WO2001034383A1

WO2001034383A1 - Film of laminated structure with excellent conformability to three-dimensional shape and use thereof

Info

Publication number: WO2001034383A1
Application number: PCT/JP2000/007746
Authority: WO
Inventors: Nobuyoshi Igarashi
Original assignee: Sumiron Co., Ltd
Priority date: 1999-11-08
Filing date: 2000-11-02
Publication date: 2001-05-17
Also published as: AU1055401A

Abstract

A film of a laminated structure comprising a core layer (1) and disposed on the both sides thereof surface layers (2) and (2), wherein the core layer indispensably comprises a layer made of a resin material comprising at least 20 wt.% thermoplastic olefin elastomer having one or more hard segments and one or more soft segments and at least one of the surface layers is a layer made of a resin material comprising at least 80 wt.% linear low-density polyethylene; and a pressure-sensitive adhesive film containing the laminated film as a support.

Description

Description Multilayer film with excellent three-dimensional shape followability and its applications

The present invention relates to an ¾s structure film suitable for sticking to a surface of an object having a three-dimensional shape, for example, for protecting the surface of an object having a three-dimensional shape rather than a plane, for example, for protecting a painted surface, and its use. . Background technology

When a car is taken out of a factory, it is normal to apply a film to the car body surface where necessary to protect its painted surface.

As such a surface protective film, a releasable adhesive film obtained by applying an adhesive such as polyisobutylene to a single-layer film made of a blended product of polypropylene and polyethylene has been used. The reason why the removable adhesive film is used is that it is necessary to remove the surface protection film before handing over a new car to the user.

Improvements to the film used as the support of the above release adhesive film mainly include enhancement of weather resistance, prevention of deformation of the coating film, improvement of release workability, and prevention of adhesive residue on the vehicle body. Biodegradability in consideration of disposal after use, preventing air bubbles from remaining between the film and the coating film, and preventing separation of overlapping at the film seam. Japanese Patent Application Laid-Open No. Hei 9-254 5 288, Japanese Patent Laid-Open No. 117-15959, Japanese Patent Laid-Open No. 1i-L3106, etc.) No surface protection film has been found so far.

When a film is applied to an object having a three-dimensional shape, such as a car body or a bumper, the surface protection film needs to have some elasticity in order to make the film conform to the surface unevenness. In other words, three-dimensional shape followability is required. Moreover

However, it must have sufficient durability and mechanical strength. Conventional surface protection film Did not take this point into consideration at all, so it was easily torn when separated from an object, and the separation workability was poor. Disclosure of the invention

Purpose of the invention

In view of such circumstances, an object of the present invention is to provide a laminated structure film having high mechanical strength and excellent conformability to a three-dimensional shape, and its use. Summary of the Invention

The structural film of the present invention, which solves the above problems, is a laminated structure film including a core layer and surface layers disposed on both surfaces thereof, wherein the core layer has a hard segment and a soft segment. A layer composed of a resin material containing 20% by weight or more of elastomer is essential, and at least one of the two layers is composed of a resin material containing 80% or more of linear low-density polyethylene. It is characterized by the following.

The self-adhesive film of the present invention, which is one of the preferable uses of the laminated structure film of the present invention, is one in which an adhesive layer is provided on one surface of the laminated structure film of the present invention. This adhesive film is particularly suitably used as a protective film for a painted surface of an automobile. Detailed description of the invention

The laminated structure film according to the present invention may have a laminated structure composed of only a core layer 1 and surface layers 2 and 2 disposed on both surfaces thereof as shown in FIG. It may have a laminated structure in which a layer (not shown) made of another material is further arranged on one side or on the side. Both surface layers 2 and 2 do not need to be the same, and at least one layer may be a layer made of a resin material containing 80% by weight or more of linear low-density polyethylene. At least one of the rain surface layers 2.2 may be an adhesion improving adhesive layer or a black light blocking layer.

The core layer may be a single layer or a laminated structure. And a single-layer place In the case of a laminated structure, at least one layer is composed of a copolymer having a hard segment and a soft segment.

-(Hereinafter referred to as TPO) must be a layer made of a resin material containing 20% or more. The core layer may also be configured such that a layer obtained by blending low-density polyethylene (hereinafter referred to as LDPE) with TP0 is superimposed on a layer composed of only PO.

