Formula of isocyanate-resistant release coating and patterned heat transfer paper thereof as well as preparation method and application of patterned heat transfer paper

Abstract

The invention relates to the technical field of patterned heat transfer paper, in particular to an isocyanate-resistant release coating formula, patterned heat transfer paper, a manufacturing method of the patterned heat transfer paper and application of the patterned heat transfer paper. According to the formula of the isocyanate-resistant release coating, the release coating is prepared from the following components in parts by mass: 15 to 30 parts of modified polyurethane acrylate, 50 to 80 parts of acrylate monomer, 1 to 8 parts of organic silicon resin and 1 to 10 parts of higher fatty acid amide, and the total amount of the components is 100 parts. The invention provides a formula of an isocyanate-resistant release coating, patterned heat transfer paper with good comprehensive performance in the aspects of hardness, solvent resistance and release stability, and a corresponding manufacturing method and application.

Description

Technical Field

[0001] The invention relates to the technical field of patterned thermal transfer paper, and in particular to an isocyanate-resistant release coating formula and patterned thermal transfer paper thereof, and a preparation method and application thereof. Background Art

[0002] In the production of artificial synthetic leather, the dry process (also known as transfer coating) is to apply the coating agent (polyurethane PU or polyvinyl chloride PVC) on the base paper, and after drying, a continuous and uniform film is formed, and then the film is coated with an adhesive and overlapped with the fabric (or wet base leather), and then dried, the pattern heat transfer paper and the leather are peeled off, and the coating film (including the adhesive layer) will be transferred from the pattern heat transfer paper to the fabric (or leather). Artificial synthetic leather is mainly polyurethane synthetic leather (PU leather) and artificial leather (PVC leather).

[0003] Due to market demand and the advancement of new chemical fiber fabric technology, the types of fabrics (or leathers) used in the manufacturing process of artificial synthetic leather have emerged in an endless stream recently. This has led to new technical problems and challenges in the continuous upgrading of artificial synthetic leather products. The main problem is that due to the use of new chemical fiber fabrics, the original adhesive has poor bonding effect on the new chemical fiber material, so a new chemical adhesive is adopted, which we usually call a two-component adhesive, and its main chemical composition is isocyanate substances. Because this type of adhesive will produce a chemical reaction at high temperature and has a strong material penetration ability, its bonding effect is very significant. Because this type of adhesive acts between the release coating and the fabric, it will also penetrate the release coating and cause the base paper to be unable to be separated from the fabric (or leather) normally. Therefore, it is necessary to improve the release coating formula so that paper and fabric can be separated normally.

[0004] In the prior art, although CN103740262A discloses a high temperature resistant release coating material for artificial synthetic leather release paper and its preparation method and application, the release coating material is composed of the following components: modified polyurethane acrylate, modified epoxy acrylate, tripropylene glycol diacrylate, ethoxylated trimethylolpropane triacrylate, perfluoromethacrylate and γ-methacryloxypropyltrimethylsilane. However, the technical solution of the invention can only be used in synthetic leather products that do not contain isocyanate, and the product has poor hydrolysis resistance.

[0005] Due to the iteration and update of technology, synthetic leather production technology is gradually replaced by new technology using isocyanate as a binder to improve the performance and hydrolysis resistance of synthetic leather. However, the surface release layer of synthetic leather pattern heat transfer paper, which is currently cured by electron beam cross-linking reaction, cannot be used due to the penetration of small molecules of isocyanate. Therefore, the current pattern heat transfer paper cannot be used under the process containing isocyanate as a binder. Summary of the invention

[0006] One of the objects of the present invention is to provide a novel electron beam curing release coating formulation that is resistant to isocyanate.

[0007] The second object of the present invention is to provide a patterned thermal transfer paper having the above release coating formulation, which has good comprehensive performance in terms of hardness, solvent resistance and release stability.

[0008] A third object of the present invention is to provide a method for making the above-mentioned patterned thermal transfer paper.

[0009] A fourth object of the present invention is to provide an artificial synthetic leather made from the above-mentioned pattern heat transfer paper.

[0010] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions: The invention discloses an isocyanate-resistant release coating formula, which comprises, by weight, 15-30 parts of modified polyurethane acrylate, 55-70 parts of acrylate monomer, 1-10 parts of silicone resin and 1-10 parts of higher fatty acid amide, and the total amount of each component is 100 parts.

