KR20160005158A

KR20160005158A - Vacuum insulation having open cell polyurethane foam and method of manufacturing the same

Info

Publication number: KR20160005158A
Application number: KR1020140082930A
Authority: KR
Inventors: 한정필; 방손철; 황승석; 전승민
Original assignee: (주)엘지하우시스
Priority date: 2014-07-03
Filing date: 2014-07-03
Publication date: 2016-01-14

Abstract

Open cell polyurethane foam; And a jacket material for vacuum packaging the open cell polyurethane foam, wherein the vacuum insulation material has an average thickness of 9.5 mm or less.
Providing an open cell polyurethane foam; Wrapping the open cell polyurethane foam with a sheath material and vacuum packing to form a vacuum insulation material; And compressing the vacuum insulation material, wherein the compressed vacuum insulation material has an average thickness of 9.5 mm or less.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a vacuum insulator including an open-cell polyurethane foam and a method of manufacturing the vacuum insulator.

The present invention relates to a vacuum insulator including an open cell polyurethane foam and a method of manufacturing the same.

BACKGROUND ART Vacuum insulation panels are generally made of a composite plastic laminate film having excellent gas barrier properties. The open-celled plastic foam or inorganic material is contained as a core material in a bag made of a composite plastic laminate film, and the inside is decompressed. And heat-sealing the laminated portions of the layers.

The core material used for the vacuum insulation material is preferably an inorganic compound having a low thermal conductivity and a low gas generation. Particularly, it is known that a vacuum insulation material in which a laminated body of glass fibers is used as a core material has excellent heat insulating performance.

However, when a laminate of glass fibers is used as a core material, there is a limit to the application as a vacuum insulation material, such as deterioration of long-term durability, increase in manufacturing cost, lowering of molding characteristics, and the need for a substitute material is increasing .

One embodiment of the present invention provides a vacuum insulator comprising an open cell polyurethane foam and a sheathing material.

Another embodiment of the present invention provides a method of manufacturing the vacuum insulator.

In one embodiment of the invention, open cell polyurethane foam; And a jacket material for vacuum packaging the open cell polyurethane foam, wherein the vacuum insulation material has an average thickness of about 9.5 mm or less.

The standard deviation of the average thickness may be about 0.4 or less.

The open-cell polyurethane foam may have a density of from about 30 kg / m ³ to about 160 kg / m ³ .

The open-cell polyurethane foam may comprise bubbles having an average diameter of from about 50 [mu] m to about 300 [mu] m.

The open cell polyurethane foam may have an open cell ratio of about 90% or more.

The thickness of the open-cell polyurethane foam may be from about 5 mm to about 100 mm.

The sheathing material may include a laminated structure of a surface protective layer, a metal barrier layer, and an adhesive layer.

And may further include a getter material.

In another embodiment of the present invention, there is provided a method of making an open cell polyurethane foam, comprising: providing an open cell polyurethane foam; Wrapping the open cell polyurethane foam with a sheath material and vacuum packing to form a vacuum insulation material; And compressing the vacuum insulation material, wherein the compressed vacuum insulation material has an average thickness of about 9.5 mm or less.

The standard deviation of the average thickness of the squeezed vacuum insulation material may be about 0.4 or less.

The step of squeezing the vacuum insulation material may be performed at a pressure of about 2 Pa to about 40 Pa.

The thickness of the squeezed vacuum insulation material may be about 20% to about 80% of the thickness before squeezing the vacuum insulation material.

The step of compressing the vacuum insulation may comprise the step of removing residual material in the open cell polyurethane foam.

The residual material may be removed through the open cell of the open-cell polyurethane foam.

The vacuum insulator can realize an excellent thermal conductivity with a uniform surface.

Due to the vacuum insulator manufacturing method, it is possible to shorten the process time cycle required for manufacturing the vacuum insulator.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a SEM photograph of an open-cell polyurethane foam comprising an embodiment of the present invention. FIG.

Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited thereto, and the present invention is only defined by the scope of the following claims.

Vacuum insulation

In one embodiment of the invention, open cell polyurethane foam; And a jacket material for vacuum packaging the open cell polyurethane foam, wherein the vacuum insulation material has an average thickness of 9.5 mm or less.