TP0 is a thermoplastic refining elastomer having a hard segment such as an ethylene-propylene copolymer and a soft segment such as an ethylene-propylene copolymer rubber. The core layer containing the elastomer as a page component has a melting point of 130 to 165 as measured according to ASTM D3418. While having heat resistance of C, it not only has excellent mechanical properties such as high tensile strength at break and elastic modulus, but also has elongation. Therefore, this core layer can impart stereoscopic shape followability to the laminated structure film.

The TP0 is preferably, but not limited to, a reactor type. Reactor type refers to a type in which a monomer is reacted directly in a reactor to directly polymerize a polymer having a hard segment and a soft segment (PO), and two or more types are separately used. Unlike TP 0, which blends different polymers, it has excellent homogeneity in components and performance.

The TP 0 is not limited, but the flexural modulus measured according to ASTM D-790 is 150 to 600 kgf / cm in order to sufficiently exhibit the three-dimensional shape followability. ^Two propylene-ethylene copolymers are preferred. If the flexural modulus is high, the film becomes hard and the three-dimensional shape followability is poor. On the other hand, if the flexural modulus is low, the film becomes soft, and heat resistance, gluing workability, and sticking workability are inferior.

Although it does not mean that the TP 0 is not limited, in order to maintain the heat resistance of the laminated film suitably, the melting point of the laminated structure film measured in accordance with ASTM D 348 is in the range of 130 to 1650 ° C. Is preferred. Outside of this range, heat shrinkage during the gluing operation and heat shrinkage of the practical adhesive product increase.

In a resin material containing TP◦, when a resin other than TP0 is contained, examples of the other resin include ethylene butene 1 copolymer and ethylene-1-hexene 1 Linear low-density polyethylene, such as polymers, ethylene-1-methylpentene-11 copolymer, and ethylene-octene-11 copolymer: ordinary low-density polyethylene: medium, high-density polyethylene: ethylene-butyl acetate copolymer, ethylene Rubbers such as monomethyl methacrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl acrylate copolymer, polybutene, ethylene-propylene rubber, styrene-butadiene rubber, butyl rubber, and 4-methylpentene-11 polymer And less than 80% by weight of the whole resin component.

When the core layer has a laminated structure and includes a layer other than a layer composed of a resin material containing 20% by weight or more of TP0, the other layer is generally used as a support for an adhesive film. And synthetic films such as polyolefin resins such as polyethylene, polyester resins, polyamide resins, polyimide resins, polyvinyl alcohol resins, and polyvinyl chloride resins.

The laminated structure film or the pressure-sensitive adhesive film according to the present invention may be provided with a synthetic resin film, paper, cellophane, cloth, May have layers such as non-woven fabric, gold foil, and vapor deposition layer.

At least one surface of the core layer is used to enhance the weather resistance and heat resistance of the film III structure, and for automotive applications, to prevent perforations from occurring when pebbles or sand hits it. In addition, a layer made of a resin material containing 80% by weight or more of LDPE is arranged.

This LDPE was measured according to J 1 SK — 670 because it is excellent in mechanical strength such as heat resistance, tensile strength at break, rigidity, etc., and thin film processing suitability. A linear LDPE having a density of 0.920 to 0.945 is preferred. Specific examples of such LDPE include ethylene butene-1 copolymer, ethylene-1 hexene-1 copolymer, ethylene-4-1-methylpentene-11 copolymer, and ethylene-1-butene-11 copolymer.

When the resin material containing LDPE includes a resin other than LDPE, examples of the other resin include ethylene-vinyl acetate copolymer, ethylene-methyl methacrylate copolymer, ethylene-butene copolymer, and the like. Ethylene Fin copolymers: TP0s; rubbers such as PB, EPR, SBR, BR: 4-methylbenzene-11 polymer, etc., if they are less than 20% by weight of the total resin content May be.

The laminated structure film of the present invention comprises, but is not limited to, the core layer and both surface layers, because it protects the coating layer by shading and imparts the weather resistance (light deterioration) of the film itself. the resin material, and 1-1 0% by weight of Ding i 0 ₂ of the resin component, (also referred to as anti-aging agent) 0.0 5-5% by weight of the weathering agent to resin component that you added Is preferred. Amount of T i 0 ₂ less effect of addition is less than 1 wt%, it exceeds 2 0 wt%, the strength of the film which may cause a problem that the vulnerable. Also, if the addition amount of the weathering agent is less than 0.5% by weight, the effect of the addition is small, and if it exceeds 5% by weight, poor adhesion of the adhesive due to the surface bleed-out of the additive and discoloration with time are remarkable. Problems may occur.

