WO2016093570A1 - Thin film polyurethane foam laminate and method for manufacturing same - Google Patents

Abstract

The present invention relates to a thin film polyurethane foam laminate and a method for manufacturing the same, the method comprising the steps of: (a) generating a foam composition of a gas-liquid mixture by feeding, as raw materials for a foam composition without using water, which is a chemical foaming agent, polyol, isocyanate, a moisture absorbent, micro hollow spheres, and an additive into a mixer, followed by mechanical foaming through a foaming gas; (b) supplying the mechanically foamed gas-liquid mixture from the mixer to a discharger connected to a connection tube; (c) coating the gas-liquid mixture, which is discharged from the discharger, on a first base film to a predetermined thickness; (d) attaching a second base film on a surface of the gas-liquid mixture coated on the first base film, and hardening the resultant structure with the attached second base film in a thermal hardener, thereby generating a polyurethane foam layer; (e) releasing the second base film after the completing of the thermal hardening step, coating a coating agent on a surface of the hardened polyurethane foam layer, and then laminating a coating film using a UV hardener; and (f) collecting the polyurethane foam laminate with the laminated coating film, using a collection roll. A low-density polyurethane foam laminate having a very thin thickness, which is required by a sealing member and a buffer applied to an electronic device, can be molded by: adding, in the foaming composition, zeolite as a moisture absorbent for absorbing residual moisture and micro hollow spheres causing less aggregation between cells; performing mechanical foaming using nitrogen as a foaming gas; and then performing thermal hardening.

Description

Thin Polyurethane Foam Laminates and Manufacturing Method Thereof

The present invention relates to a thin film polyurethane foam laminate and a method of manufacturing the same, which can be applied as a cushioning material and a sealing material used in an electronic device such as a smart phone, and more particularly, foaming during molding of the polyurethane foam laminate. A water absorbent is added to the composition to suppress chemical foaming reaction due to residual moisture contained in the foaming composition, and instead, the cell structure formed inside the foam stack by the chemical foaming reaction in the prior art has a small number of aggregation between cells. The present invention relates to a thin film polyurethane foam laminate and a method of manufacturing the same, which can form a very thin thickness polyurethane foam laminate at low density.

In general, electronic devices using a display such as a smartphone or a tablet PC use a cushioning material and a sealing material made of synthetic resin for the purpose of shock reduction, waterproofing, and dustproofing. In recent years, these electronic devices have gradually become smaller and slimmer. In accordance with the trend, these buffers / sealing materials used therein also have properties that can be thin and maintain sufficient buffering and sealing functions (specifically, a thickness of 200 μm or less, and a low density of 0.25 to 0.40 g / cm 3) And a low 25% CFD value of 0.18 to 0.36 kgf / cm 2 level).

In the past, olefin-based or acrylic-based materials were mainly used as a raw material for the buffer / sealing material used in such electronic devices. For these materials, the thickness strain at the quality inspection temperature (70 to 80 ° C.) is not less than 50%, and even at room temperature. Since there is a problem in that the thickness strain is very high when performing laminating or laminating the fabric itself, recently, a curable polyurethane material having a smaller thickness strain than the above materials has been attracting attention as disclosed in the following [Document 1].

The buffer and sealing material of the curable polyurethane material is a method of forming a bubble cell inside the foam laminate using carbon dioxide generated by the reaction of water and isocyanate contained in the foam composition as described in detail in [Document 1] (heating Since it is formed by chemical foaming in a state, the density varies according to the molding thickness (that is, the thicker the thickness, the lower the density).

However, the technique according to the following [Document 1] has the advantage of having a low density of 0.10 ~ 0.25g / ㎝ level, compared with the cushioning and sealing material of the curable polyurethane material previously developed, the molding thickness is 0.3 to 3mm level As described above, the thickness of the buffer material and the sealing material, which is recently required as described above, cannot be satisfied, so that the gap between the parts of the electronic device cannot be effectively filled.

In addition, in order to solve this problem by applying a general curable polyurethane manufacturing method to form a thickness of 150 ~ 200㎛ the required level, the foam laminate density is very high to the level of 0.7 to 0.8g / cm 3 (25% CFD value of 1 kgf / cm 2 or more) Since the cell structure formed inside the foam laminate is sparse, there is a problem in that the function as a cushioning material and a sealing material is hardly performed.

In addition, the [Document 1] is 2 to 4 times swelling foaming due to chemical foaming in the foam layer when the artificial skin film is laminated and cured, to prepare a thickness of 200㎛ coating thickness of the foam composition 50 ~ 80㎛ It should be applied on the base film at the level, but it is difficult to apply the thickness of the foam composition on the base film to 80 μm or less by conventional coating techniques (roll coater, comma coater, knife coater), and further, the coating thickness of the foam composition is 30 to 50 There is an unsuitable problem in the method for producing a polyurethane foam laminate having a molding thickness of 100 to 150 μm, which is obtained by coating at a μm level.

