阅读说明：本技术 一种丝印图层及其制备方法 (Silk-screen image layer and preparation method thereof ) 是由 周群飞 周春红 于 2018-08-01 设计创作，主要内容包括：本发明属于丝印领域,尤其涉及一种丝印图层及其制备方法。本发明提供的制备方法包括以下步骤：a)在基底上丝印第一光油,干燥,形成第一光油层；所述第一光油的组分包括4,4’-(1-甲基亚乙基)双苯酚与(氯甲基)环氧乙烷的共聚物、乙二醇丁醚、二氧化硅、密着剂和固化剂；b)在所述第一光油层上丝印金油,干燥,形成金油图层；c)在所述金油层上丝印上丝印第二光油,干燥,形成第二光油层；所述第二光油的组分包括聚酯树脂、石脑油、异佛尔酮、二氧化硅、密着剂和固化剂。相比于单独在蓝宝石或玻璃上丝印金油图案,本发明形成的复合丝印图层具有更高的光泽亮度、更强的附着力和优异的耐酸碱性能。(the invention belongs to the field of silk-screen printing, and particularly relates to a silk-screen image layer and a preparation method thereof. The preparation method provided by the invention comprises the following steps: a) silk-screening first gloss oil on a substrate, and drying to form a first gloss oil layer; the first gloss oil comprises 4, 4' - (1-methylethylidene) biphenol and (chloromethyl) ethylene oxide copolymer, ethylene glycol butyl ether, silicon dioxide, an adhesion agent and a curing agent; b) printing gold oil on the first varnish layer in a silk-screen mode, and drying to form a gold oil pattern layer; c) silk-screen printing second gloss oil on the gold oil layer, and drying to form a second gloss oil layer; the components of the second gloss oil comprise polyester resin, naphtha, isophorone, silicon dioxide, an adhesion agent and a curing agent. Compared with the method of independently silk-printing gold oil patterns on sapphire or glass, the composite silk-printing layer formed by the method has higher gloss brightness, stronger adhesive force and excellent acid and alkali resistance.)

1. A silk-screen pattern layer comprises a substrate, a first gloss oil layer, a gold oil pattern layer and a second gloss oil layer which are contacted in sequence;

the first gloss oil layer is formed by drying first gloss oil, and the components of the first gloss oil comprise:

the second gloss oil layer is formed by drying second gloss oil, and the components of the second gloss oil comprise:

2. the coating of claim 1, wherein the copolymer has an epoxy equivalent weight of 400 to 550; the epoxy value of the copolymer is 0.15-0.25; the viscosity of the copolymer at 25 ℃ is 0.05-0.2 Pa.s; the softening point of the copolymer is 60-80 ℃.

3. The coating of claim 1 wherein the polyester resin is a polyethylene terephthalate resin.

4. The coating of claim 1 wherein the polyester resin has a number average molecular weight of 2 x 104 to 3 x 104.

5. The coating according to any one of claims 1-4, characterized in that in the first varnish and in the second varnish the adhesion agent is 2-aminoisobutanol.

6. The coating of claim 5 wherein the curing agent in the first varnish and the second varnish comprises polyhexamethylene diisocyanate and/or toluene diisocyanate.

7. The coating of claim 6 wherein the gold oil coating is formed by drying a gold oil having a composition comprising:

8. the coating of claim 7, wherein the metal powder has a particle size of 1 to 10 μm.

9. method for preparing a silkscreen coating according to any one of claims 1-8, comprising the steps of:

a) Silk-screening first gloss oil on a substrate, and drying to form a first gloss oil layer;

the first gloss oil comprises 30-50 wt% of a copolymer of 4, 4' - (1-methylethylidene) biphenol and (chloromethyl) ethylene oxide, 30-50 wt% of butyl cellosolve, 1-10 wt% of silicon dioxide, 0-10 wt% of an adhesion agent and 0-20 wt% of a curing agent;

b) printing gold oil on the first varnish layer in a silk-screen mode, and drying to form a gold oil pattern layer;

c) Silk-screen printing second gloss oil on the gold oil layer, and drying to form a second gloss oil layer;

the second gloss oil comprises 50-55 wt% of polyester resin, 10-15 wt% of naphtha, 10-15 wt% of isophorone, 1-10 wt% of silicon dioxide, 0-10 wt% of adhesion agent and 0-20 wt% of curing agent.

10. the method of claim 9, wherein the drying temperature in step a) is 150 to 180 ℃; the drying time is 5-10 min;

in the step b), the drying temperature is 150-180 ℃; the drying time is 5-10 min;

In the step c), the drying temperature is 150-180 ℃; the drying time is 5-10 min.

