CN101850639B - Polyurethane foam laminate, method for producing same, and gasket - Google Patents

Abstract

The invention relates to a polyurethane foam laminate, a method for producing the same and a gasket, specifically, a foam raw material containing polyisocyanate, polyol and flame retardant is mixed and stirred with gas to generate a gas-liquid mixture, then the gas-liquid mixture is supplied onto a resin film, and then the gas-liquid mixture is heated to mix the gas and the liquidA laminate comprising a resin film layer containing a resin film and a foam layer containing a polyurethane foam produced by reacting and curing a foam raw material containing a flame retardant comprising a metal hydroxide powder comprising aluminum hydroxide and a liquid flame retardant such as a phosphorus flame retardant, wherein the metal hydroxide powder is 20 to 60 parts by mass and the liquid flame retardant is 5 to 20 parts by mass based on 100 parts by mass of a polyol, and the foam layer has a density of 100 to 280kg/m³. The gasket of the present invention can be produced by processing the laminate of the present invention.

Description

Polyurethane foam laminate, manufacturing method thereof, and gasket

technical field

The present invention relates to a polyurethane foam laminate, a method for producing the same, and a gasket. More specifically, the present invention relates to a polyurethane foam layer that contains a specific flame retardant, does not bleed out the flame retardant, is soft and hard to scratch, and has excellent appearance; and a polyurethane foam layer that is excellent in flame retardancy of a resin film layer. A pressed body, a method for producing the same, and a gasket having excellent flame retardancy and sealing properties using the polyurethane foam laminate.

Background technique

Originally, in electronic devices such as portable communication devices such as mobile phones, digital cameras, car navigation systems, and portable audio devices, gaskets are placed on the peripheral parts of the case to prevent moisture and dust from entering the interior. The gasket, especially when installed on electronic instruments and precision instruments used in harsh environments such as high-temperature atmospheres, or electronic instruments and precision instruments with high heat generation, must have the flame retardant standard specified in UL94, that is, comply with HBF Specifications for flame retardancy. In order to impart such flame retardancy, gaskets using resin foams containing halogen flame retardants such as organobromine compounds and organochlorine compounds, antimony trioxide, organophosphorus compounds, and metal hydroxides have been proposed.

Patent Document 1 discloses a flame-retardant sealing material having a foam portion formed by foaming a foam raw material mixed with 25 to 50 parts by weight of a flame retardant metal hydroxide having a specific density with respect to 100 parts by weight of polyol. This Patent Document 1 describes that when the density of the foam part is low, the contact area with the air becomes large and the flame retardancy decreases. In addition, it is described that in this flame-retardant sealing material, when the compounding amount of the metal hydroxide exceeds 50 parts by weight, the foam part becomes hardened or brittle, and sealing performance becomes a problem. In addition, as a method to deal with this problem, it is described that a polyol is used as a diluting medium for the foam stabilizer, and a method of preventing the volatilization of the foam stabilizer, which is an important obstacle to flame retardancy, by allowing the foam stabilizer to enter the polyurethane molecule .

In addition, Patent Document 2 discloses an article having a base film and a polyurethane foam layer formed on the base film, and examples of the article include sealing members used in displays such as mobile phones. In addition, it is described that arbitrary additives may be added to the foam raw material, and examples of the additives include flame retardants.

Previous patent documents

[Patent Document 1] JP-A-2005-171102

[Patent Document 2] JP-A-2007-44972

Contents of the invention

The problem to be solved by the invention

In order to form a foam part satisfying the above-mentioned flame-retardant standard, when the above-mentioned flame retardant is used, there are the following problems respectively.

Halogen-based flame retardants are not preferred because they generate halogenated compounds that have a large environmental load when burned.

It has been confirmed that antimony trioxide has a large environmental load and is harmful, so it is not preferable.

Most organophosphorus compounds are in a liquid state, and when a large amount is blended, the physical properties of the foam will decrease or ooze out, which may cause problems such as migration to the shell. In addition, when using a gasket in which the resin film and the resin foam are integrated, for example, in the flame retardant test stipulated in UL94, the resin film as the base material shrinks, and the curling of the test piece on the foam side cannot be suppressed. A matter of specification.

Metal hydroxides such as aluminum hydroxide and magnesium hydroxide have almost no impact on the above-mentioned environmental load and human body, and can be used as safe gaskets. Massive fit in foam. However, when the mechanical foaming method is used, when the powder is mixed with the foam raw material, the viscosity increases, especially when the resin foam with low density is manufactured, the viscosity increases significantly, and the resin foam using the mechanical foaming method is difficult to form the original foam. The fine pore structure has problems such as so-called pore roughness in which the surface of the foam is rough.

The present invention is made in view of the above-mentioned existing situation, and relates to a polyurethane foam layer having: a flame retardant does not bleed out, is soft, is hard to scratch, and has an excellent appearance; and a polyurethane foam layer having an excellent flame retardancy of a resin film layer A pressed body, a method for producing the same, and a gasket having excellent flame retardancy and sealing properties using the polyurethane foam laminate.

means to solve the problem

The present invention relates to the following matters.

1. The polyurethane foam laminate is characterized in that the foam raw material containing polyisocyanate, polyol and flame retardant is mixed with gas to generate a gas-liquid mixture, and then the gas-liquid mixture is supplied to the resin film, Next, in the polyurethane foam laminated body having the resin film layer comprising the resin film and the foam layer comprising the generated polyurethane foam obtained by heating the gas-liquid mixture to react the foam raw material,

The above-mentioned flame retardant contained in the above-mentioned foam raw material contains metal hydroxide powder and liquid flame retardant. 5 to 20 parts by mass, and,

The density of the foam layer is 100-280 kg/m ³ .

2. The polyurethane foam laminate according to the above 1, wherein the liquid flame retardant is a phosphorus flame retardant.

3. The polyurethane foam laminate according to the above 1, wherein the metal hydroxide powder has an average particle diameter of 10 to 100 μm.

4. The polyurethane foam laminate according to the above 1, wherein the resin film layer contains polyethylene terephthalate, and the resin film layer has a thickness of 25 to 125 μm.

5. The polyurethane foam laminate according to the above 1, wherein the foam layer has an average pore diameter of 50 to 300 μm.

6. The polyurethane foam laminate according to the above 1, wherein the foam layer has a surface layer on the surface opposite to the surface laminated on the resin film layer.

7. The polyurethane foam laminate according to the above 1, wherein the load when compressed by 40% is 0.002 to 0.02 MPa.

8. The polyurethane foam laminate according to the above 1, wherein the residual compression set when compressed by 50% at a temperature of 70° C. is 10.0% or less.

