JPH0813533B2 - Multi-layer laminated structure material - Google Patents

Description

TECHNICAL FIELD The present invention relates to a multi-layer laminated structure material in which a main material layer containing a polyethylene resin as a whole component and a polyamide resin layer are laminated via an adhesive layer. In particular, it is to provide a multilayer laminated structure material capable of detecting the presence or absence of an adhesive layer in a non-destructive state by using an ultrasonic reflection method, and a multilayer packaging material, an industrial material, a part of an automobile and an electronic / electrical device. The present invention relates to a multi-layer laminated structural material which is extremely useful in quality control or process control in materials for use.

[Conventional technology]

Polyamide resin (P
A), polyethylene resin, saponified product of ethylene-vinyl acetate copolymer (ethylene-vinyl alcohol copolymer,
EVOH), halogen-containing resins such as polyvinyl chloride resin (PVC) and polyvinylidene chloride resin (PVDC), non-polyolefin resins such as polycarbonate resin (PC), polymer alloys of polyphenylene oxide resin and PA, aluminum, iron, Multi-layer laminated structural materials obtained by laminating metals such as copper, tin, and nickel, foils such as alloys containing these metals as main components (for example, stainless steel), films of synthetic resin obtained by vacuum deposition of aluminum, silica, etc. It is widely used for various materials such as various films, containers, and industrial members, which have a function of improving appearance such as barrier properties against gas and water vapor and surface gloss.

Most of these multi-layer laminated structural materials are high-pressure polyethylene resin (low-density polyethylene resin, LDPE), medium- and low-pressure polyethylene as the main material layer in terms of economy, molding processability, sealability, moisture resistance and water resistance. Resin (linear low density or high density polyethylene resin), polypropylene resin,
An olefin-based copolymer resin and a composition containing these as main components and various fillers (for example, calcium carbonate, talc, mica, glass fiber, carbon fiber, organic fiber) are combined with each other.

By the way, since these polyolefin-based resins have a non-polar molecular structure, they are poor in adhesiveness, affinity and compatibility with the non-polyolefin-based resins and metal materials, and the polyolefin-based resin is modified with a polar monomer (graft). Polymerization), the use of copolymers of olefins (particularly ethylene) with polar monomers, the blending (blending) of polar resins, or the treatment of these properties by chemical or physical means. It is widely applied, especially in the case of molding by the coextrusion method,
It is well known that a so-called modified polyolefin resin obtained by graft-modifying a polar monomer is used as an adhesive to form a multilayer laminated structure material with the above-mentioned various materials (for example, JP-B-61-2782 and 55-55). 39448 and "'87 -2 <Packaging material report> Market trend and development direction of coextrusion multilayer films and sheets” (Sogo Packaging Publishing Co., Ltd., issued February 27, 1987), pages 285 to 293].

[Problems to be Solved by the Invention]

However, in this case, there is almost no need for a material that is used for a relatively short period of time, does not receive a very strong impact in the manufacturing process or distribution process of a product or a product, and does not require a high level of performance such as interlayer adhesive strength. Although it is considered not to exist, the adhesive performance and durability of the adhesive are extremely important for members that require long-term durability and high resistance to vibration and various impacts. When a manufacturing method is adopted in which a material is continuously extruded into a thin film, it is necessary to confirm the presence or absence of an adhesive layer over the entire surface.

On the other hand, in the multilayer laminated structure material, if there is a part where the adhesive layer is completely or partially missing for some reason,
Not only may mechanical properties be partially deteriorated, but in long-term durability evaluation, moisture, moisture, etc. from the outside air may accumulate in the missing parts, reducing the performance of the entire multilayer laminated structure material. Will end up. Therefore,
If there is such a possibility, it is necessary to confirm whether or not the adhesive layer in the multilayer laminated structure material is present over the entire surface during manufacturing, but it is relatively easy and economical. Moreover, a method for detecting the presence or absence of the adhesive layer without destroying the multilayer laminated structure material has not been known yet.

As a method of confirming that the adhesive layer of the multi-layer laminated structure material is present in advance, it is also common to cut a part of the laminated material and observe its cross section by various methods. However, it is not only a destructive inspection but also an assumption that the adhesive layer in the similarly manufactured multi-layer laminated structural material will be present on the entire surface based on this result. It is hard to say that it is a simple method.

On the other hand, in a relatively transparent multilayer laminated structure material, the presence of an adhesive layer can be confirmed by using an optical analysis analysis means, etc., but this method is limited to a relatively thin material, It is not reliable because it is affected by the molecular structure of the non-polyolefin resin material.

It is also possible to use an adhesive containing a coloring agent such as a pigment for coloring, and check the presence of the adhesive layer by visual inspection or using a color difference meter, but this gives a significant limitation to the appearance of the product. It cannot be applied when the outer layer is opaque and the layer thickness is large.

Therefore, check the method as described above, check the amount of adhesive used before and after molding the product, and compare the calculated or estimated values calculated from the thickness, surface area and density of the adhesive layer in the laminate. By doing so, a method of substituting for management of the presence of the adhesive layer is generally implemented.

From the above, the present inventors have made various searches for combinations of a main material layer containing a polyolefin-based resin as a main component and an adhesive layer in a multilayer laminated structure material in order to solve these technical problems. As a result of combining this with a detection method using ultrasonic waves, by providing a difference in acoustic characteristics between the main material layer and the adhesive layer above a certain level, nondestructive detection of the adhesive layer, which has not been heretofore known, can be performed. It becomes possible to detect by the ultrasonic reflection method, and if there is a part where the adhesive layer is missing even if it is a part, it is possible to immediately find it so as to provide a multilayer laminated material without such a lack. The purpose is to do.

