KR101483877B1 - Multi-layer co-extrusion film for vehicle interior materials - Google Patents

Abstract

The present invention relates to a co-extrusion film bonded with a polyurethane-based foaming sheet and a vehicle interior base material. Even though a tier layer is not included, there is no problem with co-extrusion, and the same can exhibit the same or greater adhesive power in terms of adhesive strength with an interior material compared to a co-extrusion film of four or more layers. The multi-layer co-extrusion film for a vehicle interior material of the present invention comprises: a polyamide layer; a polyolefin support layer laminated on one surface of the polyamide layer; and an adhesive polyolefin layer adhered on the other surface of the polyamide layer. In the adhesive polyolefin layer, 10-80 wt% of an acrylic copolymer or a maleic acid graft copolymer is compounded, and peeling strength between the polyamide layer and the adhesive polyolefin layer is 1 N/2.5 cm.

Description

[0001] MULTI-LAYER CO-EXTRUSION FILM FOR VEHICLE INTERIOR MATERIALS [0002]

More particularly, the present invention relates to a coextruded film which is inserted between a foam sheet of an automotive interior ceiling material and a substrate for an interior material to be used for adhering a foam sheet and a substrate for an interior material .

Normally, the ceiling inside the vehicle is finished with an interior material having sound insulation and heat insulation. Such an interior material is formed by stacking a plurality of materials having different characteristics so as to perform functions such as soundproofing, dampproofing, warming, and insulation in the interior of the vehicle, thereby providing a driver and a passenger with a sense of security and a comfortable environment.

For example, a skin member made of leather, leather, or the like is laminated on the lower end of a polyurethane foam sheet as an interior material constituting the front face of an automobile ceiling. The foam sheet and the skin member are thermally bonded through press- . At this time, since the respective laminated materials are completely different, adhesion has been made between the lamination members using an adhesive such as a conventional bond. However, since the worker has to apply the adhesive to the laminating surface of the lining material and to bond the lining material, there is a problem that the bonding surface is often not completely adhered and the function of the lining material is deteriorated due to the formation of voids. In particular, It is lethal to the worker as a chemical substance, and gives an indirect health problem to the driver.

In order to prevent the harmfulness of the adhesive means, Japanese Patent Application Laid-Open Publication No. 1998-0073996 discloses a method of thermally fusing the adhesive surface between the olefin resin layer and the highly flexible polypropylene layer without using an adhesive. However, when polyurethane-based foam sheets other than polypropylene materials are used as foamed sheets, there is a problem that they are not technically applicable.

Therefore, a conventional method in which an adhesive film is inserted between a foam sheet of a polyurethane type and an automobile cloth base material to thermally adhere the foam sheet and cloth base material to each other through press molding is employed, or a method in which an adhesive film is preliminarily After heat lamination, the foam sheet is placed on a substrate and press-formed to produce a ceiling material. The adhesive film used in this case is a multilayer coextruded film, which comprises a polyolefin-based support layer such as polyethylene for protecting the surface of the film, a polyamide-based resin layer for adhesion with polyurethane, and a polyolefin- A tie layer for adhesion between two layers is provided between the polyamide based resin layer and the polyolefin based resin layer, and an adhesive resin is used for the tie layer. The polyolefin support layer is peeled off before press molding with a protective layer, and the polyamide layer is bonded to the polyurethane-based foam sheet during press molding using the remaining layer of the film. The polyolefin-based resin layer is bonded to the cloth base material So that adhesion between the foam sheet and the base material is achieved.

As described above, the conventional co-extruded film is made of a coextruded film having four or more layers including a tie layer between the polyamide layer and the polyolefin resin layer. Particularly, the tie layer is a polyamide layer and a polyolefin- Extruded into four or more layers in order to prevent peeling of the polyamide layer and the polyolefin resin layer, which is caused due to the difficulty of laminating the layer.

A coextruded film for bonding an automobile interior material, in particular, a polyurethane-based foam sheet for automobile cloths and an automobile cloth base material substrate, has no problem of coextrusion without including a tie layer, There is a demand for multilayer coextruded films for automobile interior materials which can exhibit the same or more functions in terms of adhesive strength with the built-in materials, but commercialized examples have not been disclosed to date.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above problems, and it is an object of the present invention to provide a coextruded film for bonding a foam sheet of polyurethane type to a base material for automobile interior materials, The present invention provides a multilayer coextruded film for automobile interior materials which can exhibit an adhesion equal to or greater than that of the above coextruded film in terms of adhesion strength with the built-in materials.

