JP2972844B2 - Resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a specific polyethylene resin composition. In particular, it has excellent fuel oil resistance, impact resistance (especially impact resistance at low temperatures) and heat resistance,
In addition, various polyolefin resins, various polyamide resins such as nylon 6,6, various hydroxyl-containing resins such as saponified ethylene vinyl acetate copolymer, various polyester resins such as polyethylene terephthalate resin, various halogens such as polyvinyl chloride resin. In addition to various synthetic resin materials such as resin, it provides materials having affinity or adhesiveness with metal materials such as aluminum and iron, especially in the field of packaging containers and industries where various polyethylene resin materials are used. The present invention relates to a polyethylene resin composition useful in the field of materials and the like.

[0002]

2. Description of the Related Art Techniques for graft-polymerizing an unsaturated carboxylic acid or a derivative thereof (for example, an anhydride thereof) onto an ethylene homopolymer or an ethylene-based copolymer have been well known. Above all, modified polyethylene resins grafted with acrylic acid or maleic anhydride are polyamide resins, saponified ethylene-vinyl acetate copolymers,
Used as an adhesive material for coating various kinds of laminates, metal plates or metal tubes made of polar resin such as thermoplastic polyester resin, polyvinyl chloride resin, polyvinylidene chloride resin and metal foil such as aluminum foil. I have.

Further, it is often used for imparting functions such as affinity and compatibility with a matrix resin in a composite material containing various fillers, reinforcing agents, and additives such as pigments or a polymer blend material of different resins. in use.

Although a large number of modified polyethylene resins of this type have been proposed so far, it is difficult to satisfy all the various performances required by the market with a single modified polyethylene resin alone. In order to provide, it is often the case that the type of polyethylene of the modified polyethylene resin is changed, and that the modified polyethylene resin is blended with various other polyolefin resins, various elastomers, various polymers having polar groups or compounds having polar groups, and the like. Proposed. For example, a composition obtained by blending a soft resin with a modified polyolefin resin (for example, JP-B-55-18251, JP-A-61-1323)
No. 45) or a modified polyethylene resin blended with another polymer (for example, a saponified product of an ethylene-vinyl acetate copolymer, a thermoplastic polyester resin) (for example, JP-A-53-39381 and JP-A-52-381). No. 103480) has been proposed.

Furthermore, recently, environmental stress cracking resistance (ES)
CR), a linear low-density polyethylene resin having excellent properties such as heat sealing properties and low-temperature properties [hereinafter referred to as L-LD
It has been proposed to improve the heat resistance and the adhesiveness by imparting the above-mentioned properties by using PE as a base material of a modified ethylene resin or as a compounding material with a modified polyethylene resin (JP-A-57-157). -170940, 5
Nos. 7-68351 and 61-276808).

Japanese Patent Application Laid-Open No. Sho 59-68351 discloses an unmodified L-LDPE and a graft-modified L-LDP.
A laminate of a saponified ethylene-vinyl acetate copolymer, a polyamide resin and a polyolefin-based resin using a polyethylene resin composition comprising E or a high-density polyethylene resin (hereinafter referred to as HDPE) is disclosed.
As the unmodified L-LDPE and the graft-modified L-LDPE, a linear polyethylene resin having a density of 0.910 to 0.960 g / cm ³ is used.

Japanese Patent Application Laid-Open No. Sho 62-18258 discloses a linear ultra-low density polyethylene (hereinafter referred to as L-VLDPE) having a density of 0.910 g / cm ³ or less produced by a gas phase / low pressure method.
And a mixture of the polyolefin resin and a different material. Examples of such different materials include unmodified elastomers (for example, ethylene-propylene copolymer rubber) and polyamide resins.

[0008]

However, no matter which modified polyethylene resin or its composition is used, the fuel oil resistance (gasoline resistance) aimed at by the present invention is the object of the present invention.
It is extremely difficult to provide a material that has excellent impact resistance and good affinity and adhesion. For example, materials used as fuel containers for industrial chemical cans, gasoline, etc. that are used for a long time at low or high temperatures, and as materials used as related automobile parts, must not fully satisfy all of the above physical properties. In particular, these properties are not particularly limited to a polyamide resin layer and a polyethylene resin layer used in a multilayer polyethylene resin fuel container (for example, three types and five layers) such as a polyamide resin for the purpose of preventing the permeability of fuel oil such as gasoline. There is also a strong demand for an adhesive layer, and similarly, the above-mentioned inventions proposed so far cannot provide a satisfactory one. That is, a synthetic rubber or the like is added to a graft-modified polyethylene resin or a composition thereof in order to improve impact resistance, or an ethylene-α-olefin copolymer polymerized using a vanadium-based catalyst as a main catalyst or a density of 0.
Even when a graft-modified polyethylene resin containing L-VLDPE of 880 to 0.910 g / cm ³ as a main component or a composition thereof is used, the fuel oil resistance when used for a long period of time at a high temperature is extremely poor. In the case of the composition of the graft-modified HDPE alone or the composition of the graft-modified HDPE and the unmodified HDPE or the unmodified low-density polyethylene resin, even if the fuel oil resistance can be satisfied, it is difficult to obtain extremely excellent impact resistance. In addition, it is difficult to obtain better affinity and adhesion to the various resin materials and metal materials.

In the case of an irregularly shaped product produced by blow molding, burrs of usually several percent to several tens percent are generated, and these burrs are generally recycled from an economic viewpoint. Is common. As described later, in particular, a multilayer structure manufactured using a barrier material such as a polyamide resin (PA) or a saponified product of an ethylene-vinyl acetate copolymer for the purpose of preventing permeation of the contents to the outside of the container,
Normally, these barrier materials are also included in the burrs and will be recycled.