9. A method for producing a polyurethane foam laminate, comprising: mixing a foam raw material containing a polyisocyanate, a polyol, and a flame retardant with gas to generate a gas-liquid mixture, and then supplying the gas-liquid mixture to the resin film , secondly, heating the gas-liquid mixture to react the foam raw material to obtain a polyurethane foam laminate having a resin film layer comprising the resin film and a foam layer comprising a polyurethane foam generated by reaction and solidification of the foam raw material In the manufacturing method,

The above-mentioned flame retardant contained in the above-mentioned foam raw material contains metal hydroxide powder and a liquid flame retardant. When the above-mentioned polyol is 100 parts by mass, the metal hydroxide powder is 20 to 60 parts by mass, and the liquid flame retardant is 5 to 20 parts by mass, and,

The density of the foam layer is 100-280 kg/m ³ .

10. A gasket characterized by using the polyurethane foam laminate described in any one of 1 to 8 above.

11. The gasket described in 10 above, having a thickness of 0.4 to 1.5 mm.

Invention effect

According to the polyurethane foam laminate of the present invention, since the flame retardant contains a predetermined amount of metal hydroxide powder and a liquid flame retardant, the flame retardant does not bleed out, is soft, is hard to scratch, and has excellent appearance. Foam layer and resin film layer. In addition, as a whole, it is suitable as a sealing material such as a gasket with excellent flame retardancy that is placed on an instrument that is excellent in flexibility and used in a harsh environment such as a high-temperature atmosphere, or an instrument that has heat generation.

When the above-mentioned liquid flame retardant is a phosphorus flame retardant, through the combination of the phosphorus flame retardant and metal hydroxide powder, the flame retardant does not penetrate to the surface of the foam layer, has a specified density and has a soft foam layer, Excellent flame retardancy.

The above-mentioned resin film layer contains polyethylene terephthalate, and when the thickness of the resin film layer is 25 to 125 μm, the shape stability of the polyurethane foam laminate is excellent. Furthermore, when this urethane foam laminate is used as a gasket, it is possible to completely seal the peripheral portions of the two members constituting the instrument case and the like. That is, the adhesiveness between the said peripheral part and the said resin film layer is excellent.

When the average pore diameter of the above-mentioned foam layer is 50 to 300 μm, the compression residual deformation in the foam layer is small, and when used as a gasket, excellent long-term sealing performance and the like can be obtained.

In addition, when the above-mentioned foam layer has a surface layer on the surface opposite to the surface laminated on the resin film layer, the sealing of the peripheral parts of the two members constituting the instrument case and the like is completed. That is, similar to the adhesiveness on the side of the resin film layer, the side of the foam layer can also be adhered to the above-mentioned peripheral portion, and when used as a gasket for a case of a mobile phone or the like, more excellent sealing properties can be obtained.

The polyurethane foam laminate of the present invention is very soft when the load when compressed by 40% is 0.002 to 0.02 MPa. Furthermore, when the polyurethane foam laminate is processed by punching or the like using a punching die to manufacture gaskets and the like for casings such as mobile phones, the foam layer is not damaged or defects are not generated around the processed parts. In addition, when the polyurethane foam laminate of the present invention is used as a gasket or the like, excellent sealing properties and the like can be obtained.

In addition, when the polyurethane foam laminate of the present invention has a compression residual deformation of 10.0% or less at a temperature of 70°C and a 50% compression, it can be used as a gasket for a casing of a mobile phone or the like under severe environments such as a particularly high temperature. When in use, excellent airtightness etc. can be maintained for a longer period of time.

When the average pore diameter of the foam layer is 50 to 300 μm, a polyurethane foam laminate having excellent physical properties such as small compression residual deformation can be obtained.

According to the method for producing a polyurethane foam laminate of the present invention, it is possible to produce a polyurethane foam laminate having a foam layer and a resin film layer having a good appearance without exudation of the flame retardant, no rough pores, and excellent flame retardancy. .

In addition, the average pore diameter of the foam layer is smaller than that of a general flexible flat polyurethane foam of the same density produced using water or a blowing agent.

When the average particle diameter of the metal hydroxide powder contained in the foam raw material is 10 to 100 μm, the foam raw material and the gas-liquid mixture do not increase excessively in viscosity, and the handling is easy. In addition, when the foam raw material and gas are used to form a gas-liquid mixture, the two are easily mixed, and a homogeneous gas-liquid mixture can be efficiently prepared while suppressing the sedimentation of the metal hydroxide powder.

When the above-mentioned resin film contains polyethylene terephthalate, since the resin film has sufficient strength, heat resistance, etc., it is not easy to elongate when the gas-liquid mixture is heated, and the foam layer and the resin film can be stably produced. A polyurethane foam laminate with excellent layer adhesion.

According to the gasket of the present invention, the gasket has excellent flame retardancy, flexibility, and airtightness, the foam layer is hard to be scratched, and the work when disposing it between housing members such as mobile phones is easy. In addition, mobile phones and the like tend to become thinner, and when the device is completed with conventional gaskets, the casing member is bent. However, when the gasket of the present invention is used, it is possible to obtain a device with excellent airtightness without warping.

In addition, when the gasket has a thickness of 0.4 to 1.5 mm, it is easy to work when arranging between housing members of small devices such as mobile phones. Also, in this configuration, it is not necessary to overcompress the gasket. Therefore, excellent sealing properties and the like can be maintained for a long period of time.

Description of drawings

Fig. 1 is a schematic view for explaining the manufacturing process of the polyurethane foam laminate of the present invention.

Fig. 2 is a perspective view of an example of a gasket including a foam layer and a resin film layer.

Detailed ways

The present invention will be described in detail below.

1. Polyurethane foam laminate and manufacturing method thereof

The polyurethane foam laminate of the present invention has the functions of mixing the foam raw material containing polyisocyanate, polyhydric alcohol and flame retardant with gas to generate a gas-liquid mixture, and then supplying the obtained gas-liquid mixture on the resin film. Next, A laminate of a resin film layer composed of a resin film obtained by heating the gas-liquid mixture to react the foam raw materials and a foam layer composed of the generated polyurethane foam. Furthermore, the flame retardant contained in the above-mentioned foam raw material contains metal hydroxide and liquid flame retardant, and its content is 20-60 mass parts and 5-20 mass parts respectively when the polyol is 100 mass parts. In addition, the density of the formed foam layer is 100-280 kg/m ³ .

1-1. Foam raw material

The above-mentioned foam raw material is a composition containing a polyisocyanate, a polyol, and a flame retardant, and contains the following other components as necessary.

