KR101980336B1 - Laminate and composite material for vehicle containing the same - Google Patents

Abstract

TECHNICAL FIELD The present invention relates to a laminate for use in a composite material for automobiles, the laminate having a polyurethane foam layer, a synthetic fiber layer and a glass fiber layer on one side or both sides of a thermal adhesive layer comprising a polyolefin resin of a specific composition and a styrene copolymer It is possible to realize a light weight and sufficient strength of a material including a substrate layer including at least one of them and has a high thermal adhesive strength at a high temperature of 150 ° C or more and excellent in numerical stability at the time of cooling after heat bonding to provide excellent durability and appearance, Specifically, it can be usefully used for automobile headliners and the like.

Description

[0001] The present invention relates to a laminate and a composite material for the same,

The present invention relates to a laminate excellent in the durability and appearance of a material, which has a high adhesive strength in a high-temperature process and excellent numerical stability at the time of cooling, and a composite material for automobiles comprising the laminate.

As the industry develops, there is a growing demand for eco-friendly materials that can be biodegraded and recycled due to oil depletion and environmental pollution. In the automobile industry, the development of lightweight materials to improve fuel efficiency of automobiles and the development of thermoplastic materials that can be recycled using bio or natural materials to prevent environmental pollution are increasing rapidly.

Conventionally, thermoplastic composite materials for automobile interior materials developed for light weight and eco-friendliness include polyethylene, polypropylene, low-melting-point polyamide, low-melting-point polyamide and the like, which are added to reinforcing fibers such as natural fibers, inorganic fibers, and high melting point thermoplastic fibers excellent in heat resistance and rigidity. A material which is produced by impregnating or laminating adhesive organic fibers such as ester has been developed. However, due to the low stiffness and heat resistance of these adhesive fibers, the durability is low due to the low heat-sealability at the high temperature, the shrinkage of the matrix during the cooling of the material after the high temperature process proceeds and the appearance becomes poor, , There are limitations in application.

Therefore, it is urgently required to develop a material having high durability and appearance as well as being capable of reducing the weight of a material, having high adhesive strength even in a high temperature process, excellent in numerical stability at the time of cooling.

Korean Patent No. 10-1279522

An object of the present invention is to provide a composite material which can be made lightweight, has high adhesive strength in a high-temperature process, and has excellent numerical stability at the time of cooling after heat bonding, thereby providing a composite material excellent in durability and appearance.

Another object of the present invention is to provide a composite material for an automobile using the composite material.

In order to achieve the above object, the present invention provides, in one embodiment,

A thermal adhesive layer; And a base layer provided on one surface or both surfaces of the thermally adhesive layer,

Wherein the base layer comprises at least one selected from the group consisting of a polyurethane foam layer, a synthetic fiber layer and a glass fiber layer,

The laminate having a shrinkage ratio of 30% or less per unit area after 10 minutes at room temperature (22 ± 1 ° C) after heat treatment for 2 minutes under conditions of 65% RH and 125 ± 1 ° C.

The present invention also provides an automotive composite material including the laminate in one embodiment.

The laminate according to the present invention comprises a substrate layer including at least one of a polyurethane foam layer, a synthetic fiber layer and a glass fiber layer on one side or both sides of a thermal adhesive layer comprising a polyolefin resin and a styrene copolymer of a specific composition, And can be used for automobile interior and exterior materials, specifically, automobile headliners, etc., since it has a high thermal adhesive strength at a high temperature of 150 ° C or more and is excellent in numerical stability upon cooling after heat bonding.

1 is a cross-sectional view showing the structure of a laminate according to the present invention.
2 is a cross-sectional view showing the structure of the heat-adhesive layer of the present invention.
FIG. 3 is a graph showing the adhesive strength of the styrene copolymer contained in the laminate according to the present invention according to the bonding temperature according to the content of the styrene.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail.

It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

In the present invention, the terms " comprising " or " having ", and the like, specify that the presence of a feature, a number, a step, an operation, an element, a component, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

Hereinafter, the present invention will be described in detail with reference to the drawings, and the same or corresponding components are denoted by the same reference numerals regardless of the reference numerals, and a duplicate description thereof will be omitted.

