JP2010285586A - Polyethylene-based resin material for lamination and laminate using the same, foamed processed paper and insulated container, and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin material for lamination with good moldability, a laminate comprising the resin material for lamination and paper, especially a foamable laminate obtaining foaming cells (foam layer) with sufficient height by heating, foamed processed paper having a foam layer and an insulated container using the same, such as cups. <P>SOLUTION: The polyethylene-based resin material for lamination is obtained such that 0.001-1.0 pt.wt. of a free radical generator is blended based on 100 pts.wt. of at least one resin raw material (C) for modification selected from a polyethylene-based resin (A) by a high pressure radical polymerization method or a polyethylene-based resin (B) by an ionic polymerization method and is modified; and satisfies the following properties (x1) to (x3). (x1) The melt flow rate (MFR) measured based on JIS K7210 (190°C and 21.18 N load) is 0.01-100 g/10 min; (x2) at a test temperature of 23°C, the density based on JIS-K7112 is 0.880-0.960 g/cm<SP>3</SP>; and (x3) the memory effect (ME) measured on the condition of a cylinder temperature of 240°C, and a constant speed extrusion output of 3g/min is 1.5 or more, by using a melt indexer used in JIS K7210. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a polyethylene-based resin material for laminating, and a laminate using the same, foamed paper, a heat insulating container and a method for producing the same. More specifically, the molding processability at the time of laminating is good and the heating is sufficiently high. A polyethylene-based resin material for lamination from which a foam cell (foamed layer) is obtained, a foamable laminate using the resin material, a foamed paper obtained from the foamable laminate, and the foamable laminate were heated and foamed. The present invention relates to a heat insulating container such as a cup and a method for manufacturing the same.

Conventionally, as a laminating resin or a laminating resin composition used for a laminate such as a food packaging material, a low density polyethylene resin, a composition of a low density polyethylene resin and a linear low density polyethylene resin, or the like is used. Commonly used (for example, JP-A-9-234837, JP-A-10-120841, JP-A-10-278196, JP-A-2000-052514, JP-A-2000-053823, JP, 2002-127333, JP, 2003-276131, JP, 2004-256613, JP, 2005-008667, JP, 2005-153899, JP, 2000-265388, etc.).
However, in recent years, higher speeds are required due to improvement in productivity and environmental problems, and more severe processing conditions and down gauges are required.
Along with these higher speeds, resin materials with excellent performance such as stability of molding processability such as low draw resonance and neck-in during laminating, low loss, and improved mechanical strength due to down gauge It is requested. In order to satisfy these requirements, a resin composition having a wide molecular weight distribution, a composition of a low-density polyethylene resin having a high melt tension and a metallocene-based linear low-density polyethylene resin has been proposed. Not enough performance has been achieved.
In addition, laminated polyethylene resins used in laminated products using paper base materials, such as heat-insulated containers such as paper containers and foamed paper cups, require materials with excellent moldability and higher foaming performance. It has been.
For example, as a container having a heat insulating property, a foam made of a synthetic resin has been conventionally used. In addition, as a container that is easy to dispose and has good printability, a heat-insulated paper container that uses multiple sheets of paper, or a material in which both sides of a paper substrate are laminated with a polyethylene resin layer, foam the surface of the polyethylene resin layer to insulate it. There is a paper container that has been imparted with sex.

For example, as a technology based on paper, polyethylene is extruded and laminated on at least one surface of the paper, and a vapor pressure holding layer is formed on the other surface, and a processed paper having an irregular concavo-convex pattern on the surface is produced by heating. There is a technology (for example, see Patent Document 1).
In addition, 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 a foamed heat insulation layer is formed by foaming the film by heating (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 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).
Furthermore, a foamed paper made of a laminate comprising an ethylene-α-olefin copolymer foamed layer polymerized using a single-site catalyst at least from the outer surface side, a paper-based base material layer, and a thermoplastic resin layer, A laminated body has been proposed (see, for example, Patent Document 4 and Patent Document 5). The processed paper and foam laminate that has the foamed layer thus obtained, when used as a container with a foamed layer, is well-fitted with the hand, is not slippery, has excellent heat insulation properties, and is a heat-insulating container that uses multiple sheets of paper. There is a merit that the cost is low in comparison.
Moreover, in patent document 6, the time until a thermoplastic resin in a molten state comes into contact with the paper base material from the T-die on at least one surface of the paper base material of the body member raw material sheet in the paper container is 0.11 to 0.33. A body member raw material sheet of a paper container formed by extrusion lamination so as to become seconds is described, and a composition in which two kinds of low density polyethylene are mixed to adjust MFR is proposed.

  However, the conventional processed paper and laminate having a foamed layer are not sufficiently foamable, and further improvement in foamability has been desired. Further, when the MFR is increased in order to improve the foaming property, there are problems that the appearance of the foamed layer becomes poor or the workability at the time of extrusion laminating becomes unstable.

Japanese Patent Publication No. 48-32283 JP-A-57-110439 Japanese Patent Laid-Open No. 07-232774 Japanese Patent Laid-Open No. 10-128928 JP 2007-168178 A JP 2008-105747 A

  In view of the above problems, an object of the present invention is a polyethylene-based resin material having improved moldability during lamination, and a foam cell (foamed layer) having a sufficiently high height can be obtained by heating, such as a paper cup. Polyethylene resin material for laminating suitably used for heat insulating containers, foamable laminates using the same, heat-insulating containers such as foamed paper and cups having a high foam layer (cell), and a method for producing the same There is.

As a result of intensive studies to solve the above problems, the present inventor has found that at least one raw material resin for modification (C) selected from the high pressure radical polymerization polyethylene resin (A) or the ion polymerization polyethylene resin (B). ) Polyethylene resin material for lamination obtained by modifying and modifying 0.001-1.0 part by weight of radical generator with respect to 100 parts by weight is excellent in molding stability at the time of laminate molding, It has been found that it is excellent in various performances such as high-speed moldability when producing a laminate with a base material such as, excellent in foaming performance, and can be used for processed foamed paper, heat insulating containers, etc., and has completed the present invention. .
In addition, a foamable laminate having a polyethylene resin layer (I) formed of the polyethylene resin material for lamination on one side of a base material mainly composed of paper, in particular, a polyethylene resin layer (I), Furthermore, the foamable laminate in which the base (c) having a specific melting point that retains the vapor released from the base is formed on the other surface is excellent in foamability and foams if the laminate is heated. The present invention was completed by finding that a foamed paper having a good appearance of the layer (cell) or a heat insulating container such as a cup having excellent heat insulating performance can be produced using the foamable laminate.

That is, according to the first invention of the present invention, at least one raw material resin for modification (C) selected from the high pressure radical polymerization polyethylene resin (A) or the ion polymerization polyethylene resin (B) is 100 weights. It is a polyethylene-based resin material (X) for lamination obtained by blending and modifying a radical generator 0.001 to 1.0 parts by weight with respect to parts, and having the following properties (x1) to (x3) A polyethylene-based resin material for lamination, which satisfies the requirements, is provided.
(X1) Melt flow rate (MFR) measured in accordance with JIS K7210 (190 ° C., 21.18 N load) is 0.01 to 100 g / 10 min,
(X2) Test temperature 23 ° C., density according to JIS-K7112 is 0.880-0.960 g / cm ³ ,
(X3) Memory effect (ME) measured using a melt indexer used in JIS K7210 at a cylinder temperature of 240 ° C. and a constant speed extrusion rate of 3 g / min is 1.5 or more.

According to the second invention of the present invention, in the first invention, the high-pressure radical polymerization polyethylene resin (A) 95 wherein the modifying raw resin (C) satisfies the following requirements (a1) to (a2): A polyethylene resin composition for lamination, characterized in that it is a polyethylene resin composition comprising 5 to 95% by weight of an ion-polymerized polyethylene resin (B) that satisfies the following requirements (b1) to (b2): A resin material is provided.
(A1) MFR measured in accordance with JIS K7210 (190 ° C., 21.18 N load) is 0.01 to 100 g / 10 min,
(A2) The test temperature is 23 ° C., and the density according to JIS-K7112 is 0.905 to 0.940 g / cm ^3.
(B1) MFR measured in accordance with JIS K7210 (190 ° C., 21.18 N load) is 0.01 to 100 g / 10 min,
(B2) The test temperature is 23 ° C. and the density according to JIS-K7112 is 0.860 to 0.970 g / cm ^3.

According to a third invention of the present invention, in the first or second invention, the high-pressure radical polymerization polyethylene resin (A) is a high-pressure radical polymerization low-density polyethylene resin (A1). A polyethylene-based resin material for lamination is provided.
According to a fourth invention of the present invention, in any one of the first to third inventions, the ion-polymerized polyethylene resin (B) is an ultra-low density polyethylene resin (B1) and / or a linear low density. A polyethylene-based resin material for lamination, which is a polyethylene resin (B2), is provided.

  According to 5th invention of this invention, the laminated body by which the polyethylene-type resin material for lamination of any one of 1st-4th invention is laminated | stacked with a base material (a) is provided.

  According to a sixth aspect of the present invention, there is provided a laminate according to the fifth aspect, wherein the base material (a) is a base material (b) mainly composed of paper.

  According to a seventh aspect of the present invention, in the sixth aspect, the paper is mainly formed on one side of the base material (b) mainly composed of paper and the base material (b) mainly composed of the paper. The other side of the polyethylene-based resin layer (I) formed using the polyethylene-based resin material for lamination which can be foamed with the gas released from the base material (b), and the base material (b) mainly composed of the paper A laminate having a base (c) layer for holding a gas released from the base (b) mainly composed of paper is provided on the surface.

