Stretchable films, preparation methods and applications

Abstract

This disclosure provides a stretchable film, its preparation method, and its application, belonging to the field of wafer processing. The stretchable film provided in this disclosure is prepared from the following components in parts by weight: 100 parts PVC resin, 10-30 parts TPU resin, 1-4 parts maleic acid-type organotin stabilizer, 5-40 parts plasticizer, and 0.001-0.5 parts initiator. The stretchable film obtained in this disclosure has both high light transmittance and high tensile strength, as well as good processability.

Description

Technical Field

[0001] This disclosure relates to the field of wafer fabrication, and particularly to a stretchable thin film, its preparation method, and its application. Background Technology

[0002] Stretchable films are a common protective material used in wafer fabrication equipment, effectively protecting the wafer surface from scratches, contamination, and abrasion during the wafer processing. Currently, the mainstream wafer dicing technology globally is laser cutting, which offers high precision and efficiency. To ensure high laser transmittance and efficiency during laser cutting, as well as the accuracy of AOI (Automated Optical Inspection) equipment, stretchable films require high light transmittance. However, current PVC (Polyvinyl chloride) films used in wafer fabrication suffer from low light transmittance and insufficient tensile strength. This is because light scattering easily occurs during processing, affecting processing precision and laser cutting efficiency. On high-speed production lines, deformation and tearing are prone to occur, easily causing wafer cracks, burrs, and chipping, resulting in low safety and precision during processing and ultimately insufficient wafer yield. Therefore, it is necessary to provide a stretchable film that possesses both high light transmittance and high tensile strength. Summary of the Invention

[0003] This disclosure provides a stretchable film, its preparation method, and its application. The stretchable film possesses both high light transmittance and high stretchability. The technical solution is as follows:

[0004] On one hand, a stretchable film is provided, comprising the following components in parts by weight:

[0005] 100 parts of polyvinyl chloride (PVC) resin, 10-30 parts of thermoplastic polyurethane (TPU) resin, 1-4 parts of maleic acid-type organotin stabilizer, 5-40 parts of plasticizer, and 0.001-0.5 parts of initiator.

[0006] In one possible implementation, the degree of polymerization of the PVC resin is 2500 to 3000, and the gel content is less than or equal to 1.5%.

[0007] In another possible implementation, the TPU resin is a polymer of polyol and isocyanate with a molecular weight of 15,000 to 30,000.

[0008] In another possible implementation, the isocyanate is an aliphatic isocyanate.

[0009] In another possible implementation, the plasticizer includes at least one of dioctyl adipate, dioctyl azelate, dibutyric acid sebacate, diisodecyl adipate, and dioctyl sebacate.

[0010] In another possible implementation, the maleic acid-type organotin stabilizer includes at least one of di(monobutyl maleate) dibutyltin and di(monooctyl maleate) dibutyltin.

[0011] In another possible implementation, the initiator is benzoyl peroxide with a total chlorine content ≤0.20%.

[0012] On the other hand, a method for preparing a stretchable film is provided, comprising the following steps:

[0013] According to the weight parts of each component, the PVC resin and the plasticizer are mixed evenly to obtain material 1;

[0014] The maleic acid-type organotin stabilizer is added to material 1 and mixed evenly to obtain material 2;

[0015] The TPU resin is added to material 2 and mixed evenly to obtain material 3;

[0016] The material 3 is cooled to 25-35°C, and the initiator is added to the cooled material 3 and mixed evenly to obtain material 4.

[0017] The material 4 is added to an extrusion casting equipment, and the stretchable film is obtained by T-die extrusion, casting, air knife, cooling traction, thickness measurement by a thickness gauge, corona treatment, edge trimming, static elimination, and winding.

[0018] In one possible implementation, the screw temperature of the extrusion casting equipment is 120–170°C, the die temperature is 170–200°C, and the traction speed is 6–12 m / min.

[0019] On the other hand, an application of the stretchable film described in any of the above claims in wafer processing is provided.

[0020] This disclosure provides a stretchable film in which the maleic acid-type organotin stabilizer has a polarity similar to that of PVC resin, exhibiting good compatibility and resulting in high light transmittance. Simultaneously, the PVC resin and TPU resin with a flexible molecular chain structure work synergistically, giving the stretchable film high tensile strength. Therefore, the stretchable film provided by this disclosure possesses both high light transmittance and high tensile properties. Furthermore, the combination of the TPU resin with a flexible molecular chain structure and a plasticizer enhances the plasticizing properties of the flexible molecular chain structure, resulting in excellent processability for the stretchable film. Detailed Implementation

[0021] The technical solutions of this disclosure will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this disclosure.

[0022] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which embodiments of this disclosure belong. The terminology used in this specification of embodiments is for the purpose of describing particular implementations only and is not intended to limit the scope of embodiments of this disclosure. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items.

[0023] This disclosure provides a stretchable film comprising the following components in parts by weight:

[0024] 100 parts PVC resin, 10-30 parts TPU (thermoplastic polyurethane) resin, 1-4 parts maleic acid type organotin stabilizer, 5-40 parts plasticizer, and 0.001-0.5 parts initiator.

