JP2022036178A - Performance evaluation method of formable laminate and manufacture management method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a foamable laminate which enables formation of a foam cell having a sufficient height and good appearance with good productivity by heating, a foam laminate, and a container such as a cup.

SOLUTION: A foamable laminate in which a polyethylene-based resin layer (I) for foaming is formed on at least one surface of a base material containing paper as a main body, contains a resin composition (A) for forming the polyethylene-based resin layer, and satisfies the following characteristics. (i) A film thermal shrinkage at 120°C of the polyethylene-based resin layer (I) is 67% or less. (ii) The polyethylene-based resin composition (A) is one or more selected from high-pressure radical polymerization method low density polyethylene and an ethylene copolymer. (iii) A melt flow rate (MFR) of the polyethylene-based resin composition (A) is 7 g/10 min or more and less than 30 g/10 min. (iv) A density of the polyethylene-based resin composition (A) is 0.900-0.930 g/cm³. (v) A memory effect (ME) of the polyethylene-based resin composition (A) is less than 1.8.

SELECTED DRAWING: None

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention relates to an effervescent laminate and a foam laminate and a container obtained thereby. More specifically, the present invention relates to a foamable laminate in which a foamed cell (foamed layer) having a sufficient height and a good appearance can be obtained with high productivity by heating, and a foamed laminate and a container using the obtained foamable laminate.

Conventionally, a foam made of synthetic resin is often used as a container having heat insulating properties. In addition, as a container that is easy to dispose of and has good printability, a heat insulating paper container that uses multiple sheets of paper and a material in which both sides of the paper base material are laminated with a polyethylene resin layer are used to foam the polyethylene resin layer on the surface. There is a paper container that has been made to have heat insulation.

As a technology using paper as a base material, there is a technology of extruding and laminating polyethylene on at least one surface of the paper and forming a vapor pressure holding layer on the other surface to produce processed paper having an irregular uneven pattern on the surface by heating. (See, for example, Patent Document 1).
Further, a technique has been proposed in which a thermoplastic resin film is laminated or coated on one side wall surface of a body member, and the film is foamed by heating to form a foamed heat insulating layer (see, for example, Patent Document 2).
Further, in a paper container composed of a container body member and a bottom member, a part of the outer wall surface of the container body member is printed with an organic solvent-containing ink, and the entire outer wall surface of the body member is covered with a thermoplastic synthetic resin film. A technique has been proposed in which a relatively thick foam layer is present in a printed portion by heating a paper container (see, for example, Patent Document 3).

Further, a foamed paper composed of a foamed layer of an ethylene-α-olefin copolymer polymerized from at least the outer surface side using a single-site catalyst, a base material layer mainly composed of paper, and a laminated body provided with a thermoplastic resin layer. Laminates have been proposed (see, for example, Patent Document 4 and Patent Document 5). The processed paper and foamed laminate having the foamed layer thus obtained have good familiarity with the hand and are not slippery when the foamed layer is foamed to form a container, have excellent heat insulating properties, and are heat-insulated using a plurality of sheets of paper. It has the advantage of being cheaper than sex containers.

Further, in Patent Document 6, the time from the T-die to the contact of the thermoplastic resin in a molten state with the paper base material on at least one side of the paper base material of the body member raw material sheet in the paper container is 0.11 to 0.33. A raw material sheet for a body member of a paper container extruded and laminated so as to take seconds is shown, and a composition prepared by mixing two kinds of low-density polyethylene and adjusting MFR is described.

However, the conventional laminate having a foam layer and the processed paper using the same have a problem that the appearance may be poor at the time of foaming by heating if the processing speed is set to a certain level or higher at the time of extrusion laminating molding. Was there. Therefore, even in the case of high-speed processing, it has been desired to improve the foam cell so as to have a sufficient height and a good appearance. However, it has been difficult to satisfy both the effect of having sufficient foaming property and the effect of forming a good foaming appearance.

Tokukousho No. 48-32283 Gazette Japanese Unexamined Patent Publication No. 57-110439 Japanese Unexamined Patent Publication No. 07-232774 Japanese Unexamined Patent Publication No. 10-128928 Japanese Unexamined Patent Publication No. 2007-168178 Japanese Unexamined Patent Publication No. 2008-105747

In view of the above problems, an object of the present invention is an effervescent laminate capable of obtaining a foam cell (foam layer) having a sufficient height and a good appearance with good productivity by heating, a foam laminate using the same, and foam. The purpose is to provide a container such as a cup using a laminated body. Another object of the present invention is to provide a method for simply evaluating an effervescent laminate and a method for manufacturing and managing the effervescent laminate having a good effervescent appearance after heating in order to predict and evaluate the effervescent laminate. ..

However, in order to satisfy both the effect of having sufficient foamability and the effect of forming a good foamed appearance, the resin composition and various conditions for forming the resin layer are intricately related to each other. It was quite difficult to meet with the combination of. In order to solve the above problems, the present inventors have caused the formation of the polyethylene resin layer (I) of the foamable laminate in which the polyethylene resin layer (I) for foaming is formed on the base material mainly made of paper. Various studies were conducted on various conditions such as the physical properties of the resin used for formation and various resin temperatures and velocities of the extrusion forming method when forming the polyethylene resin layer on the base material.
As a result, in the polyethylene resin layer (I) formed on the paper substrate having the specific physical properties (i) to (v) obtained under a limited specific condition, sufficient foamability and foamed appearance. The present invention has been completed by finding that an effervescent laminate can be obtained by combining both effects of improving the quality of the product. This effect is particularly useful under high-speed processing of laminate molding.
Further, it is conventionally difficult to predict and evaluate the performance of the foamable laminate capable of forming a good foamed appearance after foaming in the foamable laminate before foaming, and such a preliminary evaluation has not been performed. However, a simple evaluation method and a manufacturing control method were found.

That is, according to the first aspect of the present invention, it is a foamable laminate in which a polyethylene-based resin layer (I) for foaming is formed on at least one surface of a base material mainly made of paper. Provided is an effervescent laminate containing the resin composition (A) forming a polyethylene-based resin layer and satisfying the following characteristics (i) to (v).
(I) The film heat shrinkage of the polyethylene-based resin layer (I) at 120 ° C. is 67% or less. (Ii) The polyethylene-based resin composition (A) is selected from the high-pressure radical polymerization method low-density polyethylene and the ethylene copolymer. (Iii) 7 g of melt flow rate (MFR) measured in accordance with JIS K6922-2: 1997 Annex (190 ° C, 21.18 N load) of polyethylene resin composition (A). / 10 minutes or more and less than 30 g / 10 minutes (iv) Polyethylene resin composition (A) having a density of 0.900 to 0.930 g / cm in accordance with JIS K6922-2: 1997 Annex (23 ° C.) ³
(V) The memory effect (ME) of the polyethylene-based resin composition (A) measured under the conditions of a cylinder temperature of 240 ° C. and a constant speed extrusion rate of 3 g / min using the melt indexer used in JIS K7210 is 1. Less than 0.8

Further, according to the second invention of the present invention, the foamable laminate according to the first invention is characterized in that the polyethylene-based resin composition (A) satisfies the following property (a-1). The body is provided.
(A-1) The melting point of the polyethylene resin (A) is 80 ° C to 120 ° C.

Further, according to the third aspect of the present invention, it is a foamable laminate in which a polyethylene-based resin layer (I) for foaming is formed on at least one surface of a base material mainly made of paper. The first or second invention is characterized in that the foamable laminate is provided with a thermoplastic resin layer (II) composed of a thermoplastic resin (B) on the other surface of the base material. The described effervescent laminate is provided.