Examples of the above-mentioned weathering agent include 1,4-dihydroxybenzophenone, 2-hydroxy-14-methoxybenzophenone, 2-hydroxy-14-n-year-old benzobenzophenone, 2,2'4,4 '' Hydroxybenzophenone-based weathering agents such as 1-tetrahydroxybenzofunone; 2,4-di-t-butylphenyl 3,5-di-t-butyl-14-hydroxybenzoate, etc. Hydroxybenzoic acid weathering agents: 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (3 ', 5'-di-t-butyl-2'-hydro-σ-xyphenyl) -5-chloro Hydroxybenzotriazole-based weathering agents such as benzotriazole, 2- (3'-t-butyl-12'-hydroxy-1-5'-methylphenyl) -5-chlorobenzenebenzenetriazole; Nickel Bisoctyl Bisulphide, [2,2'-thiobis (4-t one-year-old butylphenol)] n-butylamine nickel, nickel complex-based weathering agent such as nickel dibutyldithiocarbamate; bis (2,2,6 , 6-tetramethyl-4-piberidine) sebagate, a copolymer of hindered amine, poly [{6- (1,3,3-tetramethylbutyl) amino-3,5-triazine-2,4-diyl} {(2 2.6.6 6-Tetramethyl-4- (pyridyl) imino} hexamethylene {(2,2,6,6-tetramethyl-4- (pyridyl) imino)] and other hindered amine weathering agents. Can be The laminated structure film, shielding the purpose of the above T I_〇 ₂ other than ZnO, B a S 0., C aCOs, S i 0 2, the inorganic pigments such as M g◦ 5 weight ^0/6 or less Can be included. If necessary, a coloring agent, an antioxidant, a lubricant, a modifier, etc. can be added.

Examples of such colorants include organic or inorganic colorants such as titanium yellow, cobalt blue, and phthalocyanine, and A1 powder and carbon black.

Such acid inhibitors include, for example, 2.2'-oxamidobis [ethyl 3- (3,5-di-t-butyl-14-hydroxyphenyl) probionet] methane, tetrakis [methylene 1-3- (3'.5'-g-t-butyl-1-4'-hydroxyfurnyl) propionate] phenolic antioxidants such as methane: 4,4'-bisphenylenediphosphinic acid tetrakis (2,4- Phosphite systems such as di-t-butylphenyl), citralic neo-bentante triylbis (2,4-di-tert-butylphenyl phosphite), tris (2,4-di-t-butylphenyl) phosphite And antioxidants.

Such lubricants include, for example, higher grades such as ethylene bis fatty acid (C _{1 B} to (: _{1 B} ) amide), high fatty acid (C to C) amide, stearyl erucamide, and oleyl palmitamide. fatty Amai de; higher fatty acids (C _B -C); high, side effect fatty acid (C _B -C ₂₂₎ aluminum, higher fatty acid (Cs -C _22, Lecinol) Cal Shiumu, higher fatty acids (Ca ~ C ₂₂₎ magnesium , higher fatty acids (C _{_B} ~C ₁ _B) zinc, higher fatty acids (C _B ~C ₂₂₎ and lithium and the like.

Examples of such modifiers include antistatic agents such as surfactants, and inorganic and organic natural or synthetic fillers.

In the present invention, the above-mentioned calculation of the content of TP0 or LDPE means the ratio of only the resin component not containing the various additives described above in the resin material.

The laminated structure film according to the present invention preferably has a total thickness of 20 to 150 m, including, but not limited to, a core layer and both surface layers. Of the total thickness, the thickness of both surface layers is preferably 5 to 50 m on one side and 10 to 100 m on both sides. And a layer composed of a resin material containing TP0 at least 20 Sft%. Preferably has a thickness of at least 10 μm.

Although not limited, the laminated structure film according to the present invention suppresses the amount of shrinkage and swelling due to an increase in the ambient temperature during heating at the time of applying the pressure-sensitive adhesive and after actual application to an automobile paint, and In order to ensure the above protective effect, the amount of thermal deformation in an atmosphere at 110 ° C is preferably within ± 3% for both MD and TD in the processing direction of the film. The “process direction of the film” means the direction in which the film is formed and wound in the length direction, and “MD” is an abbreviation of Machine Direction, and the length and length directions are defined as "TD" is an abbreviation of Transverese Direction, which means the width and width directions.

Here, the measurement of the amount of thermal deformation is performed as follows.

Cut the film into squares of 12 O mm square (N = 3), and plot a mark between i 00 mm in the MD and TD directions of the film. After leaving it in an oven at L10 ° C for 1 hour, measure the length of each plotted mark at room temperature, and calculate the shrinkage (%) by the following formula.