Glass fiber and silica powder materials are widely used as core materials for vacuum insulation materials. However, since the glass fiber has a high shrinkage ratio of about 10% or more after vacuum molding due to its high porosity, when the vacuum insulation material is packaged with a sheath material, the sealing portion is excessively left and the vacuum insulation material product It was difficult to control the thickness.

In addition, the silica powder has a high weight, and dust is generated, so that there is a problem that the workability is lowered in the production of vacuum insulation.

Therefore, the vacuum insulator is excellent in workability because the open cell polyurethane foam is used as a core material for a vacuum insulator. The vacuum insulator is low in shrinkage ratio and lightweight as compared with a material for a core material used in general.

The open-cell polyurethane foam can be made through a foaming reaction in which polyol and isocyanate are used as the main raw materials, mixed through respective independent lines, and instantaneously mixed by a high-speed stirring rod.

The vacuum insulator can be formed by a vacuum insulator manufacturing method to be described later, the thickness of the produced vacuum insulator can be measured, and the average value of the thicknesses measured after the thickness measurement can be calculated. May be about 9.5 mm or less. The thickness of the vacuum insulation material is an average value calculated by measuring the maximum thickness of the vacuum insulation material including the irregularities formed in an arbitrary region of the vacuum insulation material. For example, the average thickness of the vacuum insulation material is about 8.5 mm or less, Or more.

In addition, the standard deviation of the average thickness may be about 0.4 or less. The standard deviation of the average thickness means the uniformity of the thickness of the vacuum insulation material produced, specifically, the uniformity of regular or irregular unevenness formed on the surface of the vacuum insulation material. The uniformity of the fine unevenness formed on the surface of the vacuum insulating material can be known through the standard deviation of the average thickness of the vacuum insulating material, and the larger the surface deviation value, the rougher the surface of the vacuum insulating material.

The standard deviation of the average thickness may be about 0.4 or less. The standard deviation is a numerical value showing the uniformity of the unevenness formed on the surface of the vacuum insulating material, and the standard deviation can be obtained by measuring the deviation with respect to the average thickness value of the vacuum insulating material.

In case of transporting vacuum insulation material, it is usually transported by using suction plate. When the standard deviation of average thickness is more than 0.4 because of unevenness of the surface of vacuum insulation material, the absorption state of the absorption plate is unstable and the vacuum insulation material may fall off during transportation Keeping the standard deviation of the average thickness below 0.4 is advantageous in that it is possible to minimize the phenomenon of dropping off during the transfer of the adsorption plate due to the unevenness formed on the surface of the vacuum insulation

The larger the standard deviation, the larger the difference between the minimum value and the maximum value of the height of the unevenness formed in the region of the vacuum insulating material. The smaller the standard deviation is, the smaller the difference between the minimum value and the maximum value of the height of the unevenness formed in the region of the vacuum insulating material The smaller the standard deviation, the more uniform the surface of the vacuum insulating material.

For example, if the standard deviation of the average thickness is greater than about 0.4, the average thickness of the vacuum insulation may be about 8.12 mm to about 9.23 mm.

If the standard deviation of the average thickness is more than about 0.4 mm, there is a risk of falling off when the adsorption plate is conveyed. By maintaining the above range, the surface irregularities can be minimized, and the defective rate during transportation can be reduced.

The open-cell polyurethane foam may have a density of from about 30 kg / m ³ to about 160 kg / m ³ . Typically, the density of the glass fibers used as the core for vacuum insulation is about 120 kg / m ³ to about 250 kg / m ^3, and the density of the fumed silica is about 120 kg / m ³ to about 180 kg / m ^3. Open cell polyurethane foam is advantageous in that when the produced vacuum insulation material is conveyed to the suction plate, the vacuum insulation material is reduced in weight, and the attracting plate dropout phenomenon is minimized.

In particular, when the vacuum insulation material produced by keeping the density of the open-cell polyurethane foam within the above range is transferred to the suction plate, the drop-off phenomenon is minimized and the vacuum insulation material can be easily attached to the end user.