Further, according to the fourth aspect of the present invention, the foamable laminate is a foamable laminate in which a polyethylene-based resin layer (I) for foaming is formed on at least one surface of a base material mainly composed of paper. A foamable laminate having a thermoplastic resin layer (II) composed of a thermoplastic resin (B) on the other surface of the base material, and the thermoplastic resin layer (II) is released from the base material. The first to third layers are the layers that hold the vapor, and the thermoplastic resin layer (II) is composed of the thermoplastic resin (B) having the following properties (b-1). The foamable laminate according to any one of the inventions is provided.
(B-1) Melting point (Tm (b)) is 100 to 140 ° C.

Further, according to the fifth aspect of the present invention, there is a method for producing an effervescent laminate provided with a polyethylene-based resin layer (I) for foaming on at least one surface of a base material mainly made of paper. ,
The polyethylene-based resin layer (I) extrudes and laminates the polyethylene-based resin composition for an effervescent laminate according to any one of the first to fourth inventions onto at least one surface of the base material. Provided is a method for producing an effervescent laminate, which is characterized by being formed by.

Further, according to the sixth aspect of the present invention, the method for producing an effervescent laminate according to the fifth aspect of the present invention is characterized in that the extrusion laminating process is performed at a processing rate of 65 m / min or more. Provided.

Further, according to the seventh aspect of the present invention, there is provided a foamed laminate in which the polyethylene-based resin layer (I) of the foamable laminate according to the first to fourth inventions is in a foamed state.

Further, according to the eighth aspect of the present invention, there is provided a container in a state of being molded from the foamed laminate according to the seventh invention.

Further, according to the ninth aspect of the present invention, there is a method for evaluating the performance of a foamable laminate in which a polyethylene-based resin layer (I) for foaming is formed on at least one surface of a base material mainly composed of paper. The film heat shrinkage rate of the polyethylene-based resin layer (I) in the foamable laminate at at least one point in the range of 100 to 150 ° C. is measured to predict the performance of the foamable laminate after foaming. Provided is a method for evaluating the performance of an effervescent laminate, which comprises evaluating.

Further, according to the tenth aspect of the present invention, there is a method for manufacturing and controlling a foamable laminate in which a polyethylene-based resin layer (I) for foaming is formed on at least one surface of a base material mainly made of paper. The film heat shrinkage of the polyethylene-based resin layer (I) in the foamable laminate at 120 ° C. is measured, and the film is manufactured so that the film heat shrinkage is 67% or less. A method for controlling the production of an effervescent laminate is provided.

According to the present invention, a foamable laminate that can obtain both sufficient foamability and a good foamed appearance even when the processing speed at the time of laminating molding is high, and a foamed laminate and a cup using the same. Insulation container can be manufactured. As a result, a foamed laminate having a good foamed appearance, a foamed paper using the same, and a heat insulating container such as a cup can be stably obtained, and can be provided with high productivity.
Further, conventionally, it has been difficult to estimate the performance evaluation of a foamable laminate having good characteristics such as having a good foaming appearance after heat foaming, but such performance evaluation is performed in advance with the foamable laminate before foaming. It is possible to provide a simple performance evaluation method or a manufacturing control method thereof.

In order to explain the method of measuring the film heat shrinkage rate of this invention, it is an image figure which illustrated the example of the sample (a) before a test, and the sample (b) after a test.

Hereinafter, the foamable laminate of the present invention, the method for producing the same, the foamed laminate obtained by this method, and the heat insulating container will be described in detail for each item.

1. 1. Foamable Laminated Material The present invention provides at least one surface of a paper-based base material with a polyethylene-based resin layer (I), and retains the steam released from the base material on the other side of the base material. The foamable laminate provided with the thermoplastic resin layer (II) to form the polyethylene-based resin layer (I) and the resin composition (A) forming the polyethylene-based resin layer have specific characteristics (i) to (i). It is characterized by having v), and more preferably, the thermoplastic resin layer (II) is composed of a thermoplastic resin (B) having a specific melting point on the other surface of the base material.
(I) The film heat shrinkage of the polyethylene-based resin layer (I) at 120 ° C. is 67% or less. (Ii) The polyethylene-based resin composition (A) is at least one selected from the high-pressure radical polymerization method low-density polyethylene and the ethylene copolymer (iii) JIS K6922- of the polyethylene-based resin composition (A). 2: The melt flow rate (MFR) measured according to the Annex 1997 (190 ° C., 21.18 N load) is 7 g / 10 minutes or more and less than 30 g / 10 minutes (iv) JIS of the polyethylene-based resin composition (A). K6922-2: Density according to 1997 Annex (23 ° C) is 0.900 to 0.930 g / cm ³
(V) The memory effect (ME) of the polyethylene-based resin composition (A) measured under the conditions of a cylinder temperature of 240 ° C. and a constant speed extrusion rate of 3 g / min using the melt indexer used in JIS K7210 is 1. Less than 0.8

(1) Paper-based base material In the foamable laminate of the present invention, the paper-based base material foams the polyethylene-based resin layer (I) on the surface by the vapor and volatile components contained in the base material. There is no particular limitation as long as it can be done. For example, high-quality paper, kraft paper, art paper and the like can be mentioned. Further, the base material mainly made of paper may be coated with a substance that generates volatile gas by heating, or a substance that generates volatile gas by heating may be mixed in the paper base material. On a base material mainly made of paper, pictures, characters, patterns, etc. can be printed on paper such as pulp paper or synthetic paper with ink or the like. The paper used as the base material preferably has a basis weight of 100 to 400 g / m ² , and particularly preferably 150 to 350 g / m ² . The water content of the paper is preferably about 4 to 10%, preferably about 5 to 8%.
Further, the paper substrate may be printed.

(2) Polyethylene resin layer (I)
As the resin constituting the polyethylene-based resin layer (I) according to the foamable laminate of the present invention, a polyethylene-based resin (A) that can be foamed in a heating temperature range of 100 ° C. to 200 ° C. can be used. In order to form a uniform foam cell having a high foaming ratio, it is preferable to select the polyethylene-based resin (A) in the range of 80 to 120 ° C., preferably 90 to 115 ° C. The polyethylene-based resin layer (I) foams, for example, due to vapors and volatile components due to the moisture contained in the base material.

The thickness of the polyethylene-based resin layer (I) is not particularly limited, but is 20 to 100 μm, and is preferably 30 to 100 μm in terms of increasing the thickness of the foamed layer. If the thickness of the polyethylene-based resin layer (I) is less than 20 μm, it is difficult to sufficiently increase the thickness of the foamed layer.
Further, the polyethylene-based resin layer (I) used in the present invention may be printed or the like, if necessary. Printing may be partially performed with colored inks or may be printed entirely. Conventionally known techniques can be appropriately selected and used for the printing position, the size of the printing area, the printing method, the ink used, and the like.

The present invention is characterized in that the heat-foamable polyethylene-based resin layer (I) formed on the above-mentioned paper-based substrate satisfies the following specific property (i).
That is, as a result of diligent studies by the present inventors, it is formed on such a base material, which can be achieved only when a plurality of conditions are constantly overlapped in order to achieve both sufficient foamability and a good foamed appearance. The characteristics of the polyethylene-based resin layer are an important factor, and such characteristics have a very good correlation when specified by the following film heat shrinkage at a specific temperature, that is, 120 ° C., which is representative of the temperature to be heated later. Found to get. This is because when the heat shrinkage rate of the film is large, when the resin is melted and foamed, the growth in the width direction of the foam cell grows early in one direction, resulting in a shape close to an ellipse and in the long axis direction. This is due to the increase in cell size starting from the growth of.
(I) The film heat shrinkage rate at 120 ° C. is 67% or less, and the property (i) specifies the properties of the polyethylene-based resin layer (I) formed on the substrate, and is measured by the following method. can do.

