KR102497290B1 - Polyurethane laminate and preparation method thereof - Google Patents

Abstract

The present invention relates to a polyurethane laminate in which a substrate layer, a first polyurethane layer and a second polyurethane layer are sequentially laminated and a method for manufacturing the same, wherein the first polyurethane layer has an Asker C type surface hardness of 15 to 35 Since the buffering effect and the anti-shrinkage effect are excellent by satisfying, the laminate including the same can be applied to outer plates made of metal such as ships, vehicles, storage tanks, pipes, valves, and refrigerators to exhibit excellent characteristics.

Description

Polyurethane laminate and its manufacturing method {POLYURETHANE LAMINATE AND PREPARATION METHOD THEREOF}

The present invention relates to a polyurethane laminate and a method for producing the same.

Polyurethane foam is lightweight and has excellent heat insulation, sound insulation and molding processability, so it is widely used as a refrigerator, building insulation, sound absorbing material, insulation material, etc. In particular, polyurethane foam is also used for outside plates made of metal such as ships, vehicles, storage tanks, pipes, valves, and refrigerators. There is a problem of causing deformation such as bending in the outer plate due to shrinkage.

Accordingly, conventionally, a nonwoven fabric capable of buffering function has been additionally used between the outer panel and the polyurethane foam. However, the non-woven fabric is expensive, and requires an adhesive process for adhering the non-woven fabric or an additional process for cutting to fit the size. Therefore, there is a problem that other defects may occur in additional processes such as bonding and cutting, as well as process cost increase due to this.

For example, Korean Patent Registration No. 0997220 provides a non-woven fabric layer having a predetermined elasticity on the inner surface of the outer door plate, so that the outer plate of the door is partially formed by the difference in shrinkage of urethane foam foamed and filled between the outer plate of the door and the inner plate of the door. Disclosed is a door structure for a refrigerator capable of preventing bending. However, since the nonwoven fabric layer is attached to the inner surface of the outer plate of the door using an acrylic adhesive, problems of cost and defects may still occur in this additional process.

Korean Registered Patent No. 0997220

Accordingly, an object of the present invention is to provide a polyurethane laminate and a manufacturing method thereof capable of effectively preventing deformation of bonded metal substrates due to excellent buffering effect and anti-shrinkage effect.

In the laminate according to one embodiment, a base layer, a first polyurethane layer, and a second polyurethane layer are sequentially laminated, and the Asker C type surface hardness of the first polyurethane layer is 15 to 35.

The laminate according to the embodiment includes the first polyurethane layer having an Asker C type surface hardness of 15 to 35, and thus has excellent buffering effect and anti-shrinkage effect. Therefore, when the laminate is applied to outer plates made of metal such as ships, vehicles, storage tanks, pipes, valves, and refrigerators, deformation such as bending occurs in the metal substrate because the effect of preventing deformation of the bonded metal substrate is excellent. If not, the quality is excellent.

In addition, the laminate according to the embodiment includes a second polyurethane layer having a higher surface hardness of Asker C type than the first polyurethane layer on one side of the first polyurethane layer, so that heat insulation and insulation effect are excellent.

Moreover, since the first polyurethane layer is manufactured by a simple process using a spray method, it can be quickly produced without conventional bonding and cutting processes, and defects that may occur in the manufacturing process can be minimized. In addition, since it is easy to apply anywhere regardless of size, utilization is high, and process costs can also be reduced.

1 schematically shows a refrigerator door manufactured using a laminate according to an embodiment.
FIG. 2 is a cross-sectional view of the refrigerator door of FIG. 1 taken along line XX'.
3 shows a laminate according to an embodiment.

Hereinafter, the invention will be described in detail through embodiments. Embodiments are not limited to the contents disclosed below, and may be modified in various forms unless the gist of the invention is changed.

In this specification, when a certain component is said to "include", this means that it may further include other components, not excluding other components, unless otherwise stated.

It should be understood that all numbers and expressions representing amounts of constituents, reaction conditions, etc. described herein are modified by the term "about" in all cases unless otherwise specified.

In this specification, when described as being formed "on" or "under" each layer, etc., "on" and "under" are "directly" or "indirectly through other components".

The size of each component in the drawing may be exaggerated for description, and may differ from the actually applied size.

In this specification, “a mixture thereof” means that two or more substances are included. The "mixture" may include, but is not limited to, a uniformly and/or non-uniformly mixed state, a dissolved state, and a uniformly and/or non-uniformly dispersed state.

In this specification, terms such as first and second are used to describe various components, and the components are not limited by the terms. These terms are only used for the purpose of distinguishing one component from another.

1 schematically shows a refrigerator door manufactured using a laminate according to an embodiment. The use of the laminate is not limited to the refrigerator door, and FIG. 1 illustrates a refrigerator door to which the laminate is applied.

Specifically, FIG. 1 illustrates the appearance of a refrigerator door provided in a typical refrigerator. The refrigerator door 1 includes a door inner plate (a) in contact with a storage space in which food and the like are stored and an exterior other than the storage space. It may include a door outer plate (b) in contact with the environment.