Technical Field

the invention belongs to the field of silk-screen printing, and particularly relates to a silk-screen image layer and a preparation method thereof.

background

The silk screen printing refers to that a silk screen is used as a plate base, and a silk screen printing plate with pictures and texts is manufactured by a photosensitive plate making method. The screen printing is composed of five major elements, namely a screen printing plate, a scraper, ink, a printing table and a printing stock. The basic principle that the meshes of the image-text part and the non-image-text part of the screen printing plate are permeable to ink and impermeable to ink is utilized to print. When printing, ink is poured into one end of the screen printing plate, a scraper plate is used for applying a certain pressure to the ink position on the screen printing plate, meanwhile, the scraper plate moves towards the other end of the screen printing plate at a constant speed, and the ink is extruded onto a printing stock from meshes of the image-text part by the scraper plate in the moving process.

in recent years, the printing cost of silk screen printing by using metal powder ink is very popular with consumers, but because the metal powder ink has special components, a series of problems exist in the silk screen printing process, and particularly in the silk screen printing process of sapphire and glass, the glossiness, the adhesive force and the acid and alkali resistance of the picture layer obtained by silk screen printing cannot meet the requirements of customers easily.

Disclosure of Invention

in view of the above, the present invention provides a silk-screen image layer and a preparation method thereof, and the silk-screen image layer with high brightness, strong adhesion and acid and alkali resistance can be formed on sapphire and glass by the preparation method provided by the present invention.

the invention provides a silk-screen pattern layer, which comprises a substrate, a first gloss oil layer, a gold oil pattern layer and a second gloss oil layer which are contacted in sequence;

the first gloss oil layer is formed by drying first gloss oil, and the components of the first gloss oil comprise:

the second gloss oil layer is formed by drying second gloss oil, and the components of the second gloss oil comprise:

preferably, the epoxy equivalent of the copolymer is 400-550; the epoxy value of the copolymer is 0.15-0.25; the viscosity of the copolymer at 25 ℃ is 0.05-0.2 Pa.s; the softening point of the copolymer is 60-80 ℃.

Preferably, the polyester resin is a polyethylene terephthalate resin.

Preferably, the number average molecular weight of the polyester resin is 2 × 104 to 3 × 104.

Preferably, in the first gloss oil and the second gloss oil, the adhesion agent is 2-aminoisobutanol.

preferably, in the first gloss oil and the second gloss oil, the curing agent includes polyhexamethylene diisocyanate and/or toluene diisocyanate.

Preferably, the gold oil pattern layer is formed by drying gold oil, and the gold oil comprises the following components:

Preferably, the particle size of the metal powder is 1-10 μm.

The invention provides a method for preparing the silk-screen image layer, which comprises the following steps:

a) Silk-screening first gloss oil on a substrate, and drying to form a first gloss oil layer;

the first gloss oil comprises 30-50 wt% of a copolymer of 4, 4' - (1-methylethylidene) biphenol and (chloromethyl) ethylene oxide, 30-50 wt% of butyl cellosolve, 1-10 wt% of silicon dioxide, 0-10 wt% of an adhesion agent and 0-20 wt% of a curing agent;

b) Printing gold oil on the first varnish layer in a silk-screen mode, and drying to form a gold oil pattern layer;

c) Silk-screen printing second gloss oil on the gold oil layer, and drying to form a second gloss oil layer;

the second gloss oil comprises 50-55 wt% of polyester resin, 10-15 wt% of naphtha, 10-15 wt% of isophorone, 1-10 wt% of silicon dioxide, 0-10 wt% of adhesion agent and 0-20 wt% of curing agent.

preferably, in the step a), the drying temperature is 150-180 ℃; the drying time is 5-10 min;

in the step b), the drying temperature is 150-180 ℃; the drying time is 5-10 min;

in the step c), the drying temperature is 150-180 ℃; the drying time is 5-10 min.

Compared with the prior art, the invention provides a silk-screen image layer and a preparation method thereof. The preparation method provided by the invention comprises the following steps: a) silk-screening first gloss oil on a substrate, and drying to form a first gloss oil layer; the first gloss oil comprises 30-50 wt% of a copolymer of 4, 4' - (1-methylethylidene) biphenol and (chloromethyl) ethylene oxide, 30-50 wt% of butyl cellosolve, 1-10 wt% of silicon dioxide, 0-10 wt% of an adhesion agent and 0-20 wt% of a curing agent; b) printing gold oil on the first varnish layer in a silk-screen mode, and drying to form a gold oil pattern layer; c) silk-screen printing second gloss oil on the gold oil layer, and drying to form a second gloss oil layer; the second gloss oil comprises 50-55 wt% of polyester resin, 10-15 wt% of naphtha, 10-15 wt% of isophorone, 1-10 wt% of silicon dioxide, 0-10 wt% of adhesion agent and 0-20 wt% of curing agent. The method comprises the steps of sequentially silk-printing a first gloss oil layer and a second gloss oil layer before and after silk-printing a gold oil pattern to obtain a composite silk-printing pattern layer containing the gold oil pattern. Compared with the method of independently silk-printing gold oil patterns on sapphire or glass, the composite silk-printing layer formed by the method has higher gloss brightness, stronger adhesive force and excellent acid and alkali resistance.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