[Means and Actions for Solving the Problems]

According to the present invention, these problems are at least a multi-layer structure having a layer structure in which a main material layer containing polyethylene resin as a main component is laminated on the outside and a polyamide resin layer is laminated on the inner side through the adhesive layer. It is a laminated structure material, and the adhesive material has a density of 0.930 g / m ³ or more, MFR 0.01 g / 10 minutes or more, and a high-density polyethylene resin having a short-chain branch number of 20 or less per 1000 C of the main chain, a density 0.910 or more and less than 0.935 g / m ³ ,
MFR 0.1 to 50 g / 10 minutes, melting point by DSC 115 to 130 ° C., linear low density polyethylene resin having 5 to 30 short chain branches per 1000 C of main chain, unsaturated carboxylic acid and / or The high-density polyethylene-based resin graft-modified with a derivative thereof, and a resin containing at least 0.1% by weight of a modified high-density polyethylene resin or a modified linear low-density polyethylene resin selected from the group consisting of the linear low-density polyethylene resin 60- 95% by weight, density 0.890 g / m ³ or more 0.910 g / m ³
Less than 18 to 60 short chain branches per 1000 C in the main chain,
MFR 0.1-30g / 10min, melting point 110-1 by differential scanning calorimetry
A density of 0.925 g / m ³ or more consisting of 5 to 40% by weight of linear ultra-low density polyethylene at 25 ° C., the grafted acid and / or
Or its derivative content 0.001-5.0% by weight, 20-25MHz
Can be solved by a multilayer laminated structure material made of a resin composition having a difference in acoustic impedance due to ultrasonic waves of 8.5 × 10 ⁻³ g / cm ² μsec or more from that of the main material. Hereinafter, the present invention will be specifically described.

The multi-layer laminated structural material according to the present invention is formed by laminating a main material layer containing polyethylene resin as a main component on the outside and a polyamide resin layer on the inside with an adhesive layer interposed therebetween.

(A) Main material The main material in the present invention usually serves as a support layer. However, the polyethylene-based resin used as the main component of the main material layer has an acoustic impedance between the main material layer and the adhesive layer. Ethylene homopolymers and copolymers of ethylene and α-olefins are mentioned, but the differences should be selected as large as possible. The α-olefin generally has 3 to 12 carbon atoms (preferably 3 to 8 carbon atoms).
Is an olefin. Representative α-olefins include propylene, butene-1, hexene-1, octene-1 and 4-methylpentene-1.

Among the polyethylene resins, as is preferred, density 0.930 g / cm ³ or more (preferably, 0.935 g / cm ³ or more) selected from copolymers of ethylene homopolymer and ethylene and α- olefin Is an ethylene-based polymer. Furthermore, in these ethylene homopolymers and copolymers of ethylene and α-olefin, low density polyethylene (LDPE) having a density of less than 0.930 g / cm ³ , linear low density polyethylene and monomers other than ethylene and α-olefin Blended with a copolymer of propylene and a propylene homopolymer and a copolymer of propylene and ethylene or another α-olefin, and the resulting ethylene-based polymer composition has a density of
0.930 g / cm ³ or more (preferably, 0.935 g / cm ³ or higher) may be used in preference to those. Among these ethylene-based polymers, medium to high density polyethylene having a density of 0.935 g / cm ³ or more is particularly preferable.

The MFR of the polyethylene resin is not particularly limited, but from the viewpoint of moldability, it is generally 0.005 g / 10 minutes or more, preferably 0.01 g / 10 minutes or more, particularly 0.02 g / min.
It is preferably g / 10 min or more.

In the present invention, only the polyethylene-based resin may be used, and a small amount (preferably not more than about 20% by weight) of an elastomer or other synthetic resin that can be uniformly mixed with the polyethylene-based resin used is blended. You may. Examples of the elastomer include polyisobutylene and ethylene-
Examples thereof include propylene copolymer rubber (EPR), ethylene-propylene-diene ternary copolymer rubber (EPDM), acrylonitrile-butadiene copolymer rubber (NBR), and block or random styrene-butadiene copolymer rubber (SBR). Other synthetic resins include PA (polyamide resin), polyester resin, EVOH (saponified ethylene-vinyl acetate copolymer), PVC (polyvinyl chloride resin).
And PVDC (polyvinylidene chloride resin).

A filler that is generally added may be added to the polyethylene resin in the present invention. As the filler, calcium carbonate, talc, mica, glass fiber,
Examples thereof include carbon fibers, metal fibers, other inorganic fibers and organic polymer fibers (for example, polyester fibers and polyamide fibers).

In the present invention, when the polyethylene resin is mixed with an elastomer, another synthetic resin and a filler, the composition ratio of these components preferably does not exceed about 40% by weight.

(B) Adhesive The adhesive of the adhesive layer in the present invention should be selected so that the difference in acoustic impedance between the adhesive layer and the main material layer is as large as possible, but the adhesive has a density of 0.930 g / High density polyethylene resin with m ³ or more, MFR 0.01 g / 10 min or more, and 20 or less short chain branches per 1000 C in the main chain, density
0.910 or more and less than 0.935 g / m ³ , MFR 0.1 to 50 g / 10 minutes, DSC melting point 115 to 130 ° C, linear low density polyethylene with 5 to 30 short chain branches per 1000 C in the main chain A resin, one or more resins selected from the group consisting of the above-mentioned high-density polyethylene-based resin graft-modified with an unsaturated carboxylic acid and / or a derivative thereof, and the above-mentioned linear low-density polyethylene resin modified in the same manner as above. The first requirement is that the above selected resin is 60 to 90% by weight in the adhesive.
The second requirement is to occupy at least 0.1% by weight or more of the above graft-modified polyethylene resin in the adhesive, and the grafted acid and / or derivative in the adhesive at 0.001 to The third requirement is to contain 5.0% by weight, density 0.890 g / m ³ or more, 0.910 g /
less than m ³ , the number of short chain branches per C number of the main chain of 1000 18 to 60
, MFR 0.1-30g / 10min, melting point 11 by differential line differential calorimeter method
0-40 ° C linear ultra-low density polyethylene in adhesive 5-40
The fourth requirement is that the adhesive material has a density of 0.92.
The fifth requirement is that it is 5 g / m ³ or more, and the acoustic impedance of the adhesive due to ultrasonic waves of 20 to 25 MHz has a difference of 8.5 × 10 ^-3 g / cm ² · μsec or more from that of the main material. The sixth requirement is that the composition is a resin composition.