This problem is due to the use of water contained in the foaming composition as a chemical blowing agent, and thus, the following [1] and the like to solve the problem, while maintaining a thin thickness of the level required by the recently developed electronic devices, There is an urgent need for a new method of production for molding curable polyurethane foam laminates having physical properties that can provide cushioning and sealing functions.

[Document 1] Korean Patent Registration No. 10-1149013 (2012.05.24. Notification)

An object of the present invention is to add a water absorbent to the foam composition during molding of the polyurethane foam laminate to suppress the chemical foaming reaction by the residual moisture contained in the foaming composition, instead of foam lamination by the chemical foaming reaction in the prior art The present invention provides a thin-film polyurethane foam laminate and a method of manufacturing the same, which can form a very thin thickness polyurethane foam laminate at low density by replacing a cell structure formed inside the sieve with a micro hollow sphere having a low inter-cell aggregation phenomenon.

In addition, another object of the present invention is to produce a thin film polyurethane foam laminate having physical properties that can be suitably used as a sealing material and a cushioning material for electronic devices such as smartphones, tablet PCs, and the like, in particular polyurethane foam lamination The sieve has a thickness of 100 to 200 µm, a density of 0.25 to 0.40 g / cm 3, 25% CFD of 0.18 to 0.36 kgf / cm 2, and a cell average size of 40 to 60 µm.

Such a method for producing a thin film polyurethane foam laminate according to an embodiment of the present invention, (a) as a raw material of the foam composition without using water as a chemical blowing agent, polyol, isocyanate, water absorbent, micro hollow spheres, and additives Introducing into the mixer and mechanically foaming with the gas for blistering to produce a foaming composition of the gas-liquid mixture; (b) feeding the mechanically foamed gas-liquid mixture in the mixer to an ejector connected to a connecting tube; (c) applying the gas-liquid mixture discharged from the ejector to a first thickness on a first substrate film; (d) attaching a second substrate film to the surface of the gas-liquid mixture applied on the first substrate film, and hardening in a thermosetting part with the second substrate film attached thereto to generate a polyurethane foam layer; (e) releasing the second base film after completing the thermal curing step, applying a coating agent to the surface of the cured polyurethane foam layer, and then laminating the coating film using a UV curing unit; And (f) recovering the polyurethane foam laminate in which the coating film is laminated, using a recovery roll.

In addition, the micro-spheres are artificial bubbles, the cell size 20 ~ 80㎛, specific gravity 0.02 ~ 0.20g / cm 3, 0.1 to 2 parts by weight is added to 100 parts by weight of the polyol.

In addition, the moisture absorbent is added 0.5 to 5 parts by weight of zeolite to 100 parts by weight of the polyol.

In addition, the first base film and the second base film is selected from polyethylene terephthalate (PET), black polyethylene terephthalate (PET) for shading, Teflon belt, release polyethylene terephthalate (PET), non-woven fabric for electron shielding, acrylic adhesive tape At least one of which is used is used as a material of a base film.

In addition, the (a) the polyol used in the foaming composition production step includes polyol A, polyol B and polyol C, the polyol A is a polyester-based molecular weight 2000 ~ 4000, functional group 20-40 (Triol-based or Diol-based) ), Ethylene oxide content of 15 to 25%, the polyol B is a polyester-based molecular weight 400-800, functional groups 200-400 (Triol-based or Diol-based), the polyol C is a caprolactone-based molecular weight 400-800, Functional group 200 ~ 400 (Triol-based or Diol-based), the polyol A, polyol B, polyol C is 50 parts by weight, 30 parts by weight, 25 parts by weight are mixed.

In addition, the additive (a) used in producing the foaming composition includes a crosslinking agent, a foam stabilizer, a catalyst, and a carbon-based pigment, the crosslinking agent is 5 parts by weight in 100 parts by weight of the polyol, and the foam stabilizer is polydimethylsiloxane. 2 parts by weight of the polyol, the catalyst is an amine catalyst (0.03 parts by weight of 100 parts by weight of the polyol) and nickel acetate (1.5 parts by weight of 100 parts by weight of the polyol) in combination, the carbon pigment Is 0.5 part by weight of 100 parts by weight of the polyol.

As described above, the thin polyurethane foam laminate according to the present invention has a thickness of 100 to 200 μm, a density of 0.25 to 0.40 g / cm 3, and 25% CFD of 0.18 to 0.36 kgf / cm 2 after curing by mixing a polyol, a moisture absorbent, and a micro hollow sphere. And cell average size of 40 to 60 µm.

Thin film polyurethane foam laminate according to the present invention and a method for manufacturing the same by adding zeolite as a moisture absorbent to the foam composition to adsorb the residual moisture contained in the foam composition to suppress the chemical foaming reaction due to the residual moisture, Very small thicknesses of polyurethane foam laminates can be molded at low density by adding small microspheres.

In addition, according to the present invention to manufacture a thin film polyurethane foam laminate which can be usefully used as a sealing material and a shock absorbing sealing material or a shock absorbing material to fill the gap between the highly integrated parts inside the case of the electronic device using the display, such as a smartphone. In particular, the polyurethane foam laminate has a physical property of 100 ~ 200㎛ thickness, density 0.25 ~ 0.40g / ㎠, 25% CFD 0.18 ~ 0.36kgf / ㎠, cell average size 40 ~ 60㎛.

