CN112549699A

CN112549699A - Self-adhesive high-temperature-resistant protective film and preparation method thereof

Info

Publication number: CN112549699A
Application number: CN202011404985.6A
Authority: CN
Inventors: 陈善文
Original assignee: Dongguan Yihong Industrial Co ltd
Current assignee: Dongguan Yihong Industrial Co ltd
Priority date: 2020-12-03
Filing date: 2020-12-03
Publication date: 2021-03-26
Anticipated expiration: 2040-12-03
Also published as: CN112549699B

Abstract

The application relates to the field of protective films, and particularly discloses a self-adhesive high-temperature-resistant protective film and a preparation method thereof. The self-adhesive high-temperature-resistant protective film comprises a self-adhesive layer, a middle layer and a surface layer, wherein the self-adhesive layer is prepared from the following raw materials in parts by weight: 40-80 parts of EVA; 20-50 parts of VLDPE; 12-20 parts of EPDM; the preparation method comprises the following steps: respectively and uniformly mixing the raw material of the self-adhesive layer, the raw material of the middle layer and the raw material of the surface layer, extruding the mixture by a three-layer co-extrusion film blowing machine, and cooling to obtain a self-adhesive high-temperature-resistant protective film; the self-adhesive high-temperature-resistant protective film has the advantages of good high-temperature resistance and good tensile property.

Description

Self-adhesive high-temperature-resistant protective film and preparation method thereof

Technical Field

The application relates to the field of protective films, in particular to a self-adhesive high-temperature-resistant protective film and a preparation method thereof.

Background

With the development of society, people pay attention to the protection of commodities, particularly the protection of the commodities during sale and transportation, besides paying attention to the use quality of the commodities; with the increasingly mature packaging technology, people begin to use protective films on commodities to reduce the possibility that the commodities are scratched and damaged. The self-adhesive protective film is a protective film without glue, and can be attached to the surface of an object through a self-adhesive layer of the protective film.

The self-adhesive layer of the related self-adhesive protective film is commonly made of EVA (ethylene vinyl acetate), namely ethylene-vinyl acetate copolymer, the adhesion between the protective film and an object is realized by utilizing the adhesive property of the EVA, however, the problem of poor structural stability often occurs when the EVA is used as the self-adhesive layer, so that the self-adhesive layer is easy to crack, and the practical use of the protective film is influenced.

In order to improve the use effect of the protective film, people add metallocene linear low-density polyethylene into the self-adhesive layer on the basis of EVA (ethylene vinyl acetate) so as to improve the structural stability of the self-adhesive layer, and the tensile property of the obtained self-adhesive protective film is improved, so that the actual use effect of the protective film is improved.

However, in practical application, it is found that the self-adhesive layer obtained by combining the EVA and the metallocene linear low-density polyethylene has low high temperature resistance, and the self-adhesive layer is easy to deform and glue residue at high temperature, so that the temperature adaptation range of the protective film in application is narrow, and the applicability of the protective film is affected.

Disclosure of Invention

In order to enable the protective film to have good high-temperature resistance, the application provides a self-adhesive high-temperature-resistant protective film and a preparation method thereof.

In a first aspect, the present application provides a self-adhesive high temperature resistant protective film, which adopts the following technical scheme:

the self-adhesive high-temperature-resistant protective film comprises a self-adhesive layer, a middle layer and a surface layer, wherein the self-adhesive layer is prepared from the following raw materials in parts by weight:

40-80 parts of EVA;

20-50 parts of VLDPE;

12-20 parts of EPDM.

By adopting the technical scheme, the EVA is an ethylene-vinyl acetate copolymer, the VLDPE is very low-density polyethylene, and the EPDM is ethylene propylene diene monomer, wherein the EPDM has good heat resistance and weather resistance, the VLDPE and the EPDM have a function of improving the high-temperature resistance of the self-adhesive layer after being mixed, and in addition, the VLDPE and the EPDM can keep the structural stability of the self-adhesive layer at a higher level after being mixed without adding mLLDPE, so that the protective film has good high-temperature resistance and good tensile property.