[0025] The TPU resin can be in the following weight proportions: 10 parts, 12 parts, 15 parts, 18 parts, 20 parts, 22 parts, 25 parts, 28 parts, or 30 parts; the maleic acid type organotin stabilizer can be in the following weight proportions: 1 part, 2 parts, 3 parts, or 4 parts; the plasticizer can be in the following weight proportions: 5 parts, 8 parts, 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, or 40 parts; and the initiator can be in the following weight proportions: 0.001 parts, 0.005 parts, 0.01 parts, 0.05 parts, 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, or 0.5 parts.

[0026] In one possible implementation, the stretchable film comprises the following components in parts by weight:

[0027] The stretchable film may further include the following components in parts by weight: 100 parts PVC resin, 10-30 parts TPU resin, 3-4 parts maleic acid-type organotin stabilizer, 16-36 parts plasticizer, and 0.009-0.012 parts initiator.

[0028] In the embodiments of this disclosure, the PVC resin is a high degree of polymerization polyvinyl chloride resin with a degree of polymerization of 2500 to 3000 and a gel content of less than or equal to 1.5%.

[0029] Compared to general-purpose PVC resin, the PVC resin with higher polymerization degree and the aforementioned gel content, when thoroughly mixed with plasticizer, results in stretchable films exhibiting excellent plasticity and processability. The aforementioned PVC resin itself has a higher molecular weight, imparting higher resilience, tensile strength, and tear resistance to the stretchable films. The lower gel content results in better surface smoothness and uniformity of the stretchable films, thus providing excellent light transmittance.

[0030] The PVC resin can be high-polymerization polyvinyl chloride YH250 produced by Haohua Aerospace Chemical Co., Ltd., with an apparent density of 0.45 g / mL.

[0031] In this embodiment, the TPU resin is a polymer of polyol and isocyanate with a molecular weight of 15,000 to 30,000. That is, the TPU resin is a block polymer with both plasticity and elasticity, polymerized from polyol and isocyanate segments. The polyol can be polypropylene glycol (or simply "PEG" in this embodiment), with a degree of polymerization of 400 to 800, and the isocyanate can be an aliphatic isocyanate. Accordingly, the TPU resin can be copolymerized from PEG and aliphatic isocyanate.

[0032] The aliphatic isocyanate may be selected from at least one of isophorone diisocyanate (or simply "IPDI" in this disclosure) and hexamethylene diisocyanate (or simply "HDI" in this disclosure).

[0033] In one possible implementation, if the aliphatic isocyanate is selected from HDI, the TPU resin is copolymerized from PEG and HDI, and the molecular weight of the TPU resin is 15,000 to 30,000. Under these conditions, both the isocyanate segment and the polyol segment are stable, compliant, saturated aliphatic long chains. The flexible molecular chain structure of the TPU resin exhibits good ductility, elongation at break, and elasticity, and also possesses excellent tensile properties. Furthermore, it imparts excellent lightfastness and light stability to the stretchable film. More importantly, as a high-molecular-weight plasticizer, TPU resin addresses the problems of high melt apparent viscosity, high extrusion pressure, and difficult processing associated with high-polymerization-degree PVC resin. In this embodiment, the use of TPU resin enables the stretchable film to achieve excellent processability.

[0034] The TPU resin used can be a custom-made TPU resin from Dongguan Lerui Plastics Co., Ltd., which is a copolymer of PEG and HDI. The polypropylene glycol has a degree of polymerization of 400–800, the aliphatic isocyanate is HDI, the molecular weight is 15,000–30,000, and the density is 1.17 g / cm³. 3 Its Rockwell hardness is Grade A, 60.

[0035] In the embodiments of this disclosure, the plasticizer is a saturated fatty acid ester plasticizer, including at least one of dioctyl adipate (or simply "DOA" in this disclosure), di(2-ethylhexyl) azelate (or simply "DOZ" in this disclosure), dibutyl sebacate (or simply "DBS" in this disclosure), diisodecyl adipate (or simply "DIDA" in this disclosure), and dioctyl sebacate (or simply "DOS" in this disclosure).

[0036] Specifically, the plasticizer is a saturated aliphatic plasticizer. Further, the plasticizer is DOA (diethylaluminate). Under these conditions, the stretchable film can be easier to process, production efficiency can be improved, and the weather resistance of the stretchable film can be enhanced.

[0037] The plasticizer can be dioctyl adipate produced by Shandong Lanfan Chemical Co., Ltd., CAS number 248-14-2, with a relative density of 0.922 g / cm³. 3 It has a melting point of -67.8℃, a color of ≤20, and a viscosity (at 20℃) of 13.7 mPa·S.

[0038] In this embodiment, the maleic acid-type organotin stabilizer includes at least one of di(monobutyl maleate)dibutyltin and di(monooctyl maleate)dibutyltin. Specifically, the maleic acid-type organotin stabilizer can be di(monooctyl maleate)dibutyltin. In this configuration, the polarity of the maleic acid-type organotin stabilizer is similar to that of PVC resin, exhibiting good compatibility with PVC resin, thus ensuring the high light transmittance of the stretchable film.

[0039] Among them, the maleic acid-type organotin stabilizer can be di(monooctyl maleate) dibutyltin BT-58C produced by Shule Industrial (Shanghai) Co., Ltd., with a density of 1.145 g / cm³. 3 Its flash point is 123℃.

