阅读说明：本技术 一种环氧粘合剂、覆盖膜及印刷网板 (Epoxy adhesive, cover film and printing screen ) 是由 邓建波 洪源 陈洪野 吴小平 于 2020-12-30 设计创作，主要内容包括：本发明涉及一种环氧粘合剂、覆盖膜及印刷网板,按质量百分比计,环氧粘合剂包括如下组分：环氧树脂20～60％、成膜树脂20～40％、增粘树脂5～20％、固化剂1～20％、固化促进剂0.1～2％。本发明通过对胶粘剂配方以及覆盖膜的改进,使得本发明的覆盖膜可以低温成型,并且本发明的覆盖膜与网板本体的粘结性能好,不易溢胶和脱层,并有良好的耐化性。本发明的印刷网板的使用寿命长,节约了材料成本,节约了产线的更换工时,提高了使用效率。(The invention relates to an epoxy adhesive, a covering film and a printing screen, wherein the epoxy adhesive comprises the following components in percentage by mass: 20-60% of epoxy resin, 20-40% of film-forming resin, 5-20% of tackifying resin, 1-20% of curing agent and 0.1-2% of curing accelerator. The cover film can be formed at low temperature by improving the formula of the adhesive and the cover film, has good bonding performance with the screen body, is not easy to overflow and delaminate, and has good chemical resistance. The printing screen plate has long service life, saves material cost, saves the replacement working hour of a production line and improves the use efficiency.)

1. An epoxy adhesive characterized by: the composite material comprises the following components in percentage by mass:

2. the epoxy adhesive of claim 1, wherein: the epoxy resin is bisphenol A epoxy, bisphenol F epoxy, novolac epoxy, biphenyl epoxy, phenol epoxy, and one or more of rubber modified product, polyurethane modified product, and acrylic modified product of the above epoxy resin.

3. The epoxy adhesive of claim 1, wherein: the film-forming resin is one or a combination of two or more of nitrile rubber, acrylic rubber and phenoxy resin, and the weight average molecular weight Mw of the film-forming resin is more than or equal to 30000.

4. The epoxy adhesive of claim 1, wherein: the tackifying resin is one or the combination of two or more of rosin resin, rosin derivative, terpene resin, petroleum resin, dicyclopentadiene resin, coumarone-indene resin and alkyl phenolic resin.

5. The epoxy adhesive of claim 1, wherein: the curing agent is at least one or the combination of two or more of a phenol curing agent, an organic amine curing agent and an acid anhydride curing agent;

the curing accelerator is at least one of an amine accelerator, a substituted urea accelerator, an imidazole and salt accelerator thereof, a boron trifluoride amine complex, a phenol accelerator, a metal organic salt accelerator and a phosphine accelerator or a combination of two or more of the above accelerators.

6. The epoxy adhesive according to any one of claims 1 to 5, characterized in that: the epoxy adhesive also comprises a solvent, and the total mass of the epoxy resin, the film-forming resin, the tackifying resin, the curing agent and the curing accelerator is 1-1.2 times of the mass of the solvent.

7. A cover film, characterized by: comprising a polyimide film layer, an adhesive layer formed on the polyimide film layer, the adhesive layer being formed of the epoxy adhesive of any one of claims 1 to 6.

8. The coverfilm of claim 7, wherein: the thickness of the polyimide film layer is 5-25 mu m; the thickness of the bonding layer is 3-20 mu m.

9. A method of making the mulch film according to claim 7 or 8 wherein: and carrying out corona treatment on the polyimide film, coating the epoxy adhesive on the corona surface of the polyimide film, and drying and curing to obtain the cover film.

10. The method for producing coverfilm according to claim 9, wherein: the drying temperature is 70-130 ℃, and the drying time is 1-10 min; the curing temperature is 40-50 ℃, and the curing time is 20-30 h.