Such a refrigerator door is essential to block and insulate a space between an external environment and a storage space for a refrigerating or freezing effect at an appropriate temperature so as to store food at a low temperature. Accordingly, a substrate such as metal is used to block the external environment and the storage space, and a heat insulating material may be used to insulate the storage space.

FIG. 2 is a cross-sectional view of the refrigerator door of FIG. 1 taken along line XX'. Specifically, FIG. 2 shows a substrate layer 100 located on the surface of the outer plate (b) of the door not in contact with a storage space where food or the like is stored, a first polyurethane layer 200 located on one side of the substrate layer, and the first The second polyurethane layer 300 located on one side of the first polyurethane layer is illustrated. More specifically, a structure in which the base layer 100, the first polyurethane layer 200 and the second polyurethane layer 300 are sequentially laminated is illustrated.

As shown in FIG. 2, the laminate includes a first polyurethane layer 200 having excellent buffering effect and anti-shrinkage effect on one side of the base layer 100, thereby effectively preventing deformation such as bending in the base layer. can In addition, by including the second polyurethane layer 300 on one side of the first polyurethane layer 200, it is possible to improve heat insulation and insulation effect.

3 shows a laminate according to an embodiment. Specifically, FIG. 3 is a laminate including a base layer 100, a first polyurethane layer 200 positioned on the base layer, and a second polyurethane layer 300 positioned on the first polyurethane layer ( The structure of 2) is exemplified. More specifically, the first polyurethane layer 200 includes a core layer 210 and a surface layer 220, the core layer 210 is located on the surface facing the base layer 100, the surface layer ( 220) is located on the surface opposite to the second polyurethane layer 300, so that the substrate layer 100, the core layer 210 of the first polyurethane layer, the surface layer 220 of the first polyurethane layer, and The structure of the laminate 2 in which two polyurethane layers 300 are sequentially laminated is shown.

Since the laminate according to the embodiment has a structure as shown in FIG. 2 or 3, it can effectively prevent deformation such as bending as well as barrier and heat insulating properties, so various products for storing contents, especially low temperature must be maintained It can be applied to a product to exhibit excellent characteristics.

laminate

In the laminate according to one embodiment, a base layer, a first polyurethane layer, and a second polyurethane layer are sequentially laminated, and the Asker C type surface hardness of the first polyurethane layer is 15 to 35.

A laminate according to another embodiment may include a first polyurethane layer having a thickness of 1 mm to 10 mm; and a second polyurethane layer having a thickness of 35 mm to 100 mm, and a thickness ratio between the first polyurethane layer and the second polyurethane layer is 1:5 to 20.

The laminate may have a thickness of 44 mm to 110 mm. For example, the thickness of the laminate is 44 mm to 110 mm, 44 mm to 105 mm, 44 mm to 103 mm, 44.2 mm to 100 mm, 44.2 mm to 90 mm, 45 mm to 85 mm, 43 mm to 80 mm. mm, 43 mm to 75 mm or 43 mm to 70 mm.

base layer

The base layer may be a material having a blocking function between the external environment and the storage space. Specifically, the base layer may be a metal material such as stainless steel or color steel. For example, the substrate layer may be a metal material that can be used for outside plates such as ships, vehicles, storage tanks, pipes, valves, and refrigerators, but is not limited thereto.

The base layer may have a thickness of 3 mm to 20 mm. For example, the thickness of the base layer may be 3 mm to 20 mm, 3 mm to 15 mm, 3 mm to 10 mm, 4 mm to 8 mm, 5 mm to 10 mm, or 10 mm to 15 mm, It is not limited. When the thickness of the substrate layer satisfies the above range, an effect of preventing deformation such as bending may be maximized.

1st polyurethane layer

The laminate according to the embodiment includes a first polyurethane layer on one side of the base layer.

Asker C type surface hardness of the first polyurethane layer may be 15 to 35. For example, the Asker C type surface hardness of the first polyurethane layer may be 15 to 35, 17 to 35, 20 to 30, or 22 to 27. When the Asker C type surface hardness of the first polyurethane layer satisfies the above range, the buffering effect and the anti-shrinkage effect may be improved.

A free rise density of the first polyurethane layer may be 15 kg/m³ to 35 kg/m³. For example, the free foam density of the first polyurethane layer is 15 kg/m³ to 35 kg/m³, 20 kg/m³ to 35 kg/m³, 20 kg/m³ to 33 kg/m³, 20 kg/m³ to 20 kg/m³ 30 kg/m³ or 22 kg/m³ to 28 kg/m³. When the free foaming density of the first polyurethane layer satisfies the above range, the buffering effect and the anti-shrinkage effect can be improved.

Specifically, the first polyurethane layer satisfies the Asker C type surface hardness and free foam density as described above, so that shrinkage hardly occurs and the buffering effect is excellent.

