Low-surface tension material, release film, preparation method and product

Abstract

The invention discloses a low-surface-tension material, a release film, a preparation method and a product, the low-surface-tension material has a composite structure, the composite structure at least comprises: a first low-tension layer, the main raw material of the first low-tension layer comprises polystyrene of a para-syndiotactic structure, the Tg point of the polystyrene is 100 DEG C, and the melting point of the polystyrene is 240-270 DEG C; the main raw material of the first middle layer is polystyrene of para-syndiotactic structure added with first resin, and the first resin is at least selected from polypropylene resin, polyethylene resin and rubber modified elastomer. According to the invention, polystyrene with specific conformation and performance is selectively adopted to overcome the dependence of a low-surface tension material on auxiliaries such as a release agent in the prior art, so that the use amount of the auxiliaries in the product is effectively reduced, and longer service life and performance stability are obtained.

Description

Technical Field

[0001] The present invention relates to thin layer material technology, in particular to a low surface tension material, a release film, a preparation method and a product. Background Art

[0002] Regarding the release films currently used for hot pressing of flexible circuit board materials, the release films used in the industry include TPX release films, PBT release films, and PET release films coated with release agents. The main disadvantages are: ①TPX release film, the raw materials used are relatively expensive; ②PBT release film, poor adhesive resistance when used for hot pressing, poor release properties for hot pressing of brown boards and double-sided boards without glue; ③PET release film coated with release agent, the release agent is subsequently coated on the PET film, and the release agent will fall off and transfer to the circuit board material during hot pressing, affecting subsequent processing.

[0003] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0004] The purpose of the present invention is to provide a low surface tension material, a release film, a preparation method and a product, which overcomes the dependence of low surface tension materials on auxiliary agents such as release agents in the prior art by selectively using polystyrene with specific conformations and properties, thereby effectively reducing the amount of auxiliary agents in the product and obtaining a longer service life and performance stability.

[0005] To achieve the above-mentioned purpose, an embodiment of the present invention provides a low surface tension material, which has a composite structure. When observed along one direction of its cross section, the composite structure at least includes: a first low tension layer, whose main raw material includes para-syndiotactic polystyrene, the Tg point of polystyrene is 100°C, and the melting point is 240-270°C; a first intermediate layer, whose main raw material is para-syndiotactic polystyrene added with a first resin, and the first resin is at least selected from polypropylene, polyethylene, a blend of polypropylene and polyethylene, ethylene-vinyl acetate copolymer, styrene-ethylene-butadiene copolymer, ethylene-octene copolymer, and rubber modified elastomer. Preferably, in the first intermediate layer, by mass fraction: para-syndiotactic polystyrene resin 30%-70%, styrene-ethylene-butadiene copolymer 5-40%, polyethylene 0-20%, rubber modified elastomer 10%-30%. Preferably, the total thickness of the low surface tension material can be 40-200μm. The first low-tension layer and / or the second low-tension layer are para-syndiotactic polystyrene, and the thickness may be 10-50 μm, and the thickness of the two may be consistent or inconsistent; the thickness of the first intermediate layer may be 20-100 μm.

[0006] In one or more embodiments of the present invention, when observed along one direction of its cross section, the composite structure comprises at least: a plurality of first low-tension layers, whose main raw material comprises para-syndiotactic polystyrene, the Tg point of polystyrene is 100°C, and the melting point is 240-270°C; a plurality of first intermediate layers, whose main raw material comprises para-syndiotactic polystyrene added with a first resin, the first resin being at least selected from polypropylene resin, polyethylene resin, and rubber-modified elastomer; a plurality of second low-tension layers, whose main raw material comprises para-syndiotactic polystyrene, the Tg point of polystyrene is 100°C, and the melting point is 240-270°C.

[0007] In one or more embodiments of the present invention, the first low-tension layer and the second low-tension layer are made of the same material.

[0008] In one or more embodiments of the present invention, the raw material composition of the first low-tension layer and / or the second low-tension layer includes, by weight: para-syndiotactic polystyrene, 60%-100%; toughening modified resin, 5%-40%; heat aging resistant additive, 0.1-2%. Preferably, the toughening modified resin is selected from ethylene-vinyl acetate copolymer, styrene-ethylene-butadiene copolymer, and ethylene-octene copolymer. The heat aging resistant additive is selected from: hindered amine light stabilizer, hindered amine antioxidant. The hindered amine antioxidant can be 2,6-di-tert-butyl-4-methylphenol, antioxidant l010, etc.