The said polyisocyanate is not specifically limited, The polyisocyanate used for the manufacture of the conventional polyurethane foam can be used. As the polyisocyanate, generally, 4,4'-diphenylmethane diisocyanate (MDI), crude MDI, toluene diisocyanate, etc. can be used. In addition, 1,6-hexamethylene diisocyanate, 1,5-naphthalene diisocyanate, p-phenylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-Trimethylhexamethylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, m-xylene diisocyanate, hexamethylene diisocyanate, hydrogenated MDI, isophorone diisocyanate Aromatic or aliphatic polyisocyanates such as isocyanates, prepolymer polyisocyanates, and the like. The above-mentioned polyisocyanates may be used in combination of two or more kinds, but only one kind is used in many cases.

The polyisocyanate is blended so that the isocyanate index becomes preferably 0.8 to 1.2, particularly preferably 0.9 to 1.1.

The above-mentioned polyol is not particularly limited, and polyols used in the production of conventional polyurethane foams can be used. As the polyol, polyether polyol, polyester polyol, polyether ester polyol obtained by copolymerizing polyether polyol and polyester polyol, etc. can be used. Moreover, in order to obtain the foam layer etc. which have sufficient tensile strength etc., you may use a polymer polyol together. The polymer polyol is, for example, graft-polymerized ethylenically unsaturated compounds such as acrylonitrile, styrene, and methyl methacrylate on polyether polyol, preferably 10 to 40% by mass, more preferably 15% by mass in terms of solid content. ~30% by mass of polyols.

The average molecular weight of the above polyol is preferably 400-5000, more preferably 800-4000.

The said polyhydric alcohol may be used only by 1 type, and may use 2 or more types together.

As the flame retardant, a metal hydroxide powder and a liquid flame retardant may be used in combination.

Examples of the metal hydroxide powder include powders containing aluminum hydroxide, magnesium hydroxide, calcium hydroxide, and the like. The metal hydroxide powder may be used alone or in combination of two or more. Among these, aluminum hydroxide powder having three hydroxyl groups and having a decomposition point as low as about 200° C. is preferable. When this aluminum hydroxide powder is used, particularly excellent flame retardancy can be imparted by using it in combination with a liquid flame retardant.

In addition, the average particle diameter of the metal hydroxide powder is preferably 10 to 100 μm, particularly preferably 25 to 75 μm. When the average particle size of the metal hydroxide powder is 10-100 μm, the foam raw material and the gas-liquid mixture will not increase viscosity excessively, and the operation is easy. In addition, when the foam raw material and gas are used to generate a gas-liquid mixture, the mixing of the two is easy, and a homogeneous gas-liquid mixture can be efficiently prepared while suppressing the sedimentation of the metal hydroxide powder. In addition, the said average particle diameter is the value measured with the particle size distribution measuring apparatus.

In addition, the above-mentioned liquid flame retardant is not particularly limited, but is preferably a liquid flame retardant at 25°C. When the liquid flame retardant is used, the viscosity of the foam raw material can be reduced. Furthermore, the mixing efficiency of the foam raw material and the gas is improved, and a homogeneous gas-liquid mixture can be formed. As a result, a homogeneous foam layer having excellent dispersibility of the flame retardant can be formed.

As the above-mentioned liquid flame retardants, there are flame retardants containing halogen atoms such as chlorine atoms and bromine atoms, and non-halogen-containing flame retardants not containing halogen. From the viewpoint of environmental load, non-halogen-containing flame retardants are preferable. Phosphorus-based flame retardants are preferable as the non-halogen-containing flame retardant, and examples of the phosphorus-based flame retardant include organic phosphorus compounds such as phosphoric acid ester-based flame retardants and polyphosphoric acid-based flame retardants. Among them, phosphoric acid ester-based flame retardants are preferred. In addition, these organophosphorus compounds may be used alone or in combination of two or more.

Phosphate-based flame retardants include trimethyl phosphate, triethyl phosphate, tributyl phosphate, triisobutyl phosphate, triphenyl phosphate, tricresyl phosphate, tri-xylyl phosphate, Cresyl diphenyl phosphate, cresyl di-2,6-xylyl phosphate, and the like.

A polyurethane foam laminate having a foam layer excellent in flame retardancy can be formed by using a foam raw material containing the above-mentioned two kinds of flame retardants in a specific content.

The content of the metal hydroxide powder contained in the foam raw material is 20 to 60 parts by mass, preferably 30 to 60 parts by mass, particularly preferably 30 to 50 parts by mass, based on 100 parts by mass of the polyol. When the content of the metal hydroxide powder is 20-60 parts by mass, since the foam raw material and the gas-liquid mixture do not increase excessively in viscosity, a foam layer with fine pores and roughness suppressed can be formed. The content of the metal hydroxide powder is usually set while investigating physical properties such as load during compression and compression residual deformation of the polyurethane foam laminate.

In addition, the content of the liquid flame retardant contained in the foam raw material is 5 to 20 parts by mass, preferably 7 to 18 parts by mass, particularly preferably 10 to 15 parts by mass, based on 100 parts by mass of the polyol. When the content of the liquid flame retardant is 5 to 20 parts by mass, the foam layer can be formed in which the viscosity increase of the foam raw material and the gas-liquid mixture is fully suppressed and the liquid flame retardant does not seep out. In addition, flame retardancy, flexibility, and the like are also sufficiently maintained. The content of the liquid flame retardant is usually set while examining the physical properties of the polyurethane foam laminate, such as load during compression and compression residual deformation.

In addition to polyisocyanates, polyols and flame retardants, the above-mentioned foam raw materials may also contain catalysts, foam stabilizers, crosslinking agents, etc.

Examples of the catalyst include organotin compounds such as stenasu octoetate, dibutyltin diacetate and dibutyltin dilaurate, organozinc compounds such as zinc octoate, organic compounds such as nickel acetylacetonate and nickel diacetylacetonate Nickel compounds, organic iron compounds such as ferric acetylacetonate, metal catalysts such as alkali metals such as sodium acetate or alkaline earth metal alkoxides and phenates, triethylamine, triethylenediamine, N-methylmorpholine Aminomethylphenol, imidazole, 1,8-diazacyclo[5.4.0]undecene and other tertiary amine catalysts, organic acid salts, etc. Among them, organotin compounds are preferable. In addition, the catalyst may be used alone or in combination of two or more.

The content of the catalyst contained in the above-mentioned foam raw material also depends on its type, the conditions for forming the foam layer, etc., and is preferably 0.05 to 2.0 parts by mass, particularly preferably 0.05 to 1.0 parts by mass, based on 100 parts by mass of the polyol.