[0040] In this embodiment, the initiator is benzoyl peroxide initiator (or simply "BPO initiator" in this embodiment), with a total chlorine content ≤0.20%. Under this scheme, the maleic acid-type organotin stabilizer completes its self-polymerization reaction through the catalytic action of the BPO initiator under the high temperature of the extrusion casting equipment. This gives the stretchable film both thermal stability and prevents the migration of small maleic acid-type organotin molecules. Furthermore, the polarity of the maleic acid-type organotin stabilizer is similar to that of PVC resin, exhibiting good compatibility with PVC resin, thus ensuring the high light transmittance of the stretchable film.

[0041] The BPO initiator can be a product with CAS number 94-36-0 produced by Dongying Haijing Chemical Co., Ltd., with a molecular weight of 242.22, a melting point of 103~106℃, and a total chlorine content of ≤0.2%.

[0042] The combined action of PVC resin, TPU resin, maleic acid-type organotin stabilizer, plasticizer, and initiator provided in this embodiment of the invention enables the prepared stretchable film to possess both high light transmittance and high tensile strength, while also exhibiting excellent processing performance.

[0043] This disclosure provides a method for preparing a stretchable film, comprising the following steps:

[0044] Step 1: Mix the PVC resin and plasticizer evenly according to the weight parts of each component to obtain material 1.

[0045] In step one, PVC resin and plasticizer can be added to a high-speed mixer for 3 to 12 hours, at a temperature of 65 to 95°C, and at a speed of 200 to 500 rpm.

[0046] The mixing time can be 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h, 11h, or 12h; the mixing temperature can be 65℃, 70℃, 75℃, 80℃, 85℃, 90℃, or 95℃; and the mixing speed can be 200rpm, 250rpm, 300rpm, 350rpm, 400rpm, 450rpm, or 500rpm. Specifically, the mixing time is 8h, the mixing temperature is 85℃, and the mixing speed is 300rpm.

[0047] Step 2: Add maleic acid type organotin stabilizer to material 1 and mix evenly to obtain material 2.

[0048] In step two, maleic acid-type organotin stabilizer is added to material 1 and mixed evenly in a high-speed mixer to obtain material 2.

[0049] In step two, the mixing time is 20–50 min, the mixing temperature is 45–65℃, and the mixing speed is 300–500 rpm.

[0050] The mixing time can be 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, or 50 min; the mixing temperature can be 45℃, 50℃, 55℃, 60℃, or 65℃; and the mixing speed can be 300 rpm, 350 rpm, 400 rpm, 450 rpm, or 500 rpm. Specifically, the mixing time is 25 min, the mixing temperature is 60℃, and the mixing speed is 400 rpm.

[0051] Step 3: Add TPU resin to material 2 and mix evenly to obtain material 3.

[0052] In step three, TPU resin is added to material 2 and mixed evenly in a high-speed mixer to obtain material 3.

[0053] In step three, the mixing time is 20–50 min, the mixing temperature is 35–55℃, and the mixing speed is 300–500 rpm.

[0054] The mixing time can be 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, or 50 min; the mixing temperature can be 35℃, 40℃, 45℃, 50℃, or 55℃; and the mixing speed can be 300 rpm, 350 rpm, 400 rpm, 450 rpm, or 500 rpm. Specifically, the mixing time is 40 min, the mixing temperature is 45℃, and the mixing speed is 500 rpm.

[0055] Step 4: Cool material 3 to 25-35°C, add the initiator to the cooled material 3 and mix evenly to obtain material 4.

[0056] In step four, material 3 can be cooled down to 25℃, 28℃, 30℃, 32℃, or 35℃. Specifically, material 3 can be cooled down to 30℃.

[0057] After material 3 has cooled down, the initiator is added to the cooled material 3 and mixed evenly in a high-speed mixer to obtain material 4.

[0058] In step four, the mixing time is 20–60 min, the mixing temperature is 25–35℃, and the mixing speed is 50–500 rpm.

[0059] The mixing time can be 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min, or 60 min; the mixing temperature can be 25℃, 28℃, 30℃, 32℃, or 35℃; and the mixing speed can be 50 rpm, 100 rpm, 200 rpm, 300 rpm, 400 rpm, or 500 rpm. Specifically, the mixing time is 50 min, the mixing temperature is 28℃, and the mixing speed is 100 rpm.

[0060] Step 5: Add material 4 to the extrusion casting equipment, and proceed through T-die extrusion, casting, air knife, cooling traction, thickness measurement with a thickness gauge, corona treatment, edge trimming, static elimination, and winding to obtain a stretchable film.

[0061] In step five, the screw temperature of the extrusion casting equipment is 120-170℃, the die temperature is 170-200℃, and the traction speed is 6-12m / min.

[0062] The screw temperature can be 120℃, 130℃, 140℃, 150℃, 155℃, 160℃, 165℃, or 170℃; the die head temperature can be 170℃, 175℃, 180℃, 185℃, 190℃, 195℃, or 200℃; and the traction speed can be 6m / min, 7m / min, 8m / min, 9m / min, 10m / min, 11m / min, or 12m / min. Specifically, the screw temperature is 155℃, the die head temperature is 190℃, and the traction speed is 6m / min.

[0063] Among them, the extrusion casting equipment can be an extrusion casting machine.

[0064] This disclosure also provides an application of a stretchable film in wafer fabrication.

[0065] Among them, stretchable films can be used as non-UV-absorbing, high-transmittance base films in wafer processing as UV anti-adhesion films.