Preferably, the self-adhesive layer is prepared from the following raw materials in parts by weight:

65-70 parts of EVA;

35-40 parts of VLDPE;

14-16 parts of EPDM.

By adopting the technical scheme, when the raw material ratio of the self-adhesive layer is in the range, the high temperature resistance and the tensile property of the self-adhesive layer are better.

Preferably, the weight content of ethylene in the EPDM is 55-60%, and the weight content of the third monomer ethylidene norbornene is 6-9%.

By adopting the technical scheme, the ethylene content and the ethylidene norbornene content of the third monomer in the EPDM are controlled, so that the high temperature resistance and the tensile property of the self-adhesive layer are better.

Preferably, the EPDM has a Mooney viscosity of 25 to 30ML at 125 ℃₁₊₄。

By adopting the technical scheme, the Mooney viscosity of the EPDM is controlled, so that the high temperature resistance and the tensile property of the self-adhesive layer are further improved.

Preferably, the melt flow rate of the VLDPE is 0.5 to 0.75g/10min at a temperature of 190 ℃ and under a load of 2.16 kg.

By adopting the technical scheme, the melt flow rate of the VLDPE is controlled, so that the oil stain resistance and the adhesive force of the self-adhesive layer are better.

Preferably, the EVA has a vinyl acetate content of 33% by weight and a melt index of 45.

Preferably, the raw material of the self-adhesive layer further comprises 2-4 parts by weight of oleamide.

By adopting the technical scheme, the oil stain resistance of the self-adhesive layer is improved after the oleamide is added, and when oil stains exist on the surface of an object, the protective film can be adhered to the surface of the object and keeps good adhesive force.

Preferably, the intermediate layer is made of raw materials containing 70-80 parts by weight of MDPE and 20-30 parts by weight of mLLDPE.

By adopting the technical scheme, the MDPE is medium-density polyethylene, the mLLDPE is metallocene linear low-density polyethylene, and the mechanical strength of the middle layer can be improved by matching the MDPE and the mLLDPE, so that the mechanical strength of the protective film is improved.

Preferably, the skin layer is made from a feedstock comprising mLLDPE.

By adopting the technical scheme, the mLLDPE can keep the mechanical strength of the surface layer and ensure that the protective film has good transparency.

Preferably, the thickness ratio of the self-adhesive layer, the middle layer and the surface layer is 1 (2.5-3) to 1.5-2.

By adopting the technical scheme, the overall tensile property of the protective film is improved.

In a second aspect, the present application provides a method for preparing a self-adhesive high temperature resistant protective film, which adopts the following technical scheme:

a preparation method of a self-adhesive high-temperature-resistant protective film comprises the following steps:

and respectively and uniformly mixing the raw material of the self-adhesive layer, the raw material of the middle layer and the raw material of the surface layer, extruding by a three-layer co-extrusion film blowing machine, and cooling to obtain the self-adhesive high-temperature-resistant protective film.

By adopting the technical scheme, the protective film is prepared and has good high-temperature resistance and good tensile property.

In summary, the present application has the following beneficial effects:

1. according to the application, the EPDM is added into the EVA self-adhesive layer, because the EPDM has good heat resistance and weather resistance, after the VLDPE and the EPDM are mixed, the high temperature resistance of the self-adhesive layer is improved, and in addition, under the condition that the mLLDPE is not added, the structural stability of the self-adhesive layer can be kept at a higher level after the VLDPE and the EPDM are mixed, so that the protective film has good high temperature resistance and good tensile property.

2. The self-adhesive layer in this application has still added oleamide for the self-adhesive layer has anti greasy dirt ability, improves protection film in-service use suitability and flexibility.

Detailed Description

The present application will be described in further detail with reference to examples.