[0011] Preferably, the modified polyurethane acrylate is prepared by polymerizing isophorone diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate and trimer thereof as raw materials with monomer raw materials of hydroxyethyl acrylate and / or hydroxyethyl methacrylate and / or pentaerythritol triacrylate and / or acrylic acid polycaprolactone; and the acrylate functionality is 1 to 3.

[0012] Preferably, the acrylate monomer is one or more of isobornyl acrylate (IBOA), isooctyl acrylate (EHA), lauric acrylate (LA), 1,6-hexanediol diacrylate (HDDA), dipropylene glycol diacrylate (DPGDA), tripropylene glycol diacrylate (TPGDA), dipropoxy neopentyl glycol diacrylate (2PO-NPGDA), trimethylolpropane triacrylate (TMPTA), triethoxytrimethylolpropane triacrylate (3EO-TMPTA), pentaerythritol triacrylate (PETA), glycidyl ether acrylate (GPTA) and dipentaerythritol hexaacrylate (DPHA).

[0013] Preferably, the silicone resin is one or more of an acrylated product of silicone oil, an epoxy-modified silicone resin, an ammonia-modified silicone resin, a polyurethane-modified silicone resin, a fatty acid-modified silicone resin, a silicone rubber resin and silicone oil.

[0014] The present invention further provides a patterned thermal transfer paper, comprising a base paper and a release coating, wherein the release coating is formed by curing the above-mentioned release coating formula.

[0015] Preferably, the release coating is a coating layer with 100% solid content. The patterned thermal transfer paper in this technical solution has the characteristics of high production efficiency, low transportation cost and energy consumption.

[0016] Preferably, the release coating formula is composed of, in percentage terms, 5% difunctional polyurethane acrylate using isophorone diisocyanate as raw material, 10% trifunctional polyurethane acrylate using isophorone diisocyanate as raw material, 10% acrylate monomer (TPGDA), 20% acrylate monomer (TMPTA), 30% acrylate monomer (DPHA), 5% silicone oil acrylate product, 5% polyurethane modified silicone resin and 5% higher fatty acid amide (-RNHCOR).

[0017] Preferably, the release coating has a pattern on its surface. The artificial synthetic leather produced by the technical solution has a patterned surface, is comfortable to the touch, and is more aesthetically pleasing.

[0018] The present invention also proposes a method for making the above-mentioned patterned thermal transfer paper, wherein an excess release coating formula is coated on the base paper through a feeding system, and the excess coating is scraped off with a scraper, and the base paper with the pre-coating passes through the surface of the embossing roller under the traction of the guide roller and is pressed into a patterned thermal transfer paper with a patterned pattern at one time under the electron beam irradiation of the electron beam irradiation chamber. The process steps in the technical solution are simplified, and the process steps cured by electron beams have the outstanding advantages of simple operation, short curing time and low curing temperature.

[0019] The invention also proposes the application of the pattern heat transfer paper in artificial synthetic leather.

[0020] Beneficial effects: 1. The present invention effectively improves the structure of the electron beam cured surface release layer and solves the problem of using synthetic leather in a process where isocyanate is used as a binder.

[0021] 2. Fundamentally solve the problem of isocyanate permeability and hydrolysis resistance of synthetic leather products.

[0022] 3. The present invention is also applicable to synthetic leather products that do not contain isocyanate, and the temperature resistance and release properties can meet the product requirements.

[0023] 4. The difference between the present invention and CN103740262A is that the product of the present invention is suitable for the release performance and hydrolysis resistance when containing isocyanate. The present invention mainly increases the chain length of the main resin and synthesizes a higher fatty acid amide (-RNHCOR) to change the chemical structure of the surface, making it impossible for isocyanate small molecules to penetrate, thereby ensuring the release performance of the surface layer.

[0024] 5. The present invention uses a release coating formula composed of multifunctional polyurethane acrylate, acrylate monomer, silicone resin and high-grade fatty acid amide. The multifunctional polyurethane acrylate in the new formula can provide a higher cross-linking density for the release coating, thereby effectively preventing the isocyanate in the new adhesive component from strongly penetrating into the release coating at high temperature, resulting in abnormal peeling of the patterned thermal transfer paper; the selected silicone resin can increase the water contact angle of the contact surface between the release coating and the adhesive, reduce the surface energy, make the new adhesive difficult to adsorb, reduce the contact area, and thus achieve effective peeling of the two.