[0066] In summary, the embodiments disclosed herein have the following beneficial effects:

[0067] 1. The stretchable film provided in this embodiment uses PVC resin with a degree of polymerization of 2500-3000 and a gel content of less than 1.5%. With the cooperation of TPU resin with a specific component flexible molecular chain structure, the stretchable film has good extensibility, elongation at break and elasticity, and excellent tear resistance.

[0068] 2. The maleic acid-type organotin stabilizer undergoes a self-polymerization reaction catalyzed by the BPO initiator, giving the stretchable film both thermal stability and preventing the migration of small maleic acid-type organotin molecules. Simultaneously, the maleic acid-type organotin stabilizer has similar polarity to PVC resin, exhibiting excellent compatibility with PVC resin, thus ensuring the high light transmittance of the stretchable film. Furthermore, using PVC resin with a lower gel content allows the stretchable film to have better surface smoothness and uniformity, resulting in excellent light transmittance. Therefore, the embodiments of this disclosure address multiple aspects to achieve high light transmittance in the prepared stretchable film.

[0069] 3. When TPU resin with a flexible molecular chain structure is used in combination with saturated fatty acid ester plasticizers as a polymer plasticizer, the plasticizing performance of the flexible molecular chain structure is more prominent, giving the stretchable film excellent processing performance.

[0070] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0071] Unless otherwise specified, all materials and reagents used in the following examples are commercially available. In the following examples and comparative examples, all amounts of ingredients used in the formulations for preparing stretchable films are by weight.

[0072] In the following examples, the PVC resin used is high-polymerization-degree polyvinyl chloride YH250 produced by Haohua Aerospace Chemical Co., Ltd.

[0073] The TPU resin used is a custom-made TPU resin from Dongguan Lerui Plastics Co., Ltd., in which the degree of polymerization of polypropylene glycol is 400-800, the aliphatic isocyanate is HDI, the molecular weight is 15,000-30,000, and the density is 1.17 g / cm³. 3 Its Rockwell hardness is Grade A, 60.

[0074] The maleic acid-type organotin stabilizer used is di(monooctyl maleate) dibutyltin BT-58C, manufactured by Shule Industrial (Shanghai) Co., Ltd., with a density of 1.145 g / cm³. 3 Its flash point is 123℃;

[0075] The plasticizer used is dioctyl adipate produced by Shandong Lanfan Chemical Co., Ltd., with CAS number 248-14-2 and a relative density of 0.922 g / cm³. 3 It has a melting point of -67.8℃, a color of ≤20, and a viscosity (at 20℃) of 13.7 mPa·s.

[0076] The BPO used is a product with CAS number 94-36-0 produced by Dongying Haijing Chemical Co., Ltd., with a molecular weight of 242.22, a melting point of 103~106℃, and a total chlorine content of ≤0.2%.

[0077] Example 1

[0078] The stretchable film provided in this embodiment is prepared from the following components in parts by weight: 100 parts PVC resin, 17 parts TPU resin, 29 parts plasticizer, 3 parts maleic acid type organotin, and 0.009 parts BPO initiator.

[0079] The method for preparing the stretchable film in this embodiment is as follows:

[0080] Step 1: Mix 100 parts of PVC resin and 29 parts of plasticizer thoroughly in a high-speed mixer to obtain material 1.

[0081] The mixing time in step one is 8 hours, the mixing temperature is 85℃, and the mixing speed is 300 rpm.

[0082] Step 2: Add 3 parts of maleic acid type organotin heat stabilizer to material 1 and mix them evenly in a high-speed mixer to obtain material 2.

[0083] The mixing time in step two is 25 minutes, the mixing temperature is 60°C, and the mixing speed is 400 rpm.

[0084] Step 3: Add 17 parts of TPU resin to material 2 and mix them evenly in a high-speed mixer to obtain material 3.

[0085] The mixing time in step three is 40 minutes, the mixing temperature is 45°C, and the mixing speed is 500 rpm.

[0086] Step 4: Cool material 3 to 30°C, add 0.009 parts of BPO initiator to the cooled material 3, and mix evenly in a high-speed mixer to obtain material 4.

[0087] The mixing time in step four is 50 min, the mixing temperature is 28℃, and the mixing speed is 100 rpm.

[0088] Step 5: Add material 4 to the extrusion casting machine, and proceed through T-die extrusion, casting, air knife, cooling traction, thickness measurement with a thickness gauge, corona treatment, edge trimming, static elimination, and winding to obtain a stretchable film.

[0089] In step five, the screw temperature of the extrusion casting machine is 155℃, the die temperature is 190℃, and the traction speed is 6m / min.

[0090] Example 2

[0091] The stretchable film provided in this embodiment is prepared from the following components in parts by weight: 100 parts PVC resin, 30 parts TPU resin, 16 parts plasticizer, 3 parts maleic acid type organotin, and 0.009 parts BPO initiator.

[0092] The method for preparing the stretchable film in this embodiment is as follows:

[0093] Step 1: Mix 100 parts of PVC resin and 16 parts of plasticizer thoroughly in a high-speed mixer to obtain material 1.

[0094] The mixing time in step one is 8 hours, the mixing temperature is 85℃, and the mixing speed is 300 rpm.

[0095] Step 2: Add 3 parts of maleic acid type organotin stabilizer to material 1 and mix them evenly in a high-speed mixer to obtain material 2.

[0096] The mixing time in step two is 25 minutes, the mixing temperature is 60°C, and the mixing speed is 400 rpm.