(B-1) Regarding the first requirement: -The adhesive of the present invention is selected from those other than the unmodified linear ultra-low density polyethylene resin, and the composition components thereof are exemplified below.

It should be noted that the term “modified” below refers to unsaturated carboxylic acid and / or
Alternatively, the derivative thereof is grafted, and “unmodified” refers to ungrafted one.

(A) Only modified high-density polyethylene resin [hereinafter referred to as "composition (I)" (b) Modified high-density polyethylene resin and unmodified linear low-density polyethylene resin [hereinafter referred to as "composition (II)" (c ) Modified high-density polyethylene resin and modified linear low-density polyethylene resin [hereinafter referred to as "composition (III)"] (d) Unmodified high-density polyethylene resin and modified linear low-density polyethylene resin [hereinafter referred to as "composition (IV )) (E) Unmodified high-density polyethylene resin and modified high-density polyethylene resin [hereinafter referred to as "composition (V)"] (f) Unmodified high-density polyethylene resin, modified high-density polyethylene resin and unmodified wire Low density polyethylene resin (hereinafter referred to as "composition (VI)") (g) Unmodified high density polyethylene resin, modified high density polyethylene resin, unmodified linear low density polyethylene Resin and Modified Linear Low Density Polyethylene Resin [Hereinafter, referred to as "Composition (VII)"] Hereinafter, each composition component and a method for producing them will be specifically described.

(B-1-1) High Density Polyethylene Resin Both the high density polyethylene resin used in the adhesive of the present invention and the high density polyethylene resin used as a material for the production of the modified high density polyethylene resin described below are ethylene alone or ethylene. It is obtained by homopolymerization or copolymerization with an α-olefin having 3 to 12 carbon atoms (preferably 3 to 8 carbon atoms) in the presence of a so-called Phillips catalyst or Ziegler catalyst. It is produced at a pressure of about 100 kg / cm ² (medium or low pressure polymerization). Preferred examples of the α-olefin include propylene and butene-
1, hexane-1,4-methylpentene-1 and octene-1. Its copolymerization ratio is at most 6.5
% By weight, and particularly preferably 6.0% by weight or less.

The number of short-chain branches per 1000 carbon atoms in the main chain of this high-density polyethylene resin is at most 20.

In addition, the density is at 0.930 g / cm ³ or more, 0.933 g / cm ³ or more preferably, is particularly preferred 0.935 g / cm ³ or more. Density is
When a polyethylene resin of less than 0.930 g / cm ³ is used, the product molded from the obtained composition is inferior in rigidity, heat resistance, fuel oil resistance and the like.

Further, the MFR is 0.01 g / 10 min or more, preferably 0.015 g / 10 min or more, and particularly preferably 0.02 g / 10 min or more.
When the MFR is less than 0.01 g / 10 minutes, it is not good in terms of moldability.

Also, the upper limit is not particularly limited, but usually 50 g / 10
Minutes, particularly preferably 35 g / 10 minutes or less.

In particular, in the modified high-density polyethylene resin described below, if the MFR of the raw material high-density polyethylene resin is less than 0.01 g / 10 minutes, it depends on the graft modification conditions, but the MFR of the obtained grafted high-density polyethylene resin is generally Is even lower than the MFR of the high-density polyethylene resin used for grafting, which reduces molding processability and significantly reduces the compatibility when producing a mixture with ungrafted high-density polyethylene resin, resulting in a uniform composition. Can't get As the FMR of this modified polyethylene resin,
Generally, 0.05g / 10 minutes or more is desirable, especially 0.1g / 10
Minutes or more are preferred.

Since these high-density polyethylene resins usually improve the adhesiveness, they are modified as described below and used as they are or in the form of being mixed with an unmodified product.

(B-1-2) Linear low-density polyethylene resin The linear low-density polyethylene resin used in the same manner as the above-mentioned high-density polyethylene resin is industrially manufactured, and its manufacturing method is well known. There is something. In particular, it is used in various fields because of its excellent resistance to environmental stress cracking, transparency, heat sealability, brittleness resistance, low temperature characteristics, etc. (for example, packaging materials such as films, industrial materials such as pipes). ).

The linear low-density polyethylene resin is produced by copolymerizing ethylene and the above α-olefin by a gas phase method, a solution method or a slurry method using a so-called Ziegler catalyst. .

The density of the linear low-density polyethylene resin is less than 0.910 g / cm ³ or more 0.935 g / cm ^3, preferably less than 0.912 g / cm ³ or more 0.935 g / cm ^3, especially 0.913 g / cm ³ or more 0.935 / cm Less than ³ is preferred.

The MFR is 0.1 to 50 g / 10 minutes, preferably 0.2 to 40 g / 10 minutes, and more preferably 0.2 to 30 g / 10 minutes. When the MFR of the linear low-density polyethylene resin is less than 0.1 g / 10 minutes, the moldability is poor. On the other hand, when it exceeds 50 g / 10 minutes, the mechanical strength of the obtained composition is not good.

Further, the melting point of the linear low density polyethylene resin by DSC is 115 to 130 ° C, preferably 118 to 130 ° C, and particularly preferably
A temperature of 118 to 125 ° C is preferable. Melting point by DSC method is 115
If the temperature is lower than ℃, the long-term solvent resistance at high temperature is not good. On the other hand, when the temperature exceeds 130 ° C, the density exceeds the upper limit of the above range.