[0025] 6. The patterned heat transfer paper proposed in the present invention adopts the above release coating formula, and various patterns are pressed on the surface through electron beam irradiation and curing, so that the surface of the artificial synthetic leather has a patterned effect, thereby improving the beauty and added value of the artificial synthetic leather. DETAILED DESCRIPTION

[0026] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific implementation methods of the present invention are described in detail below.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0028] The present invention is based on the application of a new type of adhesive. In order to avoid the strong penetration effect of the isocyanate component therein at high temperature, 15-30 parts of modified polyurethane acrylate, 55-80 parts of acrylate monomer, 1-10 parts of silicone resin and 1-10 parts of high-grade fatty acid amide are selected, and the total amount of each component is 100 parts. By selecting multifunctional polyurethane acrylate, a higher cross-linking density can be provided for the release coating, thereby effectively preventing the isocyanate in the new adhesive component from strongly penetrating into the release coating at high temperature, resulting in abnormal peeling of the patterned thermal transfer paper, and the selected silicone resin can increase the water contact angle of the contact surface between the release coating and the adhesive to effectively peel the two.

[0029] In some specific embodiments, the modified polyurethane acrylate is prepared by polymerizing isophorone diisocyanate, hexamethylene diisocyanate and its trimer and diphenylmethane diisocyanate as raw materials with monomer raw materials of hydroxyethyl acrylate and / or hydroxyethyl methacrylate and / or pentaerythritol triacrylate and / or polycaprolactone acrylate; and its acrylate functionality is 1 to 3.

[0030] In some preferred embodiments, the acrylate monomer is one or more of isobornyl acrylate (IBOA), isooctyl acrylate (EHA), lauric acrylate (LA), 1,6-hexanediol diacrylate (HDDA), dipropylene glycol diacrylate (DPGDA), tripropylene glycol diacrylate (TPGDA), dipropoxy neopentyl glycol diacrylate (2PO-NPGDA), trimethylolpropane triacrylate (TMPTA), triethoxy trimethylolpropane triacrylate (3EO-TMPTA), pentaerythritol triacrylate (PETA), glycidyl ether acrylate (GPTA) and dipentaerythritol hexaacrylate (DPHA).

[0031] In some preferred embodiments, the silicone resin is one or more of an acrylated product of silicone oil, an epoxy-modified silicone resin, an ammonia-modified silicone resin, a polyurethane-modified silicone resin, a fatty acid-modified silicone resin, a silicone rubber resin, and silicone oil. Example

[0032] In terms of mass fractions, 20% of trifunctional polyurethane acrylate with isophorone diisocyanate as raw material, 20% of difunctional polyurethane acrylate with isophorone diisocyanate as raw material, 30% of acrylate monomer (TPGDA), 22% of acrylate monomer (TMPTA), 7% of silicone oil acrylate product and 1% of higher fatty acid amide are taken, and the above components are placed in a container in turn and mixed and stirred at room temperature to fully dissolve the solid components, thereby obtaining a uniform, nearly transparent coating.

[0033] The excess coating is applied to the surface of the base paper through the feeding system, and the excess coating is scraped off with a scraper. The base paper with the primer is tractioned by the guide roller and pressed on the surface of the embossing roller to emboss the pattern, and the coating is cured under the electron beam irradiation of the electron beam irradiation chamber to form a release coating attached to the surface of the base paper, thereby preparing patterned thermal transfer paper. Specifically, the irradiation energy of the electron beam is selected to be 0.5KGY, and the release coating formed by the one-time penetration and curing of the lower electron beam energy has various light haze and textures. The surface of the artificial synthetic leather produced by this method has corresponding patterns, comfortable touch, and more aesthetics. The artificial synthetic leather can be polyurethane synthetic leather (PU leather) or polyvinyl chloride artificial leather (PVC leather).

