Coating protection film

Abstract

To provide a protective film for coated film that does not cause a pasting trace after peeling, when adhered on components such as car bodies, bumpers of automobiles and doors including coated automobiles, motor cycles or bicycles with a motor, and other resin coating film plate.SOLUTION: Provided is a protective film for coated film characterized by having a sheet-shaped substrate containing polyolefin, and an adhesive layer laminated on the substrate and containing an adhesive having a weight average molecular weight of 30×104 to 250×104, in which heat shrinkage of the substrate at 23°C is 0.10 to 2.50 N / 25 mm, and a coefficient of linear expansion of the adhesive layer is 50 to 500 μ / (m °C).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a protective film for paint films that protects painted bodies of automobiles, motorcycles, motorbikes, and other motorized bicycles, parts such as automobile bumpers, and painted parts other than automobiles, from dust and dirt, and prevents deformation of the paint film. [Background technology]

[0002] BACKGROUND ART Protective films having an adhesive layer and a film layer that are attached to the coating of painted automobiles, motorcycles, mopeds, and other vehicle bodies, automobile bumpers, doors, and other parts, as well as painted parts other than automobiles, have been known to prevent damage, discoloration, and other deterioration due to foreign matter such as dust, dirt, and rain when transporting or storing such parts.

[0003] For example, Patent Document 1 discloses a protective film having an upper layer on the surface of which a fine convex structure is formed, and an adhesive layer on the back surface that adheres to the surface of the vehicle body to be protected. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-51373 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the vehicle body protection film described in Patent Document 1 has a problem in that the surface of the coating applied to the vehicle body and its parts is not hard, and therefore, after peeling off the vehicle body protection film, visible marks, also known as steps, are left near the boundary between the areas where the vehicle body protection film was attached and the areas where it was not attached.

[0006] The present invention has been made in view of the above-mentioned problems, and its object is to provide a protective film for paint films that, when applied to painted bodies of automobiles, motorcycles, mopeds, and other vehicle parts, such as automobile bumpers and doors, or painted parts other than automobiles, does not leave traces on the paint film after being peeled off. [Means for solving the problem]

[0007] [1] The present invention relates to a sheet-like substrate containing a polyolefin, and a polyolefin-based polymer having a weight-average molecular weight of 30×10 4 ~250×10 4 an adhesive layer containing an adhesive agent Using a thermomechanical analyzer, a load of 0.01 N was applied, the substrate was allowed to stand at 40°C for 3 minutes, a length strain of 0.1% was applied, the substrate was heated from 40°C to 80°C at a rate of 10°C per minute, the substrate was allowed to stand at 80°C for 10 minutes, and then cooled from 80°C to 23°C at a rate of 10°C per minute. The heat shrinkage force of the substrate at 23°C was measured as the shrinkage force at 23°C, and the heat shrinkage force was 0.10 to 2.50 N / 25 mm; The pressure-sensitive adhesive contains polyisobutylene, and the pressure-sensitive adhesive layer has a linear expansion coefficient of 50 to 500 μ / (m·°C), In the adhesive layer, a weight average molecular weight of 1×10 4 ~7×10 4 and [ka] (In the formula, m and n are each a number from 1 to 4, p and q are each a number from 5 to 20, x and y are each a number from 1 to 100, R 1 ,R 2 each represents a hydrogen atom or an alkylene group having 1 to 4 carbon atoms), [ka] (wherein x and y are numbers from 5 to 150, R 1 ,R 2 each represents a hydrogen atom or an alkylene group having 1 to 4 carbon atoms), or [ka] (wherein x and y are numbers from 1 to 80, R 1 ,R 2 each represents a hydrogen atom or an alkylene group having 1 to 4 carbon atoms), The protective film for coatings is characterized by containing at least one polyether-modified polydimethylsiloxane selected from the following:

[0009] [ 2 ] And, the above-mentioned [1] characterized in that an inorganic filler is contained in the base material. 〕to The protective film for coatings described above is a protective film for coatings described above.