According to an eighth aspect of the present invention, in the seventh aspect, the laminate having the thermoplastic resin layer (II) formed of the thermoplastic resin (D) as the base material (c) layer. The body is provided.
According to the ninth aspect of the present invention, in the eighth aspect, the difference between the melting point of the thermoplastic resin (D) and the melting point of the laminated polyethylene resin material (X) satisfies the following formula (3). The laminated body characterized by this is provided.
Tm (D) −Tm (X) ≧ 10 Formula (3)
(However, Tm (X): melting point Tm (° C.) of polyethylene resin material (X) of polyethylene-based resin layer (I), Tm (D): melting point of thermoplastic resin (D) of thermoplastic resin layer (II) Tm (° C)

  According to a tenth aspect of the present invention, there is provided a foamed paper according to any one of the sixth to ninth aspects, wherein the foam is heated and the polyethylene resin layer (I) is foamed. .

  According to an eleventh aspect of the present invention, in the tenth aspect, the foamed paper is characterized in that the height of the foamed cell formed by foaming the polyethylene resin layer (I) is 370 μm or more. Is provided.

  According to a twelfth aspect of the present invention, according to any one of the sixth to ninth aspects, after forming a container using the laminate, the container is heated to foam the polyethylene resin layer (I). The insulated container obtained by making it provide is provided.

  According to a thirteenth aspect of the present invention, in the twelfth aspect, there is provided a heat insulating container characterized in that the heat insulating container is a cup-shaped container.

  According to a fourteenth aspect of the present invention, according to any one of the first to fourth aspects, at least one of a base material (b) mainly composed of paper and a base material (b) mainly composed of the paper. On the other side of the polyethylene-based resin layer (I) formed of the polyethylene-based resin material for lamination and the base material (b) mainly composed of the paper, the base material (b) mainly composed of paper. After forming a container with a laminate comprising a thermoplastic resin layer (II) formed of a thermoplastic resin (D) that holds a gas released from the container, the container is heated to a heating temperature of 100 to 200 ° C., There is provided a method for producing a heat-insulating container, wherein the polyethylene-based resin layer (I) is foamed by a gas released from a base material (b) mainly composed of paper.

The polyethylene resin material for lamination of the present invention obtained by modifying a polyethylene resin with a radical generator has a wide range of conditions for adjusting various performances such as molecular weight distribution and melt elasticity, and a wider range of processing conditions for laminate molding. Various performances such as molding stability and foaming properties are greatly improved.
In particular, as a raw material resin for modification (C), a high-pressure radical polymerization method low-density polyethylene resin, an ion polymerization method polyethylene resin alone or a blend thereof is selected and modified in the presence of a radical generator. When resin-based resin materials are used, draw resonance does not occur even during high-speed molding during laminate molding, draw-down performance is good (small neck-in), loss is low, and various properties such as molding stability are excellent It becomes.
Also, a laminate having at least one polyethylene-based resin layer (I) formed of the polyethylene-based resin material for lamination on one side of the base material (b) mainly composed of paper, preferably, on the other side, The substrate (c) that holds a gas such as water vapor released from the substrate, preferably a laminate formed of a thermoplastic resin is heated with a gas such as water vapor generated from the paper substrate (b). The polyethylene-based resin layer (I) is foamed, and a foamed paper having an excellent foam (cell) layer and a uniform appearance having a uniform height is obtained.
Moreover, heat insulation containers, such as a cup which has the outstanding heat insulation performance, can be easily manufactured by foaming after forming a container using the laminated body which has a foamable polyethylene-type resin layer (I).

  Hereinafter, the polyethylene resin material for lamination of the present invention, the laminate using the same, the foamed paper, the heat insulating container and the production method thereof will be described in detail for each item.

I. [Polyethylene resin material for lamination (X)]
The polyethylene resin material (X) for laminating of the present invention comprises at least one polyethylene resin selected from a high-pressure radical polymerization polyethylene resin (A) or an ion polymerization polyethylene resin (B) (a raw material resin for modification) It is a polyethylene-based resin material for lamination obtained by blending and modifying a specific amount of radical generator with respect to (C).

(1) [High-pressure radical polymerization polyethylene resin (A)]
In the present invention, the high-pressure radical polymerization polyethylene resin (A) is a high-pressure radical low-density polyethylene resin (A1), a copolymer of ethylene and vinyl ester (A2), ethylene and an α, β-unsaturated carboxylic acid. Or the copolymer (A3) with the derivative (s), and at least 1 sort (s) of polyethylene-type resin selected from those mixtures are mentioned.

[High pressure radical polymerization method low density polyethylene resin (A1)]
The high pressure radical polymerization low density polyethylene resin (A1) (sometimes referred to as a low density polyethylene resin) in the present invention is a melt flow rate (MFR) measured in accordance with JIS K7210 (190 ° C., 21.18 N load). Is selected in the range of 0.01 to 100 g / 10 minutes, preferably 0.05 to 90 g / 10 minutes, more preferably 0.1 to 80 g / 10 minutes. When the melt flow rate (MFR) is 0.01 g / 10 min, the high-speed workability deteriorates and the handling becomes worse. Also, those having a melt flow rate (MFR) exceeding 100 g / 10 min are not preferable because the processing stability at the time of extrusion lamination molding deteriorates.

The test temperature is 23 ° C. and the density according to JIS-K7112 is 0.905 to 0.940 g / cm ³ , preferably 0.910 to 0.938 g / cm ³ , 0.912 to 0.937 g / cm ^3. The range is selected. If the density is less than 0.905 g / cm ³ , slip during lamination molding is poor and handling is unfavorable. Moreover, what a density exceeds 0.940 g / cm < ³ > becomes a thing which is difficult to manufacture industrially.

[Copolymer of ethylene and vinyl ester (A2)]
The ethylene and vinyl ester copolymer (A2) is composed mainly of ethylene, and vinyl ester monomers such as vinyl propionate, vinyl acetate, vinyl caproate, vinyl caprylate, vinyl laurate, vinyl stearate, and vinyl trifluoroacetate. It is a copolymer with a monomer. Among these, vinyl acetate can be mentioned as a particularly preferable comonomer. A copolymer comprising 50 to 99.5% by weight of ethylene, 0.5 to 50% by weight of vinyl ester, and 0 to 49.5% by weight of other copolymerizable unsaturated monomers is preferred. Furthermore, the vinyl ester content is selected in the range of 3 to 20% by weight, particularly preferably 5 to 15% by weight.

[Copolymer of ethylene and α, β-unsaturated carboxylic acid or derivative thereof (A3)]
Representative copolymers of ethylene and α, β-unsaturated carboxylic acid and derivatives thereof (A3) include ethylene / acrylic acid copolymer, ethylene / methacrylic acid copolymer, ethylene / anhydrous Ethylene / (meth) acrylic acid such as maleic acid copolymer, ethylene / ethyl acrylate copolymer, ethylene / butyl acrylate copolymer, ethylene / methyl methacrylate copolymer, ethylene / ethyl methacrylate copolymer Alkyl ester copolymer; binary copolymer of ethylene / maleic anhydride / vinyl acetate copolymer, ethylene / maleic anhydride / methyl acrylate copolymer, ethylene / maleic anhydride / ethyl acrylate copolymer, etc. Examples thereof include a polymer or a multi-component copolymer.

These comonomers include acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, and acrylic acid-n-butyl. -N-butyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, lauryl acrylate, lauryl methacrylate and the like.
Among these, alkyl esters such as methyl (meth) acrylate and ethyl (meth) acrylate are particularly preferable. In particular, the (meth) acrylic acid ester content is in the range of 3 to 30% by weight, preferably 5 to 20% by weight.

[High pressure radical polymerization method]
(I) Polymerization conditions In the present invention, the high-pressure radical polymerization method is a method for production by bulk or solution polymerization under ultrahigh pressure in the presence of a radical initiator such as oxygen or organic peroxide.
The polymerization temperature is 100 to 300 ° C, preferably 120 to 280 ° C, and more preferably 150 to 250 ° C. If the polymerization temperature is less than 100 ° C., there is a possibility that the yield is reduced or a stable product cannot be produced. If the polymerization temperature is more than 300 ° C., the reaction is not stable and it is difficult to obtain a polymer having a large molecular weight. . The polymerization pressure is 50 to 400 MPa, preferably 70 to 350 MPa, more preferably 100 to 300 MPa. If the polymerization pressure is less than 50 MPa, a product having a sufficient molecular weight cannot be obtained, resulting in deterioration of workability and physical properties. When it exceeds 400 MPa, it is difficult to perform a stable production operation.

(Ii) Polymerization Operation In the production of the resin (A), basically, the production equipment and technology of ordinary high-pressure radical polymerization method low-density polyethylene can be used. As the type of reactor, an autoclave type with a stirring blade or a tubular type can be used, and if necessary, a plurality of reactors can be connected in series or in parallel to perform multistage polymerization. . Furthermore, in the case of an autoclave type reactor, it is possible to provide temperature distribution or to perform more precise temperature control by dividing the inside of the reactor into a plurality of zones. By such an operation, it is possible to control a memory effect or the like.

(Iii) Radical initiator As the radical initiator, dicumyl peroxide, benzoyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2 , 5-Dimethyl-2,5-di (t-butylperoxy) hexyne-3,2,5-dimethyl-2,5-di (t-butylperoxy) hexane, lauroyl peroxide, t-butylperoxy Benzoate, 1,1,3,3-tetramethylbutyl hydroperoxide, diisopropylbenzene hydroperoxide, t-butylcumyl peroxide, α, α′-bis (t-butylperoxy-m-isopropyl) benzene, di t-Butyldiperoxyisophthalate, n-butyl-4,4-bis (t-butylperoxy) Relate, t-butyl peroxybenzoate, t-butyl peroxyacetate, cyclohexanone peroxide, t-butyl peroxylaurate, acetyl peroxide, i-butyl peroxide, octanoyl peroxide, t-butyl peroxypivalate , T-butyl hydroperoxide, cumene hydroperoxide, methyl ethyl ketone peroxide, diisopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, 1,1-bis t-butyl peroxycyclohexane, 2,2-bis t -Organic peroxides such as butyl peroxyoctane and 2,2-azobisisobutyronitrile. Among these, a decomposition temperature for obtaining a half-life of 1 minute is preferably 160 to 200 ° C.

  The blending amount of the radical generator is in the range of 0.1 to 5 parts by weight, preferably 0.3 to 3 parts by weight, more preferably 0.5 to 2 parts by weight with respect to 100 parts by weight of the raw material polyethylene. If necessary, the molecular weight may be adjusted using a chain transfer agent or the like.