[0034] In a preferred embodiment, the release coating is a 100% solid content coating layer, which has the characteristics of high production efficiency, low transportation cost and energy consumption. Example

[0035] In parts by mass, 15% of difunctional polyurethane acrylate with isophorone diisocyanate as raw material, 15% of trifunctional polyurethane acrylate with isophorone diisocyanate as raw material, 30% of acrylate monomer (TPGDA), 20% of acrylate monomer (TMPTA), 22% of acrylate monomer (DPHA), 5% of silicone oil acrylate product, and 3% of higher fatty acid amide were taken, and the corresponding patterned thermal transfer paper was prepared in the manner of Example 1. Example

[0036] In parts by mass, 10% of difunctional polyurethane acrylate with isophorone diisocyanate as raw material, 10% of trifunctional polyurethane acrylate with isophorone diisocyanate as raw material, 10% of hexafunctional polyurethane acrylate with isophorone diisocyanate as raw material, 20% acrylate monomer (TPGDA), 20% acrylate monomer (TMPTA), 20% acrylate monomer (DPHA), 2% silicone oil acrylate product, 4% polyurethane modified silicone resin and 4% high-grade fatty acid amide were taken, and the corresponding patterned thermal transfer paper was prepared in the manner of Example 1. Example

[0037] In parts by mass, 20% of difunctional polyurethane acrylate using isophorone diisocyanate as a raw material, 5% of trifunctional polyurethane acrylate using isophorone diisocyanate as a raw material, 10% of acrylate monomer (TPGDA), 20% of acrylate monomer (TMPTA), 30% of acrylate monomer (DPHA), 5% of silicone oil acrylate product, 5% of polyurethane modified silicone resin, and 5% of higher fatty acid amide were taken, and the corresponding patterned thermal transfer paper was prepared in the manner of Example 1. Example

[0038] In parts by mass, 10% of difunctional polyurethane acrylate with isophorone diisocyanate as raw material, 10% of trifunctional polyurethane acrylate with isophorone diisocyanate as raw material, 23% of acrylate monomer (TPGDA), 20% of acrylate monomer (TMPTA), 20% of acrylate monomer (DPHA), 5% of silicone oil acrylate product, 6% of polyurethane modified silicone resin, and 6% of higher fatty acid amide were taken, and the corresponding patterned thermal transfer paper was prepared in the manner of Example 1. Example

[0039] In parts by mass, 15% of difunctional polyurethane acrylate with isophorone diisocyanate as raw material, 10% of trifunctional polyurethane acrylate with isophorone diisocyanate as raw material, 10% of acrylate monomer (TPGDA), 20% of acrylate monomer (TMPTA), 24% of acrylate monomer (DPHA), 5% of silicone oil acrylate product, 7% of polyurethane modified silicone resin, and 7% of high-grade fatty acid amide were taken, and the corresponding patterned thermal transfer paper was prepared in the manner of Example 1. Example

[0040] In parts by mass, 12% of difunctional polyurethane acrylate using isophorone diisocyanate as a raw material, 10% of trifunctional polyurethane acrylate using isophorone diisocyanate as a raw material, 10% of acrylate monomer (TPGDA), 20% of acrylate monomer (TMPTA), 27% of acrylate monomer (DPHA), 5% of silicone oil acrylate product, 8% of polyurethane modified silicone resin, and 8% of higher fatty acid amide were taken, and the corresponding patterned thermal transfer paper was prepared in the manner of Example 1. Example

[0041] In parts by mass, 12% of difunctional polyurethane acrylate with isophorone diisocyanate as raw material, 10% of trifunctional polyurethane acrylate with isophorone diisocyanate as raw material, 10% of acrylate monomer (TPGDA), 20% of acrylate monomer (TMPTA), 25% of acrylate monomer (DPHA), 5% of silicone oil acrylate product, 8% of polyurethane modified silicone resin, and 10% of high-grade fatty acid amide were taken, and the corresponding patterned thermal transfer paper was prepared in the manner of Example 1.

[0042] The performance of the patterned thermal transfer paper prepared in the above embodiments was tested as follows: 1. Surface water contact angle: sessile drop method (refer to ASTM D5946-2004) 2. Isocyanate resistance (expressed as peel strength index, according to QBT / T5649-2021): Apply polyurethane (PU layer) coating to the base paper at a thickness of 80um. Bake at 140 degrees for 1 minute, then apply 10% isocyanate content adhesive to the coating surface at a thickness of 50um, bake at 150 degrees for 30 seconds to 1 minute, then apply a layer of synthetic leather base cloth on the surface, bake at 150 degrees for 1-2 minutes, and put it in a 50-degree oven for aging for 24 hours, take it out, cut it into 50mm wide and 100mm long, and test it on a peel force tester with an accuracy of 0.05N (180 degree angle). Take the average value of ten samples each time, and the value less than 15N / m is qualified.