fig. 1 is a schematic structural diagram of a silk-screen layer provided in an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

the invention provides a silk-screen pattern layer, which comprises a substrate, a first gloss oil layer, a gold oil pattern layer and a second gloss oil layer which are contacted in sequence;

The first gloss oil layer is formed by drying first gloss oil, and the components of the first gloss oil comprise:

The second gloss oil layer is formed by drying second gloss oil, and the components of the second gloss oil comprise:

referring to fig. 1, fig. 1 is a schematic structural diagram of a silk-screen layer provided in an embodiment of the present invention. Wherein, 1 is the basement, 2 is the first gloss oil layer, 3 is the gold oil picture layer, and 4 is the second gloss oil layer.

The silk-screen printing image layer provided by the invention comprises a substrate 1, a first gloss oil layer 2, a gold oil image layer 3 and a second gloss oil layer 4 which are contacted in sequence, wherein the substrate 1 comprises but is not limited to sapphire or glass.

In the present invention, the first varnish layer 2 is formed by drying a first varnish whose components include a copolymer of 4, 4' - (1-methylethylidene) biphenol and (chloromethyl) ethylene oxide, butyl cellosolve, silica, an adhesion agent, and a curing agent. Wherein the epoxy equivalent of the copolymer is preferably 400 to 550, and more preferably 450 to 525; the epoxy value of the copolymer is preferably 0.15-0.25, and more preferably 0.19-0.22; the viscosity of the copolymer at 25 ℃ is preferably 0.05-0.2 Pa.s, and more preferably 0.1-0.17 Pa.s; the softening point of the copolymer is preferably 60-80 ℃, and more preferably 64-76 ℃; the content of the copolymer in the first gloss oil is 30 to 50 wt%, specifically 30 wt%, 31 wt%, 32 wt%, 33 wt%, 34 wt%, 35 wt%, 36 wt%, 37 wt%, 38 wt%, 39 wt%, 40 wt%, 41 wt%, 42 wt%, 43 wt%, 44 wt%, 45 wt%, 46 wt%, 47 wt%, 48 wt%, 49 wt% or 50 wt%. In the invention, the content of the ethylene glycol butyl ether in the first gloss oil is 30 to 50 wt%, specifically 30 wt%, 31 wt%, 32 wt%, 33 wt%, 34 wt%, 35 wt%, 36 wt%, 37 wt%, 38 wt%, 39 wt%, 40 wt%, 41 wt%, 42 wt%, 43 wt%, 44 wt%, 45 wt%, 46 wt%, 47 wt%, 48 wt%, 49 wt% or 50 wt%. In the present invention, the content of the silica in the first varnish is 1 to 10 wt%, and specifically may be 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, 5 wt%, 5.5 wt%, 6 wt%, 6.5 wt%, 7 wt%, 7.5 wt%, 8 wt%, 8.5 wt%, 9 wt%, 9.5 wt%, or 10 wt%. In the present invention, the adhesion agent includes, but is not limited to, 2-aminoisobutanol, and the content of the adhesion agent in the first gloss oil is 0 to 10 wt%, specifically 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, 5 wt%, 5.5 wt%, 6 wt%, 6.5 wt%, 7 wt%, 7.5 wt%, 8 wt%, 8.5 wt%, 9 wt%, 9.5 wt%, or 10 wt%. In the present invention, the curing agent includes, but is not limited to, polyhexamethylene diisocyanate and/or toluene diisocyanate; the number average molecular weight of the polyhexamethylene diisocyanate is preferably 2 x 104 to 3 x 104; in one embodiment provided by the invention, the curing agent comprises polyhexamethylene diisocyanate and toluene diisocyanate, and the mass ratio of the polyhexamethylene diisocyanate to the toluene diisocyanate is preferably (50-60): (40-50), specifically 55: 45; the content of the curing agent in the first gloss oil is 0 to 10 wt%, specifically 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, 5 wt%, 5.5 wt%, 6 wt%, 6.5 wt%, 7 wt%, 7.5 wt%, 8 wt%, 8.5 wt%, 9 wt%, 9.5 wt%, or 10 wt%. In the present invention, the thickness of the first varnish layer 2 is 1 to 10 μm, and specifically may be 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm or 10 μm.