[0010] [ 3 ] And, the polyolefin contains 30 to 90 mass % of either polyethylene or polypropylene. or The above [ 2 〕to The protective film for coatings described above is a protective film for coatings described above.

[0012] [ 4 ] and the substrate has a bending hardness of 0.01 to 10.0 gf cm at 23°C. 2 / cm 3

[0023] The protective film for coatings according to any one of the preceding claims. [Effects of the Invention]

[0013] The paint film protective film of the present invention, when applied to painted automobile, motorcycle, moped, or other vehicle body, or automobile parts such as bumpers and doors, can be removed without leaving any traces of adhesion on the paint film. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a side view showing a vehicle body member having a paint protection film and a paint film according to an embodiment of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

[0015] The coating protection film according to the embodiment of the present invention will be described in detail below. The embodiment described below is a preferred example for carrying out the present invention, and therefore various technical limitations are imposed. However, the present invention is not limited to this embodiment unless otherwise specified in the following description. Furthermore, expressions indicating numerical ranges include upper and lower limits.

[0016] The protective film for coatings of the present invention comprises a predetermined substrate 1 and a predetermined adhesive layer 2, and with respect to thermal stress generated in response to a force acting to suppress thermal expansion and contraction, the substrate 1 has a predetermined thermal contraction force and the adhesive layer 2 has a predetermined linear expansion coefficient.

[0017] The substrate 1 of the present invention is a sheet-like member containing polyolefin. The substrate 1 covers painted bodies of automobiles, motorcycles, mopeds, and other vehicles, automobile bumpers, doors, and other parts, as well as painted parts of vehicles other than automobiles, thereby preventing damage, discoloration, and other deterioration caused by foreign matter such as dust, dirt, and rain.

[0018] The polyolefin used as the material for the substrate 1 is preferably a polymer obtained by copolymerizing an olefinic hydrocarbon having 2 to 6 carbon atoms, such as polyethylene, polypropylene, ethylene, or propylene, with polyethylene, polypropylene, and ethylene being more preferred. As the polyolefin, one of these may be used alone, or two or more may be used in combination. Furthermore, the polyolefin content in the substrate 1 is preferably 30 to 90 mass %, more preferably 40 to 80 mass %. The polyolefin content in the above proportions reduces thermal stress on the coating film C applied to the vehicle body or vehicle body part P, thereby preventing the coating film C from leaving traces of adhesion after peeling.

[0019] The heat shrinkage force of the substrate 1 at 23°C is preferably 0.10 to 2.50 N / 25 mm, more preferably 0.15 to 1.50 N / 25 mm, and most preferably 0.20 to 1.00 N / 25 mm. Because vehicle bodies and vehicle body parts P to which the paint protection film is applied are not necessarily stored under temperature control, thermal stress due to thermal expansion and contraction of the paint protection film acts on the vehicle body or vehicle body part P, causing the coating C applied to the vehicle body or vehicle body part P to be pulled and stretched in various directions, making it more likely that marks will be left on the coating C after the paint protection film is removed. When the heat shrinkage force of the substrate 1 at a predetermined temperature is within the above range, this, combined with the predetermined linear expansion coefficient of the adhesive layer (described below), reduces the thermal stress on the coating C applied to the vehicle body or vehicle body part P, preventing marks from being left on the coating C after removal.

[0020] The bending hardness of the substrate 1 is 0.01 to 10.0 gf cm at 23°C. 2 / cm, and 0.02 to 5.00 gf cm 2 / cm, and more preferably 0.03 to 1.00 gf cm 2 / cm. When the bending hardness of the substrate 1 at a predetermined temperature is within the above range, deterioration such as damage and discoloration caused by foreign matter such as dust, dirt, and rain on the vehicle body or vehicle body part P can be prevented, and thermal stress on the coating film C applied to the vehicle body or vehicle body part P can be alleviated, thereby preventing traces of application on the coating film C after peeling.