[0009] In one or more embodiments of the present invention, the raw material composition of the first intermediate layer includes, by weight: 30%-70% para-syndiotactic polystyrene resin; 0-15% polypropylene and / or polyethylene; 20%-50% rubber modified elastomer. Preferably, both polypropylene and polyethylene have a melt index of less than 1g / 10min.

[0010] In one or more embodiments of the present invention, the rubber modified elastomer is selected from EPDM rubber, EPDM rubber, styrene-based thermoplastic elastomer (styrene-butadiene-styrene block copolymer, hydrogenated styrene-butadiene block copolymer), propylene-based elastomer, ethylene-1-octene copolymer.

[0011] In one or more embodiments of the present invention, the surface of the first low-tension layer and / or the second low-tension layer has a rough microstructure. Preferably, the roughness Ra value of the rough microstructure is 1.0-4.5 μm.

[0012] In one or more embodiments of the present invention, the release film is made of at least the aforementioned low surface tension material.

[0013] In one or more embodiments of the present invention, the preparation method of the release film comprises: forming a first low-tension layer with a first screw extruder and / or forming a second low-tension layer with a second screw extruder, setting the processing temperature in sequence according to the zone during screw extrusion molding, the temperature is set to 210-280°C for zone 1, 260-290°C for zone 2, 260-320°C for zone 3, 260-320°C for zone 4, and 260-300°C for the flow channel; forming a first intermediate layer with a third screw extruder, and setting the temperature in sequence according to the zone during screw extrusion molding, the temperature is set to 210-260°C for zone 1, 260-290°C for zone 2, and 260- 300℃, 260-300℃ for zone 4, and 260-300℃ for flow channel; the first screw extruder and / or the second screw extruder and / or the third screw extruder feed the distributor, and the distributor is set to a temperature of 260-300℃; the temperature of the cast T-die is set to a range of 250-300℃ according to the temperature control point; feeding production begins after each section reaches the set temperature value; the extrusion amount ratio of the molding material of the first low-tension layer, the first intermediate layer and the second low-tension layer is controlled at 1:10:1-2:1:2, and the line speed is set at 13-20m / min; the temperature of the extrusion cooling roller is controlled at 30-90℃ during the molding process.

[0014] In one or more embodiments of the present invention, the release product includes the aforementioned low surface tension material or the aforementioned release film. The product here may refer to an adhesive tape or a circuit board or circuit board to which the material is applied, and related equipment and devices.

[0015] Compared with the prior art, the low surface tension material, release film, preparation method, and product according to the embodiments of the present invention utilize the low surface tension of the material itself, as well as the characteristics of a higher melting point and good temperature resistance, to make it into a three-layer composite film, which can replace the original release film material in the field of hot pressing of circuit boards. It does not need to add a release agent, and there will be no problem of release agent transfer. It has a good release effect on browned boards and non-glue double-sided boards. The present invention can achieve good glue resistance through the design of structure and formula. In addition, the release film of the present invention can also be used for the release of composite materials. DETAILED DESCRIPTION

[0016] The specific embodiments of the present invention are described in detail below, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

[0017] Unless explicitly stated otherwise, throughout the specification and claims, the term “comprise” or variations such as “include” or “comprising”, etc., will be understood to include the stated elements or components but not to exclude other elements or components.

[0018] The patent of this invention relates to a low surface tension material, the raw material of the main functional layer of which is para-syndiotactic polystyrene, which is a crystalline polystyrene formed by alternating arrangement of benzene rings in the molecular chain. The traditional atactic polystyrene has a Tg point of 100°C and no obvious melting point; the preferred polystyrene of the present invention is a para-syndiotactic structure, with a Tg point of 100°C and a melting point of 240-270°C, which has obvious advantages in temperature resistance compared to traditional polystyrene. The para-syndiotactic polystyrene involved in the present invention has good heat resistance, transparency, chemical solvent resistance, and a surface tension of 28-32mN / m.

[0019] The present invention mainly utilizes the temperature resistance of the isomeric polystyrene material and the surface tension of 28-32 mN / m, and adopts a multi-layer co-extrusion casting composite method to prepare it into a release film for use in the field of circuit board lamination.

[0020] The test conditions including but not limited to the following examples:

[0021] Release properties are mainly tested at 180°C and 100kgf / cm2 of pressure. 2 , pre-pressing time 10sec, molding time 110sec, place the FPC with glue between two release films for hot pressing, peel off the release films, and observe whether there is residual glue or damage on the surface of the FPC; ◎ means excellent, ○ means good, and △ means fair.

[0022] The adhesive resistance is tested according to the above lamination conditions, and the amount of resin flowing out of the cover film on the FPC at the window part during lamination is tested, and the control standard is ≤0.1mm.