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a laminate usable in composite materials for automobiles.

As the industry develops, there is a growing demand for eco-friendly materials that can be biodegraded and recycled due to oil depletion and environmental pollution. In the automobile industry, the development of lightweight materials for improving the fuel efficiency of automobiles is increasing rapidly.

Conventional composite materials for automotive interior materials for lightweight and eco-friendly are natural fiber, inorganic fiber and high melting point thermoplastic fiber which are excellent in heat resistance and rigidity and are used as reinforcing fibers. Lightweight and excellent processability by low specific gravity There are materials produced using thermoplastic organic fibers such as polyethylene, polypropylene, low-melting-point polyamide, low-melting-point polyester, etc., but these materials are often used in molding or after molding due to low rigidity and heat resistance of the matrix fibers There is a limited limitation in application due to problems that the shrinkage of the base material proceeds in a high temperature process and the appearance becomes poor or the reliability of the adhesion force required by automobile interior materials is not satisfied.

Accordingly, the present invention provides a laminate for use in a composite material for automobiles.

The laminate according to the present invention comprises a substrate layer including at least one of a polyurethane foam layer, a synthetic fiber layer and a glass fiber layer on one side or both sides of a thermal adhesive layer comprising a polyolefin resin and a styrene copolymer of a specific composition, And can be used for automobile interior and exterior materials, specifically, automobile headliners, etc., since it has a high thermal adhesive strength at a high temperature of 150 ° C or more and is excellent in numerical stability upon cooling after heat bonding.

Hereinafter, the present invention will be described in more detail.

The present invention provides, in one embodiment, a heat-bonding layer; And a base layer provided on one or both sides of the heat-adhesive layer.

The laminate according to the present invention is a laminate according to the present invention, which is lightweight and has high rigidity and strength on one or both surfaces of a heat-bonding layer having a specific composition, i) a polyurethane foam layer, ii) a synthetic fiber layer, and iii) It may have a laminated structure. Specifically, as shown in Fig. 1 (a), the laminate may have a two-layer structure in which a base layer is laminated on one side of the heat-adhesive layer. As shown in Figs. 1 (b) and (c) Layer structure in which two or more layers are stacked, and in some cases, a structure in which a plurality of heat-adhesive layers and two or more substrate layers are laminated can be formed.

More specifically, the laminate according to the present invention may include, but is not limited to, the following structure:

(1) Polyurethane foam layer / thermal adhesive layer / nonwoven fabric / thermal adhesive layer / polyurethane foam layer / glass fiber / heat adhesive layer / nonwoven fabric,

(2) polyurethane foam layer / thermal adhesive layer,

(3) Glass fiber / thermal adhesive layer.

(4) nonwoven fabric / thermal bonding layer,

(5) polyurethane foam layer / heat adhesive layer / nonwoven fabric,

(6) Glass fiber / thermal adhesive layer / nonwoven fabric,

(7) Polyurethane foam layer / thermal adhesive layer / glass fiber.

At this time, the base layer may have a certain average thickness in order to reduce the weight of the laminate to be manufactured and to achieve sufficient rigidity and strength. Specifically, the average thickness of the base layer may be from 1 to 15 mm, and specifically from 1 to 10 mm, from 1 to 5 mm, from 5 to 10 mm, from 4 to 8 mm, from 2 to 6 mm, from 2 to 4 mm, To 5 mm, from 4 to 6 mm, or from 2.5 to 5.5 mm. When the base layer has a multi-layer structure, the average thickness of each base layer constituting the multi-layer structure may be 1 to 10 mm in consideration of the average thickness sum, more specifically 1 to 3 mm, 3 to 6 mm, 6 to 9 mm, 1 to 5 mm, 5 to 10 mm, 2 to 4 mm, 2 to 6 mm or 4 to 8 mm.

When the base layer includes a polyurethane foam layer, the polyurethane foam layer may selectively include one of a hard urethane foam and a soft urethane foam depending on the use of the laminate, Foam and soft urethane foam can be included together.