11. A printing screen comprises a screen body, and is characterized in that: the printing screen further comprises the cover film according to claim 7 or 8 arranged on the screen body, wherein the bonding layer of the cover film is in contact with the screen body; the covering film is provided with a hollow part for forming a required circuit.

12. A method of making a printing screen according to claim 11, characterized by: and (3) attaching the bonding layer of the covering film to one surface of the screen body, then carrying out hot pressing for 30-80 min at 100-160 ℃ and 0.5-1 MPa, and then carrying out hollow-out treatment on the covering film in a laser mode to obtain the printing screen.

Technical Field

The invention particularly relates to an epoxy adhesive, a covering film and a printing screen.

Background

Photosensitive ink adopted by a traditional printing screen plate is coated on a steel mesh, and then a desired line is obtained in a film exposure and liquid medicine developing and removing mode. The traditional method has the disadvantages of large chemical pollution, short service life cycle of the obtained printing screen plate, frequent screen plate replacement required by the production line using the screen plate, influence on production efficiency, and waste of printing ink, silver paste and the like of the production line.

Disclosure of Invention

The invention aims to provide an epoxy adhesive, a covering film and a printing screen plate, which can prolong the service life of the printing screen plate.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention provides an epoxy adhesive which comprises the following components in percentage by mass:

in the invention, the weight proportion of the epoxy resin is selected to be 20-60%; the drug resistance of the system is insufficient when the content is lower than 20 percent; above 60% the adhesive layer is too hard and affects the adhesion properties. The weight proportion of the film-forming resin is 20-40%, and when the weight proportion is less than 20%, the hole shrinkage phenomenon of coating can be caused, and when the weight proportion is more than 40%, the viscosity of the adhesive is too high, so that the coating is not facilitated, and the bonding strength is influenced.

Preferably, the epoxy adhesive comprises the following components in percentage by mass:

further preferably, the epoxy adhesive comprises the following components in percentage by mass:

preferably, the epoxy resin is bisphenol a type epoxy, bisphenol F type epoxy, novolac epoxy, biphenyl type epoxy, phenol type epoxy, and one or a combination of two or more of rubber modified product, polyurethane modified product, and acrylic modified product of the above epoxy resin.

Further preferably, the epoxy resin is preferably a mixture of one or more of a double-part type A epoxy, a novolac epoxy, a rubber modified epoxy and a polyurethane modified epoxy. .

Further preferably, the epoxy resin is a combination of two epoxy resins, such as a mixture of any two of epoxy resin 128E, epoxy resin N740S, epoxy resin NPPN-272H, epoxy resin NPES 901; further preferably, the mass ratio of the two epoxy resins is 1: 1-2.

According to a preferred embodiment, the epoxy resin is a combination of epoxy resin 128E and epoxy resin N740S in a mass ratio of 1-3.

According to another preferred embodiment, the epoxy resin is a combination of epoxy resin NPPN-272H and epoxy resin NPES901 in a mass ratio of 1-3.

Preferably, the film-forming resin is one or a combination of more of nitrile rubber, acrylic rubber and phenoxy resin.

Preferably, the weight average molecular weight Mw of the film-forming resin is more than or equal to 30000.

According to a specific and preferred embodiment, the nitrile rubber is, for example, 1072CG, available from south Imperial chemical industry of Taiwan, XER-32, EXR-91, available from JSR of Japan, X-740 available from Lanxess of Germany; acrylic rubbers, e.g. DupontG，GXF，Ultra HT; phenoxy resins such as YP50, YP50S, YP70, ZX-1356-2 of Nippon Tekken, Mitsubishi chemical 1256, 4250, 4275.

Preferably, the tackifying resin is one or a combination of two or more of rosin resin, rosin derivative, terpene resin, petroleum resin, dicyclopentadiene (DCPD) resin, coumarone-indene resin and alkyl phenol resin. Wherein the rosin and its derivative resin is selected from GA-85, GA90, GA100, GA115, rosin terpene resin T803, T901, T805, T85, hydrogenated rosin GA-85H, GH100, petroleum resin such as FTR6100, FTR8100 of Mitsui chemical, and alkylphenol-phenolic resin having para (or ortho) to phenol and containing tert-butyl, octyl 1 nonyl, phenyl, cyclohexyl.

