CN115595049B

CN115595049B - Anti-graffiti polyurethane coating

Info

Publication number: CN115595049B
Application number: CN202110774656.9A
Authority: CN
Inventors: 李民; 蔡相成; 杨卉艳
Original assignee: Shanghai HIUV Applied Materials Technology Co Ltd; Shanghai HIUV New Materials Co Ltd
Current assignee: Shanghai HIUV Applied Materials Technology Co Ltd; Shanghai HIUV New Materials Co Ltd
Priority date: 2021-07-08
Filing date: 2021-07-08
Publication date: 2023-06-27
Anticipated expiration: 2041-07-08
Also published as: CN115595049A

Abstract

The invention provides an anti-graffiti polyurethane coating, which comprises the following components in parts by weight: 100 parts of long carbon chain polyurethane, 1-10 parts of reactive organic silicon and other auxiliary agents; and (3) drying the coating slurry, and performing radiation crosslinking to obtain the anti-graffiti polyurethane coating. The long carbon chain polyurethane and the reactive organosilicon form a compact network structure through radiation crosslinking, the organosilicon structure with low surface energy endows the coating with anti-graffiti performance, and no micromolecular solvent volatilizes in the use process.

Description

Anti-graffiti polyurethane coating

Technical Field

The invention belongs to the technical field of coating, and particularly relates to an anti-graffiti polyurethane coating.

Background

The coating mainly plays a role in decoration or protection of the surfaces of various objects. The surface of the coating needs to have lower surface tension to improve the self-cleaning property of the surface of the object, thereby producing the anti-graffiti effect.

At present, the anti-graffiti technology obtains a certain use effect based on the anti-graffiti performance of low surface energy resin or inorganic mineral particles such as organic silicon or fluorocarbon. The organosilicon, fluororesin or inorganic mineral particles are mixed with other resins (such as acrylic resin) or physical solutions of auxiliary agents to obtain oil-soluble paint products based on organic solvents. The method is simple and practical, has low cost, but the components are only physically combined, the necessary chemical bond connection is lacked, a homogeneous and tough coating film is difficult to obtain, and the effective components playing the anti-graffiti role are easy to freely migrate out of the film, so that the anti-graffiti performance is obviously reduced with the extension of time, and even the anti-graffiti performance is completely lost. Although some anti-graffiti coatings attempt to solve this problem by chemically crosslinking the coating, which overcomes the migration of the active ingredients to some extent, the large amount of organic solvents in the coating formulation are extremely prone to cause significant environmental damage during production and use.

Therefore, finding an environment-friendly coating with anti-graffiti performance is an important point of research.

Disclosure of Invention

In order to solve the technical problems, the invention provides an anti-graffiti polyurethane coating, which comprises the following components in parts by weight: 100 parts of long carbon chain polyurethane, 1-10 parts of reactive organic silicon and other auxiliary agents; and (3) drying the coating slurry, and performing radiation crosslinking to obtain the anti-graffiti polyurethane coating.

The long carbon chain polyurethane is obtained by polycondensation reaction of polyisocyanate and hydroxyl-terminated long carbon chain polyol serving as raw materials. The hydroxyl-terminated long carbon chain polyol comprises one or more of hydroxyl-terminated polyol, polyol polyoxyalkylene ether and polyol ester, wherein the longest carbon chain length of single hydroxyl connection is more than 6. The polyisocyanate component comprises one or more polyisocyanates. The end group of the reactive organosilicon is epoxy group, alkenyl group or acrylate group. Other adjuvants include co-crosslinking agents and crosslinking promoters. The polyurethane coating with the anti-graffiti performance is obtained through the treatment.

The polyurethane coating used in the invention has no low boiling point and volatile small organic molecules. The carbon chain length in the polyurethane molecular soft segment structure in the coating is greater than 6, the long carbon chain in the polyurethane molecular soft segment can be initiated by radiation crosslinking to serve as an active crosslinking point to carry out crosslinking reaction with an active group in the reactive organosilicon to form a three-dimensional network structure, the density of the active crosslinking point is increased by the long carbon chain structure, so that the crosslinking network density is improved, a homogeneous and tough coating film is obtained, and the organosilicon component with the anti-graffiti function is not easy to migrate out of the film due to chemical bond connection with the polyurethane main chain, so that the polyurethane coating with better performance and anti-graffiti and no volatile gas is obtained.

Detailed Description

In order to make the objects, technical solutions and advantageous technical effects of the present invention clearer, the present invention will be described in detail with reference to specific embodiments. It should be understood that the examples described in this specification are for the purpose of illustrating the invention only and are not intended to limit the invention.

For simplicity, only a few numerical ranges are explicitly disclosed herein. However, any lower limit may be combined with any upper limit to form a range not explicitly recited; and any lower limit may be combined with any other lower limit to form a range not explicitly recited, and any upper limit may be combined with any other upper limit to form a range not explicitly recited. Furthermore, each point or individual value between the endpoints of the range is included within the range, although not explicitly recited. Thus, each point or individual value may be combined as a lower or upper limit on itself with any other point or individual value or with other lower or upper limit to form a range that is not explicitly recited.