[0097] Step 3: Add 30 parts of TPU resin to material 2 and mix them evenly in a high-speed mixer to obtain material 3.

[0098] The mixing time in step three is 30 minutes, the mixing temperature is 45°C, and the mixing speed is 500 rpm.

[0099] Step 4: Cool material 3 to 30°C, add 0.009 parts of BPO initiator to the cooled material 3, and mix evenly in a high-speed mixer to obtain material 4.

[0100] In step four, the mixing time is 50 minutes, the mixing temperature is 28°C, and the mixing speed is 100 rpm.

[0101] Step 5: Add material 4 to the extrusion casting machine, and proceed through T-die extrusion, casting, air knife, cooling traction, thickness measurement with a thickness gauge, corona treatment, edge trimming, static elimination, and winding to obtain a stretchable film.

[0102] In step five, the screw temperature of the extrusion casting machine is 155℃, the die temperature is 195℃, and the traction speed is 7m / min.

[0103] Example 3

[0104] The stretchable film provided in this embodiment is prepared from the following components in parts by weight: 100 parts PVC resin, 10 parts TPU resin, 36 parts plasticizer, 3 parts maleic acid type organotin, and 0.009 parts BPO initiator.

[0105] The method for preparing the stretchable film in this embodiment is as follows:

[0106] Step 1: Mix 100 parts of PVC resin and 36 parts of plasticizer thoroughly in a high-speed mixer to obtain material 1.

[0107] The mixing time in step one is 8 hours, the mixing temperature is 85℃, and the mixing speed is 300 rpm.

[0108] Step 2: Add 3 parts of maleic acid type organotin stabilizer to material 1 and mix them evenly in a high-speed mixer to obtain material 2.

[0109] In step two, the mixing time is 25 minutes, the mixing temperature is 60°C, and the mixing speed is 400 rpm.

[0110] Step 3: Add 10 parts of TPU resin to material 2 and mix them evenly in a high-speed mixer to obtain material 3.

[0111] The mixing time in step three is 40 minutes, the mixing temperature is 45°C, and the mixing speed is 500 rpm.

[0112] Step 4: Cool material 3 to 30°C, add 0.009 parts of BPO initiator to the cooled material 3, and mix evenly in a high-speed mixer to obtain material 4.

[0113] The mixing time in step four is 50 min, the mixing temperature is 28℃, and the mixing speed is 100 rpm.

[0114] Step 5: Add material 4 to the extrusion casting machine, and proceed through T-die extrusion, casting, air knife, cooling traction, thickness measurement with a thickness gauge, corona treatment, edge trimming, static elimination, and winding to obtain a stretchable film.

[0115] In step five, the screw temperature of the extrusion casting machine is 160℃, the die temperature is 195℃, and the traction speed is 8m / min.

[0116] Example 4

[0117] The stretchable film provided in this embodiment is prepared from the following components in parts by weight: 100 parts PVC resin, 17 parts TPU resin, 29 parts plasticizer, 4 parts maleic acid type organotin, and 0.012 parts BPO initiator.

[0118] The method for preparing the stretchable film in this embodiment is as follows:

[0119] Step 1: Mix 100 parts of PVC resin and 29 parts of plasticizer thoroughly in a high-speed mixer to obtain material 1.

[0120] The mixing time in step one is 8 hours, the mixing temperature is 85℃, and the mixing speed is 300 rpm.

[0121] Step 2: Add 4 parts of maleic acid type organotin stabilizer to material 1 and mix them evenly in a high-speed mixer to obtain material 2.

[0122] The mixing time in step two is 25 minutes, the mixing temperature is 60°C, and the mixing speed is 400 rpm.

[0123] Step 3: Add 17 parts of TPU resin to material 2 and mix them evenly in a high-speed mixer to obtain material 3.

[0124] The mixing time in step three is 40 minutes, the mixing temperature is 45°C, and the mixing speed is 500 rpm.

[0125] Step 4: Cool material 3 to 30°C, add 0.012 parts of BPO initiator to the cooled material 3, and mix evenly in a high-speed mixer to obtain material 4.

[0126] The mixing time in step four is 50 min, the mixing temperature is 28℃, and the mixing speed is 100 rpm.

[0127] Step 5: Add material 4 to the extrusion casting machine, and proceed through T-die extrusion, casting, air knife, cooling traction, thickness measurement with a thickness gauge, corona treatment, edge trimming, static elimination, and winding to obtain a stretchable film.

[0128] In step five, the screw temperature of the extrusion casting machine is 155℃, the die temperature is 185℃, and the traction speed is 6m / min.

[0129] Example 5

[0130] The stretchable film provided in this embodiment is prepared from the following components in parts by weight: 100 parts PVC resin, 20 parts TPU resin, 26 parts plasticizer, 3 parts maleic acid type organotin, and 0.009 parts BPO initiator.

[0131] The method for preparing the stretchable film in this embodiment is as follows:

[0132] Step 1: Mix 100 parts of PVC resin and 26 parts of plasticizer thoroughly in a high-speed mixer to obtain material 1.

[0133] The mixing time in step one is 8 hours, the mixing temperature is 85℃, and the mixing speed is 300 rpm.

[0134] Step 2: Add 3 parts of maleic acid type organotin stabilizer to material 1 and mix them evenly in a high-speed mixer to obtain material 2.