In order to solve the above-described problems, the present invention provides a polyamide laminate comprising: a polyamide layer; A polyolefin support layer laminated on one surface of the polyamide layer; And an adhesive polyolefin layer adhered to the other surface of the polyamide layer, wherein the adhesive polyolefin layer comprises an acrylic acid-based copolymer or a maleic acid graft copolymer in an amount of 20 to 80% by weight And the peel strength between the polyamide layer and the adhesive polyolefin layer is at least 1N / 2.5 cm.

The multilayer coextrusion film for automobile interior material is characterized in that the polyamide layer has a melt temperature (DSC measurement) of 80 to 140 ° C and a melt index (160 ° C, 2.16 kgf load) of 5 to 40 g / 10 min do.

In addition, the polyamide layer may be formed of at least one selected from the group consisting of poly (hexamethylene adipamide), poly (hexamethylene sebacamide), poly (heptamethylene pimelamide), poly (octamethylene suveramide) Poly (7-aminopentanoic acid), poly (7-aminoheptanoic acid), poly (8-aminooctanoic acid), poly ), Poly (9-aminononanoic acid), poly (10-aminodecanoic acid), poly (11-aminoundecanoic acid), poly (12-aminododecanoic acid), caprolactam / hexamethylene adipamide copolymer, Hexamethylene adipamide / caprolactam copolymer, poly (caprolactam), poly (caprolactam), hexamethylene adipamide / caprolactam copolymer, trimethylene adipamide / hexamethylene adipamide / hexamethylene adipamide / caprolactam copolymer, Hexamethylene adipamide), poly (hexamethylene isophthalamide A multilayer coextruded film for automotive interior materials, characterized in that it comprises at least one selected from the group consisting of poly (hexamethylene terephthalamide), poly (hexamethylene terephthalamide) and poly (dodecamethylene terephthalamide).

In the adhesive polyolefin layer, the olefin resin may be a low density polyethylene, a linear low density polyethylene, a medium density polyethylene, a high density polyethylene, a polypropylene, a polybutylene, a polybutene-1, 1, poly-4-methylpentene-1, polyisobutylene, polyhexene, ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-pentene copolymer, ethylene-hexene copolymer and ethylene- The present invention provides a multilayer coextruded film for automotive interior materials, which comprises at least one selected from the group consisting of polyolefins, polyesters, and polymers.

Also, the acrylic acid copolymer may be selected from the group consisting of ethylene methyl acrylate copolymer (EMA), ethylene butyl acrylate copolymer (EBA), ethylene ethyl acrylate copolymer (EEA), ethylene acrylic acid copolymer (EAA) and ethylene methacrylic acid (EMAA). The present invention also provides a multilayer coextruded film for automotive interior materials.

Also, the adhesive polyolefin layer has a content of acrylic acid (AA) of 3 to 20% by weight.

The total weight of the coextruded film excluding the polyolefin support layer is 10 to 120 g / m 2, the unit weight of the polyamide layer is 3 to 50 g / m 2, the unit weight of the adhesive polyolefin layer is 7 to 80 g / m < 2 >.

According to the present invention, there is provided a three-layer or more coextruded film inserted between a foam sheet of an automotive interior ceiling material and a substrate for an interior material to adhere the foam sheet and the substrate for an interior material, The adhesive polyolefin layer compounded with the optimum amount of the acrylic acid-based copolymer or the maleic acid graft copolymer can be adhered without constitution, so that the co-extrusion process can be performed smoothly without the tie layer, and the peeling with the polyamide layer can be prevented And can exhibit sufficient adhesion performance with a polyurethane foam sheet and a substrate for an interior material during press molding using a coextruded film, it is possible to reduce the raw material cost compared to a multilayer coextrusion film for existing automotive interior materials, A coextruded film can be provided.

Hereinafter, the present invention will be described in detail with reference to preferred embodiments. Prior to this, terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms, and the inventor should appropriately interpret the concepts of the terms appropriately It is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. It is to be understood that various equivalents and modifications may be substituted for those at the time of the present application.

The present inventors have found that a coextruded film inserted between a polyurethane foam sheet and a substrate for an interior material of an automobile interior ceiling material to adhere the foam sheet and the base material for an interior material is a polyolefin support layer / polyamide layer / tie layer / polyolefin Extruded film including four or more layers of extruded resin layers, it is possible to produce a three-layer or more coextruded film which can meet the manufacturing cost burden caused by the demand of four or more extruders, The inventors of the present invention have found that the use of a tie layer as a special polyolefin resin layer can be used as a special composition.