The chain transfer agent, hydrogen, propylene, butene _-1, C 1 _{-C 20} or more saturated aliphatic hydrocarbons or halogenated hydrocarbons, such as methane, ethane, propane, butane, isobutane, n- hexane, n- heptane, cycloparaffins, chloroform, carbon _{tetrachloride,} C 1 _{-C 20} or more saturated aliphatic alcohols, such as methanol, ethanol, propanol and _isopropanol, C 1 _{-C 20} or more saturated aliphatic carbonyl Compounds such as acetone and methyl ethyl ketone, and aromatic compounds such as toluene, diethylbenzene and xylene are mentioned.

(2) [Ion polymerization polyethylene resin (B)]
In the present invention, the ion-polymerized polyethylene resin (B) is (b1) a melt flow rate (MFR) measured in accordance with JIS K7210 (190 ° C., 21.18 N load) is 0.01 to 100 g / 10 min. (B2) an ethylene homopolymer satisfying a test temperature of 23 ° C. and a density according to JIS-K7112 of 0.860 to 0.970 g / cm ³ or ethylene and an α-olefin having 3 to 20 carbon atoms; It is a copolymer.
The ion-polymerized polyethylene resin (B) generally has (i) an ethylene / α-olefin copolymer with a density of 0.860 to less than 0.910 g / cm ³ and an MFR of 0.01 to 100 g / 10 min. Polymer (also referred to as ultra-low density polyethylene resin), (ii) an ethylene / α-olefin copolymer (linear) having a density of 0.910 to less than 0.940 g / cm ³ and an MFR of 0.01 to 100 g / 10 min (Iii) ethylene / α-olefin copolymer having a density of 0.940 to 0.970 g / cm ³ and an MFR of 0.01 to 100 g / 10 min (high density polyethylene). (Also referred to as resin).

The melt flow rate (MFR) measured according to (b1) JIS K7210 (190 ° C., 21.18 N load) of the ion-polymerized polyethylene resin (B) is 0.01 to 100 g / 10 min, preferably 0.8. It is selected in the range of ^{3 to} 80 g / 10 minutes, more preferably 0.5 to 70 g / cm ³ .
An MFR of less than 0.01 g / 10 min is not preferable because high-speed processability during extrusion laminating deteriorates. Moreover, when MFR exceeds 100 g / 10min, since the workability of extrusion lamination becomes unstable, it is not preferable.

The density according to (b2) test temperature 23 ° C. and JIS-K7112 of the ion-polymerized polyethylene resin (B) is 0.860 to 0.970 g / cm ³ , preferably 0.880 to 0.960 g / cm ^3. More preferably, it is 0.890-0.950g / cm < ³ >. If the density is less than 0.860 g / cm ³ , slip during lamination molding is poor and handling is unfavorable. Moreover, what a density exceeds 0.970 g / cm < ³ > becomes a thing which is difficult to manufacture industrially.

The α-olefin is preferably a linear or branched olefin having 3 to 20 carbon atoms, such as propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1- Examples include octene and 1-decene. Among these copolymers, binary such as ethylene / 1-butene copolymer, ethylene / 1-hexene copolymer, ethylene-4-methyl-1-pentene copolymer, ethylene / 1-octene copolymer, etc. A terpolymer such as a copolymer, an ethylene / propylene / 1-hexene copolymer, and an ethylene / 1-butene / 1-hexene copolymer is preferred.
The total content of these α-olefins is usually 30 mol% or less, preferably 3 to 20 mol%.

  The above-mentioned ion polymerization polyethylene resin (B) is a low, medium or high pressure, slurry polymerization method, solution using an ion polymerization catalyst such as a Ziegler catalyst, a Philips catalyst, a single site catalyst (including a metallocene catalyst), etc. It can be suitably produced by controlling polymerization conditions such as polymerization temperature and pressure, cocatalyst, and the like by a polymerization method, a gas phase polymerization method or the like.

Among the above-mentioned ion polymerization method polyethylene resins (B), polyethylene resins (B) produced with a single site catalyst are preferable, and in particular, ultra-low density polyethylene resins having a density of 0.860 to less than 0.910 g / cm ³ and 0 A linear low density polyethylene resin of .910 to 0.940 g / cm ³ is preferred.
Ultra-low density polyethylene resins and linear low density polyethylene resins produced with these single-site catalysts have fewer low molecular weight components than those produced with conventional Ziegler catalysts and Philips catalysts, and have transparency and blocking resistance. It has a low melting point and good low temperature heat sealability (high speed), and is suitably used for extrusion laminate molding, sealant film and the like.

  The ultra-low-density polyethylene resin, linear low-density polyethylene resin, and high-density polyethylene resin produced with the above single-site catalyst are generally a periodic table containing a ligand having a cyclopentadienyl skeleton. It is obtained by copolymerizing ethylene and an α-olefin having 3 to 20 carbon atoms in the presence of a group IV transition metal compound and, if necessary, a catalyst containing a cocatalyst, an organoaluminum compound and a carrier. is there. For example, JP-A-60-35006, JP-A-60-35007, JP-A-60-35008, JP-A-3-16388, JP-A-61-296008, JP-A-63. -22804, JP-A-58-19309, JP-A-63-61010, JP-A-63-152608, JP-A-63-264606, JP-A-63-280703, etc. Can be produced using the metallocene catalyst disclosed in (1).

[Production Method of Ion Polymerized Polyethylene Resin (B)]
In the present invention, the ion-polymerized polyethylene resin (B) is produced by a gas phase polymerization method, a slurry polymerization method, a solution polymerization method or the like substantially free of a solvent in the presence of the catalyst. In the state where the above are excluded, aliphatic hydrocarbons such as butane, pentane, hexane and heptane, aromatic hydrocarbons such as benzene, toluene and xylene, and alicyclic hydrocarbons such as cyclohexane and methylcyclohexane are exemplified. Produced in the presence or absence of an active hydrocarbon solvent. The polymerization conditions are not particularly limited, but the polymerization temperature is usually from 15 to 350 ° C., preferably from 20 to 200 ° C., more preferably from 50 to 110 ° C. The polymerization pressure is usually from normal pressure to 70 kg / kg in the low-medium pressure method. cm ² G, preferably normal pressure to 20 kg / cm ² G, the case of high pressure process, usually less desirable 1500kg / cm ² G. The polymerization time is usually from 3 minutes to 10 hours, preferably from about 5 minutes to 5 hours in the case of the low and medium pressure method. In the case of the high pressure method, it is usually 1 minute to 30 minutes, preferably about 2 minutes to 20 minutes. Further, the polymerization method is not particularly limited to a single-stage polymerization method or a multi-stage polymerization method having two or more stages in which polymerization conditions such as a hydrogen concentration, a monomer concentration, a polymerization pressure, a polymerization temperature, and a catalyst are different from each other.

  The above-mentioned ionic polymerization polyethylene resin (B) is not particularly limited to the production catalyst, process, etc., and the book “Polyethylene Technology Reader” (edited by Kazuo Matsuura and Naotaka Mikami, published by Industrial Research Council, 2001) P. 123-160, p. It is possible to manufacture by the method described in 163-196 etc.

(3) [Modifying raw resin (C)]
The modified raw material resin (C) in the present invention is the high-pressure radical method polyethylene resin (A) and / or the ion polymerization method polyethylene resin (B), and the high-pressure radical method low-density polyethylene resin (A1), ethylene and vinyl. At least one selected from a copolymer with an ester (A2), a copolymer with ethylene and an α, β-unsaturated carboxylic acid or derivative thereof (A3), and a mixture thereof, and an ion-polymerized polyethylene resin ultra low density polyethylene resin density of ^{(B) 0.860~0.910g / cm 3 (} B1), linear low density polyethylene resin of a density ^{0.910~0.940g / cm 3 (B2),} 0. At least one selected from high-density polyethylene resins (B3) of 940 g / cm ³ or more, and mixtures (formulations) thereof are included.

  Specifically, high-pressure radical method low-density polyethylene resin (A1), ethylene-vinyl acetate copolymer (A2), ethylene- (meth) acrylic acid ester (A3) and other high-pressure radical method polyethylene resins alone or in excess Single or two types of high-pressure radical method low-density polyethylene resin compositions, high-pressure radical method low-density polyethylene resins (A1), such as low-density polyethylene resin, linear low-density polyethylene resin, and high-density polyethylene resin. ) And an ethylene-vinyl acetate copolymer (A2), a copolymer of a high-pressure radical method low-density polyethylene resin (A1) and an ethylene- (meth) acrylic acid alkyl ester such as ethylene-ethyl acrylate ( A3) and the like are preferred, especially the high pressure radical process low density polyethylene tree (A1) a composition mainly composed of is preferable because of good moldability at the time of lamination molding.

  In addition, the ion-polymerized polyethylene resin (B) is an ultra low density polyethylene resin (B1), a linear low density polyethylene resin (B2), or a high density polyethylene resin (B3) alone, or a composition thereof. A composition of an ultra low density polyethylene resin (B1) and a linear low density polyethylene resin (B2), a composition of an ultra low density polyethylene resin (B1) and a high density polyethylene resin (B3), Examples thereof include a composition of chain low density polyethylene (B2) and high density polyethylene (B3).