Preferably, the curing agent is at least one of a phenol curing agent, an organic amine curing agent and an acid anhydride curing agent, or a combination of two or more of the above curing agents. Among them, phenol curing agents such as linear phenol formaldehyde resin, linear bisphenol a formaldehyde resin, linear o-cresol formaldehyde resin curing agents, organic amines such as Dicyandiamide (DICY), 4-diaminodiphenyl sulfone (4,4-DDS), diaminodiphenylmethane (DDM), acid anhydride curing agents such as methylnadic anhydride MNA-a, polyazelaic anhydride; among them, preferred is a mixture of one or more of DICY, 4-DDS, linear phenol formaldehyde resin, and linear bisphenol A formaldehyde resin.

Preferably, the curing accelerator is at least one of an amine accelerator, a substituted urea accelerator, an imidazole and its salt accelerator, a boron trifluoride amine complex, a phenol accelerator, a metal organic salt accelerator, and a phosphine accelerator, or a combination of two or more thereof.

Further preferably, the curing accelerator is 2-ethyl-4-methylimidazole (2E4MZ), 1-cyanoethyl-2-ethyl-4-methylimidazole 2E4MZ-CN, 2, 4-diamino-6 [2 ' -ethyl-4 ' -methylimidazole- (1 ') ] ethyl-S-triazine 2E4MZ-a, 2-methylimidazole-isocyanurate 2MZ-OK, etc., more preferably 2E4 MZ-CN.

Preferably, the epoxy adhesive further comprises a solvent, and the total mass of the epoxy resin, the film-forming resin, the tackifying resin, the curing agent and the curing accelerator is 1-1.2 times of the mass of the solvent.

The second aspect of the present invention provides a coverlay film comprising a Polyimide (PI) film layer, and an adhesive layer formed on the polyimide film layer, wherein the adhesive layer is formed of the above epoxy adhesive.

Preferably, the thickness of the polyimide film layer is 5-25 μm; the thickness of the bonding layer is 3-20 mu m. If the bonding layer is too thin, the bonding effect of the bonding layer can be influenced, and if the bonding layer is too thick, glue overflow can be generated to the other side of the printing screen plate, so that the laser processing is influenced; if the thickness of the polyimide film layer is too thick, the laser processing efficiency is also affected, larger laser energy and longer processing time are needed, the screen plate can be punched due to too high laser energy and too long processing time, and the rejection rate is increased.

The third aspect of the invention provides a method for preparing the cover film, which comprises the steps of carrying out corona treatment on a polyimide film, coating the epoxy adhesive on the corona surface of the polyimide film, drying and curing to obtain the cover film.

Preferably, the drying temperature is 70-130 ℃, and the drying time is 1-10 min; the curing temperature is 40-50 ℃, and the curing time is 20-30 h.

The fourth aspect of the invention provides a printing screen, which comprises a screen body, and further comprises a cover film arranged on the screen body, wherein a bonding layer of the cover film is in contact with the screen body; the covering film is provided with a hollow part for forming a required circuit.

The screen body in the invention is a printing steel mesh in the prior art.

The fifth aspect of the invention provides a preparation method of the printing screen, wherein the bonding layer of the cover film is attached to one surface of the screen body, then the screen body is hot-pressed for 30-60 min at 80-120 ℃ and 0.5-1 MPa, and then the cover film is hollowed out in a laser mode to obtain the printing screen.

According to the invention, by adopting laser processing, thinner hollows can be obtained, and silver paste is transferred and attached to a product through the hollows during printing, so that a thinner line drawing can be obtained, and the material cost can be saved.