The free foaming density is a measurement of the density when produced in a state in which interference from the outside is minimized. For example, the density of the first polyurethane layer prepared by foaming in an open box without a lid may be measured, but is not limited thereto.

In addition, the thickness of the first polyurethane layer may be 1 mm to 10 mm. For example, the thickness of the first polyurethane layer is 1 mm to 10 mm, 1 mm to 9 mm, 2 mm to 9 mm, 2 mm to 8 mm, 3 mm to 8 mm, 3 mm to 7 mm, 4 mm to 9 mm, 1 mm to 3.5 mm, 1 mm to 3 mm, 1.2 mm to 3 mm, 3.5 mm to 8 mm or 4.5 mm to 5.5 mm.

The first polyurethane layer according to the embodiment may include a core layer and a surface layer. Specifically, the first polyurethane layer may include a core layer positioned on a surface facing the base layer and a surface layer positioned on a surface facing the second polyurethane layer (see FIG. 3).

Here, the core layer refers to an area from a surface in contact with the base layer to a portion of 1 mm to 3 mm in the thickness direction based on the first polyurethane layer formed on the base layer. In addition, the surface layer refers to a region ranging from 0.1 mm to 1 mm in the thickness direction from the opposite surface to which the base layer contacts, based on the first polyurethane layer formed on the base layer.

A thickness of the surface layer may be thinner than a thickness of the core layer. Specifically, the thickness of the core layer may be 1 mm to 3 mm, and the thickness of the surface layer may be 0.1 mm to 1 mm. For example, the thickness of the core layer may be 1 mm to 3 mm, 1 mm to 2.7 mm, 1.3 mm to 2.5 mm, 1.5 mm to 2.5 mm, or 2 mm to 3 mm, and the thickness of the surface layer may be 0.1 mm. to 1 mm, 0.3 mm to 1 mm, 0.3 mm to 0.7 mm, 0.1 mm to 0.5 mm, 0.4 mm to 0.8 mm, or 0.7 mm to 1 mm. When the thicknesses of the core layer and the surface layer respectively satisfy the above ranges, the buffering effect and the effect of preventing absorption of other materials may be maximized.

A density of the surface layer may be greater than that of the core layer. For example, the density of the surface layer may be greater than 25 g/cm 3 to less than 35 g/cm 3 , 28 g/cm 3 to 35 g/cm 3 or 28 g/cm 3 to 33 g/cm 3 , and the density of the core layer may be 15 g/cm 3 to less than 25 g/cm 3 , 15 g/cm 3 to 23 g/cm 3 or 18 g/cm 3 to 20 g/cm 3 .

Specifically, since the density of the surface layer is greater than that of the core layer, it is possible to prevent the surface layer from being mixed with or absorbed with a material in contact with one surface of the surface layer. More specifically, when the second polyurethane layer is formed on the surface layer, it is possible to prevent the second polyurethane layer from being absorbed into the first polyurethane layer.

The first polyurethane layer according to the embodiment may be a spray foam. Specifically, the first polyurethane layer may be a spray foam formed using a spray device. Since the first polyurethane layer is a spray foam, it is easy to form a thin layer. In addition, the first polyurethane layer has an excellent buffering effect while having a thin thickness.

In addition, the laminate according to the embodiment does not include a separate adhesive layer between the base layer and the first polyurethane layer. Specifically, since the first polyurethane layer is sprayed and formed on the substrate layer using a spray device, it does not include a separate adhesive layer. Therefore, deformation such as bending hardly occurs compared to a conventional laminate including an adhesive layer.

The first polyurethane layer according to the embodiment may be formed using the first polyol composition and the first diisocyanate composition.

Specifically, the first polyol composition may include a trifunctional or higher functional aliphatic alcohol, an alkylene oxide including ethylene oxide or propylene oxide, and glycol having a weight average molecular weight of 50 g/mol to 3,000 g/mol.

More specifically, the first polyol composition may be a mixture of polyol composition A and polyol composition B.

The polyol composition A may include a trifunctional or higher functional aliphatic alcohol and an alkylene oxide including ethylene oxide or propylene oxide, and the polyol composition B may include glycol having a weight average molecular weight of 50 g/mol to 3,000 g/mol, And it may include an alkylene oxide including ethylene oxide or propylene oxide.

The trifunctional or higher functional aliphatic alcohol may be at least one selected from the group consisting of glycerin, trimethylolpropane, erythritol, pentaerythritol, and sorbitol. The glycerin may be preferable in terms of crosslinking degree improvement, but is not limited thereto.

The glycol may have a weight average molecular weight of 50 g/mol to 3,000 g/mol. For example, the weight average molecular weight of the glycol is 50 g / mol to 3,000 g / mol, 50 g / mol to 2,500 g / mol, 70 g / mol to 2,500 g / mol, 80 g / mol to 2,200, 100 g /mol to 1,800, 100 g/mol to 1,300 g/mol, 100 g/mol to 1,000 g/mol, 100 g/mol to 800 g/mol or 50 g/mol to 600 g/mol.