1 is a perspective view of a thin film polyurethane foam laminate according to the present invention.

2 is a view showing a manufacturing process of a thin film polyurethane foam laminate according to the present invention.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

As shown in FIG. 1, the thin film polyurethane foam laminate manufactured according to the present invention includes a first base film 21 and a polyurethane foam layer 31 formed on an upper surface of the first base film 21. And a coating layer 81 coated on the surface of the polyurethane foam layer 31.

In addition, the thin film polyurethane foam laminate according to the present invention is mechanically foaming the foam composition (that is, the raw material composition for forming the polyurethane foam laminate) is configured as described later after the first base film 21 It is obtained by a manufacturing process of applying a predetermined thickness above and then thermosetting.

In this case, the term "mechanical foaming" in the entire specification and claims is to stir the mixture of the foaming composition by using a mechanical stirring device or the like (by supplying polyol and isocyanate to the mixing header and mixing nitrogen for mixing). Process) means that bubbles (or bubbles) are generated in the foam composition.

In the case of the present invention, the foam composition includes polyol and isocyanate, which are raw materials for synthesizing polyurethane, and other additives including a surfactant, a catalyst, a carbon-based pigment, a water absorbent, and a microsphere.

In addition, the polyol may be used by mixing a polyester-based and caprolactone-based, in the present embodiment is configured by mixing polyol A, polyol B, and polyol C.

In this case, the polyol A is a polyester-based molecular weight 2000 ~ 4000, functional groups 20-40 (Triol-based or Diol-based), ethylene oxide content 15-25%, polyol B is a polyester-based molecular weight 400-800, functional group 200 It is ˜400 (Triol-based or Diol-based), the polyol C is a caprolactone polyol-based and has a molecular weight of 400-800, functional groups 200-400 (Triol-based or Diol-based).

In addition, the polyol is used by mixing in a ratio of 40 to 60 parts by weight of polyol A, 15 to 35 parts by weight of polyol B, and 15 to 35 parts by weight of polyol C. In this embodiment described below, 50 parts by weight of polyol A and polyol B 30 It used by mixing in the ratio of 25 weight part of polyol C and a weight part.

In addition, the isocyanate (MDI: Methylene Diphenyl Diisocyanate) may be at least one of aromatic, alicyclic, and aliphatic, bifunctional isocyanate having two isocyanate groups in one molecule, three or more isocyanate groups in one molecule Trifunctional or higher isocyanate having, or a combination thereof.

In addition, the isocyanate may be used alone or mixed at a constant ratio according to product characteristics (hardness, density, and reactivity) of the polymeric MDI, Monomeric MDI, Modified MDI, the index (NCO group required compared to the OH group) is It is preferable to set it as 90-110.

In addition, the isocyanate is preferably used by mixing in a ratio of 25 to 40 parts by weight with respect to 100 parts by weight of polyol. In this embodiment described later, a mixture is used in an amount of 35 parts by weight with respect to 100 parts by weight of polyol.

In addition, if necessary, a crosslinking agent may be further added during the synthesis of polyurethane, but if the crosslinking agent is not mixed, the crosslinking density becomes coarse, and thus the heat resistance of the polyurethane foam is deteriorated.

At this time, the crosslinking agent may be used 1,4BD (1,4 butanediol), TEG (triethylene glycol), TPG (tripropylene glycol), DEG (diethylene glycol), etc., excellent reactivity and not affected by moisture It is preferable to use TEG, which can improve physical properties because of its low freezing point.

In addition, the addition amount of the crosslinking agent is preferably 2 to 7 parts by weight with respect to 100 parts by weight of the polyol, in the case of this embodiment described later participated in a ratio of 5 parts by weight with respect to 100 parts by weight of the polyol.

On the other hand, the foam stabilizer is a non-ionic surfactant such as polydimethylsiloxane or polyoxyalkylene is suitable for stabilizing the bubble cell, by using the non-ionic surfactant as a foam stabilizer It is possible to form a suitable bubble cell structure inside the polyurethane foam.

In addition, the foam stabilizer is preferably added in a ratio of 1 to 3 parts by weight with respect to 100 parts by weight of the polyol. In this embodiment described later, it is added in a ratio of 2 parts by weight to 100 parts by weight of the polyol.

The catalyst may be at least one of an amine catalyst or a metal catalyst (organic metal compound catalyst, nickel acetate), and the amine catalyst may be a monoamine compound, a diamine compound, a triamine compound, a polyamine compound, or a cyclic amine. It may be at least one kind selected from a compound, an alcohol amine compound and an ether amine compound.

 In addition, when the amine catalyst and the metal catalyst (nickel acetate) are used in combination, the amine catalyst is 0.03 parts by weight based on 100 parts by weight of the polyol, and the metal catalyst (nickel acetate) is contained in the proportion of 1.5 parts by weight based on 100 parts by weight of the polyol. It is preferable to add.