The open-cell polyurethane foam may comprise bubbles having an average diameter of from about 50 [mu] m to about 300 [mu] m. The average diameter refers to a value obtained when the open cell polyurethane foam is cut based on the center of the bubble.

When the average diameter of the bubbles is less than about 50 탆, the initial thermal conductivity performance deteriorates. When the average diameter of the bubbles exceeds about 300 탆, the long-term durability may deteriorate. Thus, the initial durability performance and the long-term durability performance can be realized simultaneously.

The open cell polyurethane foam may have an opened cell content of about 90% or more. The open cell ratio means a fraction of open cells among cells formed in a unit area.

When the open cell ratio is less than the above range, the subsequent vacuum process time can be increased and the remaining substance such as formaldehyde, residual phenol, water, It remains inside the urethane foam and causes outgassing that occurs after forming the vacuum insulation.

The thickness of the open-cell polyurethane foam may be from about 5 mm to about 100 mm. The thickness of the open cell polyurethane foam before compression may differ from the thickness after compression by the compression of the vacuum insulation material to be described later. The thickness of the foam may be, for example, from about 3 mm to about 30 mm, after compression. It is advantageous in that the thickness of the above range is maintained to maintain a certain level of adhesion.

The sheathing material may include a laminated structure of a surface protective layer, a metal barrier layer, and an adhesive layer. By vacuum packing the open cell polyurethane foam with the sheathing material, the vacuum insulation material can have the best airtightness and long term durability.

The surface protection layer is a layer exposed to the outermost layer of the outer cover material, and may include a laminated structure of a polyethylene terephthalate film and a nylon film.

The metal barrier layer is for protecting the gas barrier and the open cell polyurethane foam, and aluminum foil is the most used. Since the aluminum is a metal material, there is a possibility that cracks are generated when folded. To prevent this, the surface protection layer is formed on the metal barrier layer.

If the degree of cracking in the metal barrier layer is severe enough to damage the surface protection layer, a vinyl resin layer may be coated on the surface protection layer.

The vinyl-based resin layer includes at least one selected from polyvinyl chloride (PVC), polyvinyl acetate (PVA), polyvinyl alcohol (PVAL), polyvinyl butalate (PVB), and polyvinylidene chloride .

The adhesive layer is a layer formed at the innermost angle of the envelope material, and functions as a layer which is thermally welded to each other by heat sealing to maintain a vacuum state.

The adhesive layer may be formed of a high density polyethylene (HDPE), a low density polyethylene (LDPE), a linear low density polyethylene (LLDPE), an unoriented polypropylene (CPP), a stretched polypropylene (OPP), a polyvinylidene chloride And a thermoplastic plastic film containing at least one selected from polyvinyl chloride (PVC), ethylene-vinyl acetate copolymer (EVA) and ethylene-vinyl alcohol copolymer (EVOH).

The vacuum insulator may further include a getter material. Gas and moisture may be generated inside the envelope by external temperature change, and the getter material may be included to prevent this. For example, it is possible to obtain a moisture absorbing performance of 25% or more by using a quicklime powder having a purity of 95% or more as the getter material and forming a pouch with a wrinkle paper and a polypropylene impregnated nonwoven fabric.

Method of manufacturing vacuum insulation

Another embodiment of the present invention is directed to a method of making a polyurethane foam, comprising: providing an open-cell polyurethane foam; Wrapping the open cell polyurethane foam with a sheath material and vacuum packing to form a vacuum insulation material; And compressing the vacuum insulation material, wherein the compressed vacuum insulation material has an average thickness of 9.5 mm or less.

Conventionally, after pressing a core material for a vacuum insulation material, the pressed core material is wrapped with a sheath material and vacuum-packed to form a vacuum insulation material. For example, when an open cell polyurethane foam is used as a core material for a vacuum insulator, and the foam is wrapped with a sheath material to form a vacuum insulation material, the foam in the foam is horizontally arranged by compression, The residual material in the foam could not be removed or took a long time to be removed.

Therefore, the vacuum insulator manufacturing method can remove the residual material through the open cell of the bubble when the bubble contained in the foam maintains a certain average diameter by pressing the vacuum insulator after manufacturing the vacuum insulator , And the removal time is also shortened, so that the process time cycle for manufacturing the vacuum insulation material can be minimized.