  In the composition of the high pressure radical polymerization polyethylene resin (A) and the ion polymerization polyethylene resin (B), (1) the high pressure radical low density polyethylene resin (A1) and the ultra low density polyethylene resin (B1). (2) High pressure radical method low density polyethylene resin (A1) and linear low density polyethylene resin (B2) composition, (3) High pressure radical method low density polyethylene resin (A1) and high density A composition with a polyethylene resin (B3), (4) a composition with a high pressure radical process low density polyethylene resin (A1), an ethylene-vinyl acetate copolymer (A2) and an ultra low density polyethylene resin (B1), (5 ) Composition with high pressure radical method low density polyethylene resin (A1), ethylene-vinyl acetate copolymer (A2) and linear low density polyethylene resin (B2) (6) High pressure radical method low density polyethylene resin (A1), ethylene-vinyl acetate copolymer (A2) and composition with high density polyethylene resin (B3), (7) High pressure radical method low density polyethylene resin (A1) , Composition of ultra-low density polyethylene resin (B1) and linear low-density polyethylene resin (B2), (8) composition of ethylene-vinyl acetate copolymer (A2) and ultra-low density polyethylene resin (B1) , (9) Composition of ethylene-vinyl acetate copolymer (A2) and linear low density polyethylene resin (B2), (10) Ethylene-vinyl acetate copolymer (A2), ultra-low density polyethylene resin Composition with (B1) and linear low density polyethylene resin (B2), (11) Composition with ethylene-ethyl acrylate copolymer and ultra-low density polyethylene resin (B1) , (12) ethylene - include compositions such as the ethyl acrylate copolymer and linear low density polyethylene resin (B2).

The blending ratio of the resins in the composition is 95 to 5% by weight of the high-pressure radical polymerization polyethylene resin (A) and 5 to 95% by weight of the ion polymerization polyethylene resin (B), preferably resin (A) / resin. (B) is 90 to 10% by weight / 10 to 90% by weight, more preferably the resin (A) / resin (B) is selected in the range of 85 to 15% by weight / 15 to 85% by weight. .
When the resin (A) and the resin (B) of the composition deviate from the above ranges, there is a possibility that the mutual effect is not exhibited. In particular, in the above composition, when emphasis is placed on the processability at the time of lamination, it is desirable to use a composition mainly composed of a high-pressure radical polymerization low-density polyethylene resin (A1).

Hereinafter, the modification method will be described in detail.
[Modification method]
The modification method of the raw material resin for modification (C) in the present invention is not particularly limited, but usually a melt reaction method in which the resin and the radical generator are simultaneously melt-kneaded and reacted in an extruder, or an organic solvent A solution reaction method or the like in which the resin and the radical generator are dissolved in the mixture and reacted while warming and stirring is preferably used.

  In order to suitably perform the modification, it is necessary to quantitatively blend the resin and the radical generator and uniformly disperse them before the radical reaction. Specifically, a method of supplying a resin and a radical generator while measuring with a quantitative supply device to a radical reaction facility, and dry blending the resin and the radical generator using a mixing device such as a tumbler mixer or a Henschel mixer. A method of supplying to a radical reaction facility, a method of supplying to a radical reaction facility after dry blending, melt blending with an extruder, and a radical reaction facility after melt-blending while supplying a resin and a radical generator to each of the extruder quantitatively. The method of supplying to

When the modification reaction is performed in the presence of the radical generator, it is important to sufficiently disperse the radical generator in the resin at a temperature at which the radical reaction is suppressed. For this purpose, kneading that can suppress the radical reaction is necessary. The selection of temperature is important.
The radical reaction temperature [T (1)] (° C.) during modification desirably satisfies the following formula (1), and preferably satisfies formula (1-1).
T ₆₀ +30 <T (1) <T ₆₀ +120 Equation (1)
T ₆₀ +40 <T (1) <T ₆₀ +110 Equation (1-1)
(In the formula, T ₆₀ represents the one-hour half-life temperature [° C.] of the radical generator (C).)

Also, in the melt blending method, a method of melt blending the entire amount of resin and radical generator necessary for the radical reaction, a method of melt blending only the entire amount of radical generator and a part of the resin, and diluting and blending at the time of the radical reaction, etc. However, a method of melt blending the total amount of resin and radical generator necessary for the radical reaction is suitable.
The purpose of melt blending is to sufficiently disperse the radical generator in the resin at a temperature at which radical reaction is suppressed. For this purpose, it is important to select a kneading temperature capable of suppressing radical reactions. In the present invention, the kneading temperature [T (2)] (° C.) preferably satisfies the following formula (2).
Tm <T (2) <T ₆₀ +5 (2)

Since it is melt kneading, kneading is substantially impossible below the melting point (Tm) of the resin.
On the other hand, if the kneading temperature exceeds the upper limit of the above formula (2), a radical generator that cannot be ignored is decomposed, which is not preferable. Furthermore, since the decomposition rate of the radical generator increases as the temperature increases, it is desirable to perform kneading at as low a temperature as possible in order to perform melt blending that does not cause radical reaction, and it is more preferable to perform the following equation (2-1). .
Tm <T (2) <T ₆₀ −3 (2-1)

As a preferred method for producing the modified polyethylene resin (E) according to the present invention, polyethylene and a radical generator are melt-kneaded at a temperature T (1) that satisfies the above formula (1) or formula (1-1). A method including a step may be used, and as another method, a first step of melt-kneading polyethylene and a radical generator at a temperature T (2) satisfying the above formula (2) or formula (2-1). Then, a method including a second step of melt-kneading the product of the first step at a temperature T (1) satisfying the formula (1) or the formula (1-1) may be used.

  Examples of the radical generator include organic peroxides, dihydroaromatics, dicumyl compounds and the like. Examples of the organic peroxide include (i) hydroperoxides such as t-butyl hydroperoxide, cumene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, (ii) Ketone peroxides such as methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide, acetylacetone peroxide, cyclohexanone peroxide, (iii) diacyl peroxides such as isobutyryl peroxide, lauroyl peroxide, benzoyl peroxide, (iv) dic Milperoxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, t-butylcumyl peroxide, di-t-butylperoxide, 2,5-dimethyl-2,5-di − ( -Butylhexyne) -3, dialkyl peroxides such as di-t-amyl peroxide, (v) peroxyketals such as 2,2-di- (t-butylperoxy) butane, (vi) t-hexylper Oxypivalate, t-butyl peroxypivalate, t-amyl peroxy 2-ethylhexanoate, t-butyl peroxy 2-ethylhexanoate, t-butyl peroxyisobutyrate, t-butyl peroxy Alkyl peresters such as benzoate, (vii) percarbonates such as bis (4-tert-butylcyclohexyl) peroxydicarbonate, di-isopropylperoxydicarbonate, t-amylperoxyisopropylcarbonate, (viii) 3 , 6,9-triethyl-3,6,9-trimethyl-1, And cyclic organic peroxides such as 7-tri par oxo Nan and the like. Of these, cyclic organic peroxides are preferred.

  The blending amount of the radical generator is 0.001 to 1.0 part by weight, preferably 0.005 to 0.5 part by weight, more preferably 0.01 to 0.3 part by weight based on 100 parts by weight of the raw material resin for modification. It is preferable that it is a weight part. If the blending amount of the radical generator is less than 0.001 part by weight, the effect is not exhibited, and if it exceeds 1.0 part by weight, the fluidity is deteriorated and the gel and fisheye in the film after molding are generated. A fear arises.

  In the composition obtained by the above modification, (1) a relatively high memory effect (ME) high-pressure radical polymerization low-density polyethylene resin (A1) and an ion polymerization polyethylene resin (B1) excellent in mechanical strength, etc. By combining and modifying with a small amount of radical generator, micro-crosslinking occurs in the polyethylene resin, and the ME (memory effect) value can be easily improved and controlled, (2) During laminating (3) Improvement of memory effect (ME) and ease of preparation, improvement of foam cell height and uniformity, improvement of product appearance, (4) ) Advantages such as easy measures against foam breakage of foamed cells are exhibited.

(5) [Polyethylene resin material for lamination (X)]
The polyethylene resin material for laminating of the present invention comprises at least one raw material resin for modification (C) selected from a high pressure radical polymerization polyethylene resin (A) and / or an ion polymerization polyethylene resin (B) 100 weight. It is important that the polyethylene resin material for lamination after modification is modified in the presence of 0.001 to 1.0 part by weight of a radical generator with respect to parts, and satisfies the following properties. .
(X1) Melt flow rate (MFR) measured according to JIS K7210 (190 ° C., 21.18 N load) is 0.01 to 100 g / 10 min,
(X2) Test temperature 23 ° C., density according to JIS-K7112 is 0.880-0.960 g / cm ³ ,
(X3) Memory effect (ME) 1.5 or higher

The melt flow rate (MFR) of the polyethylene-based resin material for lamination of the present invention is measured in accordance with (x1) JIS K7210 (190 ° C., 21.18 N load), and is 0.01 to 100 g / 10 min, preferably 0. The range is from 0.05 to 80 g / 10 min, and more preferably from 0.1 to 70 g / 10 min.
When the MFR is less than 0.01 g / 10 min, there is a concern that molding processability is deteriorated and handling is lowered.
The density is (x2) at a test temperature of 23 ° C. and in accordance with JIS-K7112, 0.880 to 0.960 g / cm ³ , preferably 0.890 to 0.950 g / cm ³ , more preferably 0.900. It is desirable to be in the range of ˜0.940 g / cm ³ . When the density is less than 0.880 g / cm ³ , slipping is poor, and handling may be reduced.
Furthermore, in order to improve the molding stability at the time of laminate molding and the foaming performance of the foamed laminate and the heat insulating container described later, the polyethylene resin material for lamination is required from the need to increase the melt elasticity of the polyethylene resin material (X) for lamination. The memory effect (ME) of (X) preferably satisfies the characteristics of (x3) memory effect (ME) 1.5 or more.
In particular, in order to easily satisfy the properties of (x3), it is preferable to select the high-pressure radical polymerization low-density polyethylene resin (A1) as the modification raw material resin (C). A memory effect (ME) of 1.5 or more, which is a high-density polyethylene resin measured using a melt indexer used in JIS K7210 under the conditions of a cylinder temperature of 240 ° C. and a constant speed extrusion rate of 3 g / min. It is desirable to select a high-pressure radical polymerization low-density polyethylene resin that preferably satisfies 1.6 or more, more preferably 1.7 or more.