As the above-mentioned foam stabilizer, a silicone-based foam stabilizer can generally be used. Examples of the silicone-based foam stabilizer include dimethylsiloxane-based compounds, polyether dimethylsiloxane-based compounds, phenylmethylsiloxane-based compounds, and the like. These may be used alone or in combination of two or more. In addition, these compounds may also be compounds having an organic functional group. In the present invention, polyether dimethylsiloxane compounds are preferred, and block copolymers of dimethylpolysiloxane and polyether are particularly preferably used.

The content of the foam stabilizer contained in the foam raw material depends on its type, desired foam properties, etc., and is preferably 2.0 to 10 parts by mass, particularly preferably 3.0 to 8.0 parts by mass, based on 100 parts by mass of the polyol.

Examples of the crosslinking agent include ethylene glycol, trimethylolpropane, etc. as initiators, ester oligomers chain-extended with ε-caprolactone, and trifunctional polymers with a molecular weight of about 400 to 700. High molecular weight cross-linking agents such as ether polyols, or short-chain diols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, glycerin, and trimethylolpropane agent. When high molecular weight crosslinkers are used, lower hardness foams can be formed. In addition, when a short-chain diol-based crosslinking agent is used, since the ratio of the hard segment tends to increase, it is preferable to set the compounding amount in consideration of this point. The crosslinking agent may be used alone or in combination of two or more.

The content of the crosslinking agent contained in the foam raw material depends on its type, desired foam properties, etc., and is preferably 1.0 to 10 parts by mass, particularly preferably 2.0 to 5.0 parts by mass, based on 100 parts by mass of the polyol.

Additives generally used in the production of polyurethane foams, such as ultraviolet absorbers, antioxidants, organic and inorganic fillers, and colorants, may be blended in appropriate amounts as necessary in the above-mentioned foam raw materials.

1-2. Manufacturing method of polyurethane foam laminate

The raw material for producing the polyurethane foam laminate of the present invention is a gas-liquid mixture containing the foam raw material having the above-mentioned constitution, a gas, and a resin film.

The gas mixed with the foam raw material is not particularly limited, and nitrogen, inert gas, dry air and the like can be used. Among them, nitrogen gas is preferable.

In the present invention, the above-mentioned foam raw material and gas are stirred by a mixer 11 to form a gas-liquid mixture 21a. Then, the gas-liquid mixture 21a is supplied to be coated on the resin film 22a, and then, on the surface of the flow-cast gas-liquid mixture 21a, from the upper side, a release paper (or a processed resin film for release) is supplied. )3. And the thickness of the uncured layer 21b which consists of the gas-liquid mixture 21a is adjusted by the roll coater 12 etc. with this laminated state as it is. Also, regardless of whether the release paper 3 is used, when the release paper 3 is used, the thickness adjustment of the uncured layer 21b is easy, and a surface layer can be formed on the surface of the foam layer 21 obtained after heat treatment (the release paper 3 side). . Through these steps, a three-layer laminate is obtained in which the uncured layer 21b has the resin film 22a on one side (lower surface) (forming the resin film layer 22 ) and the release paper 3 is laminated on the other side (upper side).

Then, the laminate is heated using a heat treatment device. Thereby, the foam raw material is reacted, the uncured layer 21b is cured, and the polyurethane foam laminated body 2 in which the foam layer 21 was formed can be obtained. In this polyurethane foam laminate 2, the foam layer 21 and the resin film layer 22 are firmly bonded. The obtained urethane foam laminate 2 is wound up on a paper tube or the like in a three-layer structure to form a roll body, or as shown in FIG. winding to form a roll body. Alternatively, it may be cut into a predetermined size on a production line to form a sheet. Next, the sheets can also be stacked and packed. In this case, the three layers may be laminated as they are, or may be laminated as a two-layer laminate.

Next, a method for producing a polyurethane foam laminate will be specifically described.

As described above, the raw materials for the manufacture of the polyurethane foam laminate are the gas-liquid mixture 21a and the resin film 22a obtained by using the foam raw material and gas.

The preparation method of the above-mentioned foam raw material is not particularly limited, but it is preferred to mix polyisocyanate with a mixture of polyols, flame retardants, catalysts, etc. (hereinafter referred to as "the first mixture") without polyisocyanate. method. In addition, additives blended as needed are usually included in the first mixture.

The preparation method of the above-mentioned gas-liquid mixture 21a is not particularly limited. When the volume ratio of the foam material and the gas reaches 100% by volume in total, the foam material and the gas are mixed, preferably reaching 5-30% by volume and 70% by volume respectively. -95% by volume, more preferably 8-25% by volume and 75-92% by volume. With this mixing ratio, the gas-liquid mixture 21a suitable for forming a foam layer having the above-mentioned specific density can be prepared. In addition, the mixer 11 used for mixing the foam raw material and the gas is not particularly limited, and an Oaks mixer, a Hobart mixer, or the like is preferably used. With these mixers 11, the foam raw material and the gas can be uniformly mixed, the foaming can be easily controlled, and the foamed homogeneous gas-liquid mixture 21a can be produced as a more homogeneous mixture.

Also, the method of mixing the foam material and the gas is preferably a method of blowing gas into the foam material stored in advance in a mixing chamber or the like, and a method of simultaneously supplying the foam material and the gas into the chamber. At this time, as a foam raw material, polyisocyanate and the above-mentioned first mixture may be separately supplied into the chamber.

The foam layer using the above-mentioned gas-liquid mixture is preferably formed by a mechanical foaming method. According to this method, the volume of the gas-liquid mixture used is almost the same as the volume of the polyurethane foam obtained. Therefore, the density of the polyurethane foam can be adjusted by the composition of the gas-liquid mixture, that is, the amount of gas introduced into the above-mentioned foam raw material.

In order to make the foam density a predetermined value, the gas mixing amount used to form the gas-liquid mixture can be determined as follows.

First, the weighted average of the density (true specific gravity) of each component contained in the foam raw material of predetermined mass is calculated|required, and this is made into the foam raw material total density (ρ). Then, the mass of the foam raw material used was divided by the above-mentioned density (ρ) to calculate the total volume of the foam raw material.

Next, from the total volume of the foam raw material and the target foam density (target density), the gas volume introduced into the foam raw material is obtained. Using it in actual manufacturing, a polyurethane foam layer with a desired density can be formed.