In addition, the vacuum insulation material produced by the above-described method maintains an average thickness of about 9.5 탆 or less, and the surface of the vacuum insulation material is relatively uniform, so that excellent thermal conductivity can be realized.

The standard deviation of the average thickness of the squeezed vacuum insulation material may be about 0.4 or less, and details are as described above.

The step of squeezing the vacuum insulation material may be performed at a pressure of about 2 Pa to about 40 Pa. Compression is performed at a high pressure in comparison with the case of pressing a core material for a vacuum insulator in the past, and it is advantageous in terms of moldability of the vacuum insulation material to perform compression at the pressure in the above range.

The thickness of the squeezed vacuum insulation material may be about 20% to about 80% of the thickness before squeezing the vacuum insulation material. The thickness of the vacuum insulation material may be different from the thickness of the vacuum insulation material before compression and the thickness of the vacuum insulation material after compression may be reduced by about 20% to about 80% have.

For example, the thickness of the vacuum insulation before compression may be about 18 mm to about 50 mm, and the vacuum insulation thickness after compression may be about 10 mm to 14.4 mm.

The step of compressing the vacuum insulation may comprise the step of removing residual material in the open cell polyurethane foam. By squeezing the vacuum insulation, the remaining material can be removed through the open cell of the open cell polyurethane foam, specifically through the open cell of the bubble containing the foam.

After the vacuum insulation material is manufactured, the open cell polyurethane foam is subjected to a compression process. Most of the cells of the open cell polyurethane foam are open cells, and the bubbles maintain an average diameter of a certain size, .

Hereinafter, specific embodiments of the present invention will be described. However, the embodiments described below are only intended to illustrate or explain the present invention, and thus the present invention should not be limited thereto.

< Example And Comparative Example >

Example One

An open-cell polyurethane foam having an average particle diameter of 150 μm, an open cell ratio of 95% and a density of 49 kg / m ³ was prepared in a size of 27 × 190 × 250 mm (thickness × width × length) (S1) .

Next, a jacket material formed of a structure of 12 占 퐉 polyvinylidene chloride (PVDC) / polyethylene terephthalate film (PET), 25 占 퐉 of nylon film, 7 占 퐉 of aluminum foil and 50 占 퐉 of a linear low density polyethylene (LLDPE) .

Thereafter, a getter material prepared by putting 25 g of calcium oxide (CaO) having a purity of 95% in a pouch was inserted into the surface of the foam.

Next, the open-cell polyurethane foam was inserted into a jacket material and sealed under a vacuum of 10 Pa to produce a vacuum insulation material (S2).

Thereafter, the prepared vacuum insulation material was pressed with a 12 mm spacer at a pressure of 2 Pa to remove all the remaining material through the open cell of the open cell polyurethane foam, and a vacuum insulation material having a thickness of 10 mm was produced S3).

Example 2

A vacuum insulator having a thickness of 10 mm was produced in the same manner as in Example 1, except that the vacuum insulator was pressed with a 10 mm spacer at a pressure of 6 Pa.

Example 3

A vacuum insulator having a thickness of 6 mm was prepared in the same manner as in Example 1, except that the vacuum insulator was pressed with an 8 mm spacer at a pressure of 10 Pa.

Comparative Example One

A vacuum insulator having a thickness of 12 mm was produced in the same manner as in Example 1 except that the step (S3) of pressing the vacuum insulator was not performed.

Comparative Example 2

An open-cell polyurethane foam having an average particle diameter of 120 μm, an open cell ratio of 80% and a density of 49 kg / m ³ was prepared in a size of 12 × 190 × 250 mm (thickness × width × length) (S1) .

Next, the open cell polyurethane foam was pressed at a pressure of 5 Pa to remove all the remaining material through the open cell of the open cell polyurethane foam (S3).

Next, the open-cell polyurethane foam was inserted into a jacket material and sealed under a vacuum of 10 Pa to produce a vacuum insulation material having a thickness of 10 mm (S2).