By the way, the impact resistance of these barrier materials is generally relatively high molecular weight H used for blow molding.
It is known that there is a drawback that it is significantly inferior to DPE, and particularly inferior in impact resistance at low temperatures. Therefore, in order to industrially and economically obtain a container having a multilayer structure, if a burr containing a material having poor impact resistance is recycled and used as a layer of the main material, the impact resistance of the container is reduced, It may be difficult to satisfy the required performance. Needless to say, in order to solve this problem, a new layer (burr layer) for recycling burrs is provided on the multilayer structure, or the main material (mainly polyethylene resin) is bonded to the barrier material. There has been proposed a method in which burrs are mixed into an adhesive layer to be used for recycling. However, the former is not economical in that a new multi-layering equipment is required, and in the latter case, the barrier material (such as PA) in the burr reacts with the graft group of the graft-modified polyolefin resin to cause gelation. It is not preferable because it may occur or is inferior in long-term adhesion durability.

For these reasons, even if the multi-layered burrs are recycled, in order to prevent the impact resistance of the obtained product from lowering, for example, JP-B-60-3446.
No. 1, JP-B-61-42625, it has been proposed to use a polyolefin resin or a polyamide resin having excellent specific adhesiveness. However, in these inventions, the fuel resistance of each resin for a long period of time is proposed. Poor oiliness, not practical.

From the above, the present invention solves all of these disadvantages, that is, even if used for a long time,
It not only has good fuel oil resistance under high temperature atmosphere, but also has excellent impact resistance (especially low temperature). In addition, burrs generated during molding processing are mixed with multilayer components and recycled. It is an object of the present invention to obtain a material that has remarkably excellent affinity with a material to be mixed and adhesion with a barrier material.

[0013]

According to the present invention, there are the following objects: (a) a density (g / cm ³ ) of 0.935 or more, a melt flow rate (g / 10 minutes) [JIS K7210 A high-density polyethylene resin (resin A) having a measurement of 4 under the condition, hereinafter referred to as “MFR”] of 0.01 g or more; (b) [5 to 30 short-chain branches] / [C number of 10 in the main chain]
00 pieces], density (g / cm ³ ) exceeding 0.910 and 0.9
L-LDPE (resin B) having an MFR (g / 10 min) of less than 35, a melting point of 115 to 130 ° C. by differential scanning calorimetry of less than 35, and an unsaturated carboxylic acid and Modified L-LDPE (resin C) grafted with at least one monomer selected from the group consisting of derivatives thereof; and (d) [number of short-chain branches 18 to 60] / [number of C in main chain 1
000 pieces], density (g / cm ³ ) 0.890-0.91
0, MFR (g / 10 min) 0.1 to 30, L-VL having a melting point of 110 to 125 ° C. by differential scanning calorimetry
A composition comprising DPE (resin D), wherein resin B / (resin B + resin C) is 0.1 to 99.9% by weight, resin A /
(Resin A + Resin B + Resin C) is 5 to 75% by weight, Resin D
/ (Resin A + Resin B + Resin C + Resin D) is solved by the resin composition in which 5 to 40% by weight and the total amount of the grafted monomer in the total composition is 0.001 to 5.0% by weight. I found something to gain.

Hereinafter, the contents of the present invention will be described in detail. (1) HDPE (Resin A) The HDPE used in the present invention is ethylene alone or ethylene and ethylene having 3 to 12 carbon atoms (preferably 3 to 8 carbon atoms).
) With an α-olefin in the presence of a so-called Phillips catalyst or Ziegler catalyst, and is generally produced at normal pressure to a pressure of about 100 kg / cm ² (medium to Low pressure polymerization). Preferred examples of the α-olefin include propylene, butene-1, hexene-
1,4-methylpentene-1 and octene-1 whose copolymerization ratio is at most 6.5% by weight;
In particular, it is desirably 6.0% by weight or less. The number of short-chain branches per 1000 carbon atoms in the main chain of HDPE is at most 20.

Further, density of the 0.935 g / cm ³ or more, preferably 0.937 g / cm ³ or more, particularly 0.94
0 g / cm ³ or more is preferable. The density is 0.935g / cm
^When a polyethylene resin having a molecular weight of less than ³ is used, products molded using the obtained composition are inferior in rigidity, heat resistance, fuel oil resistance, surface hardness and the like. Further, the MFR is 0.0
It is at least 1 g / 10 min, preferably at least 0.015 g / 10 min, and particularly preferably at least 0.02 g / 10 min. If the MFR is less than 0.01 g / 10 minutes, the moldability is not good. The upper limit is not particularly limited, but is usually 50 g / 10 minutes, and particularly preferably 35 g / 10 minutes or less. These HDPEs may be used alone or in combination of two or more.

(2) L-LDPE (Resin B) L-LDPE used in the present invention and modified L-LDPE
L-LDPE for producing LDPE has a density of 0.910 g /
cm ³ but less than 0.935 g / cm ³ ;
It is preferably at least 912 g / cm ³ , particularly 0.915 g / cm ^3.
g / cm ³ or more, but preferably less than 0.935 g / cm ³ . Further, the number of branches of the short chain per 1000 carbon atoms of the main chain is 5 to 30, particularly preferably 5 to 25. Whether the density is below the lower limit or above the upper limit,
Further, even if the number