Due to the adoption of the technical scheme, compared with the prior art, the invention has the following advantages:

the invention improves the adhesive formula and the cover film, so that the cover film can be hot-pressed at low temperature, and the cover film has good bonding property with the screen body, is not easy to overflow and delaminate, and has good chemical resistance.

The printing screen plate has long service life, saves material cost, saves the replacement working hour of a production line and improves the use efficiency.

Drawings

FIG. 1 is a schematic view of a structure of a cover film attached to a screen body;

fig. 2 is a schematic diagram of processing a cover film by a laser method.

Detailed Description

The technical solution of the present invention is further described below with reference to specific embodiments, but the present invention is not limited to the following embodiments. The implementation conditions used in the examples can be further adjusted according to specific requirements, and the implementation conditions not indicated are generally the conditions in routine experiments.

The starting materials and reagents used in the present invention are commercially available.

Example 1

128E/20 parts of epoxy resin, 30 parts of epoxy resin NPPN-272H, rosin resin: GA90A/10 parts, nitrile rubber 1072CG/40 parts, 4,4-DDS/15 parts, 2E4MZ-CN/0.5 part, butanone solvent/100 parts are used for dissolving or dispersing to prepare the epoxy adhesive.

Pre-corona-treating a PI film, coating an epoxy adhesive on the corona surface of the PI film, drying a solvent at 80 ℃/5mins, compounding release paper, rolling, placing in an oven, and curing at 45 ℃/24H to obtain the PI cover film.

After the release paper is torn off from the PI cover film, the adhesive layer is attached to one surface of the steel mesh, and then hot pressing is carried out in a hot press under the hot pressing condition of 120 ℃/60 mins/0.5-1.0 Mpa. And (3) carrying out partial hollow-out treatment on the PI covering film on the screen plate after hot press molding in a laser mode to obtain the desired circuit.

Example 2

128E/30 parts of epoxy resin, NPPN-272H/30 parts of epoxy resin, rosin resin: 100/10 parts of GA, 1072CG/30 parts of nitrile rubber, 4,4-DDS/18 parts of 2E4MZ-CN/0.5 part of butanone solvent per 100 parts of nitrile rubber, and dissolving or dispersing to prepare the epoxy adhesive.

Pre-corona-treating a PI film, coating an epoxy adhesive on the corona surface of the PI film, drying a solvent at 80 ℃/5mins, compounding release paper, rolling, placing in an oven, and curing at 45 ℃/24H to obtain the PI cover film.

After the release paper is torn off from the PI cover film, the adhesive layer is attached to one surface of the steel mesh, and then hot pressing is carried out in a hot press under the hot pressing condition of 120 ℃/60 mins/0.5-1.0 Mpa. And (3) carrying out partial hollow-out treatment on the PI covering film on the screen plate after hot press molding in a laser mode to obtain the desired circuit.

Example 3

128E/30 parts of epoxy resin, NPPN-272H/30 parts of epoxy resin, rosin resin: 100/10 parts of GA, 1072CG/40 parts of nitrile rubber, 6 parts of DICY and 0.5 part of 2E4MZ-CN, and dissolving or dispersing the components by using butanone solvent per 100 parts to prepare the epoxy adhesive.

Pre-corona-treating a PI film, coating an epoxy adhesive on the corona surface of the PI film, drying a solvent at 80 ℃/5mins, compounding release paper, rolling, placing in an oven, and curing at 45 ℃/24H to obtain the PI cover film.

After the release paper is torn off from the PI cover film, the adhesive layer is attached to one surface of the steel mesh, and then hot pressing is carried out in a hot press under the hot pressing condition of 120 ℃/60 mins/0.5-1.0 Mpa. And (3) carrying out partial hollow-out treatment on the PI covering film on the screen plate after hot press molding in a laser mode to obtain the desired circuit.