< Experimental Example > - Performance evaluation of vacuum insulation

1) Average thickness and standard deviation: The thickness of the vacuum insulation material was measured in any area of the above examples and comparative example of the vacuum insulation material, the average thickness was calculated, and then the standard deviation of the average thickness was calculated. The surface irregularity of the surface of the vacuum insulating material can be determined through the surface deviation value.

The standard deviation is an index indicating the uniformity of the object to be measured, and can be calculated through the following equation.

[expression]

S: standard deviation, Xi: thickness of vacuum insulation material,

X bar: average thickness of vacuum insulation, n: integer

2) Cycle time: The time required for the manufacturing process (S1->S2-> S3) of the above example, the time required for the manufacturing process (S1-S2) > S2), and the cycle time was calculated from the average value of the time required for the above-described manufacturing process.

3) Thermal conductivity: The above examples and comparative examples were placed in a constant temperature chamber at 85 캜, and the thermal conductivity was measured after 3 months. HC-074-200 (manufactured by EKO) thermal conductivity meter was used for the measurement of the thermal conductivity.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Average thickness (mm) 8.21 8.12 8.06 9.62 9.79 Standard Deviation 0.26 0.24 0.22 0.29 0.43

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Cycle time (sec) 156 146 149 152 182

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Thermal conductivity (W / mK) 0.0047 0.0039 0.0033 0.0065 0.0055

Examples 1 to 3 are vacuum insulation materials formed by squeezing the produced vacuum insulation materials, Comparative Example 1 is vacuum insulation materials not subjected to a compression process, and Comparative Example 2 is vacuum insulation materials produced by compression molding of open cell polyurethane foam.

At this time, the Examples 1 to 3 had lower average thicknesses and standard deviations than those of Comparative Examples 1 and 2, and the thermal conductivity was also excellent.

On the other hand, the comparative example 1 did not pass the compression step itself, and thus the cycle time for producing the vacuum insulation material was small. However, since the cycle time of Examples 1 to 3 was smaller than that of Comparative Example 2, when the produced vacuum insulation material was compressed, a large amount of residual material in the open-cell polyurethane foam was rapidly removed to shorten the cycle time .

Claims

Open cell polyurethane foam; And
And a cover material for vacuum-packaging the open-cell polyurethane foam,
Having an average thickness of 9.5 mm or less
Vacuum insulation.

The method according to claim 1,
The standard deviation of the average thickness is 0.4 or less
Vacuum insulation.

The method according to claim 1,
The open-cell polyurethane foam has a density of 30 kg / m ³ to 160 kg / m ³
Vacuum insulation.

The method according to claim 1,
Wherein the open cell polyurethane foam comprises bubbles having an average diameter of from 50 [mu] m to 300 [mu] m
Vacuum insulation.

The method according to claim 1,
When the open cell polyurethane foam has an open cell ratio of 90% or more
Vacuum insulation.

The method according to claim 1,
The thickness of the open-cell polyurethane foam is 5 mm to 100 mm
Vacuum insulation.

The method according to claim 1,
Wherein the sheathing material comprises a laminated structure of a surface protective layer, a metal barrier layer and an adhesive layer
Vacuum insulation.

The method according to claim 1,
Further comprising a getter material
Vacuum insulation.

Providing an open cell polyurethane foam;
Wrapping the open cell polyurethane foam with a sheath material and vacuum packing to form a vacuum insulation material; And
And pressing the vacuum insulation material,
The average thickness of the squeezed vacuum insulator is 9.5 mm or less
Method of manufacturing vacuum insulation.

10. The method of claim 9,
The standard deviation of the average thickness of the squeezed vacuum insulation material is 0.4 or less
Vacuum insulation.

10. The method of claim 9,
The step of pressing the vacuum insulation material is performed at a pressure of 2Pa to 40Pa
Method of manufacturing vacuum insulation.

10. The method of claim 9,
The thickness of the squeezed vacuum insulation material is 20% to 80% of the thickness before squeezing the vacuum insulation material
Method of manufacturing vacuum insulation.

10. The method of claim 9,
Wherein compressing the vacuum insulation comprises removing residual material in the open-cell polyurethane foam
Method of manufacturing vacuum insulation.

14. The method of claim 13,
The remaining material is removed through the open cell of the open-cell polyurethane foam
Method of manufacturing vacuum insulation.