<Film heat shrinkage at 120 ° C>
The polyethylene-based resin layer (I) of the foamable laminate was peeled off from the paper base material so that the paper base material did not remain, and used as a sample.
The peeled film sample was punched with a 10 mmφ punch to prepare three test pieces. The sample image before the test is shown in FIG. 1 (a). A 50 ml beaker containing 30 ml of silicone oil (Shinetsu Silicone KF-96-100CS) was immersed in an oil bath, and the temperature of the oil bath was adjusted so that the temperature of the silicone oil in the beaker was 120 ° C.
The test piece was put into a beaker and left for 1 minute.
After 1 minute, the beaker was taken out of the oil bath and the beaker was allowed to cool at room temperature. After the sample had solidified, the sample was taken out of the beaker, and the length L (see FIG. 1) on the short axis side of the elliptical sample was measured to the unit of 0.1 mm. A sample image diagram after the test is shown in FIG. 1 (b). The heat shrinkage rate (%) at 120 ° C. was calculated by the following calculation.
120 ° C heat shrinkage rate (%) = ((L0-L) / L0) * 100
L0: Sample diameter before test (10 mm)
L: Length of sample minor axis after test (mm)
The average value of the three test pieces was calculated, and the first decimal place was rounded off to obtain an integer.

When the film heat shrinkage rate at 120 ° C. is 67% or less, the area of the foam cells in the foamed laminate obtained after heating is small and is uniformly and finely arranged on the surface, so that the foamed appearance is extremely smooth. Become. On the other hand, if it exceeds 67%, the area of the foam cell rapidly increases, the shape of the foam cell tends to collapse, and the surface becomes uneven, which impairs the surface appearance. On the other hand, even in terms of foaming height, if the film heat shrinkage rate is 67% or less, a sufficient foaming height can be obtained.
The lower limit of the film heat shrinkage rate is not particularly limited, but may be practically 30 to 67%, preferably 40 to 65%.

In order to obtain the polyethylene resin layer (I) satisfying the property (i), specifically, the physical properties of the polyethylene resin (A) constituting the polyethylene resin composition used for forming the resin layer (I). Based on the method disclosed in Examples of the present invention, conditions such as resin temperature and processing speed when forming the polyethylene resin composition on a substrate are specified under certain specific conditions. It can be achieved by doing.

(3) Effervescent polyethylene resin composition (A)
(Ii) Examples of the polyethylene-based resin (A) constituting the polyethylene-based resin composition used for forming the foamable polyethylene-based resin layer (I) include an ethylene homopolymer and both ethylene and α-olefin. Examples thereof include polymers, high-pressure radical polymerization methods, low-density polyethylene, ethylene copolymers, and mixtures thereof.
Examples of the monomer copolymerized with ethylene in the ethylene copolymer include conjugated diene (for example, butadiene and isoprene), non-conjugated diene (for example, 1,4-pentadiene), acrylic acid, and acrylic acid ester (for example, methyl acrylate). (Ethyl acrylate), methacrylic acid, methacrylic acid esters (for example, methyl methacrylate and ethyl methacrylate), vinyl ethylene acetate and the like are exemplified.
The polyethylene-based resin (A) is preferably low-density polyethylene obtained by a high-pressure radical polymerization method (high-pressure radical polymerization method low-density polyethylene). High-pressure radical polymerization method Low-density polyethylene is produced by bulk or solution polymerization under ultra-high pressure of 1000 to 4000 atm using radical generators such as oxygen and organic peroxides.
Further, the low-density polyethylene obtained by the high-pressure radical polymerization method includes low-density polyethylene obtained by an autoclave reactor and low-density polyethylene obtained by a tubular reactor, and the molecular weight varies depending on the reaction type. Low-density polyethylene with different distributions can be obtained. Further, the polyethylene-based resin (A) of the present invention may be one kind or a plurality of kinds. If the polyethylene resin composition of the present invention contains one type of polyethylene-based resin, the following characteristics correspond to the characteristics of the polyethylene-based resin, and the polyethylene resin composition of the present invention contains a plurality of polyethylene-based resins. If it is a seed, it corresponds to the characteristics of the mixture of the plurality of polyethylene-based resins.

(Iii) MFR
In the present invention, the melt frate (MFR) of the polyethylene resin (A) contained in the polyethylene resin composition is 7 g / 10 minutes or more and less than 30 g / 10 minutes, preferably 9 g / 10 minutes or more and less than 30 g / 10 minutes. It is more preferably 11 to 30 g / 10 minutes, and even more preferably 12 to 30 g / 10 minutes. If the MFR is less than 7 g / 10 minutes, it is difficult for the foamed cell to have an appropriate size, while if the MFR is 30 g / 10 minutes or more, the cell bursts during foaming, which is not preferable. Here, MFR is a value measured in accordance with JIS K6922-2: 1997 Annex (190 ° C., 21.18N load).

(Iv) Density In the present invention, the density of the polyethylene-based resin (A) contained in the polyethylene resin composition is preferably 0.900 to 0.930 g / cm ³ , and more preferably 0.905 to 0.930 g / cm. It is ³ , more preferably 0.910 to 0.930 g / cm ³ . If the density is less than 0.900 g / cm ³ , the slip of the resin layer is poor and the handling is poor, which is not preferable. If the density exceeds 0.930 g / cm ³ , it is not preferable because the temperature for foaming needs to be raised.
Here, the density is a value measured in accordance with JIS K6922-2: 1997 Annex (23 ° C.).

(V) Memory effect (ME)
In the present invention, the memory effect (ME) of the polyethylene-based resin (A) contained in the polyethylene resin composition is less than 1.8, preferably 1.75 or less, and more preferably 1.7 or less. .. When the memory effect (ME) is 1.8 or more, the foaming appearance deteriorates when the processing speed is increased, which is not preferable.
The memory effect was measured under the following conditions using the melt indexer used in JIS K7210 (1999).
[Measurement condition]
The procedure was carried out as follows under the conditions of a cylinder temperature of 240 ° C. and a constant speed extrusion rate of 3 g / min.
A 2.095 mmφ MFR measurement nozzle is set in the measuring device, and the resin is filled in the furnace.
A piston is placed and held at a constant speed extrusion of 0.09 g / min for 5 minutes, and then a constant speed extrusion of 3 g / min is performed to bleed air until 6 minutes and 30 seconds. After 6 minutes and 30 seconds, the strands were cut while maintaining 3 g / min, and the diameter of the strands when the strand length from the lower end of the orifice became 20 mm was measured by KEYENCE laser dimensions at a position 15 mm from the lower end of the orifice. Measurement is performed using a measuring instrument (LS-3033). The ME was calculated by the following equation with the measured strand diameter as D and the die orifice diameter as D0 (2.095 mm) (however, the measured value was rounded off to the second decimal place).
ME = D / D0

(Vi) Antioxidant In the present invention, it is preferable to add an antioxidant to the polyethylene resin composition constituting the polyethylene resin layer (I).
Specifically, the amount of the antioxidant contained in the polyethylene resin composition of the present invention is preferably 80 ppm or more, preferably 150 ppm or more, and more preferably 300 ppm or more and less than 2000 ppm. In the present invention here, ppm represents a weight ratio.