In addition, the carbon-based pigment is for coloring the polyurethane foam laminate is preferably added in a proportion of 0.5 parts by weight based on 100 parts by weight of the polyol.

On the other hand, the moisture absorbent serves to limit the expansion of the foam laminate by inhibiting the chemical foaming reaction due to the moisture remaining in the foam composition is configured as described above, the water absorbed in the polyol production or packaging step (polyol 100 Approximately 0.05 to 0.08 parts by weight relative to parts by weight) or absorb the water naturally produced during the blending of raw materials.

In the prior art, since foaming cells are formed inside the polyurethane foam laminate using water (water) contained in the foaming composition as a chemical blowing agent, in order to maintain low density, foam lamination as described in [Document 1] above is performed. In the present embodiment, there was an inevitable problem in that the thickness was increased during the sieving process. In this embodiment, in order to solve the problem, polyurethane foam is laminated by suppressing unnecessary chemical foaming by removing moisture contained in the foaming composition in advance using a moisture absorbent. The technical feature is that the thickness of the sieve is formed very thinly below the recently required level of 200 μm.

To this end, zeolite was used as the water absorbent in this embodiment. Specifically, the brand name Molecular sieve was used as a synthetic zeolite manufactured by Linde, USA.

The molecular sieve is manufactured in a powder form and blended, and has a high adsorption capacity for liquid water or steam. In addition, the molecular sieve powder has 3A, 4A, 5A, etc., depending on the pore size, has a constant pore size, is useful for adsorption of specific molecules, high catalytic properties and most of the fine pore structure has a low relative humidity Or high adsorption capacity in low temperature environment.

The moisture absorbent (that is, the molecular weight powder in the present embodiment) is preferably added in a ratio of 0.5 to 5 parts by weight with respect to 100 parts by weight of the polyol, in the case of the present embodiment to be described later 3 parts by weight based on 100 parts by weight of polyol Add in negative proportions.

On the other hand, when the moisture contained in the foam composition is removed, the thickness of the foam laminate may satisfy the required level of 200 μm or less, but the density is low because the content of bubble cells contained in the foam laminate is small. There arises a problem that the increase can not be performed as a cushioning material and a sealing material.

Therefore, in the present invention, in order to replace the cell structure by chemical foaming according to the prior art, by adding a micro-hollow sphere and a foaming gas to the foam composition, while the polyurethane foam laminate satisfies the recently required thickness level of 200㎛ or less Another technical feature is to have low density properties of 0.25 to 0.40 g / cm 3 that can provide sufficient cushioning and sealing.

In this case, the micro hollow sphere uses a cell size of 20 to 80 μm and a specific gravity of 0.02 to 0.20 g / cm 3 as a hollow sphere having a hollow size, and preferably has a density of 0.04 g / cm 3 and a cell size of A hollow sphere of 40 μm is used.

In addition, the material of the microspheres is made of plastic, glass, and the like, which is used by synthesizing an acrylic copolymer, a glass-based acrylic copolymer, and a polyvinyldine chloride.

As such, by adding the microspheres inside the foaming composition, not only the density of the foam laminate can be maintained at a low density, but also the artificially processed microspheres have a very small property of being entangled with each other to maintain independent bubbles ( That is, the surface smoothness of the polyurethane foam foam can also be stabilized due to the characteristics of the micro-hollow spheres with little aggregation between cells.

That is, when bubbles are formed depending only on the gas (nitrogen), which will be described later, a phenomenon in which the gas-liquid mixture is partially retained is caught by a coternal for adjusting the thickness in the process of transferring the foam composition, which is a gas-liquid mixture, to the substrate film. When this occurs, the large surface of the foam laminate is deteriorated by generating bubbles of large size due to the strong aggregation phenomenon between the bubble cells.

However, when the micro hollow spheres are added as in the present invention, even if some of the gas-liquid mixture stays by the cotternal during the transfer process, aggregation between bubble cells is remarkably decreased, so that the cell size is stable and the cells are small and uniformly produced even after thermal curing. This makes it possible to increase the surface smoothness of the foam laminate.

When the micro hollow spheres are added without generating bubbles through chemical foaming with water contained in the foaming composition as in the present invention, the average size of the cell can be maintained stably and uniformly at a level of 40 to 60 μm, and furthermore, Since the ratio of free bubbles inside the foam laminate increases, it can be usefully used as a waterproof foam having excellent waterproof function.

In addition, the foaming gas is a gas for mixing the foam composition in the mechanical foaming step to form a bubble cell inside the foam laminate does not adversely affect the reaction between the polyol and the isocyanate (in this embodiment, nitrogen as an example) Preference is given to using.

At this time, it is preferable to include the said foaming base so that the mixing ratio in a polyurethane raw material may be 30-75% of the volume ratio with respect to the total volume of foaming composition.

The manufacturing process of the thin film polyurethane foam laminate according to the present invention using the foaming composition configured as described above will be described with reference to the drawings.