[0021] The thickness of the substrate 1 is preferably 10 to 200 μm, and more preferably 20 to 150 μm. When the thickness of the substrate 1 is within the above range, the vehicle body, vehicle body parts P, and painted parts other than automobiles can be protected from damage and deterioration such as discoloration caused by foreign matter such as dust, dirt, and rain.

[0022] Furthermore, it is preferable that an inorganic filler is contained in the substrate 1. The inorganic filler is an additive for modifying the substrate 1, and specifically, is added to reduce the thermal shrinkage force of the substrate 1, thereby alleviating the thermal stress on the coating film C applied to the vehicle body or vehicle body part P, thereby more effectively preventing the coating film C from leaving traces of adhesion after peeling.

[0023] Specific examples of the inorganic filler include calcium carbonate, talc, mica, silica, titanium oxide, etc. The shape of the inorganic filler is not particularly limited, but particles or flakes having an average diameter of 20 nm to 500 μm can be used.

[0024] The adhesive layer 2 has a weight average molecular weight of 30×10 4 ~250×10 4 and is laminated to the base 1. The adhesive layer 2 is a member for fixing the paint protection film of the present invention to a coating C applied to a vehicle body, a vehicle body part P, or a painted part other than an automobile.

[0025] The adhesive used in the adhesive layer 2 is preferably a synthetic polymer such as polyisobutylene or a copolymer of isobutylene and maleic anhydride, and more preferably polyisobutylene. One of these adhesives may be used alone or in combination as the adhesive layer 2. The weight-average molecular weight of the adhesive used in the adhesive layer 2 is preferably 30×10 4 ~250×10 4 Preferably, it is 50×10 4 ~100×10 4Preferably, the weight average molecular weight is 70 to 100 mass %, more preferably 80 to 95 mass %. The weight average molecular weight is preferably measured by GPC using polystyrene as a standard substance. The polyisobutylene content in the adhesive layer 2 is preferably 70 to 100 mass %, and more preferably 80 to 95 mass %. By blending the synthetic polymer used as the adhesive layer 2 within the above-mentioned range of weight average molecular weight and in the above-mentioned blending ratio, thermal stress on the coating film C applied to the vehicle body, vehicle body part P, or painted parts other than automobiles can be alleviated, thereby preventing the coating film C from leaving traces of adhesion after peeling.

[0026] In the adhesive layer 2, the weight average molecular weight is 1×10 4 ~7×10 4 and [ka] (In the formula, m and n are each a number from 1 to 4, p and q are each a number from 5 to 20, x and y are each a number from 1 to 100, R 1 ,R 2 each represents a hydrogen atom or an alkylene group having 1 to 4 carbon atoms), [ka] (wherein x and y are numbers from 5 to 150, R 1 ,R 2 each represents a hydrogen atom or an alkylene group having 1 to 4 carbon atoms), or [ka] (wherein x and y are numbers from 1 to 80, R 1 ,R 2 each represents a hydrogen atom or an alkylene group having 1 to 4 carbon atoms), It is preferable that the surface conditioner contains at least one polyether-modified polydimethylsiloxane selected from the following:

[0027] The polyether-modified polydimethylsiloxane is uniformly blended into the adhesive layer 2 and can reduce the linear expansion coefficient of the adhesive layer 2, thereby alleviating the thermal stress on the coating film C applied to the vehicle body or vehicle body part P, thereby preventing the coating film C from leaving traces of adhesion after peeling.

[0028] The weight average molecular weight of the polyether-modified polydimethylsiloxane is 1×10 4 ~7×10 4 Preferably, it is 3×10 4 ~5×10 4 It is more preferable that the weight average molecular weight is measured by GPC using polystyrene as a standard substance. [Example]

[0029] EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following examples.