<Measuring method of memory effect (ME)>
The memory effect (ME) of the above-mentioned polyethylene-based resin material (X) for lamination and the high-pressure radical polymerization method low-density polyethylene resin (A) is a melt indexer used in JIS K7210 (semi-automatic melt tension meter manufactured by Misuzu Erie Co., Ltd.). ) At 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 apparatus, and the furnace is filled with resin. Place the piston, hold at 0.09 g / min constant speed extrusion for 5 minutes, then perform 3 g / min constant speed extrusion and release air until 6 minutes 30 seconds. After 6 minutes and 30 seconds, the strand was cut while maintaining 3 g / min. The diameter of the strand when the strand length from the lower end of the orifice became 20 mm was measured at 15 mm from the lower end of the orifice. Measure using a measuring instrument (LS-3033). The measured strand diameter is D and the die orifice diameter is D ₀ (2.095 mm), and the ME is obtained by the following equation (however, the measured value of ME is obtained by rounding off the second decimal place).
ME = D / D ₀

As described above, the polyethylene-based resin material (X) for laminating of the present invention has a wide range of adjustment conditions such as molecular weight distribution and melt elasticity, a wide range of processing conditions for laminate molding, molding stability, foamability, etc. The performance of the is greatly improved. In particular, the high-pressure radical polymerization method low-density polyethylene resin (A1) is selected as the raw material resin for modification (C), and the single-site resin (B) is selected as the ion polymerization method polyethylene resin, in the presence of a radical generator. By modifying, it is excellent in low-temperature heat sealability, mechanical strength and the like, and excellent in various properties such as high-speed moldability and molding stability at the time of laminate molding.
In addition, by being slightly cross-linked, the melt elasticity of the resin material is improved, the foaming characteristics of the material are improved, and the heat insulation container such as a cup that requires the uniformity of the foam cell, the height of the foam cell, etc. Can be suitably used.

  In the present invention, phenolic and phosphorus antioxidants, metal soaps and other neutralizers, antiblocking agents, lubricants, dispersants, as long as the properties of the polyethylene resin material (X) for lamination are not impaired. Colorants such as pigments and dyes, antifogging agents, antistatic agents, ultraviolet absorbers, light stabilizers, and nucleating agents may be added. Moreover, you may mix | blend another polyolefin resin etc. in the range which does not impair the characteristic of the said polyethylene-type resin material (X) for lamination | stacking.

II. [Laminate]
The laminate of the present invention is a laminate in which the polyethylene resin material (X) for lamination and the substrate (a) are laminated, and the polyethylene resin material (X) for lamination is excellent during lamination molding. Various properties are exhibited.

  Examples of the substrate (a) include polyethylene resins such as high, medium and low density polyethylene; propylene resins such as polypropylene and propylene-ethylene copolymer; vinyl alcohols such as polyvinyl alcohol and ethylene-vinyl alcohol copolymer. Resin; polyvinyl chloride; polyvinylidene chloride resin; styrene resin such as polystyrene, styrene-acrylonitrile copolymer, styrene-acrylonitrile-butadiene copolymer; polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene Polyester resins such as naphthalate (PEN) and polybutylene naphthalate; nylons such as nylon 6, nylon 66, nylon 610, nylon 612, nylon 11 and nylon 12, or polyamide resins A polyacrylonitrile-based resin; a polycarbonate-based resin, a thermoplastic resin film or sheet having a film-forming ability such as a cellulosic polymer such as cellophane (stretched material or printed material thereof), aluminum, iron, copper, or these as a main component Metal foil or metal plate such as alloy, vapor deposition film of inorganic oxide such as silica vapor deposition plastic film, alumina vapor deposition plastic film, vapor deposition film of metal such as gold, silver, aluminum or compounds other than these metal oxides, Paper such as high quality paper, kraft paper, paperboard, glassine paper, synthetic paper, cellophane, woven fabric, non-woven fabric, etc. are used.

The laminate of the present invention can be produced in a variety of laminates by the usual laminating method and the like using the above-mentioned substrate (a) and the polyethylene resin material for lamination of the present invention.
In addition, the polyethylene-based resin material for lamination of the present invention is excellent in lamination performance (high-speed molding additivity, drawdown property, low neck-in, etc.) particularly when producing a laminate laminate, Can be laminated. Therefore, the laminated body using the polyethylene-based resin material for lamination of the present invention is utilized as a packaging material, a container or the like. For example, various laminated films or sheets extruded and laminated on metals such as Al are dried foods such as confectionery, snacks, instant ramen, sprinkles, powdered soups, meat products such as ham, sausage, livestock meat, konjac, pickles, miso, liquid soup Excellent adhesiveness, low-temperature heat-sealability, heat-seal strength, hot tack, etc. for bags and containers used in food products such as aquatic foods, liquid containers and other foods, liquid detergents, and liquid chemicals It can be used effectively by taking advantage of properties such as the properties, bag breaking strength, and automatic filling / packaging suitability. Moreover, it is used suitably for the medical field | area etc. for paper containers used for dairy products, such as milk, fruit juice, tea, liquor, soft drinks, etc., or an infusion bag, a container.

  The method for producing the laminate of the present invention is not particularly limited, but may be an extrusion lamination method in which a molten resin is directly laminated, a sandwich lamination method in which a film is laminated in advance, a dry lamination method, a coextrusion method, or the like. Various substrates can be extrusion coated or coextruded with the substrate.

The extrusion laminating method is a molding method in which a molten resin film extruded from a T-die is continuously coated and pressure-bonded on a substrate, and coating and adhesion are performed simultaneously.
The sandwich lamination method is a method in which a molten resin is poured between a substrate and a film to be laminated, and the molten resin acts as an adhesive to bond and laminate.
The dry laminating method is a method of manufacturing a laminate by applying an adhesive for laminating a base material or a film to be laminated, and crimping the laminating surface. The co-extrusion method uses a plurality of extruders to co-extrude the resin constituting the base material and the polyethylene resin composition for lamination of the present invention together, and join them before the exit of the co-extrusion die. And a method of manufacturing a laminate.

[Foaming laminate]
The foamable laminate of the present invention is a laminate comprising at least a base material (b) mainly composed of paper and a polyethylene resin material (X) for lamination.
The foamability of the foamable laminate in the specification of the present invention refers to the property of foaming by heating. Good foaming refers to a state in which a high foaming ratio can be obtained mainly, and is water vapor generated mainly by heating water contained in a paper-based substrate, and the thickness of the laminate. The height of the foam cell when the foam cell grows in the direction is a measure. Also, the uniformity of the foam cell height is taken into account.

The polyethylene-based resin material (X) for laminating of the present invention is not only excellent in laminating performance (high-speed molding additivity, drawdown property, low neck-in, etc.) particularly when a laminated body is produced by laminating, but also in paper cups and the like. In addition to the excellent foaming characteristics during the production of heat-insulating materials, it has a unique effect when producing foamed paper, heat-insulating containers, etc., especially using paper-based substrates. is there.
The foamable laminate of the present invention will be described in detail below.

The laminate of the polyethylene-based resin material for lamination (X) of the present invention and the base material (b) mainly composed of paper comprises a base material (b) mainly composed of paper and one of the base material (b). A laminate in which a polyethylene resin layer (I) formed using a polyethylene resin material (X) for lamination is provided on the surface, and the laminate is heated to mainly contain paper. It is a foamable laminate capable of evaporating moisture contained in the base material (b) and foaming the polyethylene resin layer (I). In particular, on the other surface of the base material (b) mainly composed of paper, a base material that holds a gas such as water vapor or volatile gas released from the base material (b) mainly composed of paper when heated ( c) A layer, preferably a thermoplastic resin layer, is provided to form a laminate in which only the polyethylene resin layer (I) is foamed.
The foamable laminate of the present invention can be produced in the same manner as the laminate production method described above.

[Base material mainly composed of paper (b)]
In the present invention, the base material (b) mainly composed of paper is particularly suitable if the polyethylene resin layer (I) on the surface can be foamed by a vapor such as moisture or a volatile gas contained in the base material (b). It is not limited.
In the present invention, the base material (b) mainly composed of paper is (i) paper, or (ii) a base material previously coated with a substance that generates volatile gas by heating, and paper and polyethylene in a laminate molding process. Means a base material in which a substance that generates volatile gas by heating is coated between the resin layers (I), and (iii) a base material that contains a substance that generates volatile gas by heating in a base material mainly composed of paper. To do.
In the present invention, the polyethylene-based resin layer (I) on the surface of the base material is foamed mainly by the action of water vapor generated by heating of water contained in the paper. There is no particular limitation as long as the polyethylene resin layer (I) on the surface of the material can be foamed.

Examples of the above (i) paper include high-quality paper, craft paper, art paper, recycled paper, synthetic paper, sheets containing inorganic substances such as resin and zeolite, and calcium carbonate. The basis weight of the paper is preferably 100 to 400 g / m ² , particularly 150 to 350 g / m ² . The water content of the paper is 4 to 15% by weight, preferably 5 to 13% by weight, and more preferably about 5 to 12% by weight.
Examples of the base material obtained by coating (ii) paper with a substance that generates volatile gas by heat include a base material obtained by coating paper with solvent-based ink, water-soluble ink, paint, or adhesive. For example, as seen in Japanese Patent Application Laid-Open No. 2000-238225, etc., an adhesive layer to which a foamable material is added is provided between the base material and the polyethylene resin layer (I), and volatilization generated from the foamable material generated by heating. The foaming of the polyethylene-based resin layer (I) on the substrate surface can be promoted by the property gas.
In addition, (iii) a substance that generates a volatile gas used in a base material mixed with a substance that generates a volatile gas by heating includes an inorganic or organic foaming agent, a water-containing polymer, a microcapsule encapsulating a foaming agent, and the like. For example, as seen in Japanese Patent Application Laid-Open No. 2002-145239, etc., paper made by adding a heat-foaming foaming agent in the paper making process, or microcapsules containing the foaming agent in the paper, water-containing Examples include base materials blended with water-absorbing polymers and the like.
Furthermore, a picture, a character, a pattern, etc. can also be printed with ink etc. on paper, such as a pulp paper and a synthetic paper, to the base material (b) which has paper as a main body.