EVA, VLDPE and EPDM were all purchased from Akoma, France;

MDPE is selected from RiandBarschel industries, Inc., model Lupolen 5261Z;

mLLDPE was selected from Exxon Mobil corporation, model 3527 PA.

Examples

Example 1

adding the raw materials of the self-adhesive high-temperature-resistant protective film into a three-layer co-extrusion film blowing machine, wherein 4kg of EVA, 2kg of VLDPE and 2kg of EPDM are added into an outer layer hopper, 16.8kg of MDPE and 7.2kg of mLLDPE are added into a middle layer hopper, and 12kg of mLLDPE is added into an inner layer hopper;

wherein the selected VLDPE has a melt flow rate of 1g/10min at 190 ℃ under a load of 2.16kg, the selected EPDM has an ethylene content of 68% by weight, a third monomer of ethylidene norbornene of 12% by weight, and the EPDM has a Mooney viscosity of 50ML at 125 ℃₁₊₄；

And uniformly mixing all the hoppers, extruding the mixture through a three-layer co-extrusion film blowing machine, and cooling to obtain the self-adhesive high-temperature-resistant protective film.

Example 2

adding raw materials of the self-adhesive high-temperature-resistant protective film into a three-layer co-extrusion film blowing machine, wherein 8kg of EVA, 5kg of VLDPE and 1.2kg of EPDM are added into an outer layer hopper, 34.08kg of MDPE and 8.52kg of mLLDPE are added into a middle layer hopper, and 28.4kg of mLLDPE is added into an inner layer hopper;

Example 3

adding the raw materials of the self-adhesive high-temperature-resistant protective film into a three-layer co-extrusion film blowing machine, wherein 6.5kg of EVA, 3.5kg of VLDPE and 1.4kg of EPDM are added into an outer layer hopper, 19.95kg of MDPE and 8.55kg of mLLDPE are added into a middle layer hopper, and 17.1kg of mLLDPE is added into an inner layer hopper;

Example 4

adding raw materials of the self-adhesive high-temperature-resistant protective film into a three-layer co-extrusion film blowing machine, wherein 7kg of EVA, 4kg of VLDPE and 1.6kg of EPDM are added into an outer layer hopper, 25.2kg of MDPE and 6.3kg of mLLDPE are added into a middle layer hopper, and 18.9kg of mLLDPE is added into an inner layer hopper;

In order to clearly show the differences of examples 1 to 4, the weights of the different raw materials of examples 1 to 4 are shown in table 1.

TABLE 1

	Example 1	Example 2	Example 3	Example 4
					EVA(kg)	4.00	8.00	6.50	7.00
VLDPE(kg)	2.00	5.00	3.50	4.00
					EPDM(kg)	2.00	1.20	1.40	1.60
MDPE(kg)	16.80	34.08	19.95	25.20
					mLLDPE (kg) in middle layer hopper	7.20	8.52	8.55	6.30
mLLDPE (kg) in inner hopper	12.00	28.40	17.10	18.90

Example 5

This example differs from example 4 in that 0.2kg of oleamide was also added to the outer layer hopper in this example.

Example 6

This example differs from example 4 in that 0.4kg of oleamide was also added to the outer layer hopper in this example.

Example 7

This example is different from example 6 in that EPDM was selected to have an ethylene content of 55% by weight and a third monomer, ethylidene norbornene, was selected to have a weight content of 9% by weight.

Example 8

This example is different from example 6 in that EPDM was selected to have an ethylene content of 60% by weight and a third monomer, ethylidene norbornene, was selected to have a weight content of 6% by weight.

Example 9

This example differs from example 8 in that the EPDM used in this example had a Mooney viscosity of 25ML at 125 ℃₁₊₄。

Example 10

This example differs from example 8 in that the EPDM used in this example had a Mooney viscosity of 30ML at 125 ℃₁₊₄。

Example 11

This example differs from example 10 in that in this example the VLDPE selected had a melt flow rate of 0.75g/10min at a temperature of 190 ℃ and a load of 2.16 kg.