[0030] Example 1 The substrate 1 is made of 100% by mass of polypropylene with a thickness of 40 μm as the polyolefin, and the adhesive has a weight average molecular weight of 130 × 10 4 Polyisobutylene is 93% by mass and 3.3 × 10 4 A protective film for coatings was prepared, comprising an adhesive layer 2 containing 7% by mass of polyether-modified polydimethylsiloxane (manufactured by BYK Japan, model number: BYK330) having the structure shown in Chemical Formula 1. The heat shrinkage force of the substrate 1 at 23°C was 0.75 N / 25 mm, and the bending hardness was 0.330 gf cm. 2 / cm, and the linear expansion coefficient of adhesive layer 2 was 77.2 μ / (m·°C). The weight average molecular weights of the adhesives, polyisobutylene and polyether-modified polydimethylsiloxane, were determined using a differential refractometer with GPC and chloroform as the developing solvent, and were calculated based on standard polyethylene.

[0031] <Example 2> A coating protection film was prepared in the same manner as in Example 1, except that a 40 μm thick substrate 1 was used, which consisted of 50% by mass of polyethylene as the polyolefin and 50% by mass of calcium carbonate as the inorganic filler dispersed in the polyolefin. The heat shrinkage force of the substrate 1 at 23°C was 0.50 N / 25 mm, and the flexural hardness was 0.152 gf cm. 2 / cm, and the linear expansion coefficient of the adhesive layer 2 was 77.2 μ / (m·°C).

[0032] Example 3 A coating protection film was prepared in the same manner as in Example 1, except that a 40 μm thick substrate 1 was used, which consisted of 50% by mass of polypropylene as the polyolefin and 50% by mass of calcium carbonate as the inorganic filler dispersed in the polyolefin. The heat shrinkage force of the substrate 1 at 23°C was 0.20 N / 25 mm, and the flexural hardness was 0.168 gf cm. 2 / cm, and the linear expansion coefficient of the adhesive layer 2 was 77.2 μ / (m·°C).

[0033] Example 4 A coating protection film was prepared in the same manner as in Example 1, except that a 40 μm thick substrate 1 was used, which consisted of 40% by mass of a mixture of polypropylene and polyethylene as the polyolefin and 60% by mass of calcium carbonate as the inorganic filler dispersed in the polyolefin. The heat shrinkage force of the substrate 1 at 23°C was 0.25 N / 25 mm, and the bending hardness was 0.148 gf cm. 2 / cm, and the linear expansion coefficient of the adhesive layer 2 was 77.2 μ / (m·°C).

[0034] < Reference example 1 > The substrate 1 has a thickness of 40 μm and is made of 40 mass % of a mixture of polypropylene and polyethylene as polyolefin and 60 mass % of calcium carbonate as inorganic filler dispersed in the polyolefin. 4A protective film for coatings was prepared, consisting of an adhesive layer 2 made of 100% by mass of polyisobutylene. The heat shrinkage force of the substrate 1 at 23°C was 0.25 N / 25 mm, and the bending hardness was 0.148 gf cm. 2 / cm, and the linear expansion coefficient of the adhesive layer 2 was 338 μ / (m·°C).

[0035] < Reference example 2 > The substrate 1 is made of 100% by mass of polypropylene having a thickness of 20 μm as the polyolefin, and the weight average molecular weight is 130×10 4 A protective film for coatings was prepared, which had an adhesive layer 2 made of 100% by mass of polyisobutylene. The heat shrinkage force of the substrate 1 at 23°C was 0.75 N / 25 mm, and the bending hardness was 0.031 gf cm. 2 / cm, and the linear expansion coefficient of the adhesive layer 2 was 338 μ / (m·°C).

[0036] <Comparative Example 1> The substrate 1 is a polyethylene terephthalate substrate with a thickness of 38 μm, which is different from polyolefin, and the weight average molecular weight is 130 × 10 4 A protective film for coatings was prepared, which had an adhesive layer 2 containing 100% by mass of polyisobutylene. The heat shrinkage force of the substrate 1 at 23°C was 3.00 N / 25 mm, and the bending hardness was 0.291 gf cm. 2 / cm, and the linear expansion coefficient of the adhesive layer 2 was 338 μ / (m·°C).