In addition, the glycol is one selected from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, tetramethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, hexylene glycol and neopentyl glycol may be ideal Dipropylene glycol may be preferred in terms of forming a stable structure, but is not limited thereto.

The polyol composition A may include 1 wt % to 15 wt % of the trifunctional or higher functional aliphatic alcohol, and may include 85 wt % to 99 wt % of the alkylene oxide. For example, the polyol composition A contains 1% to 15% by weight, 1% to 13% by weight, 2% to 10% by weight, 3% to 10% by weight, or 3% by weight of the trifunctional or higher functional aliphatic alcohol. % to 8% by weight, and 85% to 99% by weight, 88% to 98% by weight, 90% to 98% by weight, or 92% to 97% by weight of the alkylene oxide. can

In addition, the polyol composition B may include 1 wt% to 25 wt% of the glycol and 75 wt% to 99 wt% of the alkylene oxide. For example, the polyol composition B comprises 1% to 25%, 3% to 20%, 3% to 18%, 5% to 15%, or 8% to 13% by weight of the glycol. %, and may include 75% to 99% by weight, 80% to 95% by weight, 83% to 92% by weight, or 87% to 92% by weight of the alkylene oxide.

The first polyol composition may further include at least one catalyst selected from the group consisting of an alkali metal compound, an alkaline earth metal compound, triethylamine, dimethyloctylamine, a phosphazene compound, and a phosphazenium compound.

In addition, the first polyol composition may further include 0.0001 wt% to 15 wt% of a catalyst based on the total weight of the first polyol composition. For example, the content of the catalyst is 0.0001 wt% to 15 wt%, 0.0005 wt% to 13 wt%, 0.001 wt% to 13 wt%, 0.01 wt% to 10 wt% based on the total weight of the first polyol composition. % or from 0.1% to 8% by weight.

The first polyol composition may further include at least one selected from the group consisting of a foaming agent, a foam stabilizer, and a crosslinking agent.

The blowing agent may be at least one selected from the group consisting of water, methylene chloride, liquid carbon dioxide, n-pentane, cyclopentane, and hydrochlorofluorocarbon. For example, it is preferable to use water, but it is not limited thereto.

In addition, the first polyol composition may further include a foaming agent of 1 wt% to 20 wt% based on the total weight of the first polyol composition. For example, the content of the blowing agent is 1% to 20% by weight, 3% to 18% by weight, 5% to 18% by weight, 8% to 16% by weight based on the total weight of the first polyol composition. , 10% to 16% or 13% to 16% by weight. When the content of the foaming agent satisfies the above range, stability during the foaming process may be improved.

The foam control agent facilitates mixing of the composition and can improve stability, fluidity and uniformity during a foaming process using the same later. For example, a silicone foam control agent may be used, but is not limited thereto.

The first polyol composition may further include 1 wt% to 10 wt% of a foam stabilizer based on the total weight of the first polyol composition. For example, the amount of the foam stabilizer may be 1 wt% to 10 wt%, 1 wt% to 8 wt%, or 1.5 wt% to 6.5 wt% based on the total weight of the first polyol composition.

The crosslinking agent may be ethylene glycol, diethylene glycol, thiodiethylene glycol, neopentyl glycol, triethylene glycol, tetraethylene glycol, tripropylene glycol, diethanolamine, triethanolamine, butanediol or a mixture thereof, but is limited thereto It is not.

The first polyol composition may further include 1 wt% to 20 wt% of a crosslinking agent based on the total weight of the first polyol composition. For example, the content of the crosslinking agent is 1% to 20% by weight, 3% to 18% by weight, 5% to 18% by weight, or 7% to 16% by weight based on the total weight of the first polyol composition. can be When the content of the crosslinking agent satisfies the above range, not only durability of the first polyurethane layer can be improved, but also uniformity and stability can be improved by increasing the crosslinking density.

In addition, the first diisocyanate composition may include first diisocyanate. Specifically, the first diisocyanate is monomeric methylenediphenyl diisocyanate, polymeric methylenediphenyl diisocyanate, toluene diisocyanate, naphthalene diisocyanate, phenylene diisocyanate, dimethylbiphenyl diisocyanate, xylene diisocyanate, methylene diisocyanate isocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, norborene diisocyanate, or combinations thereof.

In addition, the first diisocyanate composition may include a trifunctional or higher functional aliphatic alcohol. The trifunctional or higher functional aliphatic alcohol may be at least one selected from the group consisting of glycerin, trimethylolpropane, erythritol, pentaerythritol, and sorbitol.

The first diisocyanate composition may include 1% to 30% by weight of a trifunctional or higher functional aliphatic alcohol based on the total weight of the first diisocyanate composition. For example, the content of the first diisocyanate is 1% to 30% by weight, 5% to 30% by weight, 10% to 28% by weight, 15% to 25% by weight or 18% to 23% by weight. may be %.