The above-mentioned resin film 22a is not particularly limited as long as it does not cause deformation, deterioration, etc. during the formation of the foam layer. In addition, as a support material supporting the foam layer, a material having tensile strength, tear strength, heat resistance, and the like is preferable. As the resin film 22a, a film made of synthetic resin can generally be used. Examples of synthetic resins include polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polyurethane resins, polyolefin resins such as polyethylene and polypropylene, and polyamide resins. Among them, polyester resins, polyurethane resins, and polyamide resins are preferable from the viewpoint of strength, heat resistance, and the like. In addition, when the polyurethane foam laminate of the present invention having a resin film containing these resins is used as a gasket for sealing two members, excellent adhesion and sealing properties can be obtained. In the present invention, for the above-mentioned resin film 22a, polyester resin is more preferable, and polyethylene terephthalate is particularly preferable.

The thickness of the above-mentioned resin film 22a (thickness of the resin film layer 22 constituting the polyurethane foam laminate) is also not particularly limited. The preferred thickness is more than 25 μm, more preferably 25-125 μm, especially preferably 25-100 μm, particularly preferably 30-70 μm. When the thickness is more than 25 μm, the tensile stress of the foam layer 11 in the molding direction can be sufficiently withstood when continuous production is performed as shown in FIG. 1 , making it possible to stably produce the polyurethane foam laminate. In addition, when the above-mentioned resin film 22a is polyethylene terephthalate and its thickness is 25 to 125 μm, the shape stability is excellent. In addition, when the polyurethane foam laminate of this configuration is used as a gasket, it does not become too rigid, and it is easy to insert between housing members such as mobile phones, and can obtain excellent sealing properties and the like.

The above-mentioned gas-liquid mixture 21a is supplied to the surface of the above-mentioned resin film 22a, and then, the release paper 3 is supplied to the surface of the cast gas-liquid mixture 21a from the upper side thereof to form a laminate. Next, the three-layer laminate is heated with a heat treatment device 13 set at a predetermined temperature to react the foam raw material contained in the uncured layer 21 b to form the foam layer 21 .

The method for heating the above-mentioned three-layer laminate is not particularly limited, and may be appropriately selected according to the type of heat treatment device 13 and the like.

The heating temperature can be appropriately selected according to the types of polyol and polyisocyanate in order to cure the foam raw material contained in the uncured layer 21b. The heating temperature is preferably 120°C to 200°C, more preferably 140°C to 180°C, particularly preferably 150°C to 170°C.

In addition, the heating time is preferably 1 to 10 minutes, more preferably 1 to 5 minutes.

As said heat processing apparatus 13, a heating furnace, a far-infrared ray irradiation apparatus, etc. are mentioned. When using a heating furnace, heat treatment is performed while the 3-layer laminate is stationary or moving using a heat source fixed in the device. At this time, hot air may also be supplied. In addition, when continuously producing a polyurethane foam laminate, it is preferable to heat the three-layer laminate while moving it in a heating furnace.

The above-mentioned three-layer laminate is heated on either one of the resin film side and the release paper side, or from both sides. In the present invention, it is preferable to heat from both sides of the 3-layer type laminate in order to uniformly heat the entirety thereof and form a more homogeneous foam layer 21 more efficiently.

When the method for producing a polyurethane foam laminate of the present invention is the production system shown in FIG. 1 , the preparation of the gas-liquid mixture 21a, the supply of the gas-liquid mixture 21a to the resin film 22a, and the release of release paper or the like to the uncured The supply of the upper surface of the layer 21b, the adjustment of the thickness using a roll coater or the like, and the heating of the three-layer laminate can be performed continuously, and a polyurethane foam laminate can be produced continuously. That is, the gas-liquid mixture 21a prepared by the mixer 11 is continuously sent out, and is continuously supplied to the moving resin film 22a at a predetermined supply rate, and the release paper 3 is mixed with the resin on the surface of the flow-cast gas-liquid mixture 21a. The film 22a is fed at the same speed, and the thickness is adjusted by the roll coater 12 . Then, the 3-layer laminate is introduced into a heat treatment device 13, such as a heating furnace, arranged adjacent to the roll coater 12. When using a heating furnace, usually the 3-layer laminate can be introduced from one opening, moved to the heating furnace at the same or similar moving speed as the resin film 22a, and then exported from the other opening. Thereby, the polyurethane foam laminated body which has the release paper 3 can be manufactured. Then, if necessary, the release paper 3 is removed to form a polyurethane foam laminate including the foam layer 21 and the resin film layer 22 .

In addition, in the manufacturing method of the polyurethane foam laminated body of this invention, the foam layer 21 can be formed on both surfaces of the resin film layer 22. Examples of this method include a method in which foam layer 21 is formed on each side, and a method in which uncured layer 21b is formed on both sides of resin film 22a and heated simultaneously to form foam layer 21 simultaneously.

The polyurethane foam laminate of the present invention can be produced by a mechanical foaming method without mixing water and a foaming agent in the foam raw material as described above. In addition, water and/or a foaming agent may be mixed with the foam raw material to produce it by a so-called chemical foaming method. At this time, as water, ion-exchanged water, tap water, distilled water, etc. can be used. The amount of water used is not particularly limited, but is usually 0.1 to 0.5 parts by mass, particularly preferably 0.2 to 0.4 parts by mass, per 100 parts by mass of the polyol. In addition, the blowing agent is not particularly limited, and hydrocarbons, substituted Freon, and the like can be used. The amount of the foaming agent used is also not particularly limited. Therefore, when the chemical foaming method of the foam raw material mixed with water and/or foaming agent is used instead of the mechanical foaming method, the foaming state of the gas-liquid mixture can be maintained stably without rough pores, etc., and can be easily formed. Foam layer of desired density and thickness. As a result, a polyurethane foam laminate having a foam layer having excellent physical properties can be obtained.

1-3. Physical properties of polyurethane foam laminate

The polyurethane foam laminate of the present invention is a bonded product of the foam layer 21 and the resin film layer 22 produced by the method described above. The density of the foam layer is 100-280 kg/m ³ , preferably 120-260 kg/m ³ , particularly preferably 150-240 kg/m ³ .

The density of the foam layer is calculated by dividing the mass obtained by subtracting the mass of the resin film layer from the mass of the laminate by the volume of the foam layer. In addition, the volume of the foam layer is calculated as follows. That is, for example, a rectangle is cut out from the laminate to prepare a test piece, and the vertical and horizontal dimensions of the test piece are measured with a caliper or the like. Then, after measuring the total thickness of the test piece with a dial gauge thickness gauge or the like, the thickness of the resin film layer is subtracted to obtain the thickness of the foam layer. Furthermore, the volume of the foam layer can be calculated from the above-mentioned vertical and horizontal dimensions and the thickness of the foam layer.

