyurea coating is added with polycaprolactone polyol PCL-2044, which originally contains more polycaprolactone segments, and with the increase of the addition amount of caprolactone in the epoxy coating, the same structure of the two coatings is more and more, the compatibility is better and better, resulting in the interlayer adhesion of the two coatings is better and better.

[0191] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A caprolactone-modified composite coating, characterized in that, This includes caprolactone-modified epoxy resin coatings used as primers and caprolactone-modified polyurea topcoats used as topcoats. The caprolactone-modified epoxy resin coating comprises component A and component B; component A comprises caprolactone-modified epoxy resin and a diluent; component B comprises an amine curing agent and a first auxiliary agent. The caprolactone-modified polyurea topcoat comprises component C and component D; component C is a semi-prepolymer; component D comprises a caprolactone-modified amino chain extender, a colorant, and a second auxiliary agent. The mass ratio of caprolactone-modified epoxy resin, diluent, and first auxiliary agent is 400-510:20-55:1-5; The mass ratio of caprolactone-modified epoxy resin to amine curing agent is 400-510:165-180; The mass ratio of caprolactone-modified amino chain extender, color paste, and second auxiliary agent is 450-570:5-10:0.5-1; the mass ratio of caprolactone-modified amino chain extender to semi-prepolymer is 450-570:1150-1250. The preparation method of the caprolactone-modified epoxy resin is as follows: Caprolactone-modified epoxy resin is prepared by reacting caprolactone with the hydroxyl groups in E51 epoxy resin at 100-150℃ for 4-10 hours under the action of a first catalyst; wherein the mass ratio of caprolactone to E51 epoxy resin is 16-80:380, and the epoxy equivalent of E51 epoxy resin is 190; the first catalyst is dibutyltin dilaurate, and the addition amount is 50-200 ppm. The preparation method of the caprolactone-modified amino chain extender is as follows: A caprolactone-modified amino chain extender was prepared by reacting a diamino chain extender with caprolactone at 120-150°C under the action of a second catalyst; wherein the mass ratio of the diamino chain extender to caprolactone was 396:57-171; the second catalyst was stannous octoate, and the amount of stannous octoate added ranged from 10-200 ppm; the diamino chain extender was 4,4-diaminodiphenylmethane. The semi-prepolymer is prepared by reacting polycaprolactone polyol with polyisocyanate at 60-90℃ for 2-3 hours; the polycaprolactone polyol is PCL-2044 from Hunan Juren New Materials Co., Ltd.

2. The caprolactone-modified composite coating as described in claim 1, characterized in that, The diluent is propylene glycol methyl ether; the first additive is curing accelerator DMP-30; and the amine curing agent is isophorone diamine.

3. The caprolactone-modified composite coating as described in claim 1, characterized in that, The color paste is BT-508 black, a special black color paste for polyurea; the second additive is a defoamer, which is BYK-066N from BYK GmbH, Germany.

4. A method for preparing a caprolactone-modified composite coating according to any one of claims 1-3, characterized in that, Includes the following steps: Step 1: Prepare the primer coating: 1.1) Preparation of caprolactone-modified epoxy resin: Caprolactone-modified epoxy resin was prepared by reacting caprolactone with the hydroxyl groups in E51 epoxy resin at 100-150℃ for 4-10 hours under the action of a first catalyst. 1.2) Component A is obtained by mixing caprolactone-modified epoxy resin and diluent; 1.3) The amine curing agent and the first additive are mixed to form component B; component A and component B are packaged separately to form the primer coating; Step 2: Prepare the topcoat: 2.1) Preparation of semi-prepolymer: A semi-prepolymer was prepared by reacting polycaprolactone polyol with polyisocyanate at 60-90℃ for 2-3 hours, which was used as component C. 2.2) Preparation of caprolactone-modified amino chain extender: A caprolactone-modified amino chain extender was prepared by reacting a diamino chain extender with caprolactone at 120-150℃ under the action of a second catalyst. 2.2) The caprolactone-modified amino chain extender, color paste and second auxiliary agent are mixed to form component D; component C and component D are packaged separately to form a topcoat.

5. A method of using a caprolactone-modified composite coating according to any one of claims 1-3, characterized in that, Includes the following steps: S1: Mix components A and B and spray them as a primer to form a base coat; the thickness of the base coat is 80-120um. S2: Mix components C and D and spray them as topcoat onto the incompletely cured primer. Then wait for it to cure to form a caprolactone-modified composite coating. The thickness of the topcoat is 0.5mm-2mm.

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