[0135] The mixing time in step two is 25 minutes, the mixing temperature is 60°C, and the mixing speed is 400 rpm.

[0136] Step 3: Add 20 parts of TPU resin to material 2 and mix them evenly in a high-speed mixer to obtain material 3.

[0137] The mixing time in step three is 40 minutes, the mixing temperature is 45°C, and the mixing speed is 500 rpm.

[0138] Step 4: Cool material 3 to 30°C, add 0.009 parts of BPO initiator to the cooled material 3, and mix evenly in a high-speed mixer to obtain material 4.

[0139] The mixing time in step four is 50 min, the mixing temperature is 28℃, and the mixing speed is 100 rpm.

[0140] Step 5: Add material 4 to the extrusion casting machine and extrude it through T-shaped die, casting, air knife, cooling and traction, thickness measurement with a thickness gauge, corona treatment, edge trimming, static elimination, and winding to obtain a stretchable film.

[0141] In step five, the screw temperature of the extrusion casting machine is 160℃, the die temperature is 190℃, and the traction speed is 9m / min.

[0142] Comparative Example 1

[0143] This comparative example provides a PVC film prepared from the following components in parts by weight: 100 parts PVC resin, 17 parts TPU resin, 29 parts plasticizer, 3 parts maleic acid type organotin stabilizer, and 0.009 parts BPO initiator.

[0144] The PVC resin was purchased from WS-1300S of Shanghai Chlorine Peak, with an apparent density of 0.42-0.52 g / mL and an average degree of polymerization of 1250-1350. The TPU resin, plasticizer, maleic acid-type organotin stabilizer, and BPO initiator were the same as those in Example 1.

[0145] The PVC film preparation method for this comparative example is as follows:

[0146] Step 1: Mix 100 parts of PVC resin and 29 parts of plasticizer thoroughly in a high-speed mixer to obtain material 1.

[0147] The mixing time in step one is 8 hours, the mixing temperature is 85℃, and the mixing speed is 300 rpm.

[0148] Step 2: Add 3 parts of maleic acid type organotin stabilizer to material 1 and mix them evenly in a high-speed mixer to obtain material 2.

[0149] The mixing time in step two is 25 minutes, the mixing temperature is 60°C, and the mixing speed is 400 rpm.

[0150] Step 3: Add 17 parts of TPU resin to material 2 and mix them evenly in a high-speed mixer to obtain material 3.

[0151] The mixing time in step three is 40 minutes, the mixing temperature is 45°C, and the mixing speed is 500 rpm.

[0152] Step 4: Cool material 3 to 30°C, add 0.009 parts of BPO initiator to the cooled material 3, and mix evenly in a high-speed mixer to obtain material 4.

[0153] The mixing time in step four is 50 min, the mixing temperature is 28℃, and the mixing speed is 100 rpm.

[0154] Step 5: Add material 4 to the extrusion casting machine, and proceed through T-die extrusion, casting, air knife, cooling traction, thickness measurement with a thickness gauge, corona treatment, edge trimming, static elimination, and winding to obtain PVC film.

[0155] In step five, the screw temperature of the extrusion casting machine is 155℃, the die temperature is 190℃, and the traction speed is 6m / min.

[0156] Comparative Example 2

[0157] This comparative example provides a PVC film prepared from the following components in parts by weight: 100 parts PVC resin, 17 parts EVA-CO resin, 29 parts plasticizer, 3 parts maleic acid type organotin stabilizer, and 0.009 parts BPO initiator.

[0158] The EVA-CO resin used was purchased from Hanwha Group in South Korea under the brand name 2014CO, with a density of 0.933 g / cm³. 3 The melt flow rate was 2.0 g / 10 min at 190°C and 2.16 kg load. The PVC resin, plasticizer, maleic acid-type organotin stabilizer, and BPO initiator were the same as in Example 1.

[0159] The PVC film preparation method for this comparative example is as follows:

[0160] Step 1: Mix 100 parts of PVC resin and 29 parts of DOP plasticizer thoroughly in a high-speed mixer to obtain material 1.

[0161] The mixing time in step one is 8 hours, the mixing temperature is 85℃, and the mixing speed is 300 rpm.

[0162] Step 2: Add 3 parts of maleic acid type organotin stabilizer to material 1 and mix them evenly in a high-speed mixer to obtain material 2.

[0163] The mixing time in step two is 25 minutes, the mixing temperature is 60°C, and the mixing speed is 400 rpm.

[0164] Step 3: Add 17 parts of EVA-CO resin to material 2 and mix them evenly in a high-speed mixer to obtain material 3.

[0165] The mixing time in step three is 40 minutes, the mixing temperature is 45°C, and the mixing speed is 500 rpm.

[0166] Step 4: Cool material 3 to 30°C, add 0.009 parts of BPO initiator to the cooled material 3, and mix evenly in a high-speed mixer to obtain material 4.

[0167] The mixing time in step four is 50 min, the mixing temperature is 28℃, and the mixing speed is 100 rpm.

[0168] Step 5: Add material 4 to the extrusion casting machine and extrude it through a T-shaped die, casting it, air knife it, cooling and traction it, thickness measurement it with a thickness gauge, corona treatment it, edge trimming it, static elimination it, and winding it up to obtain PVC film.

[0169] In step five, the screw temperature of the extrusion casting machine is 155℃, the die temperature is 190℃, and the traction speed is 6m / min.