In the past, when only metal hydroxide powder was added as a flame retardant to form a low-density foam layer with a density of, for example, 280 kg/m ³ or less, rough pores occurred, and a practical polyurethane foam laminate could not be formed. However, according to the production method of the present invention, by using a metal hydroxide and a liquid flame retardant in combination, it is possible to form a flexible foam layer having the above-mentioned specific density and suppress defects such as rough pores, and to form a flame-retardant foam layer. Excellent polyurethane foam laminate.

In addition, the polyurethane resin portion forming the foam layer contains metal hydroxide powder and a liquid flame retardant as a flame retardant, and these are retained without bleeding. In addition, in applications such as those described later, even when a load such as compression is applied, bleeding does not occur similarly. The contents of the metal hydroxide powder and the liquid flame retardant are preferably 20-60 parts by mass and 5-20 parts by mass, more preferably 20-40 parts by mass and 5-10 parts by mass, respectively, relative to 100 parts by mass of polyurethane.

The polyurethane foam laminate produced by the above-mentioned method of the present invention can have a foam layer with a smaller cell diameter than a flexible flat polyurethane foam produced by a conventionally known chemical foaming method. That is, the average pore diameter in the foam layer is preferably 50 to 350 μm, particularly preferably 50 to 250 μm. When the pore diameter of the foam layer is within the above-mentioned range, a polyurethane foam laminate having excellent physical properties such as small compression residual deformation can be formed. When a urethane foam laminate with a small compression residual deformation is used as a gasket for sealing two members, both the resin film side surface and the foam layer side surface of the urethane foam laminate can be fully adhered to the two members , excellent sealing performance can be obtained.

The above-mentioned average pore diameter was observed with a scanning electron microscope at a magnification of 200 times the cross section of the foam layer, and the total value of the pore diameter was divided by the number of pores to calculate.

The thickness of the above-mentioned foam layer can be appropriately selected according to the purpose, use, etc., and is usually 0.4 to 1.5 mm.

Moreover, the thickness of the polyurethane foam laminate of this invention is not specifically limited, Usually, it is 0.5-1.8 mm, Especially preferably, it is 0.5-1.0 mm.

The polyurethane foam laminate of the present invention can be formed as a laminate having foam layers on both surfaces of a resin film layer as described above. At this time, the density, average pore diameter, and thickness in the two foam layers may be the same as or different from each other.

In addition, it is preferable to form a surface layer on the exposed surface (the surface opposite to the surface laminated on the resin film layer) of the foam layer in the polyurethane foam laminate of the present invention. When this polyurethane foam laminate having a surface layer is used as a gasket, it is possible to completely seal the peripheral portions of two members constituting an instrument case or the like. The above-mentioned surface layer can be confirmed by observing a cross section of the foam layer with an electron microscope or the like.

The 40% compression load of the polyurethane foam laminate of the present invention is preferably 0.002 to 0.02 MPa, particularly preferably 0.005 to 0.015 MPa. The 40% compression load is 40% CLD measured in accordance with JIS K 6254.

In addition, in the polyurethane foam laminate, the compression residual set at a temperature of 70°C and 50% compression is preferably 10.0% or less, particularly preferably 6.0% or less. Also, the lower limit is usually 0.3%. This compression residual deformation can be measured in accordance with JIS K 6401.

2. Application of polyurethane foam laminate

The polyurethane foam laminate of the present invention is a polyurethane foam laminate useful for applications such as gaskets.

The gasket of the present invention can be formed into a shape according to the purpose, use, and the like. For example, the gasket 100 shown in FIG. 2 is obtained by processing the polyurethane foam laminate of the present invention, and is an annular gasket having a resin film layer 102 and a foam layer 101 joined to the surface of the resin film layer 102, The surface of the foam layer 101 (the upper surface in FIG. 2 ) preferably has a surface layer. Like this, one side of gasket 100 is made up of resin film layer 102, and the gasket 100 that forms the foam layer 101 that has surface layer on the other side side, when adopting when the peripheral portion of two members that constitute the housing of instrument etc. is sealed, The intrusion of dust can be suppressed from between two members. That is, the intrusion of dust from both sides of the gasket 100 (the foam layer 101 side and the resin film layer 102 side) can be sufficiently prevented.

The shape of the gasket of the present invention is not limited to having an opening larger than that of the main body as shown in FIG.

The thickness of the gasket is not particularly limited, but is usually 0.4 to 1.5 mm, particularly preferably 1.0 to 1.5 mm. When the thickness of the gasket is 0.4 to 1.5 mm, excellent sealing performance can be obtained while producing the flexibility of the polyurethane foam laminate.

The method of obtaining the ring-shaped gasket 100 shown in FIG. 2 is not particularly limited, and examples thereof include a method of punching with a die, a method of continuous cutting with a cutting machine, and the like. Among them, the blanking method is preferable. In addition, as described above, since the foam layer 101 has a low density and excellent flexibility, it does not scratch the foam layer 101 or cause defects around the processed part during punching or the like.

The gasket of the present invention can be inserted between housing members of electronic equipment. The electronic device is not particularly limited, and examples thereof include portable electronic devices such as mobile phones, digital cameras, digital video cameras, portable computers, portable audio systems, portable game machines, and navigation devices. Among these electronic devices, it is preferable to use the gasket of the present invention, especially mobile phones that are carried by many people and often carried when going out, and are likely to come into contact with fibers of clothes and the like.

The housing of an electronic instrument is usually composed of a plurality of housing members facing each other, and gaskets are inserted between the housing members. There is no need to insert the groove of the gasket on the body member, and the gasket has excellent sealing performance. In addition, since the thickness of the case member is thinned, the case member may warp when the same members are connected to each other as before, and therefore a sufficiently flexible gasket is required. Under such circumstances, the gasket of the present invention is low-density and very flexible, and is also advantageous in coping with miniaturization, particularly thinning, of electronic devices.

Example

Hereinafter, the present invention will be specifically described by way of examples. In addition, the following "part" is not specifically limited, It is a mass basis.

The raw materials used in the production of the polyurethane foam laminate are as follows.

(1) Polyether polyol A

"GP-3000" (trade name) manufactured by Sanyo Chemical Co., Ltd. was used.

(2) Polyether polyol B

"GP-600" (trade name) manufactured by Sanyo Chemical Co., Ltd. was used.

(3) Catalyst

The スタナスオクトエトト produced by Johoku Chemical Co., Ltd. is used.