The polyurethane foam laminated body manufacturing apparatus 1 shown in FIG. 2 is the mixer 10, the ejector 13, the 1st winding roll 20, the pick-up roll 30, the thermosetting part 50, and the coating part 70. ), UV curing unit 80, the first recovery roll (90).

In addition, the polyurethane foam laminate manufacturing apparatus 1 includes a second winding roll 40 and a second roll for laminating and releasing the second base film 41 as an artificial skin film on the gas-liquid mixture to enter the thermosetting process. It is configured to further include a second recovery roll (60).

In addition, if necessary, the polyurethane foam laminate production apparatus 1 has a thickness adjusting member 14 behind the ejector 13 to limit the thickness of the gas-liquid mixture applied on the first base film 21. May be additionally installed.

When the raw material for producing the polyurethane foam laminate according to the present invention is introduced into the mixer 10, mechanical mixing is also performed together with their mixing in the mixer 10 to produce a foaming composition (ie, a raw material composition). do.

The foaming composition prepared as described above is supplied to an ejector 13 to be described later. For this purpose, a connecting pipe 11 is installed between the mixer 10 and the ejector 13, and in the middle of the connecting pipe 11. The control valve 12 is provided.

Accordingly, as the opening degree of the control valve 12 is manipulated, the appropriate amount of the foaming composition that has undergone the mechanical foaming process in the mixer 10 is supplied to the ejector 13 to be described later through the connecting pipe 11. The specific gravity of the foaming composition in the gas-liquid mixed state is approximately 0.25-0.40 g / ml.

 The ejector 13 discharges the foaming composition in a gas-liquid mixed state supplied from the mixer 10 onto the first base film 21 which is transported at a constant speed by the first winding roll 20 and the pickup roll 30. To perform the function of application.

The ejector 13 may be configured using a conventional ejection device such as a nozzle as in the prior art, but in the embodiment of the present invention to prevent the phenomenon that a portion of the foam composition stays at the front end of the coater as in the prior art. As an example, the ejector 13 was configured as a slot die so as to adjust the thickness of the coating liquid applied on the first base film 21 to a desired level.

Meanwhile, the second base film 41 supplied from the second winding roll 40 is transported at a predetermined interval from the first base film 21 and collected in the second recovery roll 60. In order to prevent the air bubbles contained in the polyurethane foam layer applied to 21) from being discharged, it is transported for a predetermined period while being attached to the surface of the polyurethane foam layer.

The first base film 21 and the second base film 41 are polyethylene terephthalate (PET), light-shielding black polyethylene terephthalate (PET), teflon belt, release polyethylene terephthalate (PET), non-woven fabric for electron shielding, At least one selected from the group of acrylic adhesive tape may be used as the material of the base film.

In the present embodiment, a release polyethylene terephthalate was used as the material of the second base film 41 to make the surface of the polyurethane foam laminate flat during release.

Meanwhile, the gas-liquid mixture discharged from the ejector 13 and applied onto the first base film 21 is cured in the process of passing through the thermosetting part 50 to form a polyurethane foam layer. The thermosetting unit 50 is divided into three process sections that are independent by the first to third heating units 51 to 53.

The first heating unit 51 is a free heating zone in which the raw material reaction starts, and the temperature range of this section is 60 to 80 ° C. The second heating unit 52 is a concentrated curing section, the temperature range is 100 ~ 130 ℃.

When the temperature suddenly comes out at room temperature, the surface of the polyurethane foam layer cured through the first and second heating parts 51 and 52 may be unevenly formed. In order to solve this problem, the third heating unit 53 is a section for lowering a high-temperature atmosphere, and the temperature range of the section is 60 to 80 ° C.

At this time, the second base film 41 which is attached to the polyurethane foam layer after passing through the thermosetting part 50 is released, and the released second base film 41 is recovered to the second recovery roll 60.

In addition, since the surface of the polyurethane foam cured in the thermosetting part 50 is non-slip due to strong self-adhesiveness and Tacky, a slip, semi-slip coating agent is used depending on the intended use for surface treatment in the coating part 70. To coat the surface of the polyurethane foam layer.

Then, the UV curing unit 80 cures the coating applied to the surface of the polyurethane foam layer using ultraviolet light having a very short wavelength, and the coating film 81 on the surface of the polyurethane foam layer while passing through the UV curing unit 80. ) Are stacked. After that, the polyurethane foam laminate in which the coating film 81 is laminated is recovered to the first recovery roll 90.

The first base film 21 manufactured as described above may have a thickness of 15 μm, the coating film 81 may have a thickness of 5 μm, and the polyurethane foam layer 31 may have a thickness of 80 μm to 180 μm. It has physical properties of thickness 100-200 μm, density 0.25-0.40 g / cm 3, 25% CFD 0.18-0.36 kgf / cm 2, and cell average size 40-60 μm.

In order to evaluate the physical properties of the polyurethane foam laminate according to the present invention produced by the above-described method, the physical properties of six examples prepared according to the present invention and four comparative examples prepared according to the prior art were tested. The results are shown in Table 1.

The test conditions commonly applied to the six examples and the four comparative examples to which the comparative test paper was applied, and the test conditions individually applied to each are as follows.