[0170] Comparative Example 3

[0171] This comparative example provides a PVC film prepared from the following components in parts by weight: 100 parts PVC resin, 17 parts TPU resin, 29 parts plasticizer, 3 parts maleic acid type organotin stabilizer, and 0.009 parts BPO initiator.

[0172] The plasticizer used is dioctyl phthalate (DOP) produced by Shandong Lanfan Chemical Co., Ltd. (or simply "DOP" in this embodiment), with CAS number 12-51-4 and density of 0.982-0.988 g / cm³. 3 The PVC resin, TPU resin, maleic acid-type organotin stabilizer, and BPO initiator were the same as those in Comparative Example 1.

[0173] The PVC film preparation method for this comparative example is as follows:

[0174] Step 1: Mix 100 parts of PVC resin and 29 parts of DOP plasticizer thoroughly in a high-speed mixer to obtain material 1.

[0175] The mixing time in step one is 8 hours, the mixing temperature is 85℃, and the mixing speed is 300 rpm.

[0176] Step 2: Add 3 parts of maleic acid type organotin stabilizer to material 1 and mix them evenly in a high-speed mixer to obtain material 2.

[0177] The mixing time in step two is 25 minutes, the mixing temperature is 60°C, and the mixing speed is 400 rpm.

[0178] Step 3: Add 17 parts of TPU resin to material 2 and mix them evenly in a high-speed mixer to obtain material 3.

[0179] The mixing time in step three is 40 minutes, the mixing temperature is 45°C, and the mixing speed is 500 rpm.

[0180] Step 4: Cool material 3 to 30°C, add 0.009 parts of BPO initiator to the cooled material 3, and mix evenly in a high-speed mixer to obtain material 4.

[0181] The mixing time in step four is 50 min, the mixing temperature is 28℃, and the mixing speed is 100 rpm.

[0182] Step 5: Add material 4 to the extrusion casting machine, and proceed through T-die extrusion, casting, air knife, cooling traction, thickness measurement with a thickness gauge, corona treatment, edge trimming, static elimination, and winding to obtain PVC film.

[0183] In step five, the screw temperature of the extrusion casting machine is 155℃, the die temperature is 190℃, and the traction speed is 6m / min.

[0184] Comparative Example 4

[0185] This comparative example provides a PVC film prepared from the following components in parts by weight: 100 parts PVC resin, 17 parts TPU resin, 29 parts plasticizer, 3 parts dibutyltin mercaptan stabilizer, and 0.009 parts BPO initiator.

[0186] The thiol dibutyltin stabilizer was a product manufactured by Shanghai Shule Industrial Co., Ltd., with CAS number 10584-98-2, a molecular weight of 635, and a sulfur content of 17.5-18.5%. The PVC resin, TPU resin, plasticizer, and BPO initiator were the same as those in Comparative Example 1.

[0187] The PVC film preparation method for this comparative example is as follows:

[0188] Step 1: Mix 100 parts of PVC resin and 29 parts of plasticizer thoroughly in a high-speed mixer to obtain material 1.

[0189] The mixing time in step one is 8 hours, the mixing temperature is 85℃, and the mixing speed is 300 rpm.

[0190] Step 2: Add 3 parts of thiol dibutyltin stabilizer to material 1 and mix them evenly in a high-speed mixer to obtain material 2.

[0191] The mixing time in step two is 25 minutes, the mixing temperature is 60°C, and the mixing speed is 400 rpm.

[0192] Step 3: Add 17 parts of TPU resin to material 2 and mix them evenly in a high-speed mixer to obtain material 3.

[0193] The mixing time in step three is 40 minutes, the mixing temperature is 45°C, and the mixing speed is 500 rpm.

[0194] Step 4: Cool material 3 to 30°C, add 0.009 parts of BPO initiator to the cooled material 3, and mix evenly in a high-speed mixer to obtain material 4.

[0195] The mixing time in step four is 50 min, the mixing temperature is 28℃, and the mixing speed is 100 rpm.

[0196] Step 5: Add material 4 to the extrusion casting machine, and proceed through T-die extrusion, casting, air knife, cooling traction, thickness measurement with a thickness gauge, corona treatment, edge trimming, static elimination, and winding to obtain PVC film.

[0197] In step five, the screw temperature of the extrusion casting machine is 155℃, the die temperature is 190℃, and the traction speed is 6m / min.

[0198] Comparative Example 5

[0199] The stretchable film provided in this comparative example is prepared from the following components in parts by weight: 100 parts PVC resin, 17 parts TPU resin, 29 parts plasticizer, 3 parts maleic acid type organotin stabilizer, and 0.009 parts BPO initiator.

[0200] The method for preparing the stretchable film in this comparative example is as follows:

[0201] Step 1: Mix 100 parts of PVC resin and 29 parts of plasticizer evenly in a high-speed mixer to obtain material 1.

[0202] The mixing time in step one is 25 minutes, the mixing temperature is 35°C, and the mixing speed is 300 rpm.

[0203] Step 2: Add 3 parts of maleic acid type organotin stabilizer to material 1 and mix them evenly in a high-speed mixer to obtain material 2.

[0204] The mixing time in step two is 25 minutes, the mixing temperature is 60°C, and the mixing speed is 400 rpm.

[0205] Step 3: Add 17 parts of TPU resin to material 2 and mix them evenly in a high-speed mixer to obtain material 3.