Further, the thermally adhesive layer may contain a polyolefin resin and a styrene copolymer in a specific composition. Specifically, the thermally adhesive layer may include 50 to 100 parts by weight of a polyolefin resin and 1 to 50 parts by weight of a styrene copolymer. As one example, the thermally adhesive layer may include 90 parts by weight of a polyolefin resin and 10 parts by weight of a styrene copolymer, and may include 30 parts by weight of a styrene copolymer in 70 parts by weight of a polyolefin resin. In 80 parts by weight of a polyolefin resin, 20 parts by weight of a copolymer. As the case may be, the thermally adhesive layer may include 30 parts by weight of the styrene copolymer in 70 parts by weight of the polyolefin resin, but is not limited thereto.

Although the type of the polyolefin resin is not particularly limited, the polyolefin resin may be polyethylene (PE), polypropylene (PP), or an ethylene propylene copolymer -propylene copolymer).

In addition, the polyolefin resin may include 10 to 90 parts by weight of polyethylene (PE) and 1 to 60 parts by weight of polypropylene (PP). Specifically, polyethylene (PE) is contained in an amount of 20 to 80 parts by weight, 30 to 70 parts by weight, 20 to 40 parts by weight, 30 to 50 parts by weight, 50 to 70 parts by weight, 10 to 30 parts by weight, 45 to 65 parts by weight, 70 to 80 parts by weight, 60 to 80 parts by weight or 30 to 40 parts by weight. The polypropylene (PP) may be 10 to 50 parts by weight, 20 to 40 parts by weight, 30 to 40 parts by weight, 5 to 35 parts by weight, 5 to 20 parts by weight, 40 to 60 parts by weight, or 1 to 10 parts by weight Can be. As an example, the polyolefin resin may comprise 30 to 50 parts by weight of polyethylene (PE) and 20 to 40 parts by weight of polypropylene (PP).

The polyethylene (PE) may include, but is not limited to, low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and the like.

In addition, the styrene copolymer includes a styrene-isoprene-styrene (SIS) copolymer as a copolymer containing styrene repeating units; Styrene-ethylene / butylene-styrene (S-EB-S) copolymer; Styrene-divinylbenzene (S-DVB) copolymer; Styrene-acrylonitrile (SAN) resin; Styrene-butadiene rubber (SBR); Styrene-butadiene-styrene rubber (SBSR) or styrene-butadiene-styrene rubber (SBSR). Specific examples of the styrene-butadiene rubber (SBR) Butylene-styrene (S-EB-S) copolymer, and the like.

The styrene copolymer may contain 10 to 60% by weight, preferably 10 to 50% by weight, more preferably 10 to 40% by weight, based on the weight of the styrene copolymer, of styrene repeating units based on the total weight of the styrene copolymer. 10 to 30 wt%, 20 to 40 wt%, 30 to 60 wt%, 15 to 25 wt%, 25 to 35 wt%, or 45 to 55 wt%. The present invention can maximize the sealing strength of the thermally adhesive layer by adjusting the content of the styrene copolymer to the above range.

Further, the thermally adhesive layer may include ethylene vinyl acetate (EVA) for improving the adhesive strength at a high temperature of 150 ° C or more. In this case, the ethylene vinyl acetate (EVA) % By weight vinyl group. In this case, the vinyl group may be the same as vinyl acetate (VA), and the specific content may be 5 to 15% by weight, 5 to 10% by weight, 10 to 20% by weight or 13 to 17% by weight.

When the thermoadhesive layer comprises ethylene vinyl acetate, it comprises 20 to 90 parts by weight of polyethylene (PE); 1 to 70 parts by weight of polypropylene (PP); 15 to 35 parts by weight of a styrene copolymer; And 30 parts by weight or less of ethylene vinyl acetate (EVA).

As one example, the thermally adhesive layer may comprise 20 to 40 parts by weight or 50 to 70 parts by weight of polyethylene (PE), 5 to 15 parts by weight or 20 to 40 parts by weight of polypropylene (PP) (EVA) in an amount of 1 to 15 parts by weight, 10 to 20 parts by weight, 3 to 7 parts by weight, or 8 to 12 parts by weight.