In the invention, the gold oil pattern layer 3 is completely positioned on the first varnish layer 2 and is formed by drying gold oil which is an oil solution containing metal powder, and the components of the gold oil preferably comprise metal powder, polyester resin, solvent oil, isophorone, a defoaming agent and an adhesion agent. Wherein, the metal powder is preferably aluminum silver powder; the granularity of the metal powder is preferably 1-10 mu m, and can be 1 mu m, 2 mu m, 3 mu m, 4 mu m, 5 mu m, 6 mu m, 7 mu m, 8 mu m, 9 mu m or 10 mu m; the content of the metal powder in the gold oil is preferably 10-15 wt%, and specifically 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt% or 15 wt%. In the present invention, the polyester resin is preferably a polyethylene terephthalate resin; the number average molecular weight of the polyester resin is preferably 2 x 104-3 x 104; the content of the polyester resin in the gold oil is preferably 40 to 60 wt%, and specifically may be 40 wt%, 41 wt%, 42 wt%, 43 wt%, 44 wt%, 45 wt%, 46 wt%, 47 wt%, 48 wt%, 49 wt%, 50 wt%, 51 wt%, 52 wt%, 53 wt%, 54 wt%, 55 wt%, 56 wt%, 57 wt%, 58 wt%, 59 wt%, or 60 wt%. In the present invention, the solvent oil is preferably a heavy solvent oil, and may be naphtha; the content of the solvent oil in the gold oil is preferably 10-25 wt%, and specifically may be 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, or 25 wt%. In the present invention, the content of the isophorone in the gold oil is preferably 10 to 25 wt%, and specifically may be 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, or 25 wt%. In the present invention, the defoaming agent is preferably dimethylsilane; the content of the defoaming agent in the gold oil is preferably 0-5 wt%, and specifically can be 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt% or 5 wt%. In the present invention, the optional kinds of the adhesion agent are described above and will not be described herein again, and the content of the adhesion agent in the gold oil is 0 to 10 wt%, specifically 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, 5 wt%, 5.5 wt%, 6 wt%, 6.5 wt%, 7 wt%, 7.5 wt%, 8 wt%, 8.5 wt%, 9 wt%, 9.5 wt%, or 10 wt%. In the present invention, the thickness of the gold oil layer 3 is 1 to 10 μm, and specifically may be 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm or 10 μm.

In the invention, the second gloss oil layer 4 completely covers the gold oil pattern layer 3 and is formed by drying the second gloss oil, and the components of the second gloss oil comprise polyester resin, naphtha, isophorone, silica, an adhesion agent and a curing agent. Wherein the polyester resin is preferably a polyethylene terephthalate resin; the number average molecular weight of the polyester resin is preferably 2 x 104-3 x 104; the content of the polyester resin in the second gloss oil is 50-55 wt%, specifically 50 wt%, 50.5 wt%, 51 wt%, 51.5 wt%, 52 wt%, 52.5 wt%, 53 wt%, 53.5 wt%, 54 wt%, 54.5 wt% or 55 wt%. In the present invention, the content of the naphtha in the second gloss oil is 10 to 15 wt%, specifically 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, or 15 wt%. In the invention, the content of the isophorone in the second gloss oil is 10-15 wt%, specifically 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt% or 15 wt%. In the invention, the content of the silica in the second gloss oil is 1 to 10 wt%, specifically 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt% or 10 wt%. In the present invention, the optional kinds of the adhesion agent are described above and will not be described herein again, and the content of the adhesion agent in the second gloss oil is 0 to 10 wt%, specifically 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, 5 wt%, 5.5 wt%, 6 wt%, 6.5 wt%, 7 wt%, 7.5 wt%, 8 wt%, 8.5 wt%, 9 wt%, 9.5 wt%, or 10 wt%. In the present invention, the optional kinds of the curing agent are described above and will not be described herein again, and the content of the curing agent in the second gloss oil is 0 to 10 wt%, specifically 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, 5 wt%, 5.5 wt%, 6 wt%, 6.5 wt%, 7 wt%, 7.5 wt%, 8 wt%, 8.5 wt%, 9 wt%, 9.5 wt% or 10 wt%. In the present invention, the thickness of the second varnish layer 4 is 1 to 10 μm, and specifically may be 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm or 10 μm.