Accordingly, the present invention relates to a polyamide layer; A polyolefin support layer laminated on one surface of the polyamide layer; And an adhesive polyolefin layer adhered to the other surface of the polyamide layer, wherein the adhesive polyolefin layer comprises an acrylic acid-based copolymer or a maleic acid graft copolymer in an amount of 20 to 80% by weight And a peel strength between the polyamide layer and the adhesive polyolefin layer is at least 1 N / 2.5 cm.

The multilayer coextruded film according to the present invention is used for an interior material such as two or more types of automobile interior materials having different properties, for example, inserted between the built-in ceiling materials and thermally adhered to each other during the press molding to adhere the ceiling materials. Particularly, it is used for bonding various base materials for automobile interior materials with good adhesion to polyurethane based foam sheet and polyolefin based adhesive resin. Hereinafter, a built-in ceiling material will be described as an example of an interior material.

The polyamide layer may include a polyamide homopolymer or a copolymer substantially as a layer for allowing interfacial thermal adhesion between polyurethane foam sheets in an automotive interior ceiling material.

In the present invention, the polyamide layer preferably has a melt temperature (DSC measurement) of 80 to 140 占 폚 and a melt index (160 占 폚, 2.16 kgf Load) of 5 to 40 g / 10 min is preferably used. (DSC measurement) of 120 to 130 占 폚 and a melt index (load of 160 占 폚, 2.16 kgf) of 10 to 20 g / 10 min may be used. If the melting temperature of the polyamide layer is less than 80 ° C, the heat resistance may be poor and peeling may occur during molding. If the polyamide layer has a melting temperature higher than 140 ° C, Deg.] C, peeling due to adhesion failure may occur. If the melt index of the polyamide layer is less than 5 g / 10 min, the extrusion amount may be lowered. If the melt index exceeds 40 g / 10 min, the bubble may shake and the thickness adjustment may occur.

Examples of the polyamide component included in the polyamide layer include, but are not limited to, poly (hexamethylene adipamide), poly (hexamethylene sebacamide), poly (heptamethylene pimelamide), poly Aminobutyric acid), poly (6-aminohexanoic acid), poly (7-aminobenzoic acid), poly (aminomethylenediamido) Aminodecanoic acid), poly (11-aminodecanoic acid), poly (8-aminodecanoic acid), poly , Caprolactam / hexamethylene adipamide copolymer, hexamethylene adipamide / caprolactam copolymer, trimethylene adipamide / hexamethylene adipamide copolymer, hexamethylene adipamide / hexamethylene adipamide / caprolactam Copolymer, poly (caprolact ), Poly (hexamethylene adipamide), poly (hexamethylene isophthalamide), poly (hexamethylene terephthalamide), poly (dodecamethylene terephthalamide), and the like, preferably poly (caprolactam ), Poly (hexamethylene adipamide), poly (hexamethylene isophthalamide), poly (hexamethylene terephthalamide), and more preferably poly (caprolactam).

The polyolefin support layer is laminated on one surface of the polyamide layer to protect the polyamide layer. The protective layer is used after release of the final co-extruded film by press molding of an automobile interior material. Such a polyolefin support layer may be a known polyethylene-based or polypropylene-based resin that can be used as a polyolefin-based resin layer that can be co-extruded with a polyamide layer. Specific methods of use are well known to those skilled in the art. Is omitted.

The adhesive polyolefin layer is a layer which is adhered to the other surface of the polyamide layer so as to allow thermal adhesion between the surfaces of the adherend such as a felt member used as a base material of an automotive interior ceiling material. In the present invention, And is directly adhered to the polyamide layer without lamination of a separate tie layer. That is, it is an adhesive layer that has adhesion performance with a tread material layer serving as a tie layer for preventing peeling from the conventional polyamide layer.

In the present invention, an adhesive resin is compounded in an amount of 20 to 80% by weight in the adhesive polyolefin layer component. As such an adhesive resin, an acrylic acid copolymer or a maleic acid graft copolymer is used, It is more preferable to use an acrylic acid-based copolymer in consideration of not only miniaturization but also adhering performance to the adherend and minimization of the peeling phenomenon with the polyamide layer. Further, when the acrylic acid copolymer is used, the content of the acrylic acid copolymer in the entire adhesive polyolefin layer is preferably 30 to 70% by weight, and most preferably 40 to 60% by weight.