<Conditions Commonly Applied to Each Example and Comparative Example>

-Polyol A: Polyester series, molecular weight 2000 ~ 4000, functional group 20 ~ 40 (Triol type or Diol type), ethylene oxide content 15 ~ 25%, added in the proportion of 50 parts by weight.

-Polyol B: Polyester series, molecular weight 400-800, functional group 200-400 (Triol-based or Diol-based), added in a proportion of 30 parts by weight based on 100 parts by weight of polyol.

-Polyol C: Caprolactone-based molecular weight 400-800, functional groups 200-400 (Triol-based or Diol-based), added in a proportion of 25 parts by weight based on 100 parts by weight of polyol.

Isocyanate: Polymeric MDI was used and added at a rate of 40 parts by weight based on 100 parts by weight of polyol.

Foam stabilizer: Polydimethylsiloxane was used and added in a ratio of 2 parts by weight based on 100 parts by weight of polyol.

Catalyst: A mixture of an amine catalyst (0.03 parts by weight based on 100 parts by weight of polyol) and nickel acetate (1.5 parts by weight based on 100 parts by weight of polyol) are used.

Carbon-based pigments: 0.5 parts by weight based on 100 parts by weight of polyol.

Example 1

With respect to the foaming composition according to the common conditions, the residual moisture content is 0.05 parts by weight with respect to 100 parts by weight of the polyol, 3 parts by weight with respect to 100 parts by weight of the zeolite (molecular sieve powder), and 100 parts by weight with the micro hollow spheres. 0.3 parts by weight, the coating thickness of the gas-liquid mixture to be applied by the ejector 13 is 80㎛, the nitrogen for foaming is 60% of the mixing ratio in the polyurethane raw material, artificial skin film to the second substrate film 41 To prepare polyurethane foam laminates.

Example 2

A polyurethane foam laminate was manufactured under the same conditions as in Example 1, but the coating thickness of the gas-liquid mixture applied by the ejector 13 was 100 μm.

Example 3

A polyurethane foam laminate was manufactured under the same conditions as in Example 1, except that the coating thickness of the gas-liquid mixture applied by the ejector 13 was 100 μm, and the mixing ratio of the nitrogen for the preparation was 65%.

Example 4

A polyurethane foam laminate was manufactured under the same conditions as in Example 1, except that the coating thickness of the gas-liquid mixture applied by the ejector 13 was 120 µm and the mixing ratio of the nitrogen for the preparation was 65%.

Example 5

A polyurethane foam laminate was prepared under the same conditions as in Example 1, except that the coating thickness of the gas-liquid mixture applied by the ejector 13 was 150 μm, and the mixing ratio of the nitrogen for the preparation was 67%.

Example 6

A polyurethane foam laminate was manufactured under the same conditions as in Example 1, except that the coating thickness of the gas-liquid mixture applied by the ejector 13 was 200 μm, and the mixing ratio of the nitrogen for the preparation was 75%.

(Comparative Example 1)

Among the conditions of Example 1, zeolite and micro hollow spheres were not used, and the residual moisture content of the foaming composition was 0.05 parts by weight based on 100 parts by weight of polyol, and the coating thickness of the gas-liquid mixture applied by the ejector 13. Is 200 μm, the nitrogen for the preparation is a polyurethane foam laminate using a second base film 41 as a blending ratio of 75% to the polyurethane raw material, artificial skin film.

(Comparative Example 2)

A polyurethane foam laminate was prepared under the same conditions as in Comparative Example 1, but the residual moisture content of the foam composition was 0.3 parts by weight based on 100 parts by weight of the polyol.

(Comparative Example 3)

A polyurethane foam laminate was manufactured under the same conditions as in Comparative Example 1, except that the microspheres were added at a ratio of 0.5 parts by weight per 100 parts by weight of the polyol, and the coating thickness of the gas-liquid mixture applied by the ejector 13 was 150 μm, Nitrogen for fabrication is a polyurethane foam laminate that is 50% blended to polyurethane raw materials, without the second base film 41 as an artificial skin film.

(Comparative Example 4)

A polyurethane foam laminate was manufactured under the same conditions as in Comparative Example 1, except that the coating thickness of the gas-liquid mixture applied by the ejector 13 was 150 μm, and the nitrogen for the foam was 30% mixed with the polyurethane raw material, and artificial skin. A polyurethane foam laminate was produced without using the second base film 41 as the film.

In the results of Table 1, the term "surface health bubble" means small bubbles bursting from the foam surface immediately after swelling to the maximum in the free-foaming foam, and the thin polyurethane foam laminate prepared for each case. The physical property evaluation of is as follows.

Density (g / cm 3): measured according to the method of ASTM D3574.

-25% C.F.D: Measured by Universal Testing Machine according to ASTM D3574 method.

-25% C.F.D: Measured by Universal Testing Machine according to ASTM D3574 method.