The silk-screen pattern layer provided by the invention comprises a first gloss oil layer, a gold oil pattern layer and a second gloss oil layer which are contacted in sequence, and compared with a single gold oil pattern layer, the composite silk-screen pattern layer provided by the invention has higher gloss brightness, stronger adhesive force and excellent acid and alkali resistance on a substrate.

The invention provides a method for preparing a silk-screen image layer, which comprises the following steps:

a) silk-screening first gloss oil on a substrate, and drying to form a first gloss oil layer;

The first gloss oil comprises 30-50 wt% of a copolymer of 4, 4' - (1-methylethylidene) biphenol and (chloromethyl) ethylene oxide, 30-50 wt% of butyl cellosolve, 1-10 wt% of silicon dioxide, 0-10 wt% of an adhesion agent and 0-20 wt% of a curing agent;

b) printing gold oil on the first varnish layer in a silk-screen mode, and drying to form a gold oil pattern layer;

c) silk-screen printing second gloss oil on the gold oil layer, and drying to form a second gloss oil layer;

The second gloss oil comprises 50-55 wt% of polyester resin, 10-15 wt% of naphtha, 10-15 wt% of isophorone, 1-10 wt% of silicon dioxide, 0-10 wt% of adhesion agent and 0-20 wt% of curing agent.

In the method for preparing the silk-screen pattern layer, provided by the invention, first gloss oil is silk-screen printed on a substrate. Wherein the substrate includes, but is not limited to, sapphire or glass. In the present invention, the first gloss oil has been described above and will not be described herein; the scraping hardness adopted during silk-screen printing is preferably A75 +/-5 degrees; the drying temperature is preferably 150-180 ℃, and specifically can be 150 ℃, 155 ℃, 160 ℃, 165 ℃, 170 ℃, 175 ℃ or 180 ℃; the drying time is preferably 5-10 min, and specifically can be 5min, 6min, 7min, 8min, 9min or 10 min; the drying apparatus is preferably a tunnel oven. And forming a first gloss oil layer on the substrate after drying, wherein the thickness of the first gloss oil layer is preferably 1-10 μm, and more preferably 2-4 μm.

and after a first gloss oil layer is formed, silk-printing gold oil on the first gloss oil layer. Wherein, the gold oil is already introduced above and is not described herein again; the scraping hardness adopted during silk-screen printing is preferably A75 +/-5 degrees; the drying temperature is preferably 150-180 ℃, and specifically can be 150 ℃, 155 ℃, 160 ℃, 165 ℃, 170 ℃, 175 ℃ or 180 ℃; the drying time is preferably 5-10 min, and specifically can be 5min, 6min, 7min, 8min, 9min or 10 min; the drying apparatus is preferably a tunnel oven. And forming a gold oil layer on the first gloss oil layer after drying, wherein the thickness of the gold oil layer is preferably 1-10 μm, and more preferably 2-4 μm.

And after the gold oil layer is formed, silk-screen printing of second gloss oil is carried out on the gold oil layer. Wherein, the second gloss oil is already introduced above and is not described herein again; the scraping hardness adopted during silk-screen printing is preferably A75 +/-5 degrees; the drying temperature is preferably 150-180 ℃, and specifically can be 150 ℃, 155 ℃, 160 ℃, 165 ℃, 170 ℃, 175 ℃ or 180 ℃; the drying time is preferably 5-10 min, and specifically can be 5min, 6min, 7min, 8min, 9min or 10 min; the drying apparatus is preferably a tunnel oven. And forming a second gloss oil layer on the gold oil layer after drying, wherein the thickness of the second gloss oil layer is preferably 1-10 μm, and more preferably 2-4 μm.

The method comprises the step of sequentially silk-printing a first gloss oil layer and a second gloss oil layer in front of and behind a silk-printed gold oil pattern to obtain a composite silk-printed pattern layer containing the gold oil pattern. Compared with the method of independently silk-printing gold oil patterns on sapphire or glass, the composite silk-printing image layer formed by the silk-printing process has higher gloss brightness, stronger adhesive force and excellent acid and alkali resistance.

for the sake of clarity, the following examples are given in detail.

In the following examples of the present invention, the copolymer of 4, 4' - (1-methylethylidene) biphenol and (chloromethyl) oxirane has an epoxy equivalent of 450 to 525, an epoxy value of 0.19 to 0.22, a viscosity of 0.1 to 0.17Pa.s at 25 ℃, and a softening point of 64 to 76 ℃; the number average molecular weight of the polyethylene terephthalate resin is 2 x 104-3 x 104; the curing agent comprises the following components: 55 wt% of polyhexamethylene diisocyanate (number average molecular weight of 2X 104-3X 104) and 45 wt% of toluene diisocyanate.