The number of carbon atoms in the main chain of the linear low density polyethylene resin
The number of short-chain branches per 1000 is 5 to 30, and 5 to 25 is particularly preferable. If the number of branches of the short chain per 1000 carbon atoms in the main chain is less than the lower limit or more than the upper limit, the uniformity of the composition of the present invention becomes insufficient, which is not preferable.
That is, when a composition using a linear low-density polyethylene resin in which the number of branches per 1000 carbon atoms in the main chain deviates from the above range, particularly long-term solvent resistance at high temperatures (40 ° C or higher) (For example, when evaluating fuel oil resistance), not only is the tensile elongation greatly decreased, but also under conditions where heat resistance (specifically, a durability test in an atmosphere of 100 ° C or higher) is taken into consideration. Further, the physical properties are further deteriorated, which are all considered to be due to the non-uniformity of the composition of the composition.

(B-1-3) Modified high-density polyethylene resin and modified linear low-density polyethylene resin The modified high-density polyethylene resin and modified linear low-density polyethylene resin used in the present invention are the above-mentioned high-density polyethylene resin and linear low-density polyethylene resin. It can be obtained by treating a density polyethylene resin with an unsaturated carboxylic acid and / or a derivative thereof described below in the presence of a radical initiator. At this time, the following synthetic resin or elastomer (rubber) having affinity with the high density polyethylene resin and linear low density polyethylene resin to be grafted may be present.

Examples of the unsaturated carboxylic acid and its derivative used in the graft treatment include monobasic unsaturated carboxylic acid and dibasic unsaturated carboxylic acid, and metal salts, amides, imides, esters and anhydrides thereof. Of these, the monobasic unsaturated carboxylic acid generally has at most 20 (preferably 15 or less) carbon atoms. The derivative usually has at most 20 (preferably 15 or less) carbon atoms. Further, the number of carbon atoms in the dibasic unsaturated carboxylic acid is generally at most 30 (preferably 25).
Or less). The derivative usually has at most 30 (preferably 25 or less) carbon atoms.

Representative examples of these unsaturated carboxylic acids and their derivatives are described in JP-A-62-10107.

Among these unsaturated carboxylic acids and their derivatives, acrylic acid, methacrylic acid, maleic acid and its anhydride, 5-norbornene-2,3-dicarboxylic acid and anhydride and glycidyl methacrylate are preferable, and maleic anhydride is particularly preferable. And 5-norbornene anhydride are preferred.

Further, the radical initiator used for the above graft modification usually has a decomposition temperature with a one-minute half-life of 100 ° C or higher, preferably 103 ° C or higher, particularly 105 ° C.
The above are preferred. Suitable radical initiators include dicumyl peroxide, benzoyl peroxide, di-tertiary-butyl peroxide, 2,5-dimethyl-2,5-di (tertiary-butylperoxy) hexane,
2,5-dimethyl-2,5-di (tertiary-butylperoxy)
Organic peroxides such as hexane-3, lauroyl peroxide, and tertiary-butyl peroxybenzoate can be mentioned.

The synthetic resin and elastomer that can coexist during the graft reaction will be described. Synthetic resins include high pressure low density polyethylene resin, ethylene-
Vinyl acetate copolymer, ethylene-acrylic acid copolymer,
Copolymerization of ethylene with other vinyl monomers such as ethylene-methacrylic acid copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate copolymer, ethylene-methyl methacrylate copolymer Examples include polymers.

Elastomers include ethylene-α-olefin copolymer rubbers such as ethylene-propylene copolymer rubber, ethylene-propylene-diene terpolymer rubber, ethylene-butene-1 copolymer rubber, polyisobutylene rubber, and polyurethane rubber. And synthetic rubbers such as styrene-butadiene copolymer rubber and polybutadiene rubber, and natural rubbers.

Further, when the olefin resin or elastomer is used, the proportion of the total amount of the high density polyethylene resin and the linear low density polyethylene resin is generally at most 10% by weight, and particularly preferably 5.0% by weight or less.
If the total amount of synthetic resin and / or elastomer in the total amount of high-density polyethylene resin or linear low-density polyethylene resin exceeds 15% by weight, the basis of high-density polyethylene resin or linear low-density polyethylene resin May impair the physical characteristics.

In producing the modified polyethylene resin used in the present invention, the unsaturated carboxylic acid and / or its derivative and the radical initiator used for 100 parts by weight of the high density polyethylene resin or the linear low density polyethylene resin to be grafted are used. The ratio is as follows.

The unsaturated carboxylic acid and / or the derivative thereof is generally 0.01 to 5.0 parts by weight as their total amount,
0.01 to 3.0 parts by weight is preferable, and 0.02 to 2.0 parts by weight is particularly preferable. If the proportion of the unsaturated carboxylic acid and its derivative is less than 0.01 parts by weight as the total amount thereof, the graft modification becomes insufficient and there is a problem in terms of affinity or adhesiveness which is the object of the present invention. On the other hand, if it exceeds 5.0 parts by weight, the resulting graft-modified high-density polyethylene resin and linear low-density polyethylene resin may cause gelation, coloration, deterioration, etc., and the improvement of the performance of the object of the present invention is recognized. I will not be able to.

Further, the ratio of the radical initiator is usually 0.001 to 1.0 part by weight, preferably 0.005 to 1.0 part by weight, particularly 0.005 to 1.0 part by weight.
5 to 0.5 parts by weight is preferred. The ratio of the radical initiator is 0.
When the amount is less than 001 parts by weight, the effect of the graft modification is poor, and not only a long time is required to complete the graft modification, but also unreacted substances are mixed. on the other hand,
If it exceeds 1.0 part by weight, excessive decomposition or crosslinking reaction occurs, which is not preferable.

The modified high-density polyethylene resin and modified linear low-density polyethylene resin of the present invention are the above-mentioned high-density polyethylene resin or linear low-density polyethylene resin (in which a synthetic resin and / or an elastomer is optionally present), unsaturated carboxylic acid and It can be prepared by treating the above-mentioned ratio and / or the derivative thereof and the radical initiator in the range of the above-mentioned ratio. The treatment method is disclosed in JP-A-62-10.
A publicly known method may be adopted as described in Japanese Patent Publication No. 107 and Japanese Patent Publication No. 61-132345.

Specifically, a method in which a high-density polyethylene resin or the like processed using an extruder, a Banbury mixer, a kneader or the like is kneaded in a molten state, and a polymer such as a high-density polyethylene resin or a linear low-density polyethylene resin is mixed with an appropriate solvent. Examples thereof include a solution method in which the particles are dissolved, a slurry method in which particles of a polymer such as a high-density polyethylene resin are suspended, or a so-called vapor phase graft method.

The treatment temperature is appropriately selected in consideration of deterioration of polymers such as high-density polyethylene resin or linear low-density polyethylene resin, decomposition of unsaturated carboxylic acid or its derivative, and decomposition temperature of radical initiator to be used. Taking the method of kneading in the molten state as an example, it is usually 100 to 350.
℃, preferably 150 ~ 300 ℃, especially 180 ~ 300 ℃
Is preferred.

Of course, the production of the modified high-density polyethylene resin and the modified linear low-density polyethylene resin of the present invention in this manner is already known as disclosed in JP-A-62-10107 for the purpose of improving the performance. Treatment method, for example, a method of treating with an epoxy compound or a polyfunctional compound containing an amino group or a hydroxyl group during or after graft modification, and by heating or washing, unreacted monomer (unsaturated carboxylic acid or its derivative) or A method of removing various components that are by-produced can be adopted.

(B-1-4) Resin of First Requirement One or more polyethylene resins selected from the high-density polyethylene resin, linear low-density polyethylene resin, and modified resins described above are used alone or in a blend. To be The composition of the modified or unmodified polyethylene resin blended is preferably 2.5 to 75% by weight, more preferably 5.0 to 75% by weight, and particularly 5.0.
~ 60 wt% is optimal. If it is less than 2.5% by weight, the uniformity of the composition in all compositions will be poor, and if it exceeds 75% by weight, the heat resistance and the long-term fuel oil resistance at high temperatures will be poor. The fifth
The density of the adhesive material in the requirement of 1 must be taken into consideration.

Further, the modified high-density polyethylene resin and / or the modified linear low-density polyethylene resin should be selected in consideration of the content of the grafted acid and its derivative in the third requirement.

(B-2) Second and fourth requirements:-(B-2-1) Adhesive resin component and composition Selected from the high-density polyethylene-based resin, linear low-density polyethylene-based resin, and modified resins thereof. Only the resin composition prepared in this way is inferior in adhesion durability and impact resistance of the multilayer laminated structure material. Further, the difference in acoustic impedance between the main material and the main material is not large.

Therefore, the present inventors have found that the problem can be solved by further adding a linear ultra-low density polyethylene resin,
This is inferior in oil resistance and is not often used. The composition is 5.0 to 40% by weight, preferably 5.0 to 38% by weight, and particularly preferably 7.0 to 38% by weight, based on the total resin. If the composition ratio of the linear ultra-low density polyethylene resin in the entire composition is less than 5.0% by weight, the resulting composition is inferior in impact resistance and adhesion durability. On the other hand, if it exceeds 40% by weight, the fuel oil resistance (particularly, the fuel oil resistance at 40 ° C.) is significantly lowered, which is not preferable.

(B-2-2) Linear Ultra Low Density Polyethylene Resin The method for producing the linear ultra low density polyethylene resin used in the present invention is widely known. It is manufactured industrially by legal methods and is widely used.

Therefore, a low crystallinity ethylene-α-olefin random copolymer having a crystallinity of several% to about 30% obtained by polymerizing using a conventionally known vanadium catalyst system (density 0.86 to 0.91 g / cm ³ ), for example, JP-A-57-68306, 59-23011, 61-1098.
It is a linear ultra-low density polyethylene resin produced by a slurry method or a gas phase method using a stereoregular catalyst (so-called Ziegler catalyst) as described in each publication of No. 05.

Linear ultra low density polyethylene resin in the present invention is density of 0.890 g / cm ³ or more and less than 0.910 g / cm ^3,
And, MFR is 0.1-30g / 10min, and melting point by DSC is 1
It is a linear low-density polyethylene resin having a temperature of 10 to 125 ° C. and a short chain branching number of 18 to 60 per 1000 carbon atoms in the main chain.

In the present invention, when the density of the resin is less than 0.890 g / cm ³ , there is a problem in fuel oil resistance of the obtained composition. On the other hand, if it exceeds 0.910 g / cm ³ , the resulting composition is insufficient in terms of adhesion durability and impact resistance. From these facts, those having a density of 0.892 to 0.910 g / cm ³ are preferable.

If the MFR of the resin is less than 0.1 g / 10 minutes, it is not preferable in terms of moldability and processability. On the other hand, if it exceeds 30 g / 10 minutes, there is a problem in terms of impact resistance. From these, MF
R is preferably 0.1 to 10 g / 10 minutes, and particularly preferably 0.2 to 8.0 g / 10 minutes.

Further, DSC (weigh about 5 mg of sample,
After setting in the measuring device, the temperature was raised from room temperature to 200 ° C. at a rate of 10 ° C./min, and then maintained at that temperature for 5 minutes.
The temperature is lowered to room temperature at a rate of 10 ° C./min, and the temperature at the peak of the maximum endothermic region when the temperature is further increased at the rate of temperature increase is defined as a melting point. is there. Particularly, those having a temperature of 112 to 125 ° C are preferable. When the melting point is lower than 110 ° C, the heat resistance of the resulting composition is insufficient. On the other hand, when the temperature is higher than 125 ° C., the effect of improving impact resistance is poor.

Moreover, the number of branches of the short chain per 1000 carbon atoms of the main chain of the resin is 18 to 60, preferably 18 to 50, and particularly
20-50 pieces are suitable. If the number of short chain branches per 1,000 carbon atoms in the main chain is less than 18, there is a problem in the obtained impact resistance. On the other hand, if the number exceeds 60, the fuel oil resistance is significantly inferior. Here, the short chain has substantially 1 to 10 carbon atoms.
(Preferably 1 to 6) alkyl groups.

In addition, from the viewpoint of the impact resistance improvement effect, the initial tensile modulus of the polyethylene resin is 2 × 10 ³ kg f / cm ² or less (preferably 1.5 × 10 ³ kg f / cm ² or less). Is preferred.

The polyethylene resin is obtained by copolymerizing ethylene with the α-olefin using a Ziegler catalyst.

(B-3) Third requirement: -The composition ratio of the modified polyethylene resin and / or the modified linear low-density polyethylene resin in the adhesive is at least 0.1% by weight as a total amount thereof, and the adhesive is Grafted unsaturated carboxylic acid and / or
Or the ratio of its derivatives is 0.001 as their total amount.
~ 5.0% by weight.

Generally, when a polymer (in the case of the present invention, a high-density polyethylene resin or a linear low-density polyethylene resin) is graft-modified with a monomer (in the case of the present invention, an unsaturated carboxylic acid or a derivative thereof), all the polymers must be used. It is difficult for the monomers to be grafted, and there are some polymers that are not grafted. In the present invention, the non-grafted high-density polyethylene resin or linear low-density polyethylene resin may be used as it is without being separated. Further, a high-density polyethylene resin and / or a linear low-density polyethylene resin which has not been graft-treated may be further blended.

Further, a part of all the composition components may be mixed in advance and the remaining composition components may be mixed, or all the composition components may be mixed simultaneously.

In any of the above cases, the proportion of the grafted monomers in the adhesive of the present invention is 0 as the total amount thereof.
001 to 5.0% by weight, preferably 0.01 to 2.0% by weight,
Especially, 0.02 to 1.0% by weight is preferable. When the proportion of the grafted monomers in the adhesive material is less than 0.001% by weight as the total amount thereof, various effects of the present invention cannot be sufficiently exhibited. On the other hand, even if it exceeds 5.0% by weight, the effect of the present invention cannot be further improved.

In producing the resin composition used in the present invention,
Addition of antioxidants, heat stabilizers, ultraviolet absorbers, lubricants, antistatic agents, pigments (colorants), etc., which are generally used in the field of polyolefin resins, within a range that does not substantially impair the effects of the composition. Agents can be added.

As a mixing method for producing the composition, various mixing methods generally performed in the field of synthetic resins, that is, a method of dry blending using a mixer such as a tumbler or a Henschel mixer, an extruder, a kneader, Any method of melt-kneading using a kneader such as a Banbury mixer and a roll can be employed. At this time, a more uniform composition can be obtained by carrying out two or more of these mixing methods (for example, dry blending in advance,
A method in which the resulting mixture is further melt-kneaded).

(B-4) Fifth requirement: -The density of the adhesive obtained as described above is 0.925 g / cm ³
The above is required, and 0.926 g / cm ³ or more is particularly desirable. When the density of the adhesive is less than 0.925 g / cm ³ , long-term solvent resistance is poor.

To obtain this density of 0.925 g / cm ³ or more, it is easy to mix by considering the density of modified or unmodified high-density polyethylene resin, modified or unmodified linear low-density polyethylene resin, and linear ultra-low density polyethylene resin. You can decide the ratio.

(B-5) Sixth requirement: -The acoustic impedance (Z ₀ ) of the main material layer of the multilayer laminated structure material of the present invention is not particularly limited, but is 20 to 25.
Z ₀ measured using MHz ultrasound is approximately 2.07 × 10 ^-1 g / cm ²
-Μsec or more is preferable, 2.15 x 10 ^-1 g / cm ² · μsec or more is desirable, and 2.22 x 10 ^-1 g / cm ² · μsec or more is particularly preferable.

However, in order to detect the presence or absence of the adhesive layer by the nondestructive method, the difference | Z ₀ −Z ₁ | from the acoustic impedance (Z ₁ ) of the adhesive layer is 8.5 to 10 ^-3 g / cm ² · μse or more c,
It has been found that it is desirable that it is 9.0 × 10 ⁻³ g / cm ² · μsec or more, and more preferably 9.5 × 10 ⁻³ g / cm ² · μsec or more.

If the difference in acoustic impedance is less than 8.5 to 10 ^-3 g / cm ² · μsec, it becomes extremely difficult to detect the presence or absence of the adhesive layer made of polyethylene resin inside the main polyethylene resin.

When melt-kneading to produce the adhesive, it is necessary to carry out the melting at a temperature at which various polyethylene-based resins as well as synthetic resins or elastomers melt. However, when carried out at elevated temperatures, they can decompose thermally. For the above reasons, it is generally 170 to 300 ° C (preferably 190 to 300 ° C).
~ 280 ° C).

(C) Polyamide resin Polyamide resin used to form the multilayer laminated structure material of the present invention includes nylon 6, a copolymer of nylon 6, modified nylon 6, nylon 11, nylon 12, nylon 6-6. To be Among them, the one having a melting point of 265 ° C. or less is preferable, and the one having a melting point of 230 ° C. or less is particularly preferable. These polyamide resins may be used alone or in combination of two or more. Further, metal (for example, aluminum, iron, copper) or alloy (for example, stainless steel) foil or various synthetic films obtained by vacuum deposition of these metals or alloys or silica on at least one surface of these polyamide resins, so-called metal vapor deposition You may use it as a film.

(D) Multilayer Laminated Structural Material and Laminating Method The multilayer laminated structural material of the present invention is produced by laminating the main material and the polyamide resin through the above adhesive by a method generally used in the field of synthetic resins. You can

For lamination, a method of co-extruding a main material, an adhesive and a polyamide resin using three or more extruders (for example, multi-layer blow, co-extrusion inflation, T-die film molding) or a polyamide resin as a base material As a method, a main material and an adhesive material are co-pressed at the same time, coating (coating or lamination) is performed, and heating and pressure bonding is performed. Further, there is a method in which each of them is separately formed into a film or a sheet, and these are heat-pressed.

As the constitution of the multilayer laminated structure material of the present invention, if the main material layer is A, the adhesive material layer is B, and the polyamide resin is C, A / B /
If C, A / B / C / B, A / B / C / B / A /, or a repeating structure of these structures, or if the burr layer is D, the D layer is between the A layer and the B layer. May be interposed.

[Examples and Comparative Examples]

Hereinafter, the present invention will be described in more detail with reference to examples.

In the examples and comparative examples, the density is JIS K711.
The measurement was carried out according to Method A of 2. In addition, the acoustic impedance (Z) is an ultrasonic thickness gauge equipped with a vertical probe using a piezoelectric element as a diaphragm (manufactured by Nippon Panametrics, model
5215) and a press plate with a thickness of 2 mm (30 x 30 mm)
The sound velocity when ultrasonic waves (frequency 20 MHz) was incident on the thickness direction was calculated, and calculated by the density and the following equation.

Z = ρ × C ρ: Density C: Speed of sound Furthermore, for the determination of the detectability of the adhesive material, the device used for the measurement of the acoustic impedance described above is used, and the ultrasonic wave (frequency
20MHz), the thickness of the main material layer is 3mm, and the thickness of the adhesive material layer is 0.15
mm and the thickness of the polyamide resin layer is 0.10 mm, which is incident on each multilayer laminated structure material, and the pulse wave reflected at each interface is output by a waveform viewing oscilloscope equipped with a polaroid camera for recording, and is output to the camera. The pulse waveform was recorded. The model of this record is shown in FIG.

In FIG. 1, the vertical axis represents the intensity of the reflected wave and the horizontal axis represents the distance in the thickness direction from one surface of the multilayer laminated component. The pulse input from the left side of Fig. 1 shows the reflected wave intensity peak indicated by "a" on the surface of the main material layer, then a part of the pulse enters the wall of the laminated constituent material, and the peak "a" and peak " The light passes through the thickness of the main material layer corresponding to the distance between "b" and "b" and reflects at the surface of the adhesive layer (interface with the main material layer).

In the case of this example (figure), the peaks "a" and "b" show the opposite directions because the value of the adhesive layer (Z ₁ ) is lower than the acoustic impedance (Z ₀ ) of the main material layer. (Z ₀ > Z ₁ ). Of course, if Z ₁ > Z ₀ , the peak height in the same direction is shown.

Next, a further part of the pulse passes through the thickness of the adhesive layer (the distance between the peak “b” and the peak “c”), and then the peak “c” is generated at the interface between the adhesive layer and the polyamide resin layer. Make the reflection shown. After passing through the polyamide resin layer (the distance between the peak “C” and the peak “D”), the reflection is the peak “D”.

When this measurement method is adopted, the difference between the peak of the main material layer and the adhesive layer is h ₁ , or the difference between the peak of the main material layer and the polyamide resin layer is h _2, and h ₁ / h ₂ is less than 0.08. , “No detectability”, and when h ₁ / h ₂ was 0.08 or more, it was determined to be “detectable”.

The reason is that when the value of h ₁ / h ₂ is less than 0.08, the peak is
It is extremely difficult to distinguish (identify) the waveform disturbance due to noise and noise.

In addition, the adhesive strength before treatment is obtained from the obtained laminated component,
Cut a plane piece with a width of 10 mm and a length of 150 mm and measure the adhesive strength between the adhesive and the PA (6) layer by the T-type peeling method using a tension type tensile tester at a peeling speed of 50 mm / min. It was measured.

Various modified polyethylene resins used for the adhesives in Examples and Comparative Examples were manufactured as follows.

Powder of high-density polyethylene resin having a density of 0.950 g / cm ³ and an MFR of 0.85 g / 10 minutes [hereinafter referred to as "HDPE (1)"] 0.01 part by weight of 2,5-dimethyl- 2,5-Tertiary-butylperoxyhexane was added and dry blended for 2 minutes using a Henschel mixer. Then, 0.35 part by weight of maleic anhydride [hereinafter referred to as "MAH"] was added, and dry blending was further performed for 2 minutes.
The obtained mixture was melt-kneaded at a resin temperature of 260 ° C. using an extruder to produce pellets. The resulting modified high-density polyethylene resin [pellet, hereinafter "modified HDPE
The amount of MAH grafted according to (a)] was 0.32% by weight. HDPE used to manufacture modified HDPE (a)
Instead of (1), the density is 0.943 g / cm ³ and MFR
High density polyethylene resin (hereinafter "HD
PE (2) ”] is used, and dry blending and melt kneading are performed in the same manner as in the production of modified HDPE (a), and modified high density polyethylene resin [hereinafter referred to as“ modified HDPE ”].
(B)] was produced. The amount of MAH grafted with the modified HDPE (b) was 0.30% by weight. Also, modified HDPE
Instead of HDPE (1) used in the production of (a), the density is 0.924 g / cm ³ , MFR is 0.8 g / 10 min, melting point is 120 ° C., and the number of carbon atoms in the main chain is 1000 per 1000. Linear low-density polyethylene resin having 10 ethyl groups (branches) [hereinafter referred to as "branches"] 10 [hereinafter referred to as "LLDPE (3)"]
Dry blending and melt-kneading were performed in the same manner as in the production of the modified HDPE (a) except that the above was used. The amount of MAH grafted with the obtained modified linear low-density polyethylene [hereinafter referred to as "modified LLDPE (c)] was 0.28% by weight. Furthermore, the HDPE used in producing the modified HDPE (a).
Instead of (1), the density is 0.891 g / cm ³ and MFR
Is 1.8 g / 10 min, melting point is 97 ° C, linear ultra-low density polyethylene resin having 70 branches (hereinafter referred to as "L-ULDPE (4)"), and melt kneading is changed to 230 ° C. Was dry-blended and melt-kneaded in the same manner as in the production of modified HDPE (a). Obtained modified linear ultra-low density polyethylene resin [hereinafter referred to as "modified L-ULDPE (d)"]
The amount of grafted MAH was 0.25% by weight.

Furthermore, as an unmodified linear ultra-low density polyethylene resin for producing an adhesive, a linear ultra-low density polyethylene resin produced by a slurry polymerization method [density 0.905 g
/ cm ³ , MFR 1.02g / 10 minutes, melting point 120 ° C, branch number 30, hereinafter referred to as "L-ULDPE (5)"], density 0.899g / cm ³ , and MFR 0.93g / 10 Minute linear ultra-low density polyethylene resin [melting point 114 ° C, branch number 44, hereinafter "L-U
LDPE (6) ”] and the density is 0.907 g / cm ³ ,
Linear ultra-low density polyethylene resin with MFR of 9.0g / 10min [melting point 121 ° C, branch number 23, below "L-ULDPE
(7) ”is used.

Modified high-density and linear low-density polyethylene resins [hereinafter referred to as “g-PE”] whose types and amounts are shown in Table 1
Unmodified high-density and linear low-density polyethylene resin [hereinafter referred to as "PE"] and unmodified linear ultra-low-density polyethylene resin [hereinafter referred to as "L-ULDPE"] using a Henschel mixer in advance. And dry blended for 5 minutes. Each of the resulting mixtures was kneaded while the resin temperature was 210 ° C. using an extruder (diameter 50 mm) while melting to obtain pellets (composition). The MAH content, density and acoustic impedance of the obtained composition (adhesive) were measured. They are shown in Table 1. The abbreviations of the obtained adhesive materials are shown in Table 1.

High load melt index (JIS K7
According to 210, the condition in Table 1 is 7), 5.0g / 10min, the density is 0.945g / cm ³ , and the acoustic impedance is 2.23 × 10 ^-1 g / cm ² · μsec. High density polyethylene resin [hereinafter referred to as "HDPE (A)"] and MFR
Is 0.5 g / 10 minutes, the density is 0.948 g / cm ³ , and the acoustic impedance is 2.255 × 10 ^-1 g / cm ² · μsec. High density polyethylene resin [hereinafter referred to as “HDPE (B)” I said) was used.

Further, as the polyamide resin, nylon 6 having a relative viscosity of 4.2 [hereinafter referred to as "PA (6)"] was used.

Examples 1 to 12 and Comparative Examples 1 to 8 Extruded at 230 ° C. so as to interpose the main material, the adhesive material and the PA (6) (polyamide resin) whose types are shown in Table 2 with the adhesive material interposed. Using the machine [diameter: main material 90 mm, adhesive 40 mm, PA (6) 40 mm], laminated materials [thickness: main material layer 3.5 mm, adhesive layer 0.2 mm, PA (6) layer 0.1 mm] were manufactured. .

A test piece for measuring the adhesive strength and the same test piece were cut out from the flat surface portion of each obtained multilayer laminated structure material. After each test piece was allowed to stand in an oven at 110 ° C for 72 hours, 90% by volume of commercially available regular gasoline and methyl alcohol
It was immersed in a mixed solution of 10% by volume at 40 ° C. for 1500 hours. Then, each test piece was taken out and kept under the conditions of a temperature of 23 ° C. and a relative humidity of 50% for 168 hours, and the adhesive strength after these treatments was measured. Adhesive strength before treatment, ratio after treatment to adhesive strength before treatment, difference in acoustic impedance of adhesive with respect to main material layer [hereinafter referred to as "ΔZ"], h ₁ above
Table 2 shows / h ₂ and the determination of the presence / absence of detection obtained from it.

[Effects of the Invention] The multilayer laminated structure material of the present invention exhibits the following effects.

(1) Since it is constructed by using an adhesive material having extremely excellent adhesiveness and various durability which has never been obtained, it has excellent function and performance even in a harsh environment.

(2) The best point is that the presence / absence of the adhesive layer in the structural material can be detected by the ultrasonic reflection method without destroying it. This is an undeveloped technology.

(3) Therefore, by using this specific material and the multi-layer laminated structural material in combination thereof, it is possible to confirm the inspection before the final product for the deterioration of the function and the performance due to the defect of the adhesive layer, and to confirm the quality. And in process control,
Any loss of functionality or performance due to omissions can be identified prior to final product.

The multilayer laminated structure material of the present invention can be used in various fields as a product having the structure in order to exert the above effects. Typical uses are shown below.

(1) Containers for fuel oil such as gasoline (including gasohol) (2) Various industrial cans

[Brief description of drawings]

FIG. 1 shows a pulse waveform in which an ultrasonic wave is incident from one outer surface of a multi-layered material of three kinds of three layers and the reflected pulse at each interface is output by a waveform observation oscilloscope.

Claims (1)

[Claims] 1. A multi-layer laminated structure material having a layer structure in which a main material layer containing a polyethylene resin as a main component is laminated on the outside and a polyamide resin layer is laminated on the inner side through an adhesive material layer. Material has a density of 0.930 g / m ³ or more, MFR 0.01
g / 10 min or more, high-density polyethylene resin with 20 or less short chain branches per 1000 C in the main chain, density 0.910 or more 0.935 g /
less than m ³ , MFR 0.1 to 50 g / 10 min, DSC melting point 115 to 130
℃, linear low density polyethylene resin having 5 to 30 short chain branches per 1000 C in the main chain, unsaturated carboxylic acid and /
Alternatively, at least a modified high-density polyethylene resin or a modified linear low-density polyethylene resin selected from the group consisting of the high-density polyethylene resin graft-modified with a derivative thereof and the linear low-density polyethylene resin is 0.1
Resin containing 60% to 95% by weight and a density of 0.890 g / m ^{3 to} less than 0.910 g / m ^3, 18 to 60 short chain branches per 1000 C of the main chain, MFR 0.1 to 30 g / 10 min, a density of 0.925 g / m ³ or more consisting of 5 to 40% by weight of linear ultra-low density polyethylene having a melting point of 110 to 125 ° C by a differential scanning calorimeter method, and the content of the grafted acid and / or its derivative 0.001 to 5.0% by weight, a multilayer comprising a resin composition having a difference in acoustic impedance of 20 to 25 MHz of ultrasonic waves of 8.5 × 10 ⁻³ g / cm ² · μsec or more from that of the main material Laminated structural material.