In addition, the thermal adhesive layer according to the present invention may have a single-layer structure as shown in Fig. 2 (a), and in some cases, a polyolefin film having melt adhesion properties as shown in Figs. 2 (b) And may have a multi-layered structure laminated on one surface or both surfaces.

In addition, the heat-adhesive layer may have a certain average thickness in order to realize a sufficient adhesive strength of the laminate to be manufactured regardless of its structure. Specifically, the average thickness of the thermal adhesive layer may be 1 to 500 μm, and more specifically, 10 to 450 μm, 100 to 400 μm, 200 to 400 μm, 150 to 300 μm, 250 to 500 μm, , 10 to 50 占 퐉, 50 to 100 占 퐉, 50 to 80 占 퐉, 60 to 70 占 퐉, or 65 to 75 占 퐉.

As described above, the present invention is characterized in that a base layer comprising at least one of a polyurethane foam layer, a synthetic fiber layer and a glass fiber layer is provided on one side or both sides of a thermal adhesive layer comprising a polyolefin resin and a styrene copolymer of a specific composition, It is lightweight and able to realize sufficient strength, has high thermal adhesive strength at high temperature of 150 ℃ or more, excellent in numerical stability when it is cooled after heat bonding, and is excellent in durability and appearance.

As one example, the laminate exhibits high numerical stability even at a high temperature, so that the shrinkage ratio of the laminate at high temperature can be 30% or less per unit area (10 cm x 10 cm). Specifically, the laminate had a shrinkage rate per unit area (10 cm x 10 cm) after lapse of 10 minutes at room temperature (22 1 C) after heat treatment for 2 minutes under conditions of 65% RH and 125 1 deg. Or less, and more specifically 0.1 to 50%, 0.1 to 15%, 0.1 to 10%, 0.1 to 7%, 0.1 to 5%, 0.1 to 5% 0.5 to 3%, 0.1 to 2.5%, 0.5 to 2.5%, 0.1 to 2%, 0.5 to 2%, 0.1 to 4%, 0.5 to 4%, 0.1 to 3.5%, 0.5 to 3.5%, 0.1 to 3% 1.6%, 0.5-1.6%, or 0.8-1.2%.

As another example, the laminate may have an excellent adhesive strength even at a high temperature, and the adhesive strength in evaluating the adhesive strength to the thermally adhesive layer and the substrate layer may satisfy the following formula 1:

[Formula 1]

400 g / in ² ≤ AS ≤ 800 g / in ²

In the formula (1), AS represents the applied force at the time when the heat-bonding layer and the base layer are pulled out at a speed of 50 +/- 2 mm / s, i.e., the bonding strength.

Specifically, the adhesive strength (AS) of the laminate is from 100 to 800 g / in ^2, 150 to 200 g / in ^2, 400 to 800 g / in ^2, 400 to 700 g / in ^2, 450 to 660 g / in ² , 450 to 600 g / in ² , 450 to 560 g / in ² , 450 to 500 g / in ² , 500 to 560 g / in ² , 500 to 520 g / in ² , 500 to 540 g / in ² , 530 to 580 g / in ² , 630 to 670 g / in ^2, or 700 to 750 g / in ² .

As another example, the laminate has excellent numerical stability at a high temperature as described above, and has excellent moldability in a molding process performed under high temperature conditions. For example, the layered product may satisfy the following condition (2) upon deep drawing:

[Formula 2]

10 cm ≤ D ₆₀ ≤ 40 cm

In Equation 2, D ₆₀ is the depth of the hole formed in the laminate during compression molding of the laminate for 30 2 seconds with a compressor including a punch having an average diameter of 400 +/- 20 mm under the conditions of 170 +/- 2 DEG C and 14 +/- 0.1 MPa. .

Specifically, the laminate is deep-hole formed in a laminated body forming during deep drawing (D ₆₀₎ may be up to more than, 40㎝ 35㎝, more specifically from 5 to 40㎝, 26 to 30㎝, 27 to 31, Cm, 28 to 36 cm, 21 to 23 cm, 18 to 36 cm, 18 to 25 cm, 28 to 32 cm, or 34 to 36 cm.

Further, in one embodiment of the present invention, there is provided a composite material for an automobile comprising the laminate.