Examples of the antioxidant include butyl hydroxytoluene, 4-hydroxymethyl-2,6-di-t-butylphenol, 2,6-di-t-butyl-4-ethylphenol, and n-octadecyl-β- (4). '-Hydroxy-3', 5'-di-t-butylphenyl) propionate, tocopherol, 2,4-bis (octylthiomethyl) -6-t-methylphenol, 2,4-bis [(dodecylthio) methyl] -6-Methylphenol, 2,2'-methylenebis (4-methyl-6-t-butylphenol), 2,2'-methylenebis (4-ethyl-6-t-butylphenol), 4,4'-methylenebis (2) , 6-di-t-butylphenol), 4,4'-butylidenebis (6-t-butyl-m-cresol), 4,4'-thiobis (6-t-butyl-m-cresol), N, N' -Hexamethylenebis (3,5-di-t-butyl-4-hydroxyhydrocinnamide), 3,5-di-t-butyl-4-hydroxybenzylphosphonic acid monoethyl ester calcium salt, hexamethylenebis (3,5-di-t-butyl-4-hydroxyhydrocinnamide) 3,5-Di-t-butyl-4-hydroxyhydrocinnamate), triethyleneglycolbis-3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionate, 2,2'-oxamidbis [ Ethyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,2'-5 etylidenebis (4,6-di-t-butylphenol), N, N'-1 , 3-Propanediylbis (3,5-di-t-butyl-4-hydroxyhydrocinnamide), 2,4-dimethyl-6- (1-methylpentadecyl) phenol, 2- (2'-hydroxy- 5'-Methylphenyl) benzotriazole, 2- (2'-hydroxy-3'-t-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2,5-bis [5'-t-butylbenzo Xazolyl (2)]-thiophene, [bis (3,5-di-t-butyl-4-hydroxybenzylphosphonic acid monoethyl ester) nickel salt, methyl salicylate, p-methoxyphenol, phenyl salicylate, 2- (2H-benzotriazole-2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol, 2- (2H-benzotriazole-2-yl) -4,6-bis (1-methyl) -1-phenylethyl) phenol, 4-benzoxazoyl- (2) ) -4'[5-Methylbenzoxazoyl- (2)]-Stilben, hexadecyl-3,5-di-t-butyl-4-hydroxybenzoate, 2,2'-methylenebis [4- (1,1,1) 3,3-Tetramethylbutyl) -6- (2H-benzo [d] triazole-2-yl) phenol], 2,4-di-t-butyl-6- (5-chlorobenzotriazol-2) -Il) Phenol, phenol-based such as 2-cyano-3,3-diphenylacrylic acid-2-ethylhexyl, thioether-based such as dilaurthiodipropionate, distearylthiodipropionate, tris (nonylphenyl) phosphite , Distearyl pentaerythritol diphosphite, Tris (2,4-di-t-butylphenyl) phosphite, 4,4'-butylidene-bis (3-methyl-6-t-butylphenylditridecylphosphite), Tris (cyclohexylphenyl) phosphite, tris- [2- (2,4,8,10-tetrabutyl-5,7-dioxa-6-phosphodibenzo- {a, c} cyclohepten-6-yl-oxy) ethyl] Amin, bis- [2-methyl-4,6-bis- (1,1-dimethylethyl) phenyl] ethylphosphite, 3,9-bis {2,4-bis (1-methyl-1-phenylethyl) Phenoxy} -2,4,8,10-tetraoxa-3,9-diphosphaspiro [5,5] undecane, 6- [3- (3-t-butyl-4-hydroxy-5-methylphenyl) propoxy-2, 4,8,10-Tetra-t-butylbenz [d, f] [1,3,2] dioxaphosphepine, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 3 , 9-bis (2,6-di-t-butyl-4-methylphenoxy) -2,4,8,10-tetraoxa-3,9-diphosphaspiro [5,5] undecane, carbetaximethyldiethylphosphonate Examples thereof include, but are not limited to, antioxidants such as phosphorus-based and the like.

The polyethylene resin composition for an effervescent laminate of the present invention may be a neutralizing agent such as a metal soap, an antiblocking agent, a lubricant, or a dispersion, if necessary, as long as the characteristics of the polyethylene-based resin (A) are not impaired. It may contain additives such as agents, pigments, colorants such as dyes, antifogging agents, antistatic agents, ultraviolet absorbers, light stabilizers, and nucleating agents.
Further, other thermoplastic resins may be blended as long as the characteristics of the polyethylene-based resin (A) are not impaired. Examples of the thermoplastic resin include other polyolefin resins, polyester resins, polyvinyl chloride resins, polystyrene resins and the like.

The polyethylene-based resin (A) is not particularly limited as long as it satisfies the above-mentioned characteristics, but preferably, a high-pressure radical polymerization method low-density polyethylene to which a radical generator is added and subjected to a radical reaction can be mentioned.
Examples of the radical generator include organic peroxides, dihydroaromatic compounds, dicumyl compounds and the like. Examples of the organic peroxide include (i) hydroperoxides such as t-butylhydroperoside, cumenehydroperoxide, and 1,1,3,3-tetramethylbutylhydroperoxide, (ii). Ketone peroxides such as methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide, acetyl acetone peroxide, cyclohexanone peroxide, diacyl peroxides such as (iii) isobutyryl peroxide, lauroyl peroxide, benzoyl peroxide, (iv) dik. Milperoxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, t-butylcumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-di -Dialkyl peroxides such as (t-butylhexin) -3, di-t-amyl peroxide, peroxyketal such as (v) 2,2-di- (t-butylperoxy) butane, (vi) t. -Hexylperoxypivalate, t-butylperoxypivalate, t-amylperoxy2-ethylhexanoate, t-butylperoxy2-ethylhexanoate, t-butylperoxyisobutyrate, t- Alkyl peroxides such as butylperoxybenzoate, percarbonates such as (vii) bis (4-t-butylcyclohexyl) peroxydicarbonate, di-isopropylperoxydicarbonate, t-amylperoxyisopropylcarbonate, ( vivyl) Cyclic organic peroxides such as 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-tripaoxonan can be mentioned. Of these, cyclic organic peroxides are preferable.

The amount of the radical generator to be blended is not particularly limited, but is preferably 0.5 parts by weight or less, particularly 0.1 parts by weight or less, based on 100 parts by weight of the polyethylene resin (A). If the blending amount of the radical generator exceeds 0.5 parts by weight, the fluidity deteriorates.

(4) Thermoplastic resin layer (II)
The thermoplastic resin layer (II) used in the foamable laminate of the present invention has a role of holding vapor or the like released from the base material.
The thermoplastic resin (B) constituting the same may be a resin having a melting point higher than that of the polyethylene-based resin (A) forming the polyethylene-based resin layer (I) or not melting, and is preferably thermoplastic. The melting point (Tm (b)) of the resin (B) has the property of the following formula (b-1).
(B-1) Melting point (Tm (b)) is 100 to 140 ° C.
Further, although not particularly limited, in order to preferentially foam the polyethylene-based resin layer (I) and easily obtain a uniform and high cell thickness, it is foamed by steam or the like released from the base material by heating. It is preferable that the melting point difference between the polyethylene-based resin (A) and the thermoplastic resin (B) that retains the vapor emitted from the base material satisfies the following formula (1).
Tm (b) -Tm (a) ≧ 10 Equation (1)
(However, Tm (a): melting point (° C.) of the polyethylene resin (A) of the polyethylene resin layer (I), Tm (b): melting point of the thermoplastic resin (B) of the thermoplastic resin layer (II) (however, ℃))

The thermoplastic resin (B) used in the present invention has, for example, high / medium / low density polyethylene, a polypropylene resin, a polybutene-1 resin, a poly-4-methyl-penten-1 resin, and the like, and has 2 to 10 carbon atoms. Α-olefin homopolymers, or polyolefin resins such as their mutual copolymers, polyamide resins, polyester resins, ethylene-vinyl acetate copolymer kendies, vinyl chloride resins, vinylidene chloride resins, polystyrene resins, Alternatively, a mixture with these may be mentioned. Among these, polyolefin resins such as high-density polyethylene, medium-density polyethylene, and linear low-density polyethylene are preferable.