The weight ratio of the first polyol composition and the first diisocyanate composition may be 1: greater than 0.8 and less than 1.4. For example, the weight ratio of the first polyol composition and the first diocyanate composition may be 1: greater than 0.8 to less than 1.3, 1: 0.85 to 1.25, or 1: 0.9 to 1.2.

2nd polyurethane layer

The laminate according to the embodiment includes a second polyurethane layer on one side of the first polyurethane layer. Specifically, the second polyurethane layer is different from the first polyurethane layer.

The second polyurethane layer according to the embodiment may be a rim (RIM) foam or a mold foam.

More specifically, the laminate according to the embodiment includes a second polyurethane layer of rim foam or mold foam on one side of the first polyurethane layer of spray foam, thereby improving the buffering effect and anti-shrinkage effect as well as the heat insulation and insulation effect can make it

Specifically, the laminate includes a first polyurethane layer having an Asker C type surface hardness of 15 to 35 on one side of a base layer having barrier properties from the external environment, and the first polyurethane layer on one side of the first polyurethane layer. By including the second polyurethane layer having a higher Asker C type surface hardness than the first polyurethane layer on the first polyurethane layer, heat insulation and insulation effect are also excellent.

Asker C type surface hardness of the second polyurethane layer may be 35 to 100. For example, the Asker C type surface hardness of the second polyurethane layer may be 35 to 100, 50 to 90, or 55 to 85.

In addition, the free foam density of the second polyurethane layer may be 20 kg/m³ to 30 kg/m³. For example, the free foam density of the second polyurethane layer is 22 kg/m³ to 28 kg/m³, 20 kg/m³ to 24 kg/m³, 23 kg/m³ to 27 kg/m³ or 25 kg/m³ to 25 kg/m³. It may be 30 kg/m³.

The thickness of the second polyurethane layer may be thicker than that of the first polyurethane layer. Specifically, the thickness of the second polyurethane layer may be 35 mm to 100 mm. For example, the thickness of the second polyurethane layer may be 35 mm to 100 mm, 35 mm to 70 mm, 40 mm to 80 mm, 45 mm to 55 mm, or 70 mm to 100 mm. When the thickness of the second polyurethane layer satisfies the above range, heat insulation and insulation effects may be improved without deteriorating the buffering effect and the anti-shrinkage effect.

In addition, the thickness ratio of the first polyurethane layer and the second polyurethane layer is 1:5 to 20. For example, the thickness ratio of the first polyurethane layer and the second polyurethane layer is 1: 5 to 20, 1: 5 to 18, 1: 5 to 15, 1: 5 to 10, 1: 6 to 15, It may be 1:7 to 13, 1:8 to 12 or 1:9 to 11. When the thickness ratio of the first polyurethane layer and the second polyurethane layer satisfies the above range, it is possible to have excellent buffering effect and anti-deformation effect such as bending, and at the same time, excellent thermal insulation and insulating effect.

The second polyurethane layer according to the embodiment may be formed using the second polyol composition and the second diisocyanate.

The second polyol composition may include a trifunctional or higher functional aliphatic alcohol and an alkylene oxide including ethylene oxide or propylene oxide.

The trifunctional or higher functional aliphatic alcohol may be at least one selected from the group consisting of glycerin, trimethylolpropane, erythritol, pentaerythritol, and sorbitol. The glycerin may be preferable in terms of crosslinking degree improvement, but is not limited thereto.

In addition, the second polyol composition may include a tetrafunctional or higher functional aliphatic alcohol. Specifically, the second polyol composition may be a mixture of the trifunctional aliphatic alcohol and the tetrafunctional or higher functional aliphatic alcohol. More specifically, the trifunctional aliphatic alcohol may be glycerin, and the tetrafunctional or higher functional aliphatic alcohol may be sucrose. When a mixture of trifunctional and tetrafunctional or higher functional aliphatic alcohols is included, the surface hardness can be further improved.

The second polyol composition may be a mixture of polyol composition C and polyol composition D.

The polyol composition C may include 25 wt % to 75 wt % of the tetrafunctional or higher functional aliphatic alcohol and 25 wt % to 75 wt % of the alkylene oxide. For example, the polyol composition C may include 25 wt% to 75 wt%, 30 wt% to 70 wt%, 40 wt% to 60 wt%, or 45 wt% to 55 wt% of the tetrafunctional or higher functional aliphatic alcohol. 25 wt% to 75 wt%, 30 wt% to 70 wt%, 40 wt% to 60 wt%, or 45 wt% to 55 wt% of the alkylene oxide may be included.