[Polyethylene resin layer (I)]
In the present invention, the polyethylene-based resin layer (I) uses the above-described polyethylene resin material for lamination and is formed on one surface of the base material (b) mainly composed of paper in the same manner as the above-described method for producing a laminate. In general, it can be formed by laminate molding or the like. Next, the laminate can be heated and foamed by a gas such as water vapor released from the base material (b) mainly composed of paper. Further, in order to increase the foaming ratio of the laminate and form uniform foamed cells, the melting point of the polyethylene resin material for lamination is in the range of 80 to 130 ° C, preferably 85 to 120 ° C, more preferably It is desirable to select one within the range of about 90-110 ° C.

  Although it does not specifically limit about the thickness of polyethylene-type resin layer (I), It is 20-100 micrometers, and 30-100 micrometers is preferable at the point of making a foaming layer thick. If the thickness of the polyethylene resin layer (I) is less than 20 μm, the foamed layer may not be sufficiently thick.

[Base material (c) layer]
The base material (c) layer used in the present invention has a role of holding a gas such as vapor released from the base material (b). Here, holding gas such as vapor released from the base material (b) means that the gas such as vapor released from the base material is diffused to the polyethylene resin layer (I) side, and the polyethylene resin layer (I) In order to foam preferentially, it means that water vapor is barriered and may be the same material as the base material (a), but it has a higher melting point than the polyethylene resin layer (I). A material or the like that has or does not melt by heating is selected. Particularly in a heat insulating container such as a cup, it is preferable to select the thermoplastic resin (D) as the base material (c) layer and provide the thermoplastic resin layer (II).
In addition, as a preferable example of a heat insulating container such as a cup, the melting point (Tm) of the thermoplastic resin (D) is in the range of 100 ° C. to 160 ° C., preferably 110 ° C., considering the polyethylene resin layer (I). It is desirable that the temperature be selected in the range of ˜150 ° C., more preferably 115 ° C. to 140 ° C. Here, the melting point Tm is the melting point of the second peak measured by DSC and the highest peak height.
When the melting point of the thermoplastic resin (D) is lower than 100 ° C., the heat resistance is insufficient and the thermoplastic resin layer (II) may foam, which is not preferable. Moreover, when it exceeds 160 degreeC, since there exists a possibility that low-temperature heat-sealing property may become bad, it is unpreferable. Therefore, in the case of using the thermoplastic resin (D) having a melting point exceeding 160 ° C., a laminate having a heat seal layer such as a sealant layer may be provided in consideration of the polyethylene resin layer (I).

The thermoplastic resin (D) used in the present invention includes, for example, high, medium and low density polyethylene, polypropylene resin, polybutene 1 resin, poly-4-methyl-pentene 1 resin and the like having 2 to 2 carbon atoms. Polyolefin resins, polyamide resins, polyester resins, saponified ethylene-vinyl acetate copolymers, homopolymers of 10 α-olefins or their mutual copolymers, vinyl chloride resins, vinylidene chloride resins, polystyrene resins Or a mixture thereof.
Among these, polyolefin resins such as high density polyethylene, medium density polyethylene, and linear low density polyethylene are preferable.
Unsaturation when using a resin with poor adhesion to paper base such as polyamide resin, polyester resin, saponified ethylene-vinyl acetate copolymer, vinyl chloride resin, vinylidene chloride resin, polystyrene resin, etc. It is good also as a laminated body through usual adhesive resin etc., such as a carboxylic acid modified polyolefin resin and a copolymer with ethylene-unsaturated carboxylic acid.

  In the thermoplastic resin (D), a phenolic or phosphorus antioxidant, a neutralizing agent such as a metal soap, and the like, as long as they do not impair the properties of the thermoplastic resin layer (II). Additives such as antiblocking agents, lubricants, dispersants, colorants such as pigments and dyes, antifogging agents, antistatic agents, ultraviolet absorbers, light stabilizers, and nucleating agents may be blended.

  The thickness of the substrate (c) of the present invention is not particularly limited, but is preferably 10 to 100 μm, particularly preferably 20 to 100 μm, from the viewpoint of increasing the thickness of the foamed layer. When the thickness of the substrate (c) is less than 10 μm, the thickness of the foam layer cannot be sufficiently increased.

In the foamed laminate according to the present invention, other layers may be provided in the interlayer, or the inner layer and / or the outer layer, etc., as long as the effects of the present invention are not impaired. / Polyethylene resin layer (I) / base material / thermoplastic resin layer (II)}, {polyethylene film layer / barrier layer / adhesive layer / polyethylene resin layer (I) / base material / thermoplastic resin layer (II) }, {Polyethylene resin layer (I) / base material / thermoplastic resin layer (II) / barrier layer / thermoplastic resin layer (II)} One or more film layers, a decorative layer, a reinforcing layer, an adhesive layer, a barrier layer, and the like may be provided in and / or on the outer layer of the laminate provided with the plastic resin layer (II).
Moreover, you may print etc. as needed. The printing may be performed partially or entirely with colored ink. Moreover, you may provide a foaming site | part partially or entirely using a foamable ink as needed. For the printing position, the size of the printing area, the printing method, the ink used, etc., a conventionally known technique can be appropriately selected and used.

Examples of the decorative layer include printed paper, film, nonwoven fabric, and woven fabric.
The reinforcing layer is an outer layer of the foamable polyethylene resin layer (I) so that the foamable polyethylene resin layer (I) laminated on the substrate is not foamed when heated. Laminated polyethylene resin film etc. to prevent explosion due to excessive foaming of foamed layer, correct irregular foam cells uniformly, or laminate film, nonwoven fabric etc. to give mechanical strength To fulfill. The resin is not particularly limited, and may be a polyolefin resin such as polyethylene or polypropylene, a polyamide resin, a polyester resin, or the like.
Examples of the resin forming the adhesive layer include a copolymer of ethylene and an unsaturated carboxylic acid or a derivative thereof, a modified polyolefin resin obtained by grafting an unsaturated carboxylic acid on a polyolefin resin, an ethylene-vinyl acetate copolymer, etc. A hot melt, a normal adhesive, etc. are mentioned.
As the resin for forming the barrier layer, polyamide resin, polyester resin, ethylene-vinyl acetate copolymer saponified product (EVOH), polyvinylidene chloride resin, polycarbonate resin, stretched polypropylene (OPP), stretched polyester ( OPET), stretched polyamide, metal such as alumina vapor deposition film and silica vapor deposition film, inorganic oxide vapor deposition film, metal vapor deposition film such as aluminum vapor deposition, and metal foil.

III. [Foamed paper]
The foamed paper of the present invention is obtained by heating the foamable laminate and foaming the polyethylene resin layer (I). That is, when foaming the foamable laminate, the thermoplastic resin (D) is preferably used as the base material (c) for holding a gas such as water vapor released from the polyethylene resin layer (I) and the base material (b). And the thermoplastic resin (D) satisfies the following formula (4).
Here, holding gas such as water vapor released from the base material (b) means that water vapor released from the base material is diffused to the (I) layer side under a predetermined heating condition, and the (I) layer is preferentially used. It refers to barriering vapor so as to foam. It is preferable to satisfy the formula (4) because the conditions for foaming treatment by heating can be widened and the polyethylene resin layer (I) can be preferentially foamed.
Tm (D) −Tm (X) ≧ 10 Formula (3)
(However, Tm (X): melting point Tm (° C.) of polyethylene resin material (X) for lamination of polyethylene resin layer (I), Tm (D): thermoplastic resin (D) of substrate (c) Melting point Tm (° C.))

The height of the foam cell of the foam-processed paper is 370 μm or more, preferably 380 μm or more. If the height of the foam cell is less than 370 μm, sufficient heat insulation cannot be obtained.
In the present specification, “foamability” refers to the property of foaming by heating. Good foaming refers to a state in which a high expansion ratio can be obtained mainly, and the height of the foam cell when the foam cell grows in the thickness direction of the laminate due to water vapor or the like from the paper substrate is a measure. become. Also, the uniformity of the foam cell height is taken into account.

Although there is no restriction | limiting in particular as a heating method, Hot air, a microwave, a high frequency, infrared rays, far infrared rays, etc. are mentioned. Although there is no restriction | limiting in particular in heating temperature, The water in paper should be the temperature which evaporates and a foamable resin fuse | melts, for example, 100-140 degreeC is preferable. The heating time is preferably 10 seconds to 15 minutes. If the heating temperature is less than 100 ° C. and the heating time is less than 10 seconds, a sufficient foamed cell height may not be obtained.
The foamed paper is not only used as a heat insulating and heat insulating material for heat insulating containers such as the following cups, but also used as a buffer material, sound insulating material, foamed paper, etc., sleeve material, paper plate, tray, anti-slip material, It is used as a packaging material for fruits, agricultural paper such as foamed paper, industrial materials, and daily life materials.

IV. [Insulated container]
The heat insulating container of the present invention is a laminate having at least the base material (b) mainly composed of the paper and the polyethylene resin material for laminating, preferably on the other surface of the base material mainly composed of the paper. After forming a container using the laminated body which laminated | stacked the thermoplastic resin (D) of the base material (c) which hold | maintains gas, such as water vapor | steam, this container is heated and a polyethylene-type resin layer (I) is made to foam. Is obtained.
Also in the heat insulating container of the present invention, the height of the foamed cell is preferably 370 μm or more, preferably 380 μm or more, like the foamed paper. If the height of the foam cell is less than 370 μm, there is a possibility that sufficient heat insulation cannot be obtained. The insulated container obtained by this is used as a tray, a cup, etc. Applications include hot beverage containers, cup soup containers, cup miso soup containers, cup noodle containers, natto containers, bento containers, coffee cup containers, microwave oven-compatible containers, and the like.