(4) Foam stabilizer

Silicone-based foam stabilizer "L-5617" (trade name) manufactured by Momentive Co., Ltd. was used. The product is a block copolymer of dimethylpolysiloxane and polyether.

(5) Metal hydroxide powder

Aluminum hydroxide powder "Hijilite H-10" (trade name) manufactured by Showa Denko Co., Ltd. was used.

(6) Phosphorous flame retardants

The aliphatic condensed phosphoric acid ester "DAIGUA RD880" (trade name) manufactured by Daihachi Chemical Industry Co., Ltd. was used. The product is light yellow transparent liquid at 25°C.

(7) Polyisocyanate

Coarse MDI "C-1130" (trade name) manufactured by Nippon Polyurethane Co., Ltd. was used. The content of polyisocyanate groups was 31%.

(8) Resin film

A polyethylene terephthalate film with a thickness of 50 μm was used.

Examples 1-4 and 6-15, and Comparative Examples 1-7

100 parts of polyether polyol (polyether polyol A and B are used in a mass ratio of 90/10), 0.1 part of catalyst, 5 parts of foam stabilizer, and metal hydroxides in the compounding amounts listed in Tables 1 to 4 Mix and stir the material powder and phosphorus flame retardant to prepare the first mixture.

Then, put the first mixture and the polyisocyanate whose isocyanate index reaches 0.9-1.1 into the chamber of the Oaks mixer. Then, an amount of nitrogen gas in an amount to achieve a predetermined volume ratio described in Tables 1 to 4 was simultaneously injected so that the target density of the foam layer described in Tables 1 to 4 was achieved.

Secondly, the above-mentioned ingredients are stirred and mixed indoors to prepare a foamed gas-liquid mixture. And this gas-liquid mixture is supplied on the resin film conveyed at a speed of 5 m/min, and on the surface of the cast gas-liquid mixture, from the upper side thereof, a release paper is supplied at the same speed as the resin film, and roll coating is carried out. The cloth machine is adjusted to the specified thickness to form an uncured layer composed of a gas-liquid mixture (refer to Figure 1).

Then, the three-layer laminate including the resin film, the uncured layer, and the release paper was introduced into a heating furnace heated to 160° C. with a far-infrared heater (the length of the heating furnace was 5 m, and the heating time was 1 minute). Next, the release paper was peeled off from the laminate, and the resin film and the foam layer were bonded to form a polyurethane foam laminate, which was wound up on a paper tube. The thickness of the polyurethane foam laminate was measured with a dial gauge thickness gauge (Table 1 to Table 4).

Example 5

A polyurethane foam laminate was obtained in the same manner as above except that only 100 parts of polyether polyol A was used as the polyether polyol (Table 1).

Cut test pieces from the polyurethane foam laminate produced above, measure the density of the foam layer, the average pore diameter, the load at 40% compression, and the compression residual deformation, and evaluate the appearance of the foam layer, whether there is bleeding, whether there is a scratch, and flame retardant. The results are shown in Tables 1 to 4.

(1) The density of the foam layer

A square shape (50 mm×50 mm) was cut out from the obtained polyurethane foam laminate to prepare a test piece, and the vertical and horizontal dimensions of the test piece were accurately measured with a caliper. Then, the thickness of the resin film was subtracted from the thickness of the laminate shown in each table to obtain the thickness of the foam layer. Then, the volume of the foam layer was calculated using the above-mentioned vertical and horizontal dimensions and the thickness of the foam layer. Next, the mass obtained by subtracting the mass of the resin film layer from the mass of the test piece is divided by the volume of the foam to obtain the density of the foam layer.

(2) Average pore diameter

The cross section of the foam layer in the obtained polyurethane foam laminate was observed with a scanning electron microscope at a magnification of 200 times, and the size of 50 foam cells in the image was measured. Then, the sum of these pore diameters is divided by the number of pores to obtain an average pore diameter.

(3) Load at 40% compression

Measured in accordance with JIS K 6254. Specifically, the polyurethane foam laminate was punched out to obtain a circular test piece with a diameter of 50 mm. Then, use a compression jig with the same diameter as the test piece to contact the test piece concentrically, and use a compression testing machine to perform 40% compression at a speed of 1mm/min at a temperature of 23°C (60% of the thickness before compression) ), and measure the load at this time. From the obtained load, the load at 40% compression (unit: MPa) was calculated according to the following formula.

Load at 40% compression = [Load at 40% compression (N)/area of test piece (mm ² )]

(4) Compression residual deformation

Measured in accordance with JIS K 6401. Specifically, the polyurethane foam laminate was punched out to obtain a 50 mm x 50 mm test piece. Then, the test piece was compressed by 50% at a temperature of 70° C. using a compression testing machine, and left as it was for 22 hours. Then, the compression was released, and after standing at 23° C. for 30 minutes, the thickness of the test piece was measured. Using the thickness before and after the compression test, calculate the residual compression deformation according to the following formula.

Compression residual deformation (%)=[(thickness before compression-thickness after opening)/thickness before compression]×100

(5) The appearance of the foam layer

The surface of the foam layer of the polyurethane foam laminate was observed with an optical microscope, and the number of large-diameter pores with a diameter (maximum size) of 700 μm or more present in a 10 cm square was counted to evaluate the appearance of the foam layer. "Good" in the table means that less than 20 large-diameter pores were observed, and "rough pores" means that 20 or more large-diameter pores were observed.

(6) Whether there is leakage

The polyurethane foam laminate was cut to obtain a 50 mm x 50 mm test piece. Then, after placing copper foil (60 mm x 60 mm x 0.1 mm) on the surface of the foam layer of the test piece, it was compressed by 50% at a temperature of 70° C. using a compression tester and left as it was for 168 hours. Next, it was opened and compressed, and the surface of the peeled copper foil (the contact surface with the foam layer) was visually observed to evaluate the exudation property of the phosphorus-based flame retardant. "No" in the table means that no impurities were observed on the surface of the copper foil, and no bleedout occurred, and "yes" in the table means that impurities were observed on the surface of the copper foil, and bleedout occurred.

(7) With or without scratches

The polyurethane foam laminate was cut to obtain a circular test piece with a diameter of 50 mm. Then, the foam layer of the test piece is placed upward, and placed on the central part of the disc-shaped mounting table of the test device. Then, a stainless steel extruded body with a diameter of 50 mm was contacted from above so as to be concentric with the test piece, and a load of 1.2 kg was applied to the extruded body. Next, rotate the mounting table together with the test piece at a speed of 43 revolutions per minute (the symbol on any position on the outer edge of the test piece, the movement speed reaches 50 mm/min with the rotation), and stop the rotation when it rotates 10 times. Then, the foam layer of the test piece was visually observed to evaluate scratchability. "○" in the table means that no scratches are observed on the surface of the foam layer, "Δ" means that scratches with a maximum size of less than 5 mm are observed, and "X" means that scratches with a maximum size of 5 mm or more are observed.