[0043] 3. DMF resistance: Test method: drop a few drops of DMF on the surface and leave it to evaporate completely. Observe that there is no change on the coating surface and no cracks.

[0044] The inventors obtained experimentally according to the above test method: the patterned thermal transfer paper using the new formula electron beam cross-linking and curing can be effectively peeled under the action of the new adhesive, and its peel strength meets the requirements of less than 15N / m, which meets the industry standard. The test data of the patterned thermal transfer paper made from several different functional polyurethane acrylate formulas are available, and the number of functional groups of the corresponding polyurethane acrylate is positively correlated with the peel strength; the surface water contact angle of the patterned thermal transfer paper made from several different mass fractions of mixed silicone resins is above 90 degrees, with good hydrophobicity, and the new adhesive is difficult to adsorb; the DMF resistance is excellent.

[0045] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

[0046] Those skilled in the art should understand that although the present invention is described in the form of multiple embodiments, not every embodiment includes only one independent technical solution. Such description in the specification is only for the sake of clarity. Those skilled in the art should understand the specification as a whole and regard the technical solutions involved in each embodiment as being able to be combined into different embodiments to understand the scope of protection of the present invention.

Claims

1. An isocyanate-resistant release coating formulation, characterized in that: The release coating formula comprises, by weight, 15-30 parts of modified polyurethane acrylate, 55-80 parts of acrylate monomer, 1-10 parts of silicone resin and 1-10 parts of higher fatty acid amide, and the total weight of each component is 100 parts.

2. The release coating formulation according to claim 1, characterized in that: The modified polyurethane acrylate is prepared by polymerizing isophorone diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate and trimer thereof as raw materials with monomer raw materials of hydroxyethyl acrylate and / or hydroxyethyl methacrylate and / or pentaerythritol triacrylate and / or acrylic acid polycaprolactone; the acrylate functionality is 1 to 3.

3. The release coating formulation according to claim 1, characterized in that: The acrylate monomer is one or more of isobornyl acrylate (IBOA), isooctyl acrylate (EHA), lauric acrylate (LA), 1,6-hexanediol diacrylate (HDDA), dipropylene glycol diacrylate (DPGDA), tripropylene glycol diacrylate (TPGDA), dipropoxy neopentyl glycol diacrylate (2PO-NPGDA), trimethylolpropane triacrylate (TMPTA), triethoxy trimethylolpropane triacrylate (3EO-TMPTA), pentaerythritol triacrylate (PETA), glycidyl ether acrylate (GPTA) and dipentaerythritol hexaacrylate (DPHA).

4. The release coating formulation according to claim 1, characterized in that: The silicone resin is one or more of an acrylic ester product of silicone oil, epoxy-modified silicone resin, ammonia-modified silicone resin, polyurethane-modified silicone resin, fatty acid-modified silicone resin, silicone rubber resin, silicone oil, and higher fatty acid amide (-RNHCOR).

5. Patterned thermal transfer paper, comprising base paper and release coating, characterized in that: The release coating is formed by curing the release coating formulation described in any one of claims 1 to 4.

6. The patterned thermal transfer paper according to claim 5, characterized in that: The release coating is a coating layer with 100% solid content.

7. The patterned thermal transfer paper according to claim 6, characterized in that: The release coating formula is composed of the following components in percentage: 5% difunctional polyurethane acrylate with isophorone diisocyanate as raw material, 10% trifunctional polyurethane acrylate with isophorone diisocyanate as raw material, 10% hexafunctional polyurethane acrylate with isophorone diisocyanate as raw material, 10% acrylate monomer (TPGDA), 20% acrylate monomer (TMPTA), 30% acrylate monomer (DPHA), 5% silicone oil acrylate product, 5% polyurethane modified silicone resin and 5% higher fatty acid amide (-RNHCOR).

8. The patterned thermal transfer paper according to claim 5, characterized in that: The release coating surface is formed with patterns.

9. A method for making the patterned thermal transfer paper according to claim 5, characterized in that: An excess amount of release coating formula is applied to the base paper through the feeding system, and the excess coating is scraped off with a scraper. The base paper with the primer is pulled by the guide roller and passed through the surface of the embossing roller and is pressed into a patterned thermal transfer paper with a pattern at one time under the electron beam irradiation in the electron beam irradiation room.

10. Use of the patterned heat transfer paper according to claim 5 in artificial synthetic leather.