In the description herein, unless otherwise indicated, "above" and "below" are intended to include the present number, and the meaning of "multiple" in "one or more" is two or more.

The above summary of the present invention is not intended to describe each disclosed embodiment or every implementation of the present invention. The following description more particularly exemplifies illustrative embodiments. Guidance is provided throughout this application by a series of embodiments, which may be used in various combinations. In various embodiments, the list is merely a representative group and should not be construed as exhaustive.

The invention provides an anti-graffiti polyurethane coating, which is prepared by mixing long carbon chain polyurethane, reactive organic silicon and other auxiliary agents, adding a solvent to obtain coating slurry, and coating the leather surface by using the slurry; drying the coated slurry, and performing radiation crosslinking to obtain the anti-graffiti polyurethane coating;

in some embodiments, the polyisocyanate component used to prepare the long carbon chain polyurethane includes aromatic diisocyanates such as 4,4' -methylenediphenyl isocyanate (MDI), m-Xylene Diisocyanate (XDI), benzene-1, 4-diisocyanate, naphthalene-1, 5-diisocyanate, and Toluene Diisocyanate (TDI); and aliphatic diisocyanates such as isophorone diisocyanate (IPDI), hexamethylene Diisocyanate (HDI), 1, 4-cyclohexyl diisocyanate (CHDI), decane-1, 10-diisocyanate, lysine Diisocyanate (LDI), 1, 4-Butane Diisocyanate (BDI) and dicyclohexylmethane-4, 4' -diisocyanate (H12 MDI). Mixtures of two or more polyisocyanates may be used.

In some embodiments, the hydroxyl-terminated long carbon chain polyols used to prepare the long carbon chain polyurethanes are one or more of the diols, with a single hydroxyl group attached to a carbon chain length greater than 6, including aliphatic or cycloaliphatic diols. For example: 1, 6-hexanediol, 2, 4-trimethyl 1, 6-hexanediol, 1, 10-decanediol, 1, 12-octadecanediol, 1, 3-cyclohexanediol, 1, 4-dimethylolcyclohexane, 1, 4-cyclohexanediol, 1, 3-dimethylolcyclohexane.

In some embodiments, the hydroxyl-terminated polyol polyoxyalkylene ether used to prepare the long carbon chain polyurethane is obtained by addition polymerization of a glycol having a carbon chain length greater than 6, to which a single hydroxyl group is attached, as an initiator, with one or more of ethylene oxide, propylene oxide, and tetrahydrofuran. For example, 1, 6-hexanediol, 2, 4-trimethyl-1, 6-hexanediol, 1, 10-decanediol, 1, 12-octadecanediol, 1, 3-cyclohexanediol, 1, 4-dimethylolcyclohexane, 1, 4-cyclohexanediol, homo-or block-copolymer adducts of 1, 3-dimethylolcyclohexane with ethylene oxide, propylene oxide, tetrahydrofuran.

In some embodiments, hydroxyl-terminated polyol polyesters for use in preparing long carbon chain polyurethanes have carbon chains greater than 6 in the polymer structural units and the polyester end groups are hydroxyl groups. For example: polyethylene adipate, polycaprolactone, polypropylene pimelate, polybutylene succinate, polyhexamethylene isophthalate, polyethylene cyclohexanedicarboxylate, and the like.

In some embodiments, the reactive silicone has an epoxy, alkenyl, or acrylate group at its end group, which may be double-ended or single-ended or have a reactive group in the side chain.

In some embodiments, the other auxiliary agents are co-crosslinking agents, crosslinking promoters.

The crosslinking accelerator can be one or more of organotin and metal oxide.

The co-crosslinking agent is an organic compound having multiple double bond functionalities.

In some embodiments, the long carbon chain polyurethane slurry is used to coat the leather surface; drying the coating slurry, and performing radiation crosslinking to obtain the anti-graffiti polyurethane coating;

examples

The present disclosure is more particularly described in the following examples that are intended as illustrations only, since various modifications and changes within the scope of the present disclosure will be apparent to those skilled in the art. Unless otherwise indicated, all parts, percentages, and ratios reported in the examples below are by weight, and all reagents used in the examples are commercially available or were obtained synthetically according to conventional methods and can be used directly without further treatment, as well as the instruments used in the examples.