The composite material according to the present invention is a laminate comprising a base layer comprising at least one of a polyurethane foam layer, a synthetic fiber layer and a glass fiber layer on one side or both sides of a thermal adhesive layer comprising a polyolefin resin and a styrene copolymer of a specific composition It is possible to realize a light weight, sufficient rigidity and strength, a high thermal adhesive strength at a high temperature of 150 DEG C or more, excellent numerical stability upon cooling after heat bonding, and excellent durability and appearance, Liner and the like.

Hereinafter, the present invention will be described in more detail with reference to Examples and Experimental Examples.

However, the following Examples and Experimental Examples are merely illustrative of the present invention, and the present invention is not limited to the following Examples and Experimental Examples.

Manufacturing example  1-22.

(LLDPE) and polypropylene (PP, melt index (MI): 4.0 占 .1, density: 1.0 占 퐉) as a polyolefin resin as a low density polyethylene (LDPE, 0.92 g / ml) was prepared. A styrene-butadiene rubber (SBR), a styrene-butadiene-styrene rubber (SBSR) and a styrene-ethylene / butylene-styrene (S-EB-S) copolymer were prepared as styrene copolymers, ethylene vinyl acetate , VA content: 15% by weight) were prepared and mixed according to the compositions shown in Table 1 below to prepare a hot melt composition. The prepared composition was cast to prepare a heat bonding layer (100 mm x 150 mm in length) having an average thickness of 65 5 m.

Manufacturing example Polyolefin resin Styrene copolymer EVA LDPE LLDPE PP SBR1 SBR2 SBSR SEBSR One 98 - - 2 - - - - 2 90 - - 10 - - - - 3 75 - - 25 - - - - 4 70 - - 30 - - - - 5 50 - - 50 - - - - 6 35 - 35 30 - - - - 7 35 - 35 - 30 - - - 8 35 - 35 - - 30 - - 9 35 - 35 - - - 30 - 10 50 28 2 20 - - - - 11 25 50 5 20 - - - - 12 25 25 30 20 - - - - 13 10 10 60 20 - - - - 14 35 - 30 - 30 - - 5 15 30 30 10 20 - - - 10 16 100 - - - - - - - 17 - - 100 - - - - - 18 - 100 - - - - - - 19 40 55 5 - - - - - 20 30 30 - 30 - - - 10 21 30 55 5 - - - - 10 22 30 40 - 30 - - - - * The styrene content based on the total weight of the styrene copolymer is as follows:
20% by weight of SBR1, 50% by weight of SBR2, 20% by weight of SBSR and 30% by weight of SEBSR.

Example  1 to 10.

(Average thickness: 4 占 0.5 mm) having a width of 100 mm and a length of 150 mm was prepared and bonded to the thermally adhesive layer prepared in Production Examples 6 to 15, and a pressure of 14 MPa was applied for 20 seconds at 165 占 2 占 폚 to form urethane Thereby obtaining a laminate having a structure in which a foam and a thermal adhesive layer are laminated.

Example  11.

(Average thickness: 4 ± 0.5 mm) having a width of 100 mm and a length of 150 mm was prepared, and the surface of the thermally adhesive layer prepared in Production Example 14 was subjected to corona treatment (45 ± 1 dyne) to be overlapped with the prepared urethane foam Respectively. A pressure of 14 MPa was applied to the fixed urethane foam and the thermal adhesive layer at 165 2 캜 for 20 seconds to obtain a laminate having a structure in which the urethane foam and the thermal adhesive layer were laminated.

Example  12.

(Average thickness: 4 ± 0.5 mm) and a nonwoven fabric (average thickness: 4 ± 0.5 mm) having dimensions of 100 mm × 150 mm in length were prepared and the urethane foam and the nonwoven fabric prepared in the same manner as in Example 6 And then a pressure of 14 MPa was applied for 20 seconds under the condition of 165 占 2 占 폚 to obtain a laminate having a structure in which a urethane foam, a thermally adhesive layer and a nonwoven fabric were sequentially laminated.

Example  13.