V. [Production method of insulated container]
The method for manufacturing the heat insulating container, particularly the cup, is foamed by a gas such as water vapor released from the base material (b) by heating on at least one surface of the base material mainly made of paper by using a polyethylene resin material. Forming a polyethylene resin layer (I), and forming a foamable laminate in which a base material (c) layer for holding vapor released from the base material is formed on the other surface of the base material (b). Then, after forming into a container, the polyethylene resin layer (I) is foamed by steam or the like released from the substrate (b) by heating at a heating temperature of 100 to 200 ° C.
The method for manufacturing a heat insulating container is basically the same as the method for manufacturing foamed paper. In order to laminate the resin layer on the substrate (b), a usual laminating method is applied. In the extrusion lamination, the resin temperature immediately below the die is 200 to 350 ° C, preferably 260 to 350 ° C, more preferably 270 to 350 ° C. The molding speed is 10 to 400 m / min, preferably about 10 to 350 m / min, and if necessary, in order to improve the adhesion between the base material and the polyethylene resin, corona discharge treatment, ozone treatment, Plasma treatment, flame treatment, or the like may be performed. Moreover, you may apply | coat an anchor coating agent as needed.
The foamed laminate produced in this way is rolled out or continuously drawn out, and a blank for a trunk member and a blank for a bottom plate member are punched out from the foamed laminate, and a barrel member is used with a conventional cup molding machine. After the bottom plate members are joined and molded into a cup shape, etc., they are transported on a batch or transfer belt conveyor and heated and foamed in a heating furnace, oven tunnel, etc. equipped with hot air, microwave, high frequency, infrared, far infrared, etc. A heat insulating container is formed.
In particular, in order to continuously produce an insulated container, preferably, a polyethylene resin material for lamination that is foamed by a gas such as a vapor released from the base material (b) by heating, a vapor released from the base material, etc. It is desirable that the difference in melting point with the base material (c) holding the gas, preferably the thermoplastic resin (D), satisfies the relationship of the following formula (4).
Tm (D) −Tm (X) ≧ 10 −−−−−− Formula (4)
(However, Tm (X): melting point Tm (° C.) of the polyethylene resin material (X) forming the layer (I), Tm (D): base material holding gas such as vapor in the base material (b) ( c) Melting point Tm (° C.) of thermoplastic resin (D))
As a result, high-speed moldability such as extrusion lamination is good, it is possible to continuously form a foam layer having a high foaming ratio and uniform foam cells, good appearance, good printability and productivity. improves. The heating time is preferably 10 seconds to 15 minutes. If the heating temperature is less than 100 ° C. and the heating time is less than 10 seconds, a sufficient foamed cell height may not be obtained. In addition, when the heating temperature exceeds 200 ° C. and / or the heating time exceeds 15 minutes, the generated foamed cell becomes excessively heated, causing the foamed cell to sag, etc. There is a risk of becoming.
As described above, in the method for manufacturing a heat insulating container of the present invention, the foaming layer in which uniform foaming cells are formed with a low foaming ratio and a high foaming ratio is obtained in the extrusion laminating process. Can be easily obtained.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.
In addition, the test methods of the polyethylene resin used in the present Example, its physical properties, the obtained foamed laminate, and the like are as follows.

(1) MFR: Measured according to JIS K7210 (190 ° C., 21.18 N load).
(2) Density: The pellets are hot-pressed to produce a 2 mm thick press sheet.
A beaker with a capacity of 00 ml was filled with distilled water, covered with a watch glass, and heated with a mantle heater. After boiling boiling 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 500 ml, and the time until it reached room temperature was adjusted so as not to be less than 60 minutes. Moreover, the test sheet was immersed in the substantially center part in water so that it might not contact a beaker and the water surface. The sheet was annealed at a temperature of 23 ° C. and a humidity of 50% for 16 hours or more and within 24 hours, and then punched out to a length of 2 mm and measured at a test temperature of 23 ° C. according to JIS-K7112.

(3) Memory effect (ME): Measured using a melt indexer (semi-automated ME meter manufactured by Misuzu Eli Co., Ltd.) used in JIS K7210.
<Measurement conditions>
The conditions were as follows under 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 measurement apparatus, and the furnace is filled with resin. Place the piston, hold at 0.09 g / min constant speed extrusion for 5 minutes, then perform 3 g / min constant speed extrusion and release air until 6 minutes 30 seconds. After 6 minutes and 30 seconds, the strand was cut while maintaining 3 g / min. The diameter of the strand when the strand length from the lower end of the orifice became 20 mm was measured at 15 mm from the lower end of the orifice. Measure using a measuring instrument (LS-3033). The measured strand diameter was D and the orifice diameter of the die was D ₀ (2.095 mm), and ME was determined by the following formula (however, the measured value was rounded to the second decimal place).
ME = D / D ₀

(4) Melting point: A pellet was formed into a sheet by hot pressing, and punched out to obtain a sample. The measurement was carried out under the following conditions under the procedure of first temperature rise, temperature drop, and second temperature rise, and the temperature at the maximum peak height of the second temperature rise was taken as the melting point.
Apparatus: DSC220 manufactured by Seiko Instruments Inc.
Temperature raising / lowering conditions: First temperature rise from 30 ° C to 200 ° C at 40 ° C / min
Temperature drop 10 ° C / min from 200 ° C to 20 ° C
Second temperature increase from 20 ° C. to 200 ° C. at 10 ° C./min Temperature holding time: 5 minutes after first temperature increase, 5 minutes after temperature decrease Sample amount: 5 mg
Reference: Aluminum

(5) Workability (melted film stability): When the polyethylene-based resin layer (I) was extrusion laminated, it was visually evaluated whether the processing could be performed stably.
○: The molten film is stable and can be processed.
X: The molten film is unstable and it is impossible to collect a sample having a uniform thickness.
(6) Foamed cell height: The thickness of the foamed paper was measured with a dial gauge, and the thickness of the base material and the thermoplastic resin layer (II) was gradually reduced to the foamed cell height.
(7) Uniformity of foamed cells: The surface of foamed paper was visually observed to evaluate the presence and uniformity of partial excessive foaming. ○: Good, ×: Uneven cell height

1. High pressure radical method low density polyethylene resin (A1)
High pressure radical process low density polyethylene resins (LDPE) A1-1 and A1-2 were produced in a high pressure radical process low density polyethylene production facility having an autoclave reactor.
The properties are shown below.
A1-1: High-pressure method low-density polyethylene resin
MFR 7 g / 10 min, density 0.919 g / cm ³ , ME = 2.0, Tm (melting point) = 106 ° C.
A1-2: High-pressure low-density polyethylene resin
MFR 4 g / 10 min, density 0.923 g / cm ³ , ME = 2.1, Tm (melting point) = 110 ° C.

2. Ion polymerization ethylene / α-olefin copolymer (B)
The ion polymerization ethylene / α-olefin copolymer (B) was produced by the following method.
<Catalyst preparation>
The catalyst was prepared by the method described in JP-T-7-508545. That is, to a predetermined amount of the complex dimethylsilylene bis (4,5,6,7-tetrahydroindenyl) hafnium dimethyl, tripentafluorophenyl boron was added in an equimolar amount to the complex, and diluted to 10 liters with toluene. A catalyst solution was prepared.
<Polymerization>
A stirred autoclave type continuous reactor having an internal volume of 1.5 liters was maintained at a pressure of 130 MPa, and a mixture of ethylene and 1-hexene was 40 kg / h so that the composition of 1-hexene was 66% by weight. Continuously. Further, the catalyst supply amount was adjusted so that the polymerization temperature was maintained at 158 ° C. After the completion of the reaction, an ethylene / 1-hexene copolymer (B1) having properties of MFR 17 g / 10 minutes, density 0.898 g / cm ³ , ME = 1.1, Tm (melting point) 85 ° C. was obtained.

Example 1
<Preparation of polyethylene resin material for lamination>
As resin used for polyolefin resin layer (I), high-pressure radical polymerization method low-density polyethylene resin (A1-1) and ethylene-α-olefin copolymer (B1) are blended at a ratio of 30/70 to generate radicals. Trigonox 301 manufactured by Kayaku Akzo Co., Ltd. (purity) so that 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-tripaoxonan as the agent is 0.01 parts by weight. 41%, one-hour half-life temperature is 146 ° C.) and mixed for 2 minutes with a Henschel mixer, and the mixture is subjected to radical reaction temperature (T2) 240 ° C. under a nitrogen seal with a 40 mmφ single screw extruder, extruder A radical reaction was carried out under the condition of a residence time of 90 seconds to obtain a polyethylene resin material (X1) for lamination.
The properties of the polyethylene resin material (X1) were MFR 10 g / 10 min, density 0.904 g / cm ³ , ME 1.6, Tm 101 ° C.).

<Manufacture of foamed paper>
Corona treatment (30 W · min / m ² ) is applied to one side of a paper substrate (b) having a basis weight of 157 g / m ² and a water content of 7%, and a 40Φ extruder and an extrusion laminator with an effective die width of 360 mm are used to make thermoplasticity. As a material constituting the resin layer (II), a polyethylene resin 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 and laminated at a resin temperature of 320 ° C., a processing speed of 20 m / min, and a thickness of 20 μm. A laminate of the plastic resin layer (II) and the paper substrate was obtained.
Next, the paper substrate surface opposite to the thermoplastic resin layer (II) of the laminate is subjected to corona treatment (30 W · min / m ² ), and the resin is obtained using a 40φ extruder and an extrusion laminator having a die effective width of 360 mm. The polyethylene resin material (X1) for lamination obtained above is extruded and laminated as a material constituting the polyethylene resin layer (I) at a temperature of 320 ° C., a processing speed of 20 m / min, and a thickness of 40 μm. A foamable laminate comprising (I), a paper substrate and a thermoplastic resin layer (II) was obtained.
The obtained foamed laminate was left in an oven at 130 ° C. for 2 minutes, then taken out of the oven and allowed to cool at room temperature to obtain foamed paper. The foamed cell height of this foamed paper was 450 μm. The results are shown in Table 1.

(Example 2)
As a resin used for the polyethylene resin layer (I), a high pressure method low density polyethylene resin (A1-1) and an ethylene / α-olefin copolymer (B1) are blended at a ratio of 60/40, and Examples 1 is mixed for 2 minutes with a Henschel mixer, and the mixture is melt-mixed at 160 ° C. under a nitrogen seal with a 40 mmφ single screw extruder to form a polyethylene resin layer (I). (X2) was obtained.
The properties of the polyethylene resin material for lamination (X2) were MFR 6 g / 10 min, density 0.910 g / cm ³ , ME2.1, Tm104 ° C.). Using the polyethylene resin material for lamination (X2), a foamable laminate was obtained in the same manner as in Example 1. The obtained foamed laminate was left in an oven at 130 ° C. for 2 minutes and then removed from the oven and allowed to cool at room temperature to obtain foamed paper. The foamed cell height of this foamed paper was 420 μm.
The results are shown in Table 1.