Heat shrinkage (%) = Measure the length of the gauge mark-1 0 0

The laminated structure film according to the present invention can be obtained by using an inflation film forming machine or a T-die film forming machine having three or more dies having a core layer and a surface layer. With multiple extruders set at a temperature of 10 ° C to 130 ° C for the melting point of each LDPE and TPO to be used, multi-layer processing in the same temperature range as your own is possible. It is obtained by passing through a die having a structure, pulling it down into a single film, slitting it into a desired width while continuously cooling, and winding it. After cooling, it is possible to perform corona treatment on one or both sides ^^ or one part during the process up to winding, if desired.

The pressure-sensitive adhesive film using the laminated structure film according to the present invention as a support comprises an acrylic pressure-sensitive adhesive, a natural rubber-based pressure-sensitive adhesive, a synthetic rubber-based pressure-sensitive adhesive, and an ethylene-vinyl acetate copolymer-based pressure-sensitive adhesive on the surface of the support. An adhesive layer is provided by applying a silicone adhesive, for example, in a thickness of 3 to 3. For automotive applications, an adhesive containing polyisobutylene, butyl rubber, polybutene, or the like as a main component is preferable. In order to enhance the adhesion between the support and the pressure-sensitive adhesive layer, it is preferable that the surface of the support is subjected to a surface treatment such as edge treatment or plasma treatment, or a primer is applied. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a partial cross-sectional view showing one embodiment of the laminated structure film according to the present invention. In FIG. L, i ···· core layer, 2 ... surface layer. BEST MODE FOR CARRYING OUT THE INVENTION

Example 1

A laminated structure film was produced as follows.

(Preparation of materials for both surface layers)

As LDPE①, density 0. 937, MF R (Mel Bok 'flow' rate) = 2. hexene one 1 copolymer 93.5 parts by weight ethylene to one 0, final T I_〇 ₂ concentration is 6.0 weight to prepare a master one batch (1) mixing the T i 0 ₂ such that the%. HALS was mixed with the master batch (1) in the same manner as in the preparation of the master batch (1) so that the final HALS concentration was 0.5% by weight. The resulting mixture was supplied to two extruders having a cylinder diameter of 65 mm, each having a cylinder temperature of 180 ° C., at 40 kg / h in order to form both surfaces.

(Preparation of core layer material)

Said L DP E① 44 parts by weight, as TPO②, melting point 1 60 ° C, to a flexural modulus of 3 500 kgf / cm ² of propylene one ethylene copolymer TPO 50 parts by weight, in the same manner, the final T i 0 ₂ concentration by mixing T I_〇 to be 6.0 wt%. The obtained mixture was fed at 80 kg / h to a single extruder having a diameter of 90 mm and a cylinder heated to 180 ° C. in order to form both core layers.

(Preparation of three-layer film)

The compounded resin extruded for each layer from the above three extruders is brought to 180 ° C! ^ Passed through the three-layer inflation die of die bonding type, ¾ ① / core layer / After adjusting the thickness of each surface layer to 12.5 / 25 urn / 12.5 wm and the total thickness to 50 m, both surfaces are corona treated and the surface wetting index (measured according to JIS K-676 8) Was adjusted to 45 dyne / cm to produce a three-layer film. (Adhesive application)

One side of the three-layer film was coated with a 15% by weight of a polyisobutylene-based adhesive and dried at 80 for 3 minutes to form an adhesive layer having a thickness of 10 Aim. A structural sheet was obtained.

Table 1 shows the results of measuring the mechanical properties and the three-dimensional shape following of the laminated structure film.

Here, the mechanical properties and the three-dimensional shape followability were measured as follows.

Mechanical properties:

Characteristics that are difficult to break and are difficult to elongate are required, and characteristics that are difficult to break are quantified by bow I tearing, and characteristics that are difficult to elongate are quantified by bow I tension yield strength.

The tear strength was measured by the C method of JIS K 7 12.8 method.

The bow I tension yield strength was measured by cutting the laminated structure films obtained in the examples and comparative examples into a width of 15 mm, and measuring the tensile strength at a tensile speed of 30 Omm / min (MD direction) and a chuck interval of 50 mm. The yield point was determined from the chart.

Following 3D shape:

The workability when the laminated structure films obtained in Examples and Comparative Examples were attached to a coated plate having an lmx lm square and a difference in irregularities of 30 mm was evaluated according to the following criteria. 〇: The sheet follows the uneven part and can be stuck smoothly.

Δ: Some sheets are mixed when the sheet follows the uneven portion.