A nonwoven fabric (average thickness: 4 ± 0.5 mm) and glass fibers (GF, average thickness: 0.2 ± 0.1 mm) having a width of 100 mm and a length of 150 mm were prepared, The materials were laminated in the order of the nonwoven fabric, the heat-bonding layer prepared in Production Example 6, the glass fiber and the urethane foam in this order, and then the pressure was applied at 14.5 MPa for 20 seconds at 165 캜.

Comparative Example  1 to 12.

(Average thickness: 4 0.5 mm) having a width of 100 mm and a length of 150 mm was prepared, and the thermally adhesive layers prepared in Preparative Examples 1 to 5 and Preparation Examples 16 to 22 were bonded to each other. A pressure of 14 MPa was applied to obtain a laminate having a structure in which the urethane foam and the heat-adhesive layer were laminated.

Experimental Example  One.

The laminate obtained in Examples 1 to 11 and Comparative Examples 1 to 12 according to the present invention was tested for i) high-temperature adhesive strength and ii) shrinkage ratio, and the measured results are shown in Table 2 and FIG. The specific measurement method is as follows:

1) High temperature bonding strength

A polyurethane foam layer having a width of 1 inch (inch) x 20 cm x 5 mm thick and a thermal adhesive layer were prepared and fixed so that the lower end 10 cm overlapped with the prepared foam layer and the thermally adhesive layer in the longitudinal direction, and then a pressure of 13 MPa For 30 seconds. After that, the unbonded portion of the polyurethane foam layer and the thermal adhesive layer was pulled at a speed of 50 ± 2 mm / s to measure the strength of the force acting at the time when the thermally adhered portion was desorbed. Here, the thermal bonding was performed at a temperature interval of 85 to 165 ° C at 5 ° C intervals, and the bonding strength was measured for each thermal bonding temperature. The measured results are shown in Table 2 and FIG.

2) Contraction ratio

The laminate (100 mm long × 150 mm long) obtained in Examples and Comparative Examples was aged for 2 minutes in an aging oven at 125 ± 1 ° C. and 65% RH and allowed to stand at room temperature (22 ± 1 ° C.) for 10 minutes Respectively. Then, the transverse and longitudinal shrinkage rates of the laminate were measured, respectively, and the shrinkage per unit area (10 cm x 10 cm) of the laminate was derived from the measured shrinkage ratios.

Adhesion temperature
[° C] Adhesion strength [g / in ² ] Total contraction ratio
[Landscape / Portrait] Example 1 165 ± 1 490 ± 2 0.2% [0.1% / 0.1%] Example 2 165 ± 1 550 ± 2 0.25% [0.1% / 0.15%] Example 3 165 ± 1 510 ± 2 0.25% [0.1% / 0.15%] Example 4 165 ± 1 505 ± 2 0.25% [0.1% / 0.15%] Example 5 165 ± 1 515 ± 1 4% [2% / 2%] Example 6 165 ± 1 500 ± 1 3.5% [1.5% / 2%] Example 7 165 ± 1 505 ± 1 1.5% [0.5% / 1%] Example 8 165 ± 1 495 ± 1 1.0% [0.5% / 0.5%] Example 9 165 ± 1 580 ± 2 0.2% [0.1% / 0.1%] Example 10 165 ± 1 650 ± 1 0.25% [0.1% / 0.15%] Example 11 165 ± 1 730 ± 2 0.25% [0.1% / 0.15%] Comparative Example 1 125 ± 1 180 ± 2 80% [20% / 60%] Comparative Example 2 125 ± 1 470 ± 2 75% [18% / 57%] Comparative Example 3 125 ± 1 510 ± 2 72% [17% / 55%] Comparative Example 4 125 ± 1 500 ± 2 70% [15% / 55%] Comparative Example 5 125 ± 1 520 ± 2 65% [15% / 50%] Comparative Example 6 125 ± 1 5 ± 0.5 70% [20% / 50%] Comparative Example 7 125 ± 1 0 ± 0.5 0.1% [0.05% / 0.05%] Comparative Example 8 125 ± 1 15 ± 0.5 35% [7% / 28%] Comparative Example 9 125 ± 1 10 ± 1 7% [2% / 5%] Comparative Example 10 125 ± 1 58 ± 1 20% [10% / 30%] Comparative Example 11 125 ± 1 10 ± 1 15% [5% / 10%] Comparative Example 12 125 ± 1 310 ± 1 17% [4% / 13%]

Table 2 and FIG. 3 show that the laminate according to the present invention has high adhesive strength and excellent numerical stability under high temperature conditions.