Examples of the thermoplastic resin (B) include ethylene homopolymers, ethylene / α-olefin copolymers, high-pressure radical polymerization methods, low-density polyethylenes, ethylene copolymers, polyolefins such as polypropylene, and polyolefins such as mixtures thereof. Resin is exemplified.
Examples of the monomer copolymerized with ethylene in the ethylene copolymer include conjugated diene (for example, butadiene and isoprene), non-conjugated diene (for example, 1,4-pentadiene), acrylic acid, and acrylic acid ester (for example, methyl acrylate and acrylic). Ethylene acetate), methacrylic acid, methacrylic acid esters (eg, methyl methacrylate and ethyl methacrylate), vinyl ethylene acetate and the like are exemplified.

When a polyethylene resin is used as the thermoplastic resin (B), the MFR is 2.0 to 15 g / 10 minutes, preferably 3.0 to 14 g / 10 minutes, and more preferably 4.0 to 13 g / 10. Minutes. If the MFR is less than 2.0 g / 10 minutes, the high-speed processability during the extrusion laminating process deteriorates, and if it exceeds 15 g / 10 minutes, the extrusion laminating processability may become unstable, which is not preferable.
When a polyethylene resin is used as the thermoplastic resin (B), the density is 0.930 to 0.970 g / cm ³ , preferably 0.930 to 0.965 g / cm ³ , and more preferably 0. It is preferably about 930 to 0.960 g / cm ³ . If the density is less than 0.930 g / cm ³ , the laminating resin will not slide smoothly and the handling will be poor, and if it exceeds 0.970 g / cm ³ , there is a concern that the extruded laminating workability will become unstable, which is not preferable.

Considering the polyethylene-based resin layer (I), the melting point Tm (b) of the thermoplastic resin (B) is in the range of 100 to 140 ° C., preferably 110 to 140 ° C., more preferably 115 to 140 ° C. It is preferred to be selected. If the melting point is lower than 100 ° C., the heat resistance may be insufficient and the thermoplastic resin layer may foam, and if it exceeds 140 ° C., the low temperature heat sealability may be poor, which is not preferable.

Further, the thermoplastic resin (B) has adhesiveness to a paper substrate such as a polyamide resin, a polyester resin, an ethylene-vinyl acetate copolymer saponified product, a vinyl chloride resin, a vinylidene chloride resin, and a polystyrene resin. When a resin lacking in the amount of resin is used, a laminate may be formed via a customary adhesive resin such as an unsaturated carboxylic acid-modified polyolefin resin or a copolymer with ethylene-unsaturated carboxylic acid.

The thermoplastic resin (B) may contain, if necessary, an antioxidant such as a phenol-based or phosphorus-based antioxidant, a neutralizing agent such as a metal soap, or an anti-blocking agent, as long as the characteristics of the thermoplastic resin are not impaired. Additives such as lubricants, dispersants, pigments, colorants such as dyes, antifogging agents, antistatic agents, ultraviolet absorbers, light stabilizers, and nucleating agents may be blended.

The thickness of the thermoplastic resin layer (II) is not particularly limited, but is usually selected in the range of 10 to 100 μm, particularly preferably 20 to 100 μm in that the thickness of the foamed layer can be increased. If the thickness of the thermoplastic resin layer (II) is less than 10 μm, the vapor emitted from the substrate cannot be sufficiently retained, and the thickness of the foamed layer may not be sufficiently increased. Further, when it exceeds 100 μm, no further improvement in the effect is expected, and there is a possibility that the economic demerit becomes large.

(5) Foamable Laminate In the foamed laminate of the present invention, another layer may be provided in the layers, or in the inner layer and / or the outer layer thereof, as long as the effects of the present invention are not impaired, and for example, the outer layer may be provided. From {Polyethylene film layer / Polyethylene resin layer (I) / Base material / Thermoplastic resin layer (II)}, {Polyethylene film layer / Barrier layer / Adhesive layer / Polyethylene resin layer (I) / Base material / Heat A base material and a polyethylene-based resin layer such as a plastic resin layer (II)} and a {polyethylene resin layer (I) / base material / thermoplastic resin layer (II) / barrier layer / thermoplastic resin layer (II)}. I) or the inner and / or outer layers of the laminate provided with the thermoplastic resin layer (II), or one or more film layers, decorative layers, reinforcing layers, adhesive layers, barrier layers, etc. between the layers. It may be provided.
In addition, printing or the like may be performed as needed. Printing may be performed with colored ink partially or completely. Further, if necessary, an effervescent ink may be used to partially or completely provide an effervescent portion. Conventionally known techniques can be appropriately selected and used for the printing position, the size of the printing area, the printing method, the ink used, and the like.

Examples of the decorative layer include printed paper, film, non-woven fabric, and woven fabric.
The reinforcing layer is a polyethylene resin film or the like on the outer layer of the polyethylene resin layer (I) so that the foamed layer does not burst when the polyethylene resin layer (I) laminated on the substrate is foamed by heating. It plays a role of preventing bursting due to excessive foaming of the foam layer, uniformly correcting irregular foam cells, or laminating a film, a non-woven fabric, or the like to give mechanical strength. The resin is not particularly limited, and may be a polyolefin-based resin such as polyethylene or polypropylene, a polyamide-based resin, a polyester-based resin, or the like.
The adhesive layer is a resin forming the layer, for example, a copolymer of ethylene and an unsaturated carboxylic acid or a derivative thereof, a modified polyolefin resin obtained by grafting an unsaturated carboxylic acid or the like on a polyolefin resin, or ethylene-. Examples thereof include hot melts such as vinyl acetate copolymers and ordinary adhesives.
The barrier layer is, for example, a polyamide resin, a polyester resin, an ethylene-vinyl acetate copolymer satanized product (EVOH), a polyvinylidene chloride resin, a polycarbonate resin, and a stretched polypropylene as the resin forming the layer. (OPP), stretched polyester (OPET), stretched polyamide, alumina vapor deposition film, vapor deposition film of inorganic oxide such as silica vapor deposition film, metal vapor deposition film such as aluminum vapor deposition, metal foil, barrier material coating film and the like can be mentioned.

The method for producing the foamable laminate of the present invention is not particularly limited as long as it is a method in which the polyethylene-based resin layer (I) and the thermoplastic resin layer (II) can be laminated on both sides of a base material mainly made of paper. Examples thereof include extrusion laminating processing in which molten resin is directly laminated, sand laminating processing in which pre-films are laminated, and dry laminating processing.

The extrusion laminating process is a method of continuously coating and crimping a molten resin film extruded from a T-die onto a base material, and is a molding process in which coating and adhesion are performed at the same time. The extrusion laminating process is preferably performed at a processing speed of 65 m / min or more. Further, the sand laminating process is a method in which a molten resin is poured between a film to be laminated with a paper, and the molten resin acts like an adhesive to adhere and laminate, and the dry laminating process is a method of adhering and laminating. Dehumidify the atmospheric humidity near the adhesive and / or adhesive application roll that adheres the film to be laminated with, or heat the temperature of the adhesive and / or adhesive application roll, or apply the film sheet. This is a method of drying the surface.
In the sand laminating process and the dry laminating process, on the side where the thermoplastic resin layer (II) of the base material mainly made of paper used in the present invention is formed, between the base material and the thermoplastic resin layer (II). Examples of the laminated film include an aluminum foil for improving the barrier property, a polyester-based film, and various barrier properties.
Extrusion laminating conditions for laminating are 100 mm to 300 mm as an air gap, preferably 105 mm to 250 mm, and a processing speed of 50 m / min to 150 m / min, preferably 55 m / min to 95 m / min, particularly preferably 65 m. When it is / min or more, the effect of the present invention is exhibited. The actual measured resin temperature of the resin coming out of the T-die outlet of the extruder is in the range of 300 to 350 ° C, preferably 310 to 340 ° C. From these conditions, the above characteristics are appropriately combined with the characteristics of the resin to be used. It can be applied to satisfy (i).