	Example 1	Example 2	Example 3	Example 4	Example 5	Example 6	Comparative Example 1	Comparative Example 2	Comparative Example 3	Comparative Example 4
Coating thickness applied to the base film (㎛)	80	100	100	120	150	200	200	200	150	150
Mixing ratio of crude nitrogen (volume;%)	60	60	65	65	67	75	75	75	50	30
Moisture content (part by weight)	0.05	0.05	0.05	0.05	0.05	0.05	0.05	0.3	0.05	0.05
Zeolite (parts by weight)	3	3	3	3	3	3	0	0	0	0
Micro hollow spheres (parts by weight)	0.3	0.3	0.3	0.3	0.3	0.3	0	0	0.5	0
2nd base film (artificial skin film)	○	○	○	○	○	○	○	○	×	×
Polyurethane foam thickness after curing (㎛)	80	100	100	120	150	200	300	400	150	150
Density (g / cm 3)	0.42	0.42	0.36	0.36	0.32	0.24	0.18	0.12	0.5	0.7
blowing magnification ± 5%	One	One	One	One	One	One	1.5	2	One	One
25% C.F.D (kgf / ㎠)	0.25	0.25	0.18	0.18	0.15	0.1	0.05	0.05	0.6	One
Compression set ( % )	<5	<5	<5	<5	<5	<5	<10	<10	<5	<5
Average cell size (μm)	40	50	50	50	60	60	80 ~ 150	80 ~ 150	50	100
Surface fitness bubble (health bubble) Inhibitory	◎	◎	◎	◎	◎	◎	○	○	◎	△

As shown in Table 1, the polyurethane foam laminates according to Examples 1 to 6 of the present invention are all physical properties (thin thickness of 200 μm or less, 0.25 or less) required as a cushioning material and sealing material of recent electronic devices. To a low density of 0.40 g / cm 3 and a low 25% CFD value of 0.18 to 0.36 kgf / cm 2).

Specifically, Examples 1 to 6 according to the present invention have a thickness of 80 to 200 μm, a density of 0.24 to 0.42 g / cm 3, 25% CFD of 0.1 to 0.25 kgf / cm 2, and an average cell size of 40 to 60 μm. It is shown that the polyurethane foam laminate according to the present invention has physical properties capable of providing sufficient buffering function and sealing function while having a remarkably thin thickness as compared with the prior art, and also has excellent health bubble suppression. Able to know.

 On the other hand, Comparative Examples 1 to 4 according to the prior art show that when the density is low, the thickness is thick and when the thickness is thin, the density is high, and overall satisfies the physical properties required as a cushioning material and sealing material of recent electronic devices. It can't be done.

In addition, looking at the effect of the water absorbent which is a technical feature applied in the present invention, in the case of Examples 1 to 6 of the present invention to suppress the chemical foaming by water by removing the water contained in the foam composition by the water absorbent All were found to meet the required thickness.

In particular, when comparing Example 6 and Comparative Example 1 prepared with the same coating thickness of 200㎛ and the same nitrogen mixing ratio of 75% Example 6 is the polyurethane foam thickness after curing is maintained at the same as before the curing 200㎛, Comparative Example 1 was found to be significantly thicker as compared to Example 6, the thickness after curing was 300㎛.

From these results, it can be seen directly that the thickness of the foam laminate can be remarkably thin when the moisture absorbent is used as in the present invention.

In addition, looking at the results of Comparative Example 1 and Comparative Example 2, except that the same conditions except for the water content, the more the amount of moisture contained in the foam composition appears to form a significantly thicker thickness of the foam laminate, the foam laminate It can be confirmed once again that the technical features of the present invention, to which the moisture absorbent is applied, in order to reduce the thickness of.

Furthermore, when the micro hollow spheres are applied as in the present invention, it can be seen that the thin foam laminate can be realized at low density.

Next, looking at the effect according to another micro-spheres of the technical features applied in the present invention, Example 1 to the embodiment of the present invention to suppress the chemical foaming by water by removing the water contained in the foam composition by the moisture absorbent In the case of Example 6, both the density and 25% CFD were found to satisfy the required levels, and it can be seen that the microspheres according to the present invention can effectively replace the chemical foaming effect according to the prior art.

In addition, in comparison with the results of Comparative Example 3 and Comparative Example 4, which do not commonly use an artificial skin film, they did not generate chemical foaming due to water, although the density was 0.5g / cm 3 and 0.7g / cm 3, respectively. The% CFD was 0.6kgf / cm 2 and 1kgf / cm 2, respectively, but it was high. However, in comparison with Comparative Example 4, the comparative example 3 using the micro hollow spheres showed that the effect of suppressing the surface health bubble was very effective.

From these results, it can be seen that in the case of the micro hollow spheres applied in the present invention, not only the effect of lowering the density of the foam laminate but also the effect of preventing the occurrence of surface health bubbles can be provided.

While specific embodiments of the present invention have been illustrated and described, the technical spirit of the present invention is not limited to the accompanying drawings and the above description, and various modifications can be made without departing from the spirit of the present invention. It will be apparent to those skilled in the art, and variations of this form will be regarded as belonging to the claims of the present invention without departing from the spirit of the present invention.