[0206] The mixing time in step three is 40 minutes, the mixing temperature is 45°C, and the mixing speed is 500 rpm.

[0207] Step 4: Cool material 3 to 30°C, add 0.009 parts of BPO initiator to the cooled material 3, and mix evenly in a high-speed mixer to obtain material 4.

[0208] The mixing time in step four is 50 min, the mixing temperature is 28℃, and the mixing speed is 100 rpm.

[0209] Step 5: Add material 4 to the extrusion casting machine, and proceed through T-die extrusion, casting, air knife, cooling traction, thickness measurement with a thickness gauge, corona treatment, edge trimming, static elimination, and winding to obtain PVC film.

[0210] In step five, the screw temperature of the extrusion casting machine is 155℃, the die temperature is 190℃, and the traction speed is 6m / min.

[0211] Comparative Example 6

[0212] A commercially available domestically produced UV anti-adhesion film product has its UV anti-adhesion layer removed, and a PVC base film with a thickness of 0.0753 mm is obtained after removing the release film.

[0213] The UV anti-adhesion film in this comparative example is a product of Dongguan Yizhou Adhesive Products Co., Ltd.

[0214] Application Examples

[0215] The light transmittance of the stretchable films in Examples 1-5 and the PVC films in Comparative Examples 1-6 of this disclosure was characterized by the test performance indicators of the ASTM D1003 standard. PVC film standard samples were prepared according to ASTM D1003, with a thickness of 0.075 mm, and tested. The test results are shown in Table 1.

[0216] Table 1

[0217]

[0218]

[0219] The tensile properties of the stretchable films in Examples 1-5 and the PVC films in Comparative Examples 1-6 of this disclosure were characterized by the test performance indicators of the JIS-Z-0237 standard. Standard PVC film samples were prepared and tested according to JIS-Z-0237:2000, and the test results are shown in Table 2.

[0220] Table 2

[0221]

[0222] As shown in Table 1, the light transmittance of the stretchable films prepared in Examples 1 to 5 is significantly higher than that of Comparative Examples 1 to 6, while the haze value of the stretchable films prepared in Examples 1 to 5 is significantly lower than that of Comparative Examples 1 to 6. This demonstrates that the stretchable films prepared in the embodiments of this disclosure have high light transmittance.

[0223] As shown in Table 2, the tensile strength and elongation at break of the stretchable films prepared in Examples 1 to 5 are significantly improved compared with those in Comparative Examples 1 to 5. This demonstrates that the stretchable films prepared in the embodiments of this disclosure possess high resilience, high tensile strength, and high tear resistance.

[0224] The test results in Tables 1 and 2 demonstrate that the stretchable film prepared in this embodiment exhibits high light transmittance and high tensile strength. In other words, the five components—PVC resin, TPU resin, maleic acid-type organotin stabilizer, plasticizer, and BPO initiator—must be used in combination to achieve the overall comprehensive performance of the material; substituting similar components will not achieve the superior effects of this embodiment.

[0225] The above description is only a preferred embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present disclosure should be included within the protection scope of the present disclosure.

Claims

1. A stretchable film, characterized in that, Includes the following components in parts by weight: 100 parts of polyvinyl chloride (PVC) resin, 10-30 parts of thermoplastic polyurethane (TPU) resin, 1-4 parts of maleic acid-type organotin stabilizer, 5-40 parts of plasticizer, and 0.001-0.5 parts of initiator.

2. The stretchable film according to claim 1, characterized in that, The degree of polymerization of the PVC resin is 2500-3000, and the gel content is less than or equal to 1.5%.

3. The stretchable film according to claim 1, characterized in that, The TPU resin is a polymer of polyol and isocyanate with a molecular weight of 15,000 to 30,000.

4. The stretchable film according to claim 3, characterized in that, The isocyanate is an aliphatic isocyanate.

5. The stretchable film according to claim 1, characterized in that, The plasticizer includes at least one of dioctyl adipate, di(2-ethylhexyl) azelate, dibutyl sebacate, diisodecyl adipate, and dioctyl sebacate.

6. The stretchable film according to claim 1, characterized in that, The maleic acid-type organotin stabilizer includes at least one of di(monobutyl maleate) dibutyltin and di(monooctyl maleate) dibutyltin.

7. The stretchable film according to claim 1, characterized in that, The initiator is benzoyl peroxide, with a total chlorine content ≤0.20%.

8. A method for preparing a stretchable film as described in any one of claims 1 to 7, characterized in that, Includes the following steps: According to the weight parts of each component, the PVC resin and the plasticizer are mixed evenly to obtain material 1; The maleic acid-type organotin stabilizer is added to material 1 and mixed evenly to obtain material 2; The TPU resin is added to material 2 and mixed evenly to obtain material 3; The material 3 is cooled to 25-35°C, and the initiator is added to the cooled material 3 and mixed evenly to obtain material 4. The material 4 is added to an extrusion casting equipment, and the stretchable film is obtained by T-die extrusion, casting, air knife, cooling traction, thickness measurement by a thickness gauge, corona treatment, edge trimming, static elimination, and winding.

9. The method according to claim 8, characterized in that, The screw temperature of the extrusion casting equipment is 120-170℃, the die temperature is 170-200℃, and the traction speed is 6-12m / min.

10. The application of the stretchable film according to any one of claims 1 to 7 in wafer processing.

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