2. 2. Foamed Paper The foamed paper of the present invention is obtained by heating the above-mentioned foamable laminate to foam the polyethylene-based resin layer (I). The height of the foam cell of the foamed paper is preferably 200 μm or more, more preferably 250 μm or more. If the height of the foam cell is less than 200 μm, sufficient heat insulating properties cannot be obtained.

The heating method is not particularly limited, and examples thereof include a method of heating with hot air, microwaves, high frequencies, infrared rays, far infrared rays, and the like. The heating temperature is not particularly limited, but it must be a temperature at which the water in the paper is evaporated and the foamable resin is melted, and for example, 100 to 200 ° C. is preferable. The heating time is preferably 10 seconds to 10 minutes. Within the above range, a sufficient foam cell height can be easily obtained. When the foamable resin of the present invention is used, it is possible to obtain a foamed paper having a good foamed appearance under these heating conditions.
The foamed paper is used not only as a heat insulating / heat insulating material for the following heat insulating containers such as cups, but also as a cushioning material, a sound insulating material, a foamed paper, etc., and is used as a sleeve material, a paper plate, a tray, a non-slip material, etc. It is used as a packaging material for fruits, agricultural use such as foam paper, industrial use, and daily life material.

3. 3. Insulated container The heat-insulated container of the present invention is obtained by forming a container using the above-mentioned foamable laminate, heating the container, and foaming the polyethylene-based resin layer (I).
Even in the heat insulating container, the height of the foamed cell is 200 μm or more, preferably 250 μm or more, as in the case of the foamed paper. When the height of the foam cell is 200 μm or more, sufficient heat insulating properties can be easily obtained.
The heat-insulating container thus obtained is used as a tray, a cup, or the like. Examples of applications include hot beverages, cup soups, cup miso soup, cup ramen, natto containers, microwave oven-compatible containers, and the like.

As described above, in the present invention, even when processed under high-speed conditions during extrusion laminating, the foam layer has a high foaming ratio and a uniform foam cell is formed, and is excellent in heat insulating properties, good appearance, and the like. A heat insulating container can be easily obtained.

4. Performance evaluation method or manufacturing control method of foamable laminate As described above, the foamable laminate of the present invention is formed into the shape of a container or the like, and then the container is heated to foam the polyethylene-based resin layer (I). It is characterized by having good heat insulating properties and a good foaming appearance after foaming.
Specifically, in order to obtain a foamed paper that satisfies both the effect of having sufficient foamability and the effect of forming a good foamed appearance, the resin composition, various conditions for forming the resin layer, and molding heating are required. Since the conditions are complicatedly related, it has been difficult to predict and evaluate in advance at the stage of the foamable laminate before heating, but by the method of the present invention described below, the foamable laminate can be easily prepared. Performance evaluation can be performed and manufacturing control can be performed.

That is, according to the present invention, there is a performance evaluation method for an effervescent laminate in which a polyethylene-based resin layer (I) for foaming is formed on at least one surface of a base material mainly made of paper. The feature is that the film heat shrinkage rate at at least one point of the polyethylene-based resin layer (I) in the sex laminate in the range of 100 to 150 ° C. is measured to predict and evaluate the performance of the foamable laminate after foaming. A method for evaluating the performance of an effervescent laminate is provided.
That is, as a step of the performance evaluation method,
a) Using a polyethylene-based resin composition (A) having specific physical characteristics due to a predetermined resin composition and additive formulation on a base material such as paper or a film, a predetermined air gap interval and a predetermined extruded laminate. Depending on the processing speed, a foamable laminate or a laminate on which the polyethylene-based resin layer (I) is formed is formed. The film or the like is not particularly limited, and examples thereof include polyolefin-based resins such as polypropylene, polyamide-based resins, and biaxially stretched films such as polyester-based resins, but films other than films are also possible.
b) From the foamable laminate or laminate prepared in a), the polyethylene-based resin layer (I) is peeled from the paper substrate so that the paper substrate does not remain, and used as a sample.
c) A test piece is prepared from the peeled film sample and has a predetermined shape as shown in FIG. 1 (a).
d) The test piece is maintained at a temperature of at least one point (1 temperature) in the range of 100 to 150 ° C., for example, 120 ° C. by a predetermined method. For example, a 50 ml beaker containing 30 ml of silicone oil (Shinetsu Silicone KF-96-100CS) is immersed in an oil bath, and the temperature of the oil bath is adjusted so that the silicon oil in the beaker becomes 120 ° C.
e) After a predetermined time (1 minute) has elapsed, the test piece is taken out and allowed to cool, and after the sample test piece has solidified, the length L (see FIG. 1) on the short axis side of the elliptical sample is in units of 0.1 mm. Measure up to. A sample image diagram after the test is shown in FIG. 1 (b).
The heat shrinkage rate (%) at 120 ° C. is calculated by the following calculation.
120 ° C heat shrinkage rate (%) = ((L0-L) / L0) * 100
L0: Sample diameter before test (10 mm)
L: Length of sample minor axis after test (mm)
This measurement is performed with a plurality of test pieces, for example, three or more test pieces, the average value of the three test pieces is calculated, the first decimal place is rounded off, and the heat shrinkage rate (%) is obtained as an integer.
The film heat shrinkage rate specifies the properties of the polyethylene-based resin layer (I) formed on the base material, and the specific measurement method is described in 1. As described in the section of foamable laminate.
The temperature range is not particularly limited as long as it is the film heat shrinkage rate at at least one point in the range of 100 to 150 ° C., but is preferably around 105 to 140 ° C., for example, the film heat shrinkage rate at 120 ° C. If it is 67% or less, it can be evaluated as a pass, and if it exceeds that, it can be evaluated as a failure.

Further, according to the present invention, there is a method for manufacturing and controlling an effervescent laminate in which a polyethylene-based resin layer (I) for foaming is formed on at least one surface of a base material mainly made of paper. A foamable laminate characterized in that the film heat shrinkage of the polyethylene-based resin layer (I) in the foamable laminate at 120 ° C. is measured and the film is manufactured so that the film heat shrinkage is 67% or less. A manufacturing control method is provided.

When the film heat shrinkage rate at 120 ° C. is 67% or less, the area of the foam cells in the foamed laminate obtained after heating is small and is uniformly and finely arranged on the surface, so that the foamed appearance is extremely smooth. Become. On the other hand, if it exceeds 67%, the area of the foam cell rapidly increases, the shape of the foam cell tends to collapse, and the surface becomes uneven, which impairs the surface appearance. On the other hand, even in terms of foaming height, if the film heat shrinkage rate is 67% or less, a sufficient foaming height can be obtained.
The lower limit of the film heat shrinkage rate is not particularly limited, but may be practically 30 to 67%, preferably 40 to 65%.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.
The physical characteristics of this example and the test method for the obtained foamable laminate are as follows.

1. 1. Test method (1) Measurement was performed in accordance with MFR: JIS K6922-2: 1997 Annex (190 ° C., 21.18N load).
(2) Density: The polyethylene-based resin (A) was measured under the following conditions.
The pellets were hot pressed to make a 2 mm thick press sheet, which was placed in a 1000 ml capacity beaker, filled with distilled water, covered with a watch glass and heated with a mantle heater. After boiling the distilled water for 60 minutes, the beaker was placed on a wooden table and allowed to cool. At this time, the boiling distilled water after boiling for 60 minutes was set to 500 ml, and the time until the room temperature was adjusted was adjusted so as not to be 60 minutes or less. In addition, the test sheet was immersed in a substantially central part of the water so as not to come into contact with the beaker and the water surface. After annealing the sheet under the conditions of 23 ° C and 50% humidity for 16 hours or more and 24 hours or less, punch it so that it is vertical x horizontal 2 mm, and measure it according to K6922-2: 1997 Annex (23 ° C). bottom.