Specifically, as shown in Fig. 3, the laminate of Comparative Examples 1 to 3 and 5 containing a styrene copolymer in the heat-bonding layer was bonded at a high temperature of about 125 캜 to exhibit an adhesive strength of 180 g / in ² or more, When the content of the copolymer was 10 wt% or more based on the total weight of the thermoadhesive layer, a high adhesive strength of 450 g / in ² to 550 g / in ² was exhibited. However, the laminate of Comparative Examples 6 to 8, which did not contain a styrene copolymer in the heat-bonding layer, had 15 g / in ² Lt; RTI ID = 0.0 >%< / RTI > This means that the adhesive strength of the laminate is improved when the styrene copolymer is contained in the thermal adhesive layer.

The laminate of Example 9 further comprising ethylene vinyl acetate (EVA) together with the styrene copolymer in the thermoadhesive layer had a high 570 to 590 < RTI ID = 0.0 > g / in < ^{2 &} gt ;. This indicates that the adhesive strength of the laminate is improved when ethylene vinyl acetate (EVA) is further included in the heat adhesive layer.

In addition, the laminate of Example 11 in which the surface of the heat-adhesive layer was corona-treated and then laminated with the urethane foam had an adhesive strength of 700 to 750 g / in ² , which is higher than that of the laminate of Example 9, . This means that the heat bonding strength is further improved when the surface of the heat bonding layer is subjected to surface treatment using a corona or the like and then laminated with the base layer.

Further, the laminate of Examples 5 to 8 containing polypropylene (PP) in the thermoadhesive layer exhibited a shrinkage of 4% or less per unit area (10 cm by 10 cm length) after high-temperature aging at 125 占 폚 , And the contraction ratio was found to be lower as the content of polypropylene (PP) increased. On the other hand, the laminate of Comparative Example 10 containing no polypropylene (PP) in the heat-bonding layer had a shrinkage ratio of 20% or more per unit area (10 cm by 10 cm). This means that when polypropylene (PP) is contained in the heat-bonding layer, the shrinkage of the laminate due to cooling after the heat-bonding is suppressed, thereby improving the numerical stability.

From these results, it can be seen that the laminate according to the present invention includes a substrate layer which is light in weight and high in strength, and includes a thermoadhesive layer containing a polyolefin resin as a characteristic component and a styrene copolymer in a predetermined amount, The numerical stability is improved.

Experimental Example  2.

In order to evaluate the high temperature moldability of the laminate according to the present invention, the deep drawing depth of the laminate after deep drawing was measured. Specifically, the deep drawing depth was measured in the same manner as in Examples 5 to 8, 10 and Comparative Examples 10 and 12 except that the layered product (50 cm in length x 50 cm in length) having a mean diameter of 400 Mm and a depth of 40 ± 0.5 cm at a temperature of 170 ± 1 ° C. for 30 seconds under a pressure of 14 MPa, and the average depth of the unevenness formed on the laminate was measured. The above procedure was repeated three times to obtain an average value. The results are shown in Table 3 below.

Deep drawing depth Example 5 20 ± 1 cm Example 6 22 ± 1 cm Example 7 30 ± 1 cm Example 8 35 ± 1 cm Example 10 28 ± 1 cm Comparative Example 10 15 ± 1 cm Comparative Example 12 15 ± 1 cm

As shown in Table 3, it can be seen that the laminate according to the present invention has excellent moldability and deep deep drawing depth.

Specifically, the laminate of Examples 5 to 8 and 10 including polypropylene (PP) as a polyolefin resin showed an average deep-drawn depth of 20 cm or more, and the polypropylene (PP) contained in the heat- It was confirmed that the depth increased as the content increased. In comparison, the laminated bodies of Comparative Examples 10 and 12, which did not contain polypropylene (PP), showed that the deep-drawn average depth was 15 cm or less and the molding with irregularities was not sufficiently performed.