X: When the sheet follows the irregularities, very shiny is mixed.

-Difficult Examples 2, 3- Except for changing the resin composition as shown in Table 1, the laminated structure films of Examples 1 and 3 were prepared in the same manner as in Example 1, and the mechanical properties and followability of the three-dimensional shape were obtained. And the results are shown in Table 1.

Comparative Example 1 A single-layer polyethylene / polypropylene blend type film was prepared in the same manner as in Example 1 except that the resin composition was as shown in Table 1 using a single-layer structure die, and the mechanical properties and three-dimensional shape The followability was measured and the results are shown in Table 1.

table 1

LDPE①: Density 0.937, MFR = 2.0, ethylene-1 hexene-1 copolymer

LDPE②: Ethylene ^ xene-1 polymer with density of 0.940 and MFR = 2.0

LDPE③: Density 0.927, MFR = 4.0 Ethylene-1-hexene 1-copolymer

TP◦①: Propylene-ethylene copolymer TP 0 with a temperature of 1338 ° C and a flexural modulus of 5100 kgf / cm ²

TP 0②: propylene-ethylene copolymer with a melting point of i 60 ° C and a flexural modulus of 3500 kgf / cm ²

D 〇 P〇③: propylene-ethylene copolymer TP 0 with ¾ ^ at 160 ° C and flexural modulus of 1 600 kgf / cm ²

T i 0 _2: rutile Ding i O2 powder

HALS: poly [(6- (1,1,3,3-tetramethylbutyl) amino_1,3,5-triazine-1,4-diyl} {(2.2.6.6-tetra Methyl-1-4-pyridyl) imino) hexamethylene {(2,2,6,6-tetramethyl-1-pyridyl) imino)]

PP①: Ethylene-propylene block polymer containing i 0% by weight of ethylene-propylene rubber and MFR = 5.0

In Examples and Comparative Examples, the flexural modulus was measured according to ASTM D-790, the melting point was measured according to ASTM D3418, and the density was measured according to J1SK-16760. Industrial applicability

The laminated structure film according to the present invention has a high mechanical strength because the core layer must have a layer composed of a resin material containing at least 10% by weight of a thermoplastic olefin elastomer having hard segments and soft segments. It has a three-dimensional shape followability. In the laminated structure film according to the present invention, both surface layers are low density polyethylene. It is a layer composed of a resin material containing 80% by weight or more, and has excellent weather resistance and heat resistance. In addition, perforations are less likely to occur in automotive applications.

The pressure-sensitive adhesive film according to the present invention has high mechanical strength and conformability to a three-dimensional shape because the laminated structure film is used as a support. Therefore, the pressure-sensitive adhesive film according to the present invention is excellent in perforation resistance, and thus is suitably used as a release-type surface protective film for automobiles.

Claims

The scope of the claims

1. A laminated film including a core layer and ¾ϋ disposed on both surfaces thereof.

A layer in which the core layer is made of a resin material containing at least 20% by weight of a thermoplastic elastomer having a hard segment and a soft segment is defined as ί ^, and at least one of the two layers is a linear low-density polyethylene. Characterized in that it is a layer composed of a resin material containing 80% by weight or more.

2. A propylene-ethylene copolymer having a flexural modulus of 1500 to 6000 kgf / cm ² as measured according to ASTM D-790. 3. The laminated structure film according to item 1.

3. Measured according to ASTM D 3 4 18 for ^ ΓΙself thermoplastic elastomer! 3. The laminated film according to claim 1, wherein ^ is from 130 to 165 C. 4.

4. The laminated structure film according to any one of claims 1 to 3, wherein the density of the self-linear low-density polyethylene measured according to JIS-670 is 0.920 to 0.945.

5. including the 1-2 0% by weight of the resin component and at least one layer and the core layer is a T i 0 ₂ of the both surface layers, a 0.0 5-5% by weight of the resin component of the weathering agent, The laminated structure film according to any one of claims 1 to 4.

6. The 麵 structure film according to any one of claims 1 to 5, wherein the total thickness of the knitted core layer and both surface layers is 20 to 150 m.

7. The laminated structure film according to claim 1, wherein the amount of thermal deformation in an atmosphere at 110 ° C. is within ± 3% for both MD and TD with respect to the processing direction of the film.

8. An adhesive film comprising the laminated structure film according to any one of claims 1 to 7, wherein an adhesive layer is provided on one surface of the laminated structure film.

9. The adhesive film according to claim 8, which is a protective film for a painted surface of an automobile.