Example 12

This example differs from example 10 in that in this example the VLDPE selected had a melt flow rate of 0.5g/10min at a temperature of 190 ℃ and a load of 2.16 kg.

Example 13

This example differs from example 4 in that in this example the VLDPE selected had a melt flow rate of 0.5g/10min at a temperature of 190 ℃ and a load of 2.16 kg.

Comparative example

Comparative example 1

This comparative example differs from example 4 in that in this comparative example 8.82kg of EVA and 3.78kg of mLLDPE were fed into the outer hopper.

Comparative example 2

This comparative example differs from example 4 in that in this comparative example the VLDPE was replaced by an equal amount of EVA.

Comparative example 3

This comparative example differs from example 4 in that the same amount of EVA was used instead of EPDM in this comparative example.

Comparative example 4

This comparative example differs from example 4 in that in this comparative example the VLDPE was replaced by an equal amount of mLLDPE.

Performance test

And (3) testing adhesive force: according to GB/T2792-;

and (3) testing high-temperature resistance: according to GB/T32368-;

and (3) testing tensile strength: the protective films obtained in the respective examples and comparative examples of the present application were subjected to tensile property tests in accordance with GB/T1040-;

and (3) oil stain resistance test: taking a stainless steel plate with a smooth surface, drawing six square frames with the size of 5mm multiplied by 5mm on the surface of the stainless steel plate, uniformly coating peanut oil in the square frames, respectively sticking the protective films obtained in the embodiments and the comparative examples of the application to the stainless steel plate, covering the six square frames with the protective films along the length direction, and then carrying out 180-degree peel strength test, wherein the test results are shown in table 2.

TABLE 2

According to table 2, comparative example 1 is a common self-adhesive layer formulation in the related art, and compared with example 4, the time of deformation and adhesive residue of the protective film of example 4 is later, which indicates that the high temperature resistance of the protective film of example 4 is better, and the reason may be that the heat resistance of EPDM is good, and the mixing dispersion degree of EPDM in EVA system is improved after VLDPE and EPDM are mixed and added, thereby improving the high temperature resistance of the self-adhesive layer.

The comparative example 2 is that VLDPE is not added to the self-adhesive layer, the comparative example 3 is that EPDM is not added to the self-adhesive layer, compared with the example 4, the time for deformation and adhesive residue of the protective film of the example 4 is later, which indicates that the high temperature resistance of the example 4 is better than that of the comparative examples 2 and 3, probably because VLDPE cannot improve the high temperature resistance of the self-adhesive layer, and EPDM can better exert the capability of improving the high temperature resistance of the self-adhesive layer under the synergistic action of VLDPE; in addition, the tensile strength of example 4 is lower than that of comparative example 1, but the reduction is not large, while the tensile strength of comparative example 2 is much lower than that of comparative example 1, probably because the tensile property of the protective film is reduced by adding the EPDM, but the structural stability of the self-adhesive layer can be maintained after the VLDPE and the EPDM are mixed with the addition of the VLDPE, so that the self-adhesive layer can maintain good tensile property on the basis of the addition of the EPDM.

Comparative example 4 in which VLDPE was replaced with mLLDPE for the self-adhesive layer, the time for deformation and culling of the protective film of example 4 was later compared to example 4, and the tensile strength of example 4 was higher, probably because mLLDPE could not improve the high temperature resistance and maintain the tensile properties of the self-adhesive layer in cooperation with EPDM.

Examples 5-6 are the self-adhesive layer with oleamide, compared with example 4, the protective film of examples 5-6 has the same deformation time and has earlier residual glue, which indicates that the addition of oleamide has a certain adverse effect on the high temperature resistance of the self-adhesive layer, while the protective film of example 5 has improved tensile strength and greatly improved oil stain resistance, probably because the addition of oleamide improves the oleophobic property of the self-adhesive layer and improves the oil stain resistance of the self-adhesive layer, so that the self-adhesive layer can maintain better adhesion when adhered to the greasy surface.