(Example 3)
As resin used for polyolefin resin layer (I), high-pressure radical polymerization method low density polyethylene resin (A1-2) and ethylene-α-olefin copolymer (B1) are blended at a ratio of 30/70 to generate radicals. Trigonox 301 manufactured by Kayaku Akzo Co., Ltd. (purity) so that 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-tripaoxonan as the agent is 0.01 parts by weight. 41%, one-hour half-life temperature is 146 ° C.) and mixed for 2 minutes with a Henschel mixer, and the mixture is subjected to radical reaction temperature (T2) 240 ° C. under a nitrogen seal with a 40 mmφ single screw extruder, extruder A radical reaction was performed under the condition of a residence time of 90 seconds to obtain a polyethylene resin material (X3) for lamination.
The properties of the polyethylene resin material (X3) were MFR 9 g / 10 min, density 0.905 g / cm ³ , ME 1.6, Tm 103 ° C.). Using the polyethylene resin material for lamination (X3), a foamable laminate was obtained in the same manner as in Example 1. The obtained foamed laminate was left in an oven at 130 ° C. for 2 minutes and then removed from the oven and allowed to cool at room temperature to obtain foamed paper. The foamed cell height of this foamed paper was 400 μm.
The results are shown in Table 1.

(Comparative Example 1)
As a resin used for the polyethylene resin layer (I), a high-pressure low-density polyethylene resin (A1-1) and an ethylene / α-olefin copolymer (B1) are blended at a ratio of 30/70, and a radical generator is added. Without blending, the mixture was mixed for 2 minutes with a Henschel mixer, and the mixture was melt-mixed at 160 ° C. under a nitrogen seal with a 40 mmφ single-screw extruder to form a polyethylene resin layer (IFR) (MFR 13 g / 10 min, density 0.904 g / cm ³ , ME 1.4, Tm 100 ° C.). Other than that was carried out similarly to Example 1, and obtained the foamable laminated body.
The obtained foamed laminate was left in an oven at 130 ° C. for 2 minutes and then removed from the oven and allowed to cool at room temperature to obtain foamed paper. The foamed cell height of this foamed paper was 360 μm. The results are shown in Table 1.

(Comparative Example 2)
As a resin used for the polyethylene-based resin layer (I), a high-pressure method low-density polyethylene resin (A1-1: MFR 7 g / 10 min, density 0.919 g / cm ³ , ME = 2.0, Tm = melting point 106 ° C.) Used as is. Otherwise, a foamable laminate was obtained in the same manner as in Comparative Example 1.
The obtained foamed laminate was left in an oven at 130 ° C. for 2 minutes and then removed from the oven and allowed to cool at room temperature to obtain foamed paper. The foamed cell height of this foamed paper was 320 μm. The results are shown in Table 1.

(Comparative Example 3)
As a resin used for the polyethylene resin layer (I), a high-pressure method low-density polyethylene resin (A1-2: MFR 4 g / 10 min, density 0.923 g / cm ³ , ME = 2.1, Tm (melting point) 110 ° C.) Was used as is. Other than that was carried out similarly to Example 1, and obtained the foamable laminated body.
The obtained foamed laminate was left in an oven at 130 ° C. for 2 minutes and then removed from the oven and allowed to cool at room temperature to obtain foamed paper. The foamed cell height of this foamed paper was 300 μm. The results are shown in Table 1.

(Comparative Example 4)
As the resin used for the polyethylene resin layer (I), the ethylene / α-olefin copolymer (B1) was used as it was. Otherwise, an attempt was made to produce a foamable laminate in the same manner as in Example 1. However, the molten film from the T-die was unstable, and a uniform foamable laminate could not be obtained.

〔Evaluation results〕
As is clear from Table 1 showing the above results, Examples 1 to 3 satisfying the constitutional requirements of the present invention are all good in processing stability of the molten film, and in any example, the foaming is uniform, The height of the foam cell was also higher than the target of 370 μm.
On the other hand, in Comparative Example 1, since the radical generator was not blended with the modifying raw material resin, the stability of the molten film was poor at the time of laminate molding, a normal foamable laminate was not obtained, foaming was uneven, foaming The height of the cell was also as low as 360 μm.
In Comparative Examples 2 and 3, since the high-pressure method low-density polyethylene resin was used alone, the height of the foamed cells could not achieve the target of 370 μm of the present invention.
Moreover, since the comparative example 4 was an ion polymerization method low density polyethylene resin alone, its moldability was poor, a normal foamable laminate could not be obtained, and the foaming characteristics could not be measured.

The polyethylene-based resin material for lamination of the present invention has good moldability and is laminated with various base materials and used for packaging materials, packaging containers and the like.
In addition, the foamable laminate of the material and the paper base material can obtain a foam cell (foamed layer) having a sufficiently high height by heating, and heat insulation of foamed paper and a cup using the foamable laminate. Applicable to the manufacture of containers. The foamed laminate is used as cushioning material, heat insulating material, foamed paper, and used as agricultural material for daily use such as sleeve material, paper plate, tray, anti-slip material, fruit packaging material, foamed paper, etc. Is done. Insulated containers are used as trays and cups. As its use, it is extremely useful industrially, such as being used as a hot beverage, cup soup, cup miso soup, cup ramen, natto container, microwave oven compatible container and the like.

Claims (14)

0.001 to 1 radical generator for 100 parts by weight of at least one raw material resin for modification (C) selected from high-pressure radical polymerization polyethylene resin (A) or ion polymerization polyethylene resin (B). Polyethylene resin material for lamination (X) obtained by blending and modifying 0.0 parts by weight, and satisfying the following properties (x1) to (x3): Polyethylene resin material for lamination .
(X1) Melt flow rate (MFR) measured in accordance with JIS K7210 (190 ° C., 21.18 N load) is 0.01 to 100 g / 10 min,
(X2) Test temperature 23 ° C., density according to JIS-K7112 is 0.880-0.960 g / cm ³ ,
(X3) Memory effect (ME) measured using a melt indexer used in JIS K7210 at a cylinder temperature of 240 ° C. and a constant speed extrusion rate of 3 g / min is 1.5 or more. The denaturing raw material resin (C) satisfies the following requirements (a1) to (a2): 95 to 5% by weight of the high-pressure radical polymerization polyethylene resin (A) and the following requirements (b1) to (b2): The polyethylene resin material for lamination according to claim 1, which is a polyethylene resin composition comprising 5 to 95% by weight of a satisfactory ion polymerization method polyethylene resin (B).
(A1) MFR measured in accordance with JIS K7210 (190 ° C., 21.18 N load) is 0.01 to 100 g / 10 min,
(A2) The test temperature is 23 ° C., and the density according to JIS-K7112 is 0.905 to 0.940 g / cm ^3.
(B1) MFR measured in accordance with JIS K7210 (190 ° C., 21.18 N load) is 0.01 to 100 g / 10 min,
(B2) The test temperature is 23 ° C. and the density according to JIS-K7112 is 0.860 to 0.970 g / cm ^3.   The polyethylene resin material for lamination according to claim 1 or 2, wherein the high-pressure radical polymerization polyethylene resin (A) is a high-pressure radical polymerization low-density polyethylene resin (A1).   The ion-polymerized polyethylene resin (B) is an ultra-low density polyethylene resin (B1) and / or a linear low density polyethylene resin (B2), according to any one of claims 1 to 3. Polyethylene resin material for lamination.   The laminated body by which the polyethylene-type resin material for lamination | stacking in any one of Claims 1-4 is laminated | stacked with a base material (a).   The laminate according to claim 5, wherein the substrate (a) is a substrate (b) mainly composed of paper.   The laminate according to claim 6, wherein the base material (b) mainly composed of paper and the base material (b) mainly composed of paper are provided on one side of the base material (b) mainly composed of the paper. A polyethylene-based resin layer (I) formed of a polyethylene-based resin material for lamination, which can be foamed with a released gas, and the other side of the base material (b) mainly composed of the paper, A laminate having a base material (c) layer for holding a gas released from the base material (b).   The laminate according to claim 7, comprising a thermoplastic resin layer (II) formed of a thermoplastic resin (D) as the base material (c) layer. The laminate according to claim 8, wherein the difference between the melting point of the thermoplastic resin (D) and the melting point of the polyethylene resin material (X) for lamination satisfies the following formula (3).
Tm (D) −Tm (X) ≧ 10 Formula (3)
(However, Tm (X): melting point Tm (° C.) of polyethylene resin material (X) of polyethylene-based resin layer (I), Tm (D): melting point of thermoplastic resin (D) of thermoplastic resin layer (II) Tm (° C)   Foamed paper obtained by heating the laminate according to any one of claims 6 to 9 to foam the polyethylene resin layer (I).   The foamed paper according to claim 10, wherein the height of the foamed cell formed by foaming the polyethylene resin layer (I) is 370 µm or more.   The heat insulation container obtained by forming a container using the laminated body in any one of Claims 6-9, heating this container, and foaming a polyethylene-type resin layer (I).   The heat insulation container of Claim 12 is a cup-shaped container, The heat insulation container characterized by the above-mentioned.   The polyethylene-based resin material for lamination (X) according to any one of claims 1 to 4, on at least one surface of a base material (b) mainly composed of paper and a base material (b) mainly composed of the paper. And the other surface of the base material (b) mainly composed of the paper, and the heat that holds the gas released from the base material (b) mainly composed of the paper. After forming a container with a laminate including the thermoplastic resin layer (II) formed of the plastic resin (D), the container is heated to a heating temperature of 100 to 200 ° C. A method for producing a heat insulating container, wherein the polyethylene-based resin layer (I) is foamed by a gas released from b).