The polyol composition D may include 5 wt% to 35 wt% of the tetrafunctional or higher functional aliphatic alcohol and 65 wt% to 95 wt% of the alkylene oxide. For example, 5% to 35% by weight, 8% to 30% by weight, 10% to 28% by weight, 12% to 20% by weight, or 12% to 18% by weight of the trifunctional or higher functional aliphatic alcohol 65 wt% to 95 wt%, 65 wt% to 90 wt%, 68 wt% to 85 wt%, 70 wt% to 80 wt%, or 72 wt% to 88 wt% of the alkylene oxide. can be included with

In addition, the second polyol composition may further include at least one selected from the group consisting of a catalyst, a foaming agent, a foam stabilizer, and a crosslinking agent. Descriptions of the catalyst, blowing agent, foam stabilizer and crosslinking agent are as described above.

The second diisocyanate is monomeric methylenediphenyl diisocyanate, polymeric methylenediphenyl diisocyanate, toluene diisocyanate, naphthalene diisocyanate, phenylene diisocyanate, dimethylbiphenyl diisocyanate, xylene diisocyanate, methylene diisocyanate, hexane It may be at least one selected from the group consisting of methylene diisocyanate, trimethylhexamethylene diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, and norborene diisocyanate.

In addition, the weight ratio of the second polyol composition and the second diisocyanate may be 1:0.7 to 1.3. For example, the weight ratio of the second polyol composition and the second diiocyanate composition may be 1:0.7 to 1.3, 1:0.75 to 1.3, or 1:0.8 to 1.25.

non-woven layer

According to another embodiment, the laminate may further include a nonwoven fabric layer interposed between the first polyurethane layer and the second polyurethane layer.

Specifically, since the nonwoven fabric conventionally used as a buffer is directly attached using an adhesive on a base layer of a metal material, deformation such as bending is likely to occur in the bonding process, and thus the quality is highly likely to be deteriorated. However, the laminate according to the embodiment includes a nonwoven fabric layer on one side of the first polyurethane layer having an Asker C type surface hardness of 15 to 35, thereby significantly reducing the defect rate that may occur during formation of the nonwoven fabric layer. More specifically, since the first polyurethane layer has an Asker C type surface hardness of 15 to 35, it has excellent viscoelasticity. Therefore, when the nonwoven fabric layer is formed on one side of the first polyurethane layer, deformation such as bending hardly occurs.

When the laminate according to the embodiment further includes a nonwoven fabric layer, it is possible to more effectively prevent mixing or absorption between the first polyurethane layer and the second polyurethane layer.

Manufacturing method of laminate

A method for manufacturing a laminate according to another embodiment includes forming a first polyurethane layer by spraying a first liquid and a second liquid on a substrate layer; and forming a second polyurethane layer on the first polyurethane layer, wherein the first polyurethane layer has an Asker C type surface hardness of 15 to 35.

First, the first polyurethane layer is formed by spraying the first liquid and the second liquid on the substrate layer.

Specifically, the forming of the first polyurethane layer may be performed using a spray device equipped with a two-liquid separation container capable of spraying a first liquid and a second liquid different from the first liquid, respectively. According to the embodiment, the first polyurethane layer may be formed by spraying the first liquid and the second liquid on the substrate layer using a spray device. Description of the base layer is as described above.

Therefore, the manufacturing method of the laminate according to the embodiment includes the step of forming the first polyurethane layer using the spray device, so that the conventional bonding and cutting processes are not required, and the manufacturing method is not limited to the size of the base layer. It can be formed quickly with a simple process, so it can be highly utilized and reduce process costs.

According to the embodiment, the first liquid and the second liquid may be injected at the same time. Alternatively, the first liquid and the second liquid may be sequentially injected. Specifically, after the first liquid is injected, the second liquid may be injected, and after the second liquid is injected, the first liquid may be injected.

Also, forming the first polyurethane layer according to the embodiment may include forming a core layer and forming a surface layer. Specifically, the forming of the core layer and the forming of the surface layer may be performed simultaneously.

More specifically, when the first liquid and the second liquid are simultaneously sprayed on the substrate layer, a core layer may be formed on the substrate layer and a surface layer may be formed on the core layer. While the first liquid and the second liquid are sprayed at the same time, the density of the surface layer in contact with the outside may be greater than the density of the core layer in contact with the base layer.

More specifically, when the first liquid and the second liquid are simultaneously sprayed on the substrate layer, a core layer may be formed on the substrate layer and a surface layer may be formed on the core layer. While the first liquid and the second liquid are sprayed at the same time, the density of the surface layer in contact with the outside may be greater than the density of the core layer in contact with the base layer.

In addition, since the first polyurethane layer is formed by a spray process, it is easy to form the first polyurethane layer with a thin thickness, and the process time is short, so that deformation of the base layer hardly occurs during formation of the first polyurethane layer. don't

The first liquid may be a first polyol composition, and the second liquid may be a first diisocyanate composition. Descriptions of the first polyol composition and the first diisocyanate composition are as described above.

An injection ratio of the first liquid and the second liquid may be 1:0.9 to 1.1. For example, the injection ratio of the first liquid and the second liquid may be 1:0.95 to 1.05 or 1:1. Specifically, the injection ratio of the first liquid and the second liquid may be performed by adjusting each injection speed. When the injection ratio of the first liquid and the second liquid satisfies the above range, the buffering effect and the anti-shrinkage effect may be maximized.