[0023] Temperature resistance refers to whether the release film has adhesion under different hot pressing temperatures. The overall effect is good. The more soft materials there are, the lower the temperature resistance will be.

[0024] By comparing the above embodiments with the TPX release film sold on the market, the release film of the present invention can meet the market demand for hot pressing release and has more advantages than the TPX release film in terms of adhesive resistance.

[0025] Examples 1-5

[0026] The production process of the low surface tension material of this group of embodiments may include the following steps:

[0027] A1. The screws for processing the first low-tension layer and the second low-tension layer are polyolefin screws, and the processing temperature is set in sequence according to the zones. The temperature is set to 210°C for zone 1, 260°C for zone 2, 260°C for zone 3, 260°C for zone 4, and 260°C for the flow channel;

[0028] A2. The screw for processing the first intermediate layer is a polyolefin screw, and the temperature is set in sequence by zone. The temperature is set to 210℃ for zone 1, 260℃ for zone 2, 260℃ for zone 3, 260℃ for zone 4, and 260℃ for the flow channel;

[0029] A3. Set the temperature of the distributor to 260℃; set the temperature of the cast T-die to 250℃ according to the temperature control points; start feeding and production after each section of the equipment reaches the set temperature value;

[0030] A4, the extrusion ratio of the first low-tension layer (feeding bucket A), the first intermediate layer (feeding bucket B) and the second low-tension layer (feeding bucket C) is controlled at 1:10:1, and the line speed is set at 13m / min;

[0031] A5. The temperature of the extrusion cooling roller is controlled at 30℃.

[0032]

[0033]

[0034] Examples 1-5 were all made into products with a thickness of 130 μm, and compared with a commercially available TPX release film (Comparative Example 1). The TPX release film for comparison was 130 μm, and the differences in release properties and adhesive resistance were mainly tested.

[0035]

[0036]

[0037] Examples 6-10

[0038] A production process of a low surface tension material may include the following steps:

[0039] A1. The screws for processing the first low-tension layer and the second low-tension layer are polyolefin screws, and the processing temperature is set in sequence according to the zones. The temperature is set to 250°C for zone 1, 270°C for zone 2, 280°C for zone 3, 280°C for zone 4, and 290°C for the flow channel;

[0040] A2. The screw for processing the first intermediate layer is a polyolefin screw, and the temperature is set in sequence by zone. The temperature is set to 250°C for zone 1, 270°C for zone 2, 270°C for zone 3, 270°C for zone 4, and 280°C for the flow channel;

[0041] A3. Set the temperature of the distributor to 290℃; set the temperature of the cast T-die to 280℃ according to the temperature control points; start feeding and production after each section of the equipment reaches the set temperature value;

[0042] The extrusion ratio of A4, the first low-tension layer (feeding bucket A), the first intermediate layer (feeding bucket B) and the second low-tension layer (feeding bucket C) is controlled at 1:4:1, and the line speed is set at 160m / min;

[0043] A5. The temperature of the extrusion cooling roller is controlled at 50℃.

[0044]

[0045]

[0046] Examples 6-10 were all made into products with a thickness of 130 μm, and the differences in release properties and adhesive resistance were mainly tested.

[0047]

[0048] Examples 11-15

[0049] A production process of a low surface tension material may include the following steps:

[0050] A1. The screws for processing the first low-tension layer and the second low-tension layer are polyolefin screws, and the processing temperature is set in sequence according to the zones. The temperature is set to 280°C for zone 1, 290°C for zone 2, 320°C for zone 3, 320°C for zone 4, and 300°C for the flow channel;

[0051] A2. The screw for processing the first intermediate layer is a polyolefin screw, and the temperature is set in sequence by zone. The temperature is set to 260°C for zone 1, 290°C for zone 2, 300°C for zone 3, 300°C for zone 4, and 300°C for the flow channel;

[0052] A3. Set the temperature of the distributor to 300℃; set the temperature of the cast T-die head to 300℃ according to the temperature control points; start feeding and production after each section of the equipment reaches the set temperature value;

[0053] The extrusion ratio of A4, the first low-tension layer (feeding bucket A), the first intermediate layer (feeding bucket B) and the second low-tension layer (feeding bucket C) is controlled at 1:0.5:1, and the line speed is set at 20m / min;

[0054] A5. The temperature of the extrusion cooling roller is controlled at 90℃.

[0055]

[0056] Examples 11-15 were all made into products with a thickness of 130 μm, and the differences in release properties and adhesive resistance were mainly tested.