(8) Flame retardancy

Flame retardancy is evaluated by passing or failing the flame retardancy standard HBF standard stipulated in UL94. "○" in the table means that the HBF specification is qualified, and "×" means that the HBF specification is unqualified.

Table 1

Note "-" means not determined.

Table 2

Note "-" means not determined.

table 3

Note "-" means not determined.

As shown in Tables 1 to 3, Examples 1 to 15 of the foam layer with a specified density range formed by using a foam material containing a specified amount of metal hydroxide powder and a phosphorus flame retardant relative to the content of polyols The polyurethane foam laminate has a very small load when compressed by 40%, and the compression residual deformation is also small. In addition, in all Examples, the appearance of the foam layer was good, and the phosphorus-based flame retardant did not bleed out, which was excellent. In addition, in the evaluation of the presence or absence of scratches, in some examples where the density of the foam layer was low, a few scratches were observed, but there was no major problem, and it is a polyurethane foam laminate that can be adequately used in applications such as gaskets body. In addition, in all the examples, the HBF standard is acceptable, and it has excellent flame retardancy.

On the other hand, as can be seen from Table 4, even if the density of the foam layer is within the preferred range, in Comparative Example 1 which does not contain a phosphorus-based flame retardant, rough pores and scratches occur. In addition, Comparative Example 2, which does not contain metal hydroxide powder, was unacceptable in flame retardancy. In addition, in Comparative Example 2 and Comparative Example 3, which did not contain metal hydroxide powder, the compression residual strain was remarkably large. In addition, in Comparative Examples 4 and 7, which contained a predetermined amount of metal hydroxide powder and a phosphorus-based flame retardant, but the density of the foam layer was too low, rough pores and scratches occurred. In addition, in Comparative Examples 5 and 6, although there is no particular problem in terms of physical properties, since the density of the foam layer is too high, it is not possible to provide a practical polyurethane foam laminate especially for gasket applications.

In addition, the present invention is not limited to the specific examples described above, and various modified examples can be formed within the scope of the present invention according to the purpose and application. For example, the same polyurethane foam laminate can be produced by a so-called chemical foaming method by mixing about 0.2 to 0.4 parts of water (100 parts of polyol) into the foam raw material.

Industrial Utilization Possibility

The present invention can be used in various fields of products that need to prevent the intrusion of water and dust. In addition, in recent years, in the field of various electronic devices that are significantly required to be thinner, smaller, and higher performance, and also require excellent design, the utility value is higher, and many people own mobile phones, digital cameras, and navigation devices. And many electronic instruments carried when going out are especially useful in mobile phones that are widely popularized and often carried.

Claims (16)

1. A method for producing a polyurethane foam laminate, which is characterized in that the foam raw material containing polyisocyanate, polyol and flame retardant is mixed with gas to generate a gas-liquid mixture, and then the gas-liquid mixture is supplied to the resin film , secondly, heating the gas-liquid mixture to react the foam raw material to obtain a polyurethane foam laminate having a resin film layer comprising the resin film and a foam layer comprising a polyurethane foam generated by reaction and solidification of the foam raw material manufacturing method, The above-mentioned flame retardant contained in the above-mentioned foam raw material contains metal hydroxide powder and a liquid flame retardant. When the above-mentioned polyol is 100 parts by mass, the metal hydroxide powder is 20 to 60 parts by mass, and the liquid flame retardant is 5 to 20 parts by mass, and, The usage amount of the above-mentioned gas used in the formation of the above-mentioned gas-liquid mixture is 70 to 95 volumes when the total of the gas and the above-mentioned foam raw material reaches 100 volumes, The density of the foam layer is 100-280 kg/m ³ . 2. The method for producing a polyurethane foam laminate according to claim 1, wherein two types of the polyols are used. 3. The method for producing a polyurethane foam laminate according to claim 1 or 2, wherein the liquid flame retardant is a phosphorus flame retardant. 4. The method for producing a polyurethane foam laminate according to claim 1 or 2, wherein the average particle diameter of the metal hydroxide powder is 10 to 100 μm. 5. The method for producing a polyurethane foam laminate according to claim 1 or 2, wherein the resin film contains polyethylene terephthalate, and the resin film has a thickness of 25 to 125 μm. 6. The polyurethane foam laminate is characterized in that the foam raw material containing polyisocyanate, polyol and flame retardant is mixed with gas to generate a gas-liquid mixture, and then the gas-liquid mixture is supplied to the resin film, Next, in the polyurethane foam laminated body having the resin film layer comprising the resin film and the foam layer comprising the generated polyurethane foam obtained by heating the gas-liquid mixture to react the foam raw material, The above-mentioned flame retardant contained in the above-mentioned foam raw material contains metal hydroxide powder and liquid flame retardant. 5 to 20 parts by mass, and, The usage amount of the above-mentioned gas used in the formation of the above-mentioned gas-liquid mixture is 70 to 95 volumes when the total of the gas and the above-mentioned foam raw material reaches 100 volumes, The density of the foam layer is 100-280 kg/m ³ . 7. The polyurethane foam laminate according to claim 6, wherein two types of the polyols are used. 8. The polyurethane foam laminate according to claim 6 or 7, wherein the liquid flame retardant is a phosphorus flame retardant. 9. The polyurethane foam laminate according to claim 6 or 7, wherein the metal hydroxide powder has an average particle diameter of 10 to 100 [mu]m. 10. The polyurethane foam laminate according to claim 6 or 7, wherein the resin film layer contains polyethylene terephthalate, and the resin film layer has a thickness of 25 to 125 μm. 11. The polyurethane foam laminate according to claim 6 or 7, wherein the foam layer has an average pore diameter of 50 to 300 [mu]m. 12. The polyurethane foam laminate according to claim 6 or 7, wherein said foam layer has a surface layer on a surface opposite to a surface laminated on said resin film layer. 13. The polyurethane foam laminate according to claim 6 or 7, wherein the load when compressed by 40% is 0.002 to 0.02 MPa. 14. The polyurethane foam laminate according to claim 6 or 7, wherein the residual compression set when compressed by 50% at a temperature of 70°C is 10.0% or less. 15. A gasket, characterized in that it is made of the polyurethane foam laminate according to any one of claims 6 to 14. 16. The gasket according to claim 15, which has a thickness of 0.4 to 1.5 mm.