If the adhesive resin content is less than 20% by weight, the peel strength between the polyamide layer and the adhesive polyolefin layer may not be satisfactory. When the adhesive resin content exceeds 80% by weight, the peel strength is not a problem, Can be a burden.

As described above, the peel strength between the polyamide layer and the adhesive polyolefin layer in the finally prepared multilayer coextruded film when the adhesive resin is compounded in an amount of 20 to 80% by weight in the adhesive polyolefin layer component is 1 N / 2.5 cm So that the co-extrusion process can be performed smoothly without using a tie layer and a sufficient adhesion performance with the polyurethane foam sheet and the substrate for an interior material can be exerted during press molding using a co-extruded film. At this time, the peel strength may preferably be maintained at 2N / 2.5cm or more, more preferably 2.5N / 2.5cm or more, still more preferably 3N / 2.5cm or more, and most preferably 5N / 2.5cm or more .

On the other hand, in order to improve the peel strength between the polyamide layer and the adhesive polyolefin layer, the adhesive resin content among the components of the adhesive polyolefin layer is an important factor, but more specifically, It was confirmed that the content of acrylic acid (AA) was the most important factor.

Accordingly, the present invention provides a multilayer coextruded film for automotive interior materials, wherein the adhesive polyolefin layer has an acrylic acid (AA) content of 3 to 20 wt%. The content of acrylic acid (AA) is preferably 5 to 15% by weight, more preferably 6 to 12% by weight, and most preferably 7 to 10% by weight.

Examples of the acrylic acid copolymer include ethylene methyl acrylate copolymer (EMA), ethylene butyl acrylate copolymer (EBA), ethylene ethyl acrylate copolymer (EEA), ethylene acrylic acid copolymer (EAA), ethylene methacrylic acid (EMAA) or the like may be used, and preferably an ethylene acrylic acid copolymer (EAA) or an ethylene methacrylic acid copolymer (EMAA) may be used.

The olefinic resin, which is the other component of the adhesive polyolefin layer components except for the adhesive resin, can be used in various components in accordance with the application in consideration of the adhering material. Examples of the olefin resin include low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, polypropylene, polybutylene, polybutene-1, poly- Ethylene-butene copolymers, ethylene-pentene copolymers, ethylene-hexene copolymers, ethylene-propylene-diene copolymers and the like can be used .

The unit weight of the two-layer film remaining after removing the polyolefin support layer in the coextruded film according to the present invention may be 10-120 g / m < 2 > depending on the ceiling material to be applied, The unit weight is 3 to 50 g / m 2, and the unit weight of the adhesive polyolefin layer is 7 to 80 g / m 2. Preferably, the unit weight of the two-layer film is 30 to 70 g / m 2, the unit weight of the polyamide layer is 10 to 30 g / m 2, and the unit weight of the adhesive polyolefin layer is 20 to 50 g / m 2.

Meanwhile, each layer of the coextruded film according to the present invention may further contain another additive depending on each use within a range not deviating from the purpose. As additional additives, pigments, dyes, slip agents, fillers, nucleating agents, plasticizers, lubricants, stabilizers, antioxidants, heat stabilizers and the like may be added alone or in admixture of two or more in a general range, 0.1 to 10 parts by weight based on 100 parts by weight of the layer.

The production of the multilayer coextruded film for automobile interior material according to the present invention is not particularly limited and may be carried out by a method commonly known in the art. A die connected to the other side of the extruder, to which blowing air is supplied and the molten resin flows out; An air ring which is located at an upper portion of the die and has a plurality of concentric flanges with stepped portions therein and in which the molten resin expands; Wherein the molten resin discharged from the dies and extending in a predetermined length is positioned between the die and the air ring and has an upper end and a lower end connected to the air ring and the die, And a guide portion having a plurality of guide rolls whose intervals become narrower toward the upper layer. Which is then transferred to the primary and secondary rolls for final winding.

For example, a multilayered film formed by feeding molten and plasticized streams of each material of a polyolefin support layer, a polyamide layer, and an adhesive polyolefin layer into one die, aligning the layers in a die, combining them, Cooling on a rotary cooling drum. Such co-extrusion techniques may use multi-manifold dies such as tie dies, circular dies, and the present invention is manufactured with blown film co-extrusion technology.