Example 4

Epoxy resin N740S/20 parts, epoxy resin NPPN-272H/40 parts, nitrile rubber 1072CG/30 parts, rosin resin: GB120/10 parts, 4,4-DDS/16 parts, 2E4MZ-CN/0.5 parts, butanone solvent/100 parts are used for dissolving or dispersing to prepare the epoxy adhesive.

Pre-corona-treating a PI film, coating an epoxy adhesive on the corona surface of the PI film, drying a solvent at 80 ℃/5mins, compounding release paper, rolling, placing in an oven, and curing at 45 ℃/24H to obtain the PI cover film.

After the release paper is torn off from the PI cover film, the adhesive layer is attached to one surface of the steel mesh, and then hot pressing is carried out in a hot press under the hot pressing condition of 120 ℃/60 mins/0.5-1.0 Mpa. And (3) carrying out partial hollow-out treatment on the PI covering film on the screen plate after hot press molding in a laser mode to obtain the desired circuit.

Example 5

Epoxy resin N740S/20 parts, epoxy resin NPES901/40 parts, nitrile rubber 1072CG/30 parts, rosin resin: GB120/10 parts, 4,4-DDS/2 parts, DICY/4 parts, 2E4MZ-CN/0.5 parts, butanone solvent/100 parts, by dissolving or dispersing to make into epoxy adhesive.

Pre-corona-treating a PI film, coating an epoxy adhesive on the corona surface of the PI film, drying a solvent at 80 ℃/5mins, compounding release paper, rolling, placing in an oven, and curing at 45 ℃/24H to obtain the PI cover film.

After the release paper is torn off from the PI cover film, the adhesive layer is attached to one surface of the steel mesh, and then hot pressing is carried out in a hot press under the hot pressing condition of 120 ℃/60 mins/0.5-1.0 Mpa. And (3) carrying out partial hollow-out treatment on the PI covering film on the screen plate after hot press molding in a laser mode to obtain the desired circuit.

Comparative example 1

128E/20 parts of epoxy resin, 10 parts of epoxy resin NPPN-272H, 1072CG/60 parts of nitrile rubber, and rosin resin: GB120/10 parts, 4,4-DDS/9 parts, 2E4MZ-CN/0.5 parts, butanone solvent/100 parts are used for dissolving or dispersing to prepare the epoxy adhesive.

Pre-corona-treating a PI film, coating an epoxy adhesive on the corona surface of the PI film, drying a solvent at 80 ℃/5mins, compounding release paper, rolling, placing in an oven, and curing at 45 ℃/24H to obtain the PI cover film.

After the release paper is torn off from the PI cover film, the adhesive layer is attached to one surface of the steel mesh, and then hot pressing is carried out in a hot press under the hot pressing condition of 120 ℃/60 mins/0.5-1.0 Mpa. And (3) carrying out partial hollow-out treatment on the PI covering film on the screen plate after hot press molding in a laser mode to obtain the desired circuit.

Comparative example 2

128E/30 parts of epoxy resin, NPPN-272H/55 parts of epoxy resin, 1072CG/10 parts of nitrile rubber, and rosin resin: GB120/5 parts, 4,4-DDS/24 parts, 2E4MZ-CN/0.5 parts, butanone solvent/100 parts are used for dissolving or dispersing to prepare the epoxy adhesive.

Pre-corona-treating a PI film, coating an epoxy adhesive on the corona surface of the PI film, drying a solvent at 80 ℃/5mins, compounding release paper, rolling, placing in an oven, and curing at 45 ℃/24H to obtain the PI cover film.

After the release paper is torn off from the PI cover film, the adhesive layer is attached to one surface of the steel mesh, and then hot pressing is carried out in a hot press under the hot pressing condition of 120 ℃/60 mins/0.5-1.0 Mpa. And (3) carrying out partial hollow-out treatment on the PI covering film on the screen plate after hot press molding in a laser mode to obtain the desired circuit.