Examples 7-8 show that the ethylene content by weight of the EPDM selected for use in the self-adhesive layer was 55 and 60%, and the ethylidene norbornene monomer third monomer was 6 and 9%, respectively, and that the protective films of examples 7-8 exhibited deformation and adhesive residue at a later time and had higher tensile strength than example 6, indicating that the selection of the ethylene content by weight of the EPDM and the ethylidene norbornene monomer third monomer affects the high temperature resistance and tensile properties of the self-adhesive layer.

Examples 9-10 Mooney viscosities at 125 ℃ of 25 and 30ML, respectively, of EPDM selected for use in the self-adhesive layer₁₊₄The protective films of examples 9-10 had reduced grease resistance but the time for the protective film to deform and gum residue was later and the tensile strength was higher compared to example 8, indicating that the selection of mooney viscosity in EPDM affected the high temperature resistance and tensile properties of the self-adhesive layer.

Examples 11-12 show that the melt flow rates of the VLDPEs selected for use in the self-adhesive layer were 0.5 and 0.75g/10min, respectively, and that the protective films of examples 11-12 exhibited improved non-greasy adhesion and greasy dirt resistance compared to example 10, indicating that the melt flow rate of the VLDPEs was adjusted to improve the deficiencies associated with the mooney viscosity change of EPDM, and that the protective films of examples 11-12 exhibited higher levels of adhesion, high temperature resistance, tensile properties, and greasy dirt resistance.

Example 13 the melt flow rate of the VLDPE selected for use in the self-adhesive layer was 0.5g/10min, and there was no significant change in the antifouling adhesion of example 13 compared to example 4, probably because the increase in the antifouling adhesion of examples 11-12 was synergistically produced by the change in the melt flow rates of oleamide and VLDPE.

The present embodiment is only for explaining the present application, and it is not limited to the present application, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present application.

Claims

1. The self-adhesive high-temperature-resistant protective film is characterized by comprising a self-adhesive layer, an intermediate layer and a surface layer, wherein the self-adhesive layer is prepared from the following raw materials in parts by weight:

40-80 parts of EVA;

20-50 parts of VLDPE;

12-20 parts of EPDM.

2. The self-adhesive high temperature resistant protective film according to claim 1, wherein: the self-adhesive layer is prepared from the following raw materials in parts by weight:

65-70 parts of EVA;

35-40 parts of VLDPE;

14-16 parts of EPDM.

3. The self-adhesive high temperature resistant protective film according to claim 1, wherein: the EPDM comprises 55-60 wt% of ethylene and 6-9 wt% of a third monomer ethylidene norbornene.

4. The self-adhesive high temperature resistant protective film according to claim 1, wherein: the EPDM has a Mooney viscosity of 25-30 ML at 125 DEG C₁₊₄。

5. The self-adhesive high temperature resistant protective film according to claim 1, wherein: the melt flow rate of the VLDPE at a temperature of 190 ℃ under a load of 2.16kg is 0.5 to 0.75g/10 min.

6. The self-adhesive high temperature resistant protective film according to claim 1, wherein: the raw materials of the self-adhesive layer also comprise 2-4 parts of oleamide by weight.

7. The self-adhesive high temperature resistant protective film according to claim 1, wherein: the middle layer is made of raw materials including 70-80 parts by weight of MDPE and 20-30 parts by weight of mLLDPE.

8. The self-adhesive high temperature resistant protective film according to claim 1, wherein: the skin layer is made from a feedstock comprising mLLDPE.

9. The self-adhesive high temperature resistant protective film according to claim 1, wherein: the weight ratio of the self-adhesive layer to the intermediate layer to the surface layer is 1 (2.5-3) to 1.5-2.

10. A preparation method of a self-adhesive high-temperature-resistant protective film is characterized by comprising the following steps: the method comprises the following steps: