JP2010143088A - Laminate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminate 10 which is excellent in appearance and slide performance and can be manufacturing by coextrusion molding. <P>SOLUTION: In the laminate 10 formed by sequentially laminating a surface layer 11A, a foamed layer 13, and a surface layer 11B, the laminate 10 is film-formed by a multilayer coextrusion molding method, and at least one surface layer 11 contains at least 90 mass% of an ethylene-methyl (meth)acrylate copolymer. The methyl (meth)acrylate component of the ethylene-methyl (meth)acrylate copolymer is 10-20 mass%, a melt flow rate (MFR) is 1.0-10.0 g/10 min, the degree of the gloss of the surface layer 11 formed of the ethylene-methyl (meth)acrylate copolymer is 20% or lower, the coefficient of static friction between the surface layers using the ethylene-methyl (meth)acrylate copolymer is 0.50 or smaller, and the coefficient of dynamic friction is 0.50 or smaller. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a laminate, and more particularly to a laminate having a good appearance even with a foam, good surface slipperiness, and excellent workability and mechanical suitability during use.

  In the present specification, “ratio”, “part”, “%” and the like indicating the composition are based on mass unless otherwise specified, and the “/” mark indicates that they are integrally laminated. “MMA” is “methyl methacrylate”, “MA” is “methyl acrylate”, “VA” is “vinyl acetate”, “EVA” is “ethylene-vinyl acetate copolymer”, “LDPE” “Low density polyethylene”, “LLDPE” is “linear low density polyethylene”, “HDPE” is “high density polyethylene”, and “MFR” is an abbreviation, functional expression, common name, or industry term for “melt flow rate” It is. “Ethylene-methyl methacrylate copolymer” means “ethylene-methyl acrylate copolymer and ethylene-methyl methacrylate copolymer (usually referred to as ethylene-methyl methacrylate copolymer)”. ".

  (Main use) The main use of the laminate of the present invention is a packaging material or cushioning material for products having a surface such as metal, glass, plastic, etc., which eliminates poor appearance and wrinkles. is there. However, the application is not particularly limited as long as the application requires good appearance and slipperiness.

(Background Art) Conventionally, foams have been used for applications such as packaging materials, cushioning materials, heat insulating materials, and soundproofing materials. Polystyrene and polyethylene resin foams, and laminates in which a non-foamed film is laminated on the foam are widely used. However, foaming of the foam was inadequate and it was difficult to eliminate foaming unevenness. For this reason, there has been a problem that the uneven foaming remains as it is. In addition, the foam itself and non-foamed film have poor surface slipperiness, wrinkles are generated during production, the front and back surfaces are in close contact with each other during use (referred to as a blocking phenomenon), the laminate is cut, There was a problem that the supply became unstable and the workability and machine suitability deteriorated. Furthermore, in the production of the laminate, the conventional production method in which it is applied after being dissolved in an organic solvent has a large fire risk and environmental burden. Therefore, it is preferable to produce by extrusion molding without using a solvent and with few production steps, excellent molding processability and excellent economic efficiency, and a multilayer coextrusion molding method is preferable. Furthermore, it is preferable that the surface state is matte in order to improve workability and texture when used.
Therefore, even if the laminate is a foam, it has a good appearance, good surface slipperiness, excellent workability and mechanical suitability during use, does not use a solvent, has few manufacturing processes, and has moldability. Therefore, it is demanded that it can be produced by extrusion molding which is excellent in economy and economy.

(Prior Art) Conventionally, a method for improving slipperiness by applying silicone oil or the like is known (for example, see Patent Document 1). However, the method of applying a lubricant such as silicone oil to the surface has a problem that it is difficult to control the slipperiness depending on the amount applied, and if the amount of lubricant applied is small, sufficient slipperiness cannot be obtained. In addition, when the amount of the lubricant applied is too large, there is a problem that it causes a poor appearance.
Moreover, the method of improving a moldability and slipperiness | lubricity by surface heat processing and improving an external appearance is known (for example, refer patent document 2). However, in the surface heat treatment, since it is brought into contact with a high-temperature heating roll, bubbles on the surface of the foam are ruptured (bubble breakage) or the surface becomes keloid, and the appearance is remarkably deteriorated. .

JP 2004-330650 A Japanese Patent Laid-Open No. 9-19968

  In order to solve the above-described problems, the present inventors have made extensive studies and have completed the present invention. Its purpose is good appearance, good surface slipperiness, excellent workability and mechanical suitability during use, no solvent, fewer manufacturing processes, and excellent molding processability. Another object of the present invention is to provide a laminate that can be produced by extrusion molding that is also excellent in economic efficiency.

In order to solve the above problems, a laminate according to the invention of claim 1 is a laminate in which a surface layer, a foam layer and a surface layer are laminated in order, and the laminate is formed by a multilayer coextrusion molding method. And at least one of the surface layers contains 90% by mass or more of ethylene- (meth) acrylic acid methyl copolymer.
The laminate according to the invention of claim 2 has a methyl (meth) acrylate component of the ethylene- (meth) methyl acrylate copolymer of 10 to 20% by mass and a melt flow rate (MFR) of 1. 0.01 to 10.0 g / 10 min.
The laminate according to the invention of claim 3 has a glossiness of a surface layer made of an ethylene-methyl (meth) acrylate copolymer of 20% or less, and an ethylene-methyl (meth) acrylate copolymer. The static friction coefficient between the used surface layers is 0.50 or less, and the dynamic friction coefficient is 0.50 or less.
In the laminate according to the invention of claim 4, the foamed layer is formed by foaming a composition comprising a thermoplastic resin and a chemical foaming agent simultaneously with the film formation by the multilayer coextrusion method, and the foaming ratio is 1 .1 to 3.0 times.
The laminate according to the invention of claim 5 is such that the multilayer coextrusion molding method is an inflation film forming method, and the total thickness of the laminate is 200 to 500 μm.

According to the present invention of claim 1, even if it is a foam, it is produced by coextrusion molding with good appearance, good surface slipperiness, excellent workability and mechanical suitability during use, and excellent economic efficiency. A laminate that can be provided is provided.
According to the second aspect of the present invention, in addition to the effect of the first aspect, a laminate having a better appearance even if it is a foam is provided.
According to the third aspect of the present invention, in addition to the effects of the first and second aspects, a laminate having better surface slipperiness and superior workability and mechanical suitability during use is provided.
According to this invention of Claim 4, in addition to the effect of Claims 1-3, the laminated body which is more excellent in buffer property is provided.
According to the fifth aspect of the present invention, in addition to the effects of the first to fourth aspects, a laminate that can be produced by extrusion molding that does not use a solvent, has few production steps, is excellent in molding processability, and is excellent in economic efficiency. The body is provided.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a cross-sectional view of a laminate showing one embodiment of the present invention.

  (Laminate) As shown in FIG. 1, the laminate 10 of the present invention has a surface layer 11A, a foam layer 13 and a surface layer 11B laminated in this order. The laminate 10 is formed by a multilayer coextrusion molding method. The surface layer 11A and the surface layer 11B are collectively referred to as the surface layer 11.

  (Surface layer) At least one surface of the surface layer 11, that is, the surface layer 11A and / or the surface layer 11B contains 90% by mass or more of ethylene- (meth) methyl acrylate copolymer. When a layer containing 90% by mass or more of the ethylene- (meth) acrylic acid methyl copolymer resin is used as the surface layer 11, a laminate that covers the surface of the foamed layer and has a clean appearance and excellent slipperiness 10 can be obtained. Moreover, you may add polyethylene, a polypropylene, etc. to the surface layer 11 in the range which does not inhibit the function of this invention.

  (Other surface layer) In the present invention, as a surface layer composed of an ethylene- (meth) methyl acrylate copolymer, when used only on one side of the surface layer 11A or the surface layer 11B, the surface layer on the other surface As 11, any thermoplastic resin can be used as long as it can be extruded simultaneously with the surface layer and the foamed layer and can be co-extruded. Specific examples of the thermoplastic resin include, for example, polyolefin resins such as polyethylene and polypropylene, polyamide resins, polyester resins such as polybutylene terephthalate and polyethylene terephthalate, polyphenylene ether resins such as vinyl chloride, polyphenylene ether and modified polyphenylene ether, Examples thereof include styrene resins such as polystyrene and heat-resistant polystyrene, acrylonitrile / butadiene / styrene resins, and polycarbonate. These resins may be used alone or in combination of two or more. When this thermoplastic resin is used as the surface layer 11, an adhesive resin such as an acid-modified resin may be used between the foam layer 13 and the thermoplastic resin when forming the film by the multilayer coextrusion molding method. .

  (Component) The methyl (meth) acrylate component of the ethylene- (meth) methyl acrylate copolymer is 10 to 20% by mass. If it exceeds 20%, the melting point is lowered, the surface becomes sticky, the slipping property is lowered, and the workability and mechanical suitability at the time of use are unfavorable. If it is less than 10%, the melting point is high, and high-temperature processing is performed at the time of film formation. Therefore, transparency is increased, slipperiness is lowered, and a matte texture cannot be realized.

  (MFR) MFR of ethylene- (meth) acrylic acid methyl copolymer shall be 1.0-10.0 g / 10min. By using a resin having an MFR of 1.0 to 10.0 g / 10 min, it is possible to form a matte textured surface layer having good inflation film formation and low gloss.

  (Gloss) The glossiness of the surface layer 11 made of ethylene- (meth) methyl acrylate copolymer is 20% or less. If it exceeds 20%, the glossiness of the surface is increased, the matte feeling is reduced, the slipperiness is lowered, and the foaming unevenness of the foamed layer 13 becomes conspicuous and the appearance is deteriorated.

  (Friction) The static friction coefficient between the surface layers 11 using the ethylene-methyl (meth) acrylate copolymer is 0.50 or less, and the dynamic friction coefficient is 0.50 or less. If the coefficient of static friction exceeds 0.5, the coefficient of dynamic friction exceeds 0.5, the slipperiness will deteriorate, causing wrinkles and blocking during production, and the workability and mechanical suitability will be reduced during use. It is not preferable because it moves or falls easily.

  (Foaming layer) The foaming layer 13 is formed by foaming a composition comprising a thermoplastic resin and a foaming agent, preferably a chemical foaming agent, simultaneously with the film formation by the multilayer coextrusion method, and the foaming ratio is 1.1. ˜3.0 times.

  (MFR of foam layer) The foam layer 13 in the laminate of the present invention is constituted by adding a foaming agent to a base resin made of a thermoplastic resin. The base resin preferably has a low MFR exhibiting high melt strength and melt elasticity, and preferably has an MFR of 0.5 to 4.0 g / 10 min. If the MFR is less than this range, the expansion ratio cannot be obtained, and if it exceeds this range, the bubble shape becomes poor.

  (Foaming agent) The chemical foaming agent is preferably an inorganic foaming agent. Organic foaming agents are not preferred because they generate decomposition gases such as ammonia gas, nitrogen gas, and carbon monoxide gas, and decomposition residues and sublimation substances cause contamination and corrosion of processing machines and metal products. . As the inorganic foaming agent used in the present invention, a foaming agent composed of sodium hydrogen carbonate whose generated gas is carbon dioxide and water vapor is suitable.

  (Addition amount) In the present invention, the above foaming agent is added in the range of 0.1 to 2.0% by mass. By adding 0.1 to 2.0% by mass of a foaming agent to the base resin, a foamed layer having a foaming ratio of 1.1 to 3.0 times can be obtained. If the expansion ratio is less than this range, the buffering property is insufficient, and if it exceeds this range, it is difficult to obtain closed cells and the surface state is deteriorated. By setting the expansion ratio to 1.1 to 3.0 times, a buffer function, handling suitability, and strength can be realized. A more preferable addition of the blowing agent is 0.2 to 1.0% by mass. If the amount is less than 0.1% by mass, the dispersion is poor and sufficient foaming cannot be obtained. If the amount exceeds 2.0% by mass, fine foaming cannot be realized, and may not easily occur during production.

  (Meani) Extrusion molding method has a defect that when it is extruded from a die, resinous deposits (Mayani) such as extruded resin composition and its oxide are generated at the outlet (die lip) of the die. Must. By providing the surface layer 11, it is possible to prevent the occurrence of resinous deposits on the die lip during the molding process, and the productivity can be improved.

  The foaming agent is generally added to a desired concentration by mixing with the base resin using a high concentration master batch. What is necessary is just to determine the density | concentration of a masterbatch suitably so that the foaming agent density | concentration in the foaming layer 13 may become the range of 0.1-2.0 mass%. Further, any of the surface layer 11A, the foam layer 13 and the surface layer 11B does not affect the function, for example, a lubricant, a plasticizer, a filler, an antistatic agent, an antiblocking agent, a crosslinking agent, an antioxidant. Additives such as ultraviolet absorbers, light stabilizers, colorants such as dyes and pigments, and others may be added.

(Production method)
As a manufacturing method of the laminated body 10, there are an inflation film forming method, a T-die film forming method, and the like. The T-die film forming method is not preferable because the molten resin is rapidly cooled immediately after being discharged from the T-die so that the transparency becomes high and a matte texture cannot be obtained. The inflation film forming method is preferable because cooling can be performed gradually and a matte surface with low gloss can be obtained.

  (Thickness) The laminate 10 is a laminate having a three-layer structure of surface layer 11A / foam layer 13 / surface layer 11B, and the thickness is preferably 200 μm to 500 μm. If it is less than 200 μm, the amount of gas contained is small and the foaming feeling is insufficient. The thickness of the surface layer 11A (surface layer 11B) is about 5 to 150 μm, preferably 10 to 100 μm, and the remaining thickness may be the thickness of the foam layer 13. If it is less than this range, foamed foam will be repelled or uneven, resulting in poor appearance, and if it exceeds this range, the thickness of the foam layer 13 will be relatively thin and the buffer function will be reduced.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, it is not limited to this. In addition, except a solvent, each composition of each layer is a mass part of solid content conversion.

(Example 1) As the surface layer 11A, the foam layer 13, and the surface layer 11B, each of the following compositions was used, and a three-layer multi-layer coextrusion molding was carried out by an air-cooling top blown inflation film forming method. Thus, the laminated body 10 of Example 1 having a total thickness of 300 μm, which is composed of three layers having a surface layer 11A of 25 μm / a foam layer 13 of 250 μm / a surface layer 11B of 25 μm, was manufactured.
(Surface layer 11A) ethylene-methyl methacrylate copolymer resin, Sumitomo Chemical Co., Ltd. ACLIFT CM8014 (MMA content = 17.5%, density = 0.940 g / cm ³ , MFR = 4.0 g / 10) Min) was adjusted to 100 parts by mass.
As the foamed layer 13, Sumikasen G201F (low density polyethylene resin, trade name, manufactured by Sumitomo Chemical Co., Ltd., density = 0.919 g / cm ³ , MFR = 2.0 g / 10 min, tensile modulus = 115 MPa) is 97. 3 parts by mass of a mass part, a foaming agent masterbatch manufactured by Nitto Kako Co., Ltd., and fine blow S-20N (20% masterbatch) were prepared.
As the (surface layer 11B), Sumikasen G201F (low density polyethylene resin, trade name, manufactured by Sumitomo Chemical Co., Ltd., density = 0.919 g / cm ³ , MFR = 2.0 g / 10 min, tensile elastic modulus = 115 MPa) is 100. The mass part was adjusted.
The expansion ratio of the foam layer 13 of the multilayer body was 2.0 times. Table 1 shows the glossiness and friction coefficient of the surface layer 11A.

(Example 2) A laminate 10 of Example 2 was manufactured in the same manner as Example 1 except that the following compositions were used as the surface layer 11A, the foam layer 13, and the surface layer 11B.
As (surface layer 11A), ethylene-methyl acrylate copolymer resin, Lexpearl EB033FC manufactured by Nippon Polyethylene Co., Ltd. (MA content = 15%, density = 0.940 g / cm ³ , MFR = 2.0 g / 10 min) ) Was adjusted to 100 parts by mass.
As the foamed layer 13, Sumikasen G201F (low density polyethylene resin, trade name, manufactured by Sumitomo Chemical Co., Ltd., density = 0.919 g / cm ³ , MFR = 2.0 g / 10 min, tensile modulus = 115 MPa) is 97. 3 parts by mass of a mass part, a foaming agent masterbatch manufactured by Nitto Kako Co., Ltd., and fine blow S-20N (20% masterbatch) were prepared.
As the (surface layer 11B), Sumikasen G201F (low density polyethylene resin, trade name, manufactured by Sumitomo Chemical Co., Ltd., density = 0.919 g / cm ³ , MFR = 2.0 g / 10 min, tensile elastic modulus = 115 MPa) is 100. The mass part was adjusted.
The expansion ratio of the foam layer 13 of the multilayer body was 2.0 times. Table 1 shows the glossiness and friction coefficient of the surface layer 11A.

(Comparative example 1) The laminated body 10 of the comparative example 1 was manufactured like Example 1 except having used the following composition as the surface layer 11A, the foam layer 13, and the surface layer 11B, respectively.
As the (surface layer 11A), Sumikasen G201F (low density polyethylene resin, trade name, manufactured by Sumitomo Chemical Co., Ltd., density = 0.919 g / cm ³ , MFR = 2.0 g / 10 min, tensile elastic modulus = 115 MPa) is 100. The mass part was adjusted.
As the foamed layer 13, Sumikasen G201F (low density polyethylene resin, trade name, manufactured by Sumitomo Chemical Co., Ltd., density = 0.919 g / cm ³ , MFR = 2.0 g / 10 min, tensile modulus = 115 MPa) is 97. 3 parts by mass of a mass part, a foaming agent masterbatch manufactured by Nitto Kako Co., Ltd., and fine blow S-20N (20% masterbatch) were prepared.
As the (surface layer 11B), Sumikasen G201F (low density polyethylene resin, trade name, manufactured by Sumitomo Chemical Co., Ltd., density = 0.919 g / cm ³ , MFR = 2.0 g / 10 min, tensile elastic modulus = 115 MPa) is 100. The mass part was adjusted.
The expansion ratio of the foam layer 13 of the multilayer body was 2.0 times. Table 1 shows the glossiness and friction coefficient of the surface layer 11A.

(Comparative example 2) The laminated body 10 of the comparative example 2 was manufactured like Example 1 except having used the following composition as the surface layer 11A, the foam layer 13, and the surface layer 11B, respectively.
As the (surface layer 11A), 100 parts by mass of a linear low density polyethylene resin, Umerit 1520F manufactured by Ube Maruzen Polyethylene Co., Ltd. (density = 0.913 g / cm ³ , MFR = 2.0 g / 10 min) was adjusted.
As the foamed layer 13, Sumikasen G201F (low density polyethylene resin, trade name, manufactured by Sumitomo Chemical Co., Ltd., density = 0.919 g / cm ³ , MFR = 2.0 g / 10 min, tensile modulus = 115 MPa) is 97. 3 parts by mass of a mass part, a foaming agent masterbatch manufactured by Nitto Kako Co., Ltd., and fine blow S-20N (20% masterbatch) were prepared.
As the (surface layer 11B), 100 parts by mass of a linear low density polyethylene resin, Umerit 1520F manufactured by Ube Maruzen Polyethylene Co., Ltd. (density = 0.913 g / cm ³ , MFR = 2.0 g / 10 min) was adjusted.
The expansion ratio of the foam layer 13 of the multilayer body was 2.0 times. Table 1 shows the glossiness and friction coefficient of the surface layer 11A.

  (Evaluation method) Using the laminates 10 of Examples 1 and 2 and Comparative Examples 1 and 2, the buffer function was evaluated from the appearance and foaming magnification, the matte feeling was evaluated from the glossiness, and the workability was evaluated from the static and dynamic friction coefficients.

(Measuring method)
The foaming ratio was determined by forming the laminate 10 of Example and Comparative Example and leaving it at 23 ° C. for 1 day, then cutting in the thickness direction, photographing the cut surface with an optical microscope, And the expansion ratio was calculated from the area ratio of the unfoamed part.
The glossiness of the laminate 10 is determined according to JIS-K7105 by using a digital variable gloss meter (Suga Test Instruments Co., Ltd. “UGV-5K”) at an incident angle of 60 degrees and a light receiving angle of 60 degrees. The glossiness of the surface layer 11A surface was measured.
The coefficient of friction was measured according to JIS-K-7125.
The appearance was visually observed.
In addition, MFR measured the outflow amount for 10 minutes on 190 degreeC and load 21.18N conditions based on JIS-K-7210.

(Evaluation results) In the laminated body 10 of Examples 1 and 2, as is apparent from the measurement results of the glossiness and the friction coefficient, the buffering property and the slipperiness are good, the matte appearance is good, and the visual appearance is not a problem. It was.
In Comparative Example 1, the friction was poor, the gloss was high, and the matte feeling was small. In Comparative Example 2, the friction property was remarkably poor, the gloss was slightly high, and the mat feeling was small.

It is sectional drawing of the laminated body which shows one Example of this invention.

Explanation of symbols

11, 11A, 11B: Surface layer 13: Foam layer

Claims (5)

In a laminate in which a surface layer, a foam layer and a surface layer are sequentially laminated, the laminate is formed into a film by a multilayer coextrusion molding method, and at least one surface layer is made of an ethylene- (meth) methyl acrylate copolymer. A laminate comprising 90% by mass or more. The methyl (meth) acrylate component of the ethylene- (meth) methyl acrylate copolymer is 10 to 20% by mass, and the melt flow rate (MFR) is 1.0 to 10.0 g / 10 min. The laminate according to claim 1. The glossiness of the surface layer made of an ethylene- (meth) methyl acrylate copolymer is 20% or less, and the static friction coefficient between the surface layers using the ethylene- (meth) methyl acrylate copolymer is 0. The laminate according to claim 1, wherein the laminate has a dynamic friction coefficient of 50 or less and a dynamic friction coefficient of 0.50 or less. The foam layer is formed by foaming a composition comprising a thermoplastic resin and a chemical foaming agent simultaneously with the film formation by the multilayer coextrusion method, and the foaming ratio is 1.1 to 3.0 times. The layered product according to any one of claims 1 to 3. The laminate according to any one of claims 1 to 4, wherein the multilayer coextrusion molding method is an inflation film forming method, and the total thickness of the laminate is 200 to 500 µm.

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