(3) Melting point: The pellet was made into a sheet by hot pressing and punched into a sample. The measurement was carried out by the method of JIS K7121-1987 under the following conditions in the procedure of first raising temperature, lowering temperature and second raising temperature, and the temperature at the maximum peak height of the second raising temperature was taken as the melting point.
Equipment: DSC7020 manufactured by Seiko Instruments
Lifting temperature condition: First temperature rise from 30 ° C to 200 ° C at 40 ° C / min
Lowering temperature from 200 ° C to 20 ° C at 10 ° C / min
Second temperature rise from 20 ° C to 200 ° C at 10 ° C / min Temperature retention time: 5 minutes after the first temperature rise, 5 minutes after the temperature drop Sample volume: 5 mg
Temperature calibration: Indium Reference: Aluminum

(4) Film heat shrinkage at 120 ° C. The polyethylene-based resin layer (I) of the foamable laminate was peeled off from the paper substrate so that the paper substrate did not remain, and used as a sample.
The peeled film sample was punched with a 10 mmφ punch to prepare three test pieces. A 50 ml beaker containing 30 ml of silicone oil (Shinetsu Silicone KF-96-100CS) was immersed in an oil bath, and the temperature of the oil bath was adjusted so that the temperature of the silicone oil in the beaker was 120 ° C.
The test piece was put into a beaker and left for 1 minute.
After 1 minute, the beaker was taken out of the oil bath and the beaker was allowed to cool at room temperature. After the sample had solidified, the sample was taken out of the beaker, and the length L (see FIG. 1) on the short axis side of the elliptical sample was measured to the unit of 0.1 mm. The heat shrinkage rate (%) at 120 ° C. was calculated by the following calculation.
120 ° C heat shrinkage rate (%) = ((L0-L) / L0) * 100
L0: Sample diameter before test (10 mm)
L: Length of sample minor axis after test (mm)
The average value of the three test pieces was calculated, and the first decimal place was rounded off to obtain an integer.

(5) Appearance evaluation after foaming The laminate obtained in the example was cut into 10 cm × 10 cm, allowed to stand in a perfect oven (manufactured by PH-102 type Espec) heated to 117 ° C. for 300 seconds, and then foamed. It was taken out and cooled to room temperature in the air.
The foamed cell size is measured with a digital microscope (HDM-2100 manufactured by SCARA) from the bottom, and the area of each foamed cell of 1.3 cm x 1.3 cm square is measured, and then the average is calculated. Those having an average value of more than 0.9 mm ² were evaluated as having poor appearance (×), and those having an average value of less than 0.9 mm ² were evaluated as having good appearance (◯).

(6) Foam height After photographing the cross section of the foam used in the above appearance evaluation with a digital microscope (HDM-2100 manufactured by SCARA), the height of the foam layer is measured at 10 points and the average value is calculated. bottom.

2. 2. Resin (1) Polyethylene resin (A)
As shown in Tables 2 and 3, a resin composition for forming the polyethylene-based resin layer (I) is prepared by using the resins (A-1) to (A-7) shown in Table 1 alone or in combination. bottom.
For A-1, a-2-1 and a-3-2, 150 ppm of octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate as an antioxidant was added to Tris. 150 ppm of (2,4-di-tert-butylphenyl) phosphite is added.

(2) Thermoplastic resin (B)
B1: MFR 10 g / 10 min, density 0.936 g / cm ³ , Tm (b) polyethylene resin at 129 ° C.

(Example 1)
A 90 mmφ extruder, an air gap of 110 mm, and an extruded laminator with an effective die width of 560 mm are used to heat one side of a paper substrate with a basis weight of 320 g / ^{m 2} and a water content of 7%. As a material constituting the plastic resin layer (II), a thermoplastic resin (B1) having an MFR of 10 g / 10 min, a density of 0.936 g / cm ³ , and a melting point of 129 ° C. is extruded at a resin temperature of 320 ° C., a processing speed of 50 m / min, and a thickness of 40 μm. Lamination processing was performed to obtain a laminate of the thermoplastic resin layer (II) and the paper substrate.
Next, the paper substrate surface opposite to the thermoplastic resin layer (II) of the laminate was subjected to corona treatment (30 W · min / m ² ), a 90 mmφ extruder (L / D28), an air gap of 150 mm, and a die. Using an extruded laminator with an effective width of 560 mm and a die slip gap of 0.75 mm, set the cylinder set temperature to 220 ° C, 300 ° C, 345 ° C, 345 ° C, and 345 ° C from the hopper side, and then set the head, adapter, and T-die set temperatures. As a material constituting the polyethylene-based resin layer (I) having a processing speed of 60 m / min and a thickness of 70 μm at a processing speed of 60 m / min at 345 ° C., the high-pressure method low-density polyethylene-based resin (A-1) (antioxidant). As an extrusion laminate, 150 ppm of octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate and 150 ppm of tris (2,4-di-tert-butylphenyl) phosphite are added. processed. At this time, the measured resin temperature at the outlet of the T die was 320 ° C. The surface of the polyethylene-based resin layer (I) of the foamable laminate is subjected to corona treatment (10 W · min / m ² ) from the polyethylene-based resin layer (I), the paper substrate, and the thermoplastic resin layer (II). An effervescent laminate was obtained. Table 2 shows the evaluation results of the obtained effervescent laminate. Both the processing speed of 60 m / min and the processing speed of 75 m / min had a good foaming appearance and a sufficient foaming height.

(Example 2)
A foamable laminate was obtained in the same manner as in Example 1 except that the air gap was set to 130 mm as a condition for laminating the polyethylene-based resin layer (I). Table 2 shows the evaluation results of the obtained effervescent laminate. Both the processing speed of 60 m / min and the processing speed of 75 m / min had a good foaming appearance and a sufficient foaming height.

(Example 3)
As the resin used for the polyethylene-based resin layer (I), the high-pressure method low-density polyethylene-based resin (A-2) was used, and the conditions for laminating the polyethylene-based resin layer (I) were such that the air gap was 130 mm. An effervescent laminate was obtained in the same manner as in Example 1. Table 2 shows the evaluation results of the obtained effervescent laminate. Both the processing speed of 60 m / min and the processing speed of 75 m / min had a good foaming appearance and a sufficient foaming height.

(Example 4)
The resin used for the polyethylene-based resin layer (I) is a high-pressure low-density polyethylene-based resin (A-2), and the antioxidant is octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl). ) Using a material (a2-1) to which 150 ppm of propionate and 150 ppm of tris (2,4-di-tert-butylphenyl) phosphite are added, an air gap is provided as a condition for laminating the polyethylene resin layer (I). An effervescent laminate was obtained in the same manner as in Example 1 except that the thickness was 135 mm. Table 2 shows the evaluation results of the obtained effervescent laminate. Both the processing speed of 60 m / min and the processing speed of 75 m / min had a good foaming appearance and a sufficient foaming height.

(Example 5)
As the resin used for the polyethylene resin layer (I), the high pressure method low density polyethylene resin (autoclave) (A-3) 50% by weight and the high pressure method low density polyethylene resin (tubular) (A-4) 50. A polyethylene resin composition obtained by mixing with% by weight was used as a material (a-3-1). A foamable laminate was obtained in the same manner as in Example 1 except that the air gap was set to 130 mm as a condition for laminating the polyethylene-based resin layer (I). Table 2 shows the evaluation results of the obtained effervescent laminate. Both the processing speed of 60 m / min and the processing speed of 75 m / min had a good foaming appearance and a sufficient foaming height.