In addition, the spraying speed of the first liquid and the second liquid may be 0.5 kg/min to 3.0 kg/min, respectively. For example, the injection rates of the first liquid and the second liquid are 0.5 kg/min to 3.0 kg/min, 0.7 kg/min to 2.8 kg/min, 0.9 kg/min to 2.4 kg/min, and 1.0 kg, respectively. /min to 2.2 kg/min, 1.0 kg/min to 2.0 kg/min, 1.2 kg/min to 1.8 kg/min, 1.2 kg/min to 1.6 kg/min or 1.3 kg/min to 1.5 kg/min. .

The first liquid and the second liquid may be sprayed at an angle of 10° to 170°, respectively, with respect to the substrate layer. For example, the injection angle of the first liquid and the second liquid is 10 ° to 170 °, 15 ° to 165 °, 20 ° to 160 °, 30 ° to 120 °, 50 ° to 110 °, 65 °, respectively. to 105°, 80° to 100° or 85° to 100°.

The spraying speed and spraying angle of the first liquid and the second liquid may be the same as or different from each other, respectively, and the spraying speed and spraying angle of the first liquid and the second liquid satisfy the above range, respectively, so that the first polyurethane layer The foaming uniformity of can be further improved. In addition, when the spraying speed and the spraying angle of the first liquid and the second liquid are the same, foaming uniformity of the first polyurethane layer may be maximized, but is not limited thereto.

The step of forming the first polyurethane layer may be performed at 25 °C to 80 °C for 2 seconds to 40 seconds. For example, the forming step of the first polyurethane layer is 2 seconds to 30 seconds, 2 seconds to 10 seconds at 25 ℃ to 80 ℃, 25 ℃ to 50 ℃, 30 ℃ to 60 ℃ or 40 ℃ to 80 ℃, It may be performed for 5 to 30 seconds, 5 to 20 seconds, 10 seconds to 35 seconds or 10 seconds to 30 seconds.

Then, a second polyurethane layer is formed on the first polyurethane layer.

Specifically, a second polyurethane layer may be formed by coating a polyurethane composition on one surface of the first polyurethane layer. More specifically, it may be formed by disposing a mold having a certain shape on one surface of the first polyurethane layer, injecting a polyurethane composition, and then curing it. Description of the polyurethane composition is as described above.

Forming the second polyurethane layer may be performed at 25 °C to 85 °C for 1 minute to 5 minutes. For example, the step of forming the second polyurethane layer is performed at 25°C to 85°C, 25°C to 50°C, 30°C to 60°C, or 40°C to 80°C for 1 minute to 5 minutes or 2 minutes to 4 minutes. can be performed

The above will be described in more detail by the following examples. However, the following examples are only for illustrating the present invention, and the scope of the examples is not limited only to these.

[Example]

Preparation of the first polyol composition

Preparation Example 1-1

Prepare a four-necked flask equipped with a condenser, stirrer, and temperature controller on a heating mantle, and add 5% by weight of glycerin (GLY) and 95% by weight of propylene oxide (PO) as trifunctional or higher functional aliphatic alcohols to flask A to form a polyol composition A was made. Then, 10% by weight of dipropylene glycol (DPG) and 90% by weight of propylene oxide (PO) were added to flask B to prepare a polyol composition B.

After mixing the polyol compositions A and B, 2% by weight of Niax Catalyst A-1 (manufacturer: momentive) and 6% by weight of Niax Catalyst A-33 (manufacturer: momentive) were added as catalysts, and 7% by weight of water was added. did Thereafter, the first polyol composition was prepared by slowly dissolving at 70° C. at a stirring speed of 60 rpm to 80 rpm.

Preparation Example 1-2

A first polyol composition was prepared in the same manner as in Preparation Example 1-1, except that ethylene oxide was used instead of propylene oxide.

Preparation of the first diisocyanate composition

Preparation Example 2

A four-necked flask equipped with a condenser, a stirrer, and a temperature controller was prepared on a heating mantle, and 80% by weight of monomeric methylenediphenyl diisocyanate (MMDI) and 20% by weight of glycerin (Gly) were added to the flask as a first diisocyanate. Injected to prepare a first diisocyanate composition.

Preparation of polyurethane composition

Preparation Example 3

A polyol composition C was prepared by mixing 50% by weight of a mixture of sucrose and glycerin (Gly) and 50% by weight of propylene oxide (PO) as a tetrafunctional or higher functional aliphatic alcohol, and 15% by weight of glycerin (Gly) and propylene oxide (PO) 85% by weight was mixed to prepare a polyol composition D.

After mixing the polyol compositions C and D, 2% by weight of Polyolcat-8 (manufacturer: Evonik) and 0.3% by weight of Polyolcat-5 (manufacturer: Evonik) were added as catalysts, and a foam stabilizer (TEGOSTAB B-8462, manufacturer: Evonik), 2 wt% of water, and 15 wt% of cyclopentane as a foaming agent were added, followed by slow stirring at 25° C. at a stirring speed of 60 rpm to 80 rpm to prepare a second polyol composition.