The film may be formed as is known in the art as a blown film device comprising a multi-manifold circular die head having concentric circular holes. For example, the multi-layer film may be formed by transferring the melted polyolefin support layer and the adhesive polyolefin layer independently on both sides of the polyamide layer through the molten polyamide layer through the circular die and the additional round die concentric with the first circular die And co-extruded in one die. Thereafter, it forms a polyamide layer, a polyolefin support layer and an adhesive polyolefin layer which are expanded by bubbling gas, usually air, through a jet concentric with the circular die, and the bubble cooled on the rotary cooling drum is compressed A pair of multilayered films having both rear edges are cut. Usually, a pair of attached multilayer films are separated from at least one edge and separated into a pair of multilayer films, and then transported to a plurality of guide rolls guiding the progress path by driving the rotary motor to be manufactured through rolling up .

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. However, the following examples are illustrative of the present invention, and the present invention is not limited to the examples described below.

Example 1

(Caprolactam) resin (DSC melting temperature 80 占 폚, melt index (160 占 폚, 2.16 kgf load) 5 g / 10 min) as the polyolefin support layer and ethylene polyacrylate A low density polyethylene resin composition containing 20% by weight of EAA (9% by weight of acrylic acid (AA)) was prepared and fed to three uniaxial extruders (60 mm in diameter) Extruded film die, cast on a roll maintained at 35 to 40 DEG C, and then a three-layer coextruded film having a thickness of 50 mu m and a unit weight of 45 g / m < 2 > except for the polyolefin support layer was prepared.

Example 2

A three-layer co-extruded film was produced in the same manner as in Example 1, except that a poly (caprolactam) resin having a melting temperature of 120 캜 and a melt index of 10 g / 10 min was used in Example 1.

Example 3

A three-layer co-extruded film was produced in the same manner as in Example 1, except that a poly (caprolactam) resin having a melting temperature of 120 캜 and a melt index of 20 g / 10 min was used in Example 1.

Example 4

A three-layer co-extruded film was produced in the same manner as in Example 1, except that a poly (caprolactam) resin having a melting temperature of 140 캜 and a melt index of 40 g / 10 min was used in Example 1.

Comparative Example 1

A three-layer co-extruded film was produced in the same manner as in Example 1, except that a poly (caprolactam) resin having a melting temperature of 70 ° C was used in Example 1.

Comparative Example 2

A three-layer co-extruded film was produced in the same manner as in Example 1 except that a poly (caprolactam) resin having a melting temperature of 150 캜 and a melt index of 40 g / 10 min was used in Example 1.

Example 5

A three-layer co-extruded film was produced in the same manner as in Example 2, except that a low density polyethylene resin composition containing 25% by weight of ethylene acrylic acid copolymer (EAA) was used in Example 2.

Example 6

A three-layer co-extruded film was produced in the same manner as in Example 2 except that a low density polyethylene resin composition containing 30% by weight of ethylene acrylic acid copolymer (EAA) was used in Example 2.

Example 7

A three-layer co-extruded film was produced in the same manner as in Example 2, except that a low density polyethylene resin composition containing 35% by weight of ethylene acrylic acid copolymer (EAA) was used in Example 2.

Example 8

A three-layer co-extruded film was prepared in the same manner as in Example 2, except that the low-density polyethylene resin composition containing 40 wt% of ethylene acrylic acid copolymer (EAA) was used in Example 2.

Example 9

A three-layer co-extruded film was produced in the same manner as in Example 2 except that a low density polyethylene resin composition containing 45% by weight of ethylene acrylic acid copolymer (EAA) was used in Example 2.

Example 10

A three-layer co-extruded film was produced in the same manner as in Example 2, except that a low density polyethylene resin composition containing 50% by weight of ethylene acrylic acid copolymer (EAA) was used in Example 2.

Example 11

A three-layer co-extruded film was produced in the same manner as in Example 2 except that a low density polyethylene resin composition containing 60% by weight of ethylene acrylic acid copolymer (EAA) was used in Example 2.

Example 12

A three-layer co-extruded film was produced in the same manner as in Example 2, except that a low density polyethylene resin composition containing 70% by weight of ethylene acrylic acid copolymer (EAA) was used in Example 2.

Example 13

A three-layer co-extruded film was produced in the same manner as in Example 2 except that a low-density polyethylene resin composition containing 80% by weight of ethylene acrylic acid copolymer (EAA) was used in Example 2.