This result implies that the polypropylene (PP) contained as the polyolefin resin in the thermally adhesive layer influences the deep drawing of the laminate, so that it is necessary to contain a certain amount of polypropylene (PP) for the formability of the laminate.

Claims (16)

A thermal adhesive layer; And
And a base layer provided on one surface or both surfaces of the thermal adhesive layer,
Wherein the base layer comprises at least one selected from the group consisting of a polyurethane foam layer, a synthetic fiber layer and a glass fiber layer,
The shrinkage ratio is 30% or less per unit area after 10 minutes at room temperature (22 ± 1 ° C) after heat treatment for 2 minutes at 65% RH and 125 ± 1 ° C,
A laminate satisfying the condition of the following formula (1) when evaluating the adhesion to the base layer:
[Formula 1]
100 g / in ² ? AS? 800 g / in ²
In Equation (1), AS represents the applied force at the time when the heat-bonding layer and the lower end of the substrate layer are pulled out at a speed of 50 +/- 2 mm / s to be detached.
A thermal adhesive layer; And
And a base layer provided on one surface or both surfaces of the thermal adhesive layer,
Wherein the base layer comprises at least one selected from the group consisting of a polyurethane foam layer, a synthetic fiber layer and a glass fiber layer,
The shrinkage ratio is 30% or less per unit area after 10 minutes at room temperature (22 ± 1 ° C) after heat treatment for 2 minutes at 65% RH and 125 ± 1 ° C,
A laminate satisfying the condition of the following formula (2) upon deep drawing test:
[Formula 2]
10 cm ≤ D ₆₀ ≤ 40 cm
In Equation 2, D ₆₀ is the depth of the hole formed in the laminate during compression molding of the laminate for 30 2 seconds with a compressor including a punch having an average diameter of 400 +/- 20 mm under the conditions of 170 +/- 2 DEG C and 14 +/- 0.1 MPa. .
delete 3. The method according to claim 1 or 2,
The heat-
50 to 100 parts by weight of a polyolefin resin; And
Styrene copolymer in an amount of 1 to 50 parts by weight.
5. The method of claim 4,
Wherein the polyolefin resin comprises at least one selected from the group consisting of polyethylene (PE), polypropylene (PP) and ethylene propylene copolymer.
5. The method of claim 4,
The polyolefin resin,
10 to 90 parts by weight of polyethylene (PE); And
And 1 to 60 parts by weight of polypropylene (PP).
5. The method of claim 4,
Styrene copolymers include styrene-isoprene-styrene (SIS) copolymers; Styrene-ethylene / butylene-styrene (S-EB-S) copolymer; Styrene-divinylbenzene (S-DVB) copolymer; Styrene-acrylonitrile (SAN); Styrene-butadiene rubber (SBR); And styrene-butadiene-styrene rubber (SBSR).
8. The method of claim 7,
Wherein the styrene copolymer contains styrene repeating units in an amount of 10 to 60 wt% based on the total weight of the styrene copolymer.
5. The method of claim 4,
Wherein the thermal adhesive layer further comprises ethylene vinyl acetate.
10. The method of claim 9,
And the vinyl group content of ethylene vinyl acetate is 5 to 20% by weight.
3. The method according to claim 1 or 2,
The heat-
20 to 90 parts by weight of polyethylene (PE);
1 to 70 parts by weight of polypropylene (PP);
15 to 35 parts by weight of a styrene copolymer; And
And 30 parts by weight or less of ethylene vinyl acetate.
3. The method according to claim 1 or 2,
And the average thickness of the heat-adhesive layer is 1 to 500 m.
3. The method according to claim 1 or 2,
Wherein the substrate layer has a multilayer structure.
14. The method of claim 13,
The base layer of the multi-
The average thickness of each base layer is 0.1 to 10 mm,
Wherein the total average thickness is 1 to 15 mm.
3. The method according to claim 1 or 2,
Wherein the polyurethane foam layer comprises a hard urethane foam or a soft urethane foam.
A composite material for an automobile comprising the laminate according to any one of claims 1 to 3.

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