(Example 6)
As the resin used for the polyethylene resin layer (I), the high pressure method low density polyethylene resin (autoclave) (A-3) 50% by weight and the high pressure method low density polyethylene resin (tubular) (A-4) 50. In a polyethylene resin composition obtained by mixing with% by weight, 150 ppm of octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate as an antioxidant and Tris (2,4-) A material to which 150 ppm of di-tert-butylphenyl) phosphite was added was used (a3-2). A foamable laminate was obtained in the same manner as in Example 1 except that the air gap was set to 130 mm as a condition for laminating the polyethylene-based resin layer (I). Table 2 shows the evaluation results of the obtained effervescent laminate. Both the processing speed of 60 m / min and the processing speed of 75 m / min had a good foaming appearance and a sufficient foaming height.

(Comparative Example 1)
As the resin used for the polyethylene-based resin layer (I), a high-pressure method low-density polyethylene-based resin (A-5) was used, and the conditions for laminating the polyethylene-based resin layer (I) were such that the air gap was 130 mm. An effervescent laminate was obtained in the same manner as in Example 1. Table 3 shows the evaluation results of the obtained effervescent laminate. The foamed appearance was good at a processing speed of 60 m / min, but the foamed appearance was poor at a processing speed of 75 m / min.

(Comparative Example 2)
As the resin used for the polyethylene-based resin layer (I), a high-pressure method low-density polyethylene-based resin (A-6) was used, and the conditions for laminating the polyethylene-based resin layer (I) were such that the air gap was 130 mm. An effervescent laminate was obtained in the same manner as in Example 1. Table 3 shows the evaluation results of the obtained effervescent laminate. Both the processing speed of 60 m / min and the processing speed of 75 m / min resulted in poor foam appearance.

(Comparative Example 3)
As the resin used for the polyethylene-based resin layer (I), a high-pressure method low-density polyethylene-based resin (A-7) was used, and the conditions for laminating the polyethylene-based resin layer (I) were such that the air gap was 130 mm. An effervescent laminate was obtained in the same manner as in Example 1. Table 3 shows the evaluation results of the obtained effervescent laminate. Both the processing speed of 60 m / min and the processing speed of 75 m / min resulted in poor foam appearance.

From the above Examples and Comparative Examples, on at least one surface of the paper-based base material on which the polyethylene-based resin layer (I) satisfying the specific characteristics (i) to (v) in the present invention was formed, It is confirmed that the foamable laminate on which the polyethylene-based resin layer (I) for foaming is formed has a sufficient foaming height and a good appearance after foaming.

The present invention relates to a performance evaluation method and a manufacturing control method for an effervescent laminate. More specifically, the present invention relates to a performance evaluation method and a manufacturing control method of a foamable laminate in which a foam cell (foam layer) having a sufficient height and a good appearance can be obtained with good productivity by heating.

An object of the present invention is a method for simply evaluating an effervescent laminate and a good effervescent laminate thereof in order to predict and evaluate an effervescent laminate having a good effervescent appearance after heating in view of the above problems. Is to provide a method of manufacturing control.

According to the first aspect of the present invention, there is a performance evaluation method for an effervescent laminate in which a polyethylene-based resin layer (I) for foaming is formed on at least one surface of a base material mainly made of paper. Then, the film heat shrinkage rate of the polyethylene-based resin layer (I) in the foamable laminate at at least one point in the range of 100 to 150 ° C. is measured to predict and evaluate the performance of the foamable laminate after foaming. A method for evaluating the performance of an effervescent laminate is provided.

Further, according to the second aspect of the present invention, there is a method for manufacturing and controlling a foamable laminate in which a polyethylene-based resin layer (I) for foaming is formed on at least one surface of a base material mainly made of paper. The film heat shrinkage of the polyethylene-based resin layer (I) in the foamable laminate at 120 ° C. is measured, and the film is manufactured so that the film heat shrinkage is 67% or less. A method for controlling the production of an effervescent laminate is provided.

Claims (10)

A foamable laminate in which a polyethylene-based resin layer (I) for foaming is formed on at least one surface of a base material mainly made of paper, and the resin composition (A) forming the polyethylene-based resin layer. A foamable laminate containing the above and satisfying the following characteristics (i) to (v).
(I) The film heat shrinkage of the polyethylene-based resin layer (I) at 120 ° C. is 67% or less. (Ii) The polyethylene-based resin composition (A) is selected from the high-pressure radical polymerization method low-density polyethylene and the ethylene copolymer. (Iii) 7 g of melt flow rate (MFR) measured in accordance with JIS K6922-2: 1997 Annex (190 ° C, 21.18 N load) of polyethylene resin composition (A). / 10 minutes or more and less than 30 g / 10 minutes (iv) Polyethylene resin composition (A) having a density of 0.900 to 0.930 g / cm in accordance with JIS K6922-2: 1997 Annex (23 ° C.) ³
(V) The memory effect (ME) of the polyethylene-based resin composition (A) measured under the conditions of a cylinder temperature of 240 ° C. and a constant speed extrusion rate of 3 g / min using the melt indexer used in JIS K7210 is 1. Less than 0.8 The foamable laminate according to claim 1, wherein the polyethylene-based resin composition (A) satisfies the following characteristics (a-1).
(A-1) The melting point of the polyethylene resin (A) is 80 ° C to 120 ° C. An effervescent laminate in which a polyethylene-based resin layer (I) for foaming is formed on at least one surface of a base material mainly made of paper, and a thermoplastic resin (thermoplastic resin) is formed on the other surface of the base material. The effervescent laminate according to any one of claims 1 to 2, wherein the effervescent laminate is provided with a thermoplastic resin layer (II) composed of B). A foamable laminate in which a polyethylene-based resin layer (I) for foaming is formed on at least one surface of a base material mainly made of paper, and a thermoplastic resin (thermoplastic resin (I) is formed on the other surface of the base material. A foamable laminate comprising a thermoplastic resin layer (II) composed of B), wherein the thermoplastic resin layer (II) is a layer that holds steam released from the substrate, and is the thermoplastic resin. The foamable laminate according to any one of claims 1 to 3, wherein the layer (II) is composed of a thermoplastic resin (B) having the following properties (b-1). ..
(B-1) Melting point (Tm (b)) is 100 to 140 ° C. A method for producing a foamable laminate having a polyethylene-based resin layer (I) for foaming on at least one surface of a base material mainly made of paper, wherein the polyethylene-based resin layer (I) is claimed. A foamable laminate, which is formed by extruding and laminating the polyethylene-based resin composition for an foamable laminate according to any one of 1 to 4 onto at least one surface of the substrate. Manufacturing method. The method for producing an effervescent laminate according to claim 5, wherein the extrusion laminating process is performed at a processing speed of 65 m / min or more. A foamed laminate in which the polyethylene-based resin layer (I) of the foamable laminate according to claims 1 to 4 is in a foamed state. A container molded from the foamed laminate according to claim 7. A method for evaluating the performance of an effervescent laminate in which a polyethylene-based resin layer (I) for foaming is formed on at least one surface of a base material mainly made of paper.
The film thermal shrinkage rate of the polyethylene-based resin layer (I) in the foamable laminate at at least one point in the range of 100 to 150 ° C. is measured to predict and evaluate the performance of the foamable laminate after foaming. A characteristic method for evaluating the performance of an effervescent laminate. A method for manufacturing and controlling an effervescent laminate in which a polyethylene-based resin layer (I) for foaming is formed on at least one surface of a base material mainly made of paper.
The foamable laminate is characterized in that the film heat shrinkage of the polyethylene-based resin layer (I) in the foamable laminate at 120 ° C. is measured and the film is manufactured so that the film heat shrinkage is 67% or less. Manufacturing control method.

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