[0037] <Comparative Example 2> A protective film for coatings was prepared, consisting of a 40 μm thick substrate 1 made of 50% polyethylene by mass as a polyolefin and 50% calcium carbonate by mass as an inorganic filler dispersed in the polyolefin, and an adhesive layer 2 made of 100% acrylic resin by mass. The heat shrinkage force of the substrate 1 at 23°C was 0.50 N / 25 mm, and the bending hardness was 0.152 gf cm. 2 / cm, and the linear expansion coefficient of the adhesive layer 2 was 560 μ / (m·°C).

[0038] <Comparative Example 3> A protective film for coatings was prepared, consisting of a 40 μm thick substrate 1 made of 50% by mass of polypropylene as a polyolefin and 50% by mass of calcium carbonate as an inorganic filler dispersed in the polyolefin, and an adhesive layer 2 made of 100% by mass of acrylic resin. The heat shrinkage force of the substrate 1 at 23°C was 0.20 N / 25 mm, and the bending hardness was 0.168 gf cm. 2 / cm, and the linear expansion coefficient of the adhesive layer 2 was 560 μ / (m·°C).

[0039] <Comparative Example 4> A protective film for coatings was prepared, consisting of a 40 μm thick substrate 1 made of 40% by mass of a mixture of polypropylene and polyethylene as polyolefin and 60% by mass of calcium carbonate as an inorganic filler dispersed in the polyolefin, and an adhesive layer 2 made of 100% by mass of acrylic resin. The heat shrinkage force of the substrate 1 at 23°C was 0.25 N / 25 mm, and the bending hardness was 0.148 gf cm. 2 / cm, and the linear expansion coefficient of the adhesive layer 2 was 560 μ / (m·°C).

[0040] <Comparative Example 5> The substrate 1 is a polyethylene terephthalate substrate having a thickness of 100 μm, which is different from polyolefin, and the weight average molecular weight is 130 × 10 4 A protective film for coatings was prepared, which had an adhesive layer 2 containing 100% by mass of polyisobutylene. The heat shrinkage force of the substrate 1 at 23°C was 8.00 N / 25 mm and the bending hardness was 5.508 gf cm. 2 / cm, and the linear expansion coefficient of the adhesive layer 2 was 338 μ / (m·°C).

[0041] <Comparative Example 6> A protective film for coatings was prepared consisting of a substrate 1 made of 100% polypropylene by mass with a thickness of 40 μm and an adhesive layer 2 made of 100% acrylic resin by mass. The heat shrinkage force of the substrate 1 at 23°C was 0.75 N / 25 mm and the bending hardness was 0.330 gf cm. 2 / cm, and the linear expansion coefficient of the adhesive layer 2 was 560 μ / (m·°C).

[0042] Example 1 4, Reference examples 1~2 The paint protection films of Comparative Examples 1 to 6 were applied to a bumper, which was a vehicle body part C, having Paint Film C formed on its surface, and stored at 23°C or 80°C for 72 hours. After that, all of the films were stored in a constant temperature room at 23°C for 2 hours, after which the paint protection films were peeled off from the bumper and the surface of Paint Film C was visually inspected. Films that showed no change after peeling off the paint protection film were evaluated as ◯, films that showed slight traces of adhesion such as shifting or rippling of Paint Film C were evaluated as △, and films where Paint Film C peeled off, exposing the underlying bumper were evaluated as ×. A rating of ◯ was considered good, and ratings of △ and × were considered poor.

[0043] These results are shown in Table 1.