10: mixer 11: connector

12 control valve 13 ejector

20: first winding roll 21: the first substrate

30: pickup roll 31: polyurethane foam layer

40: the second winding roll 41: the second substrate

50: heat curing unit 51: the first heating unit

52: second heating portion 53: third heating portion

60: second recovery roll 70: coating part

80: UV curing unit 90: first recovery roll

The thin film polyurethane foam laminate according to the present invention and a method of manufacturing the same may be applied to the production of a cushioning material and a sealing material used in the interior of an electronic device such as a smartphone.

Claims (9)

1. (a) adding a polyol, isocyanate, water absorbent, micro-hollow spheres, and additives as a raw material of the foaming composition without using water as a chemical blowing agent into a mixer and mechanically foaming with a foaming gas to form a foaming composition of the gas-liquid mixture. step;

   (b) feeding the mechanically foamed gas-liquid mixture in the mixer to an ejector connected to a connecting tube;

   (c) applying the gas-liquid mixture discharged from the ejector to a first thickness on a first substrate film;

   (d) attaching a second substrate film to the surface of the gas-liquid mixture applied on the first substrate film, and hardening in a thermosetting part with the second substrate film attached thereto to generate a polyurethane foam layer;

   (e) releasing the second base film after completing the thermal curing step, applying a coating agent to the surface of the cured polyurethane foam layer, and then laminating the coating film using a UV curing unit; And

   (f) recovering the polyurethane foam laminate in which the coating film is laminated by using a recovery roll; a method of manufacturing a thin film polyurethane foam laminate comprising a.
2. The method of claim 1,

   The micro hollow sphere is an artificial bubble cell size of 20 ~ 80㎛, specific gravity 0.02 ~ 0.20g / cm 3, 0.1 to 2 parts by weight of the polyol is added to the manufacturing method of the thin film polyurethane foam laminate.
3. The method of claim 1,

   The water absorbent is a method for producing a thin film polyurethane foam laminate to add 0.5 to 5 parts by weight of zeolite to 100 parts by weight of the polyol.
4. The method of claim 1,

   The first base film and the second base film is selected from polyethylene terephthalate (PET), light-shielding black polyethylene terephthalate (PET), teflon belt, release polyethylene terephthalate (PET), electron shielding nonwoven fabric, acrylic adhesive cross-section tape The manufacturing method of the thin film polyurethane foam laminated body which uses at least one as a material of a base film.
5. The method of claim 1,

   The polyol used in the (a) foaming composition generation step comprises polyol A and polyol B and polyol C,

   The polyol A is a polyester-based molecular weight of 2000 to 4000, functional groups 20 to 40 (Triol or Diol), ethylene oxide content of 15 to 25%,

   The polyol B is a polyester-based molecular weight 400 ~ 800, functional groups 200 ~ 400 (Triol-based or Diol-based),

   The polyol C is a caprolactone-based molecular weight 400 ~ 800, functional groups 200 ~ 400 (Triol-based or Diol-based),

   The polyol A, polyol B, polyol C is a method for producing a thin film polyurethane foam laminate is mixed in a proportion of 50 parts by weight, 30 parts by weight, 25 parts by weight, respectively.
6. The method of claim 1,

   The additive used in the (a) foaming composition generation step includes a crosslinking agent, a foam stabilizer, a catalyst and a carbon-based pigment,

   The crosslinking agent is 5 parts by weight of 100 parts by weight of the polyol,

   The foam stabilizer is polydimethylsiloxane is 2 parts by weight of 100 parts by weight of the polyol,

   The catalyst is used in combination with an amine catalyst (0.03 parts by weight of 100 parts by weight of the polyol) and nickel acetate (1.5 parts by weight of 100 parts by weight of the polyol),

   The carbon-based pigment is 0.5 part by weight of 100 parts by weight of the polyol manufacturing method of the thin film polyurethane foam laminate.
7. A thin film polyurethane foam laminate produced by the method of any one of claims 1 to 6.
8. The method of claim 7, wherein

   The thin film polyurethane foam laminate has a thickness of 100 to 200 μm, a density of 0.25 to 0.40 g / cm 3, 25% CFD of 0.18 to 0.36 kgf / cm 2, and a cell average size of 40 to 60 μm. .
9. A raw material of a composition containing a polyol, an isocyanate, a moisture absorbent, a micro hollow sphere, and an additive and a gas for blister are mixed to form a foam composition of the gas-liquid mixture, and then the gas-liquid mixture is supplied onto the base film, and the gas-liquid mixture is thermoset. Method of producing a polyurethane foam laminate having a polyurethane foam layer produced by

   0.5 to 5 parts by weight of zeolite is added to 100 parts by weight of the polyol as the water absorbent contained in the raw material of the foaming composition,

   0.1 to 2 parts by weight of the microspheres are added to 100 parts by weight of the polyol,

   The polyurethane foam laminate has a thickness of 100 to 200 µm, a density of 0.25 to 0.40 g / cm 3, 25% CFD of 0.18 to 0.36 kgf / cm 2, and a cell average size of 40 to 60 µm. Method for producing a foam laminate.

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