Comparative Example 3

A three-layer co-extruded film was produced in the same manner as in Example 2, except that the low-density polyethylene resin composition containing 10% by weight of the ethylene acrylic acid copolymer (EAA) in Example 2 was used.

Example 14

A three-layer co-extruded film was produced in the same manner as in Example 2 except that a low density polyethylene resin composition containing 40% by weight of a graft copolymer of maleic acid was used instead of the ethylene acrylic acid copolymer (EAA) in Example 2.

Example 15

A three-layer co-extruded film was produced in the same manner as in Example 2 except that a low density polyethylene resin composition containing 60% by weight of a graft copolymer of maleic acid was used instead of the ethylene acrylic acid copolymer (EAA) in Example 2.

The composition of the three-layer co-extruded film produced according to the above Examples and Comparative Examples is shown in Table 1 below.

division Polyamide layer The adhesive polyolefin layer Melting temperature
(° C) Melt Index
(g / 10 min) PE
(weight%) Acrylic acid series
Copolymer (% by weight) Maleic acid graft
Copolymer (% by weight) Example 1 80 5 80 20 - Example 2 120 10 80 20 - Example 3 120 20 80 20 - Example 4 140 40 80 20 - Comparative Example 1 70 5 80 20 - Comparative Example 2 150 40 80 20 - Example 5 120 10 75 25 - Example 6 120 10 70 30 - Example 7 120 10 65 35 - Example 8 120 10 60 40 - Example 9 120 10 55 45 - Example 10 120 10 50 50 - Example 11 120 10 40 60 - Example 12 120 10 30 70 - Example 13 120 10 20 80 - Comparative Example 3 120 10 90 10 - Example 14 120 10 60 - 40 Example 15 120 10 40 - 60

Test Example

The peel strength between the polyamide layer and the adhesive polyolefin layer was measured for each of the film specimens prepared according to the above Examples and Comparative Examples (Promate ^TM The results are shown in Table 2 below. The bonding temperature (small thermal press, 0 to 399 ° C, 0 to 3,000 ° C) for the automobile interior material substrate / film / (2kgf pressure, self-made) and heat resistance temperature (heat resistance tester, JS-TS01, 0 to 200 ° C, qualitative biotech, MS 715-71).

division Peel strength
(N / 2.5 cm) Example 1 1.0 Example 2 1.3 Example 3 1.3 Example 4 1.1 Comparative Example 1 0.5 Comparative Example 2 0.6 Example 5 1.8 Example 6 3.1 Example 7 4.5 Example 8 6.2 Example 9 N / D Example 10 N / D Example 11 N / D Example 12 N / D Example 13 N / D Comparative Example 3 0.4 Example 14 5.1 Example 15 5.8 *week
- N / D: Exceeded measurement limit (Excellent peel strength)

division Adhesion temperature (℃) Heat temperature (℃) Substrate face Cuticle resurfacing Example 1 130 75 80 Example 4 130 135 140 Example 5 128 110 125 Example 6 125 110 125 Example 7 123 110 125 Example 8 120 110 125 Example 9 117 110 125 Example 10 115 110 125 Example 11 113 110 125 Example 12 110 110 115 Example 13 108 110 110

First, referring to Table 2, a film (Examples 1 to 15) to which a polyamide layer having a proper melting temperature and a melt index range according to the present invention and an adhesive polyolefin layer containing an appropriate amount of a specific adhesive component were applied, , The peel strength between the polyamide layer and the adhesive polyolefin layer is at least 1 N / 2.5 cm, preferably at least 3 N / 2.5 cm, which is suitable for automobile interior materials. Particularly, it can be confirmed that the peel strength is superior to that in the case of applying a polyamide layer having a melting temperature of 120 ° C and a melt index of 10 to 20 g / 10 min (Examples 2 and 3), and further, the adhesion of the adhesive polyolefin layer It is confirmed that the component exhibits a higher peel strength than that in the case of containing 30 wt% or more (Examples 6 and 7), preferably when it is contained in 40 wt% or more (Examples 7 to 15). On the other hand, when the same amount of the adhesive component is contained, it is confirmed that the adhesive property can be further improved in the case of using the acrylic acid type copolymer (Examples 8 and 11) rather than the maleic acid graft copolymer (Examples 14 and 15) have.