[0057]

[0058] Examples 16-20

[0059] The production process of a low surface tension material is the same as that of Examples 1-5.

[0060]

[0061]

[0062] Examples 16-20 were all made into products with a thickness of 130 μm, and the differences in release properties and adhesive resistance were mainly tested.

[0063]

[0064] The foregoing description of specific exemplary embodiments of the present invention is for the purpose of illustration and demonstration. These descriptions are not intended to limit the present invention to the precise form disclosed, and it is clear that many changes and variations can be made based on the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical application, so that those skilled in the art can realize and utilize various different exemplary embodiments of the present invention and various different selections and changes. The scope of the present invention is intended to be limited by the claims and their equivalents.

Claims

1. A low surface tension material having a composite structure, wherein when viewed along one direction of its cross section, the composite structure comprises at least: The first low-tension layer, whose main raw material includes para-syndiotactic polystyrene, wherein the Tg point of the polystyrene is 100° C. and the melting point is 240-270° C.; The first intermediate layer, whose main raw material is para-syndiotactic polystyrene added with a first resin, wherein the first resin is at least selected from polypropylene, polyethylene, a blend of polypropylene and polyethylene, ethylene-vinyl acetate copolymer, styrene-ethylene-butadiene copolymer, ethylene-octene copolymer, and rubber modified elastomer.

2. The low surface tension material according to claim 1, characterized in that Observed along one direction of its cross section, the composite structure comprises at least: A plurality of first low-tension layers, wherein the main raw material thereof comprises para-syndiotactic polystyrene, wherein the polystyrene has a Tg point of 100° C. and a melting point of 240-270° C.; A plurality of first intermediate layers, the main raw material of which is para-syndiotactic polystyrene added with a first resin, wherein the first resin is at least selected from polypropylene resin, polyethylene resin, and rubber-modified elastomer; The main raw material of the plurality of second low-tension layers includes para-syndiotactic polystyrene, wherein the Tg point of the polystyrene is 100° C. and the melting point is 240-270° C.

3. The low surface tension material according to claim 2, characterized in that: The first low-tension layer and the second low-tension layer are made of the same material.

4. The low surface tension material according to claim 1, 2 or 3, characterized in that: The raw material composition of the first low-tension layer and / or the second low-tension layer includes, by weight percent: Para-syndiotactic polystyrene, 60%-100%; Toughened modified resin, 5%-40%; Heat aging resistance additive, 0.1-2%.

5. The low surface tension material according to claim 1, characterized in that: The raw material composition of the first intermediate layer includes, by weight percent: Para-syndiotactic polystyrene resin 30%-70%; Polypropylene and / or polyethylene 0-15%; Rubber modified elastomer 20%-50%.

6. The low surface tension material according to claim 5, characterized in that: The rubber modified elastomer is selected from EPDM rubber, EPDM rubber, styrene-based thermoplastic elastomer (styrene-butadiene-styrene block copolymer, hydrogenated styrene-butadiene block copolymer), propylene-based elastomer, and ethylene-1-octene copolymer.

7. The low surface tension material according to claim 5, characterized in that The surface of the first low-tension layer and / or the second low-tension layer has a rough microstructure.

8. A release film, made from at least the low surface tension material according to any one of claims 1 to 7.

9. The method for preparing the release film according to claim 1, comprising: The first low-tension layer is formed by a first screw extruder and / or the second low-tension layer is formed by a second screw extruder. During the screw extrusion molding, the processing temperature is set in sequence according to the zones. The temperature is set to 210-280°C for zone 1, 260-290°C for zone 2, 260-320°C for zone 3, 260-320°C for zone 4, and 260-300°C for the flow channel; The first intermediate layer is formed by the third screw extruder. The temperature is set in sequence according to the zone during screw extrusion molding. The temperature is set to 210-260°C for zone 1, 260-290°C for zone 2, 260-300°C for zone 3, 260-300°C for zone 4, and 260-300°C for the flow channel; The first screw extruder and / or the second screw extruder and / or the third screw extruder feed materials to the distributor, and the distributor is set at a temperature of 260-300°C; the temperature of the cast T-shaped die is set in the range of 250-300°C according to the temperature control point; and feeding production begins after each section reaches the set temperature value; The extrusion ratio of the molding materials of the first low-tension layer, the first intermediate layer and the second low-tension layer is controlled at 1:10:1-2:1:2, and the line speed is set at 13-20m / min; the temperature of the extrusion cooling roller is controlled at 30-90℃ during the molding process.

10. A release product, comprising the low surface tension material according to any one of claims 1 to 7 or the release film according to claim 8.

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