The isocyanates used in the following examples are selected from:

van der Waals chemistry, MDI-100, diphenylmethane diisocyanate;

the chemical nature of the ceramic is such that,

t-80, toluene diisocyanate;

the process of the production of the gas-liquid mixture by the gas-liquid separator,

HI 100AP, hexamethylene diisocyanate;

atanan Wei vibration chemical industry, IPDI, isophorone diisocyanate;

hubei jin Leda chemical Co., ltd., CHDI, cyclohexane-1, 4-diisocyanate;

the polyols used in the following examples are selected from:

basf, HDO,1, 6-hexanediol;

shandongli Cheng Huagong, 1, 10-decanediol;

the polyol polyethers used in the following examples are selected from:

dow chemistry, HECB, diethylene glycol hexylether;

the polyol polyesters used in the following examples are selected from:

oriental cherry seed Jiang Huagong, PCL, polycaprolactone;

the reactive silicones used in the following examples are selected from:

anhui Ai Yaoda, IOTA253, divinyl terminated phenyl silicone oil;

anhui Ai Yaoda, IOTA2031, modified polysiloxane;

anhui Ai Yaoda, IOTA105-4, epoxy singly-terminated polysiloxanes;

the crosslinking promoters used in the following examples are selected from:

jinan sea source, DY-12, dibutyl tin dilaurate;

nantong run Feng, YDH-171, vinyl trimethoxy silane;

the invention also provides a preparation method of the polyurethane coating. According to this production method, the polyurethane coating described above can be produced. The preparation method of the polyurethane coating provided by the embodiment of the invention comprises a long carbon chain polyurethane preparation step, a coating step, an embossing step and a crosslinking step.

The preparation of the long carbon chain polyurethane may be carried out using an aqueous system or a solvent system, and the preparation of both the aqueous polyurethane and the solvent polyurethane is well known, and in this embodiment, the preparation of the solvent type long carbon chain polyurethane is described as an example.

The weight ratio of the components of the polyurethane slurry is shown in table 1, and the preparation steps can be described as follows:

(1) Mixing polyisocyanate and dehydrated polyol in a stirring kettle, stirring at 40-60 ℃ until the mixture is uniform; then slowly heating to 120 ℃ to continue the reaction, and cooling to 50 ℃ after the reaction is completed;

(2) Adding acetone, reactive organic silicon, a crosslinking agent and a crosslinking accelerator, and then continuously stirring and fully reacting;

(3) Adding solvent according to the system viscosity to adjust, and fully reacting to obtain the long carbon chain polyurethane slurry

The coating step can be described as: and (3) coating the long carbon chain polyurethane slurry on the surface of leather, and drying the leather to obtain the polyurethane coating.

The irradiation crosslinking step can be described as: radiation crosslinking may be performed using alpha rays, beta rays, gamma rays, X rays, or neutron rays. The radiation crosslinking is adopted to control the crosslinking more easily, and the crosslinking process is more environment-friendly. In radiation crosslinking, the embossed coating is not in physical contact with the irradiation device, but the crosslinking reaction has already taken place in the interior. As an example, beta rays (i.e., high energy electron beams) may be used for radiation crosslinking. The radiation dose can be selected from 5 KGy-200 KGy,10 KGy-100 KGy,20 KGy-80 KGy, 50 KGy-150 KGy, etc.

The examples were carried out in a stirred tank according to the proportions indicated in Table 1:

and the leather sample with the polyurethane coating is subjected to the anti-graffiti performance test by the method described in the invention, the result is shown in table 2, and the test is as follows:

graffiti resistance test method: the marking "#" is written on the leather coating by using a common oily marking pen under the condition of 20 ℃ and 50% humidity, and after the marking is dried, the marking is wiped by using dry pure cotton cloth, and the recording is carried out according to the wiping result.

From the data of the examples, it can be seen that the polyurethane coating of the present invention gives leather products with better graffiti resistance.

The above description is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto. Various equivalent modifications and substitutions will occur to those skilled in the art, and these are intended to be included within the scope of the present invention. Therefore, the protection scope of the invention is subject to the protection scope defined by the claims.

Table 1 weight parts of the components in the examples

Table 2 example test results

Claims

1. The anti-graffiti polyurethane coating comprises the following components in parts by weight: 100 parts of long carbon chain polyurethane, 1-10 parts of reactive organic silicon and other auxiliary agents;

the long carbon chain polyurethane is obtained by polycondensation reaction of polyisocyanate and hydroxyl-terminated long carbon chain polyol serving as raw materials, wherein the longest carbon chain length of single hydroxyl connection in the hydroxyl-terminated long carbon chain polyol is more than 6;

and (3) drying the coating slurry, and performing radiation crosslinking to obtain the anti-graffiti polyurethane coating.

2. The anti-graffiti polyurethane coating of claim 1, wherein the reactive silicone is one of epoxy, alkenyl, or acrylate based on its end groups.

3. An anti-graffiti polyurethane coating as in claim 1, wherein the other auxiliary agents comprise co-crosslinking agents, crosslinking promoters.

4. The anti-graffiti polyurethane coating of claim 3, wherein the cross-linking promoter is one or more of organotin-based, metal oxide.

5. The anti-graffiti polyurethane coating of claim 3, wherein the co-crosslinking agent is an organic compound having multiple double bond functionalities.