Comparative example 3

128E/20 parts of epoxy resin, 40 parts of epoxy resin NPPN-272H, 1072CG/30 parts of nitrile rubber, and rosin resin: GB120/10 parts, 4,4-DDS/15 parts, butanone solvent/100 parts are used for dissolving or dispersing, and the epoxy adhesive is prepared.

Pre-corona-treating a PI film, coating an epoxy adhesive on the corona surface of the PI film, drying a solvent at 80 ℃/5mins, compounding release paper, rolling, placing in an oven, and curing at 45 ℃/24H to obtain the PI cover film.

After the release paper is torn off from the PI cover film, the adhesive layer is attached to one surface of the steel mesh, and then hot pressing is carried out in a hot press under the hot pressing condition of 120 ℃/60 mins/0.5-1.0 Mpa. And (3) carrying out partial hollow-out treatment on the PI covering film on the screen plate after hot press molding in a laser mode to obtain the desired circuit.

The sources of the raw materials are as follows:

epoxy resin 128E, south Taiwan Asia

Epoxy resin N740S, Nantong star chemical industry

Epoxy resin NPPN-272, south Taiwan Asia

Epoxy resin NPES901, Taiwan south Asia nitrile rubber 1072CG, Taiwan south Di chemical

4,4-DDS, Indian acanthus

DICY, Ningxia Jia peaking tool

2E4MZ-CN, Japan four kingdom chemical

The rosin resin GA90A, GA100 and GB120 is a Japanese crude Sichuan chemical product

The experimental data of the above examples and comparative examples are as follows:

comprehensive evaluation

"good" indicates acceptable performance, "very good" indicates excellent performance, "Δ" indicates general performance, and "x" indicates poor performance.

The evaluation method comprises the following steps:

bonding strength: after the PI covering film and the screen plate are hot-pressed, the PI covering film and the screen plate are cut into 1cm multiplied by 20cm, the PI film at the end part in the length direction is pulled out, 180 degrees of peeling is carried out, and the peeling is carried out at the speed of 100 mm/min.

And (3) drying by touching with fingers: after the PI covering film is subjected to hot pressing, the rubber surface is touched by fingers, the touch viscosity is OK when the touch viscosity is not high, and the touch viscosity is NG when the touch viscosity is high.

Glue overflow amount: punching 5 holes on the PI cover film by using a puncher with the diameter of 10mm, carrying out hot pressing on the PI cover film and a screen plate according to the condition of 120 ℃/60mins/0.5Mpa, and measuring the glue flow overflowing from the round holes by using an electron microscope.

Drug resistance: soaking the laser-cut screen plate in the slurry for 24H, wiping, observing whether the liquid medicine of the slurry seeps into the position between the PI and the adhesive layer on the cover film or between the adhesive layer and the screen plate through a microscope, and floating or layering the slurry, wherein if the slurry occurs, NG is performed, and if the slurry does not occur, OK is performed;

(slurry composition: silver powder/80%, bisphenol A epoxy/10%, acid anhydride curing agent 2%, methylimidazole/0.5%, butyl acetate/5%, reactive diluent 692/1.5%, tetraethyl titanate/0.5%, polyamide wax/0.5%).

Dimensional stability: after the PI covering film is hot-pressed with 200mm × 200mm and a screen plate, ABCD is selected at 4 corners of the PI film, 4 points are selected, and an oil pen is used for making a dotted mark. The distances AB ', BC ', CD ', DA ' before 4 points were measured using a two-dimensional test AB, BC, CD, DA ', and the distances between these 4 points were measured again using 10000 strokes of the squeegee. The calculated shrinkage 1 ═ AB '- [ (AB)/AB + (CD' -CD)/CD ]/2, and the calculated shrinkage 2 ═ BC '-BC)/BC + (DA' -DA)/DA ]/2, the maximum of the shrinkages 1 and 2 was recorded as a value of the dimensional stability.

The present invention is described in detail in order to make those skilled in the art understand the content and practice the present invention, and the present invention is not limited to the above embodiments, and all equivalent changes or modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.