[0044] [Table 1]

[0045] In addition, Examples 1 to 4, Reference examples 1~2 The heat shrinkage force of the substrate 1 in Comparative Examples 1 to 6 was measured using a thermomechanical analyzer (manufactured by TA Instruments Japan, model number: TMA Q400SR) by applying a load of 0.01 N, leaving the substrate at 40°C for 3 minutes, applying a length strain of 0.1%, heating from 40°C to 80°C at a rate of 10°C per minute, leaving the substrate at 80°C for 10 minutes, and then cooling from 80°C to 23°C at a rate of 10°C per minute, and measuring the shrinkage force at 23°C. The bending hardness of the substrate 1 in Examples 1 to 6 and Comparative Examples 1 to 6 was measured using a pure bending tester (manufactured by Kato Tech Co., Ltd., model number: KES-FB2-S) by bending a substrate 1 20 cm long and 10 cm wide at 23°C while holding it in chucks spaced 1 cm apart.

[0046] Furthermore, Examples 1 to 4, Reference examples 1~2The linear expansion coefficient of the adhesive layer 2 in Comparative Examples 1 to 6 was determined in accordance with JIS K7197-1991 using a thermomechanical analyzer (manufactured by TA Instruments Japan, model number: TMA Q400SR) by applying a load of 0.01 N and heating from 23°C to 80°C at a rate of 10°C per minute, and calculating the average expansion coefficient from 23°C to 80°C.

[0047] As shown in Table 1, Examples 1 to 3 each include a predetermined substrate 1 and a predetermined adhesive layer 2, and have a combination of physical properties related to thermal expansion and contraction, such as a predetermined thermal contraction force in the substrate 1 and a predetermined linear expansion coefficient in the adhesive layer 2. 4 It was found that this paint protection film can prevent marks from being left on the paint film C after peeling, particularly in cases where large temperature changes occur, by alleviating the thermal stress on the paint film C applied to the bumper, which is the vehicle body part P. Thus, the paint protection film of the present invention can be used as a film for protecting a vehicle body having a paint film, as a film for protecting an automobile paint film, and as a film for protecting a resin paint film. 。 [Explanation of symbols]

[0048] 1...Base material 2...adhesive layer C...Coating film P... Body parts

Claims

1. a sheet-like substrate containing a polyolefin; A polymer having a weight average molecular weight of 30×10 4 ~250 x 10 4 an adhesive layer containing an adhesive agent Using a thermomechanical analyzer, a load of 0.01 N is applied, the substrate is allowed to stand at 40°C for 3 minutes, a length strain of 0.1% is applied, the substrate is heated from 40°C to 80°C at a rate of 10°C per minute, the substrate is allowed to stand at 80°C for 10 minutes, and then cooled from 80°C to 23°C at a rate of 10°C per minute. The heat shrinkage force of the substrate at 23°C is measured as the shrinkage force at 23°C and is 0.10 to 2.50 N / 25 mm; The pressure-sensitive adhesive contains polyisobutylene, The adhesive layer has a linear expansion coefficient of 50 to 500 μ / (m ° C.), In the adhesive layer, a weight average molecular weight of 1×10 4 ~7 x 10 4 and 【Chemistry 1】 (wherein m and n are each a number from 1 to 4, p and q are each a number from 5 to 20, x and y are each a number from 1 to 100, R 1 , R 2 each represents a hydrogen atom or an alkylene group having 1 to 4 carbon atoms. 【Chemistry 2】 (wherein x and y are numbers from 5 to 150, R 1 , R 2 each represents a hydrogen atom or an alkylene group having 1 to 4 carbon atoms. or 【Transformation 3】 (wherein x and y are numbers from 1 to 80, R 1 , R 2 each represents a hydrogen atom or an alkylene group having 1 to 4 carbon atoms.

1. A protective film for coatings, comprising at least one polyether-modified polydimethylsiloxane selected from the following:

2. 2. The coating protection film according to claim 1, wherein the substrate contains an inorganic filler.

3. 3. The coating protection film according to claim 1, wherein the polyolefin contains 30 to 90% by mass of either polyethylene or polypropylene.

4. The substrate has a bending hardness at 23°C of 0.01 to 10.0 gf cm 2 4. The coating protection film according to claim 1, wherein the thickness is 1 / cm.

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