On the contrary, when a polyamide layer having an excessively low or high melt temperature and a high melt index (Comparative Examples 1 and 2) was applied, the coextrusion was not properly performed and the peel strength with the adhesive polyolefin layer was remarkably decreased .

It is also confirmed that the peeling strength between the polyamide layer and the adhesive polyolefin layer is unsatisfactory even when an adhesive polyolefin layer having an excessively low content of acrylic acid copolymer is applied (Comparative Example 3).

Next, the adhesion temperature and heat resistance temperature test results for the adhering material will be described with reference to Table 3.

In automobile headline molding, molding usually takes place at 120 to 135 ° C. The heat-resistant temperature (softening point) is 90 ° C or higher, but it is a standard for the most stable adhesion of the film to temperature and pressure during molding. It is a part where tension is applied to the bending part, It is proved that the weak point in the molding process is preferable in the heat cycle of the headline automobile when the heat resistance temperature (softening point) is 115 ° C or more.

The heat resistance temperature (softening point) can be tested by the MS 715-71 standard itself and the accredited certification body. This is a test for the automotive heat cycle cycle, and it should finally meet the automotive heat cycle cycle MS 257-13. The heat cycle can be verified by the molding company and the final test is carried out in the automobile. In addition, it is continuously tested and proven when new cars are applied.

Referring to Table 3, it was proved that the most stable film properties applicable to headlines in Examples 8 to 12 were satisfied in order to satisfy molding and heat cycle. In Table 3, the base material can be used for F10 base, PU foam base, PET nonwoven base, PA nonwoven base, PP nonwoven base base, glass fiber base, PET Felt Base Base, Resin Felt Base Base, , Non-woven fabric, natural leather and the like.

While the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, Such modifications and changes are to be considered as falling within the scope of the following claims.

Claims (7)

A polyamide layer;
A polyolefin support layer laminated on one surface of the polyamide layer; And
An adhesive polyolefin layer adhered to the other surface of the polyamide layer;
A multilayer coextruded film for an automobile interior material,
The polyamide layer has a melting temperature (DSC measurement) of 120 to 130 ° C and a melt index (160 ° C, 2.16 kgf load) of 10 to 20 g / 10 min,
Wherein the adhesive polyolefin layer is compounded with an ethylene acrylic acid copolymer (EAA) having an acrylic acid (AA) content of 7 to 10 wt% in an amount of 40 to 60 wt%
Characterized in that the peel strength between the polyamide layer and the adhesive polyolefin layer is at least 6.2 N / 2.5 cm, and is inserted between the foam sheet of the automotive ceiling panel and the substrate for the interior material to bond the foam sheet and the interior material substrate Multilayer coextruded film for automobile interior materials used for making. delete The method according to claim 1,
The polyamide layer may be formed of a material selected from the group consisting of poly (hexamethylene adipamide), poly (hexamethylene sebacamide), poly (heptamethylene pimelamide), poly (octamethylene suveramide) Aminopentanoic acid), poly (8-aminooctanoic acid), poly (8-aminocaproic acid), poly Poly (9-aminononanoic acid), poly (10-aminodecanoic acid), poly (11-aminoundecanoic acid), poly (12-aminododecanoic acid), caprolactam / hexamethylene adipamide copolymer, Hexamethylene adipamide / hexamethylene adipamide / caprolactam copolymer, poly (caprolactam), poly (hexamethylene adipamide / hexamethylene adipamide / caprolactam), adipamide / caprolactam copolymer, trimethylene adipamide / Adipamide), poly (hexamethylene isophthalamide), poly Lee (hexamethylene terephthalamide), and poly (dodeca-terephthalamide), co-extrusion multi-layer film for a car interior, characterized in that it comprises at least one member selected from the group consisting of. The method according to claim 1,
In the adhesive polyolefin layer, the olefin resin is selected from the group consisting of low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, polypropylene, polybutylene, polybutene-1, , Poly-4-methylpentene-1, polyisobutylene, polyhexene, ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-pentene copolymer, ethylene-hexene copolymer and ethylene-propylene-diene copolymer Wherein the multilayer coextruded film comprises at least one selected from the group consisting of polypropylene and polypropylene. delete delete The method according to claim 1,
Wherein the total weight of the coextruded film excluding the polyolefin support layer is 10 to 120 g / m 2, the unit weight of the polyamide layer is 3 to 50 g / m 2, the unit weight of the adhesive polyolefin layer is 7 to 20 g / 80 g / m < 2 >.