Thereafter, 45% by weight of the second polyol composition and 55% by weight of polymeric methylenediphenyl diisocyanate (PMDI) (M-200, manufacturer: Kumho Mitsui) as a second diisocyanate were mixed at a temperature of 20 ° C. and A polyurethane composition was prepared by mixing at a pressure of 130 bar.

Manufacture of laminates

Example 1

(1) Preparation of the first polyurethane layer

A stainless steel plate serving as a substrate layer was prepared, and a spray device equipped with a two-liquid separation type container capable of spraying a first liquid and a second liquid different from the first liquid, respectively, was prepared. After putting the first polyol composition prepared in Preparation Example 1-1 as a first liquid into the two-liquid separation container and adding the first diisocyanate composition prepared in Preparation Example 2 as a second liquid, 1.4 kg/min A first polyurethane layer having a thickness of 5 mm was formed by simultaneously spraying at a spraying speed of and a spraying angle of 90° with respect to the substrate layer. At this time, the injection rate was performed at 1:1 by making the injection speed of the first liquid and the second liquid the same.

(2) Manufacture of the second polyurethane layer

After disposing a mold on the first polyurethane layer, injecting the polyurethane composition prepared in Preparation Example 3, and curing at 45 ° C. for 3 minutes, a laminate having a second polyurethane layer having a thickness of 50 mm is formed. was manufactured.

Example 2

A laminate was prepared in the same manner as in Example 1, except that the first polyol composition prepared in Preparation Example 1-2 was used.

[Experimental example]

Experimental Example 1: Surface Hardness

With respect to the first polyurethane layer prepared in step (1) of Examples 1 and 2, surface hardness was measured using an Asker C type durometer (manufacturer: Asker).

Experimental Example 2: Free Foam Density

The free foam density was measured by forming the first polyurethane layers of Examples 1 and 2 in an open plywood box having a width of 20 cm, a length of 20 cm and a height of 20 cm.

Specifically, using the spray device used in step (1) of Examples 1 and 2, spraying at a spraying speed of 1.4 kg/min and a spraying angle of 90° with respect to the open box, the first polyurethane layer After forming, it was cut into 100 mm wide, 100 mm long and 100 mm high, and the density was measured.

Experimental Example 3: Maximum volume reaching time (rising time)

When the first polyurethane layer of Examples 1 and 2 was formed in an open plywood box having a width of 20 cm, a length of 20 cm and a height of 20 cm, the time to reach the maximum volume was measured.

Specifically, using the spray device used in step (1) of Examples 1 and 2, spraying at a spraying speed of 1.4 kg/min and a spraying angle of 90° with respect to the open box to reach the highest volume. time was measured. At this time, the injection rate was performed at 1:1 by making the injection speed of the first liquid and the second liquid the same.

division surface hardness free foam density
(kg/m³) maximum volume
Reach time (seconds) Example 1 23 25.1 5 Example 2 25 26.3 6

As shown in Table 1, the surface hardness, free foam density, and time to reach the maximum volume of the first polyurethane layer of the laminates of Examples 1 and 2 all fell within preferred ranges.

Specifically, since the laminates of Examples 1 and 2 include the first polyurethane layer excellent in surface hardness, free foam density, and time to reach maximum volume, they are applied to various products that store contents, especially products that need to maintain low temperatures. It has excellent buffering and deformation prevention effects.

1: Refrigerator door
a: door inner plate
b: door shell
2: Laminate
100: base layer
200: first polyurethane layer
210: core layer
220: surface layer
300: second polyurethane layer

Claims (8)

A base layer, a first polyurethane layer, and a second polyurethane layer are sequentially laminated,
The Asker C type surface hardness of the first polyurethane layer is 15 to 35,
The first polyurethane layer is a spray foam, the second polyurethane layer is a rim foam or a mold foam,
The first polyurethane layer includes a core layer located on a surface facing the base layer and a surface layer located on a surface facing the second polyurethane layer,
A laminate wherein the density of the surface layer is greater than that of the core layer. delete According to claim 1,
A laminate that does not include a separate adhesive layer between the base layer and the first polyurethane layer. According to claim 1,
The Asker C type surface hardness of the second polyurethane layer is 35 to 100, the laminate. delete According to claim 1,
The thickness of the surface layer is 0.1 mm to 1 mm,
The thickness of the core layer is 1 mm to 3 mm, the laminate. According to claim 1,
The thickness of the first polyurethane layer is 1 mm to 10 mm,
The thickness ratio of the first polyurethane layer and the second polyurethane layer is 1: 5 to 20, the laminate. According to claim 1,
The free foam density of the first polyurethane layer is 15 kg / m³ to 35 kg / m³,
wherein the second polyurethane layer has a free foam density of 20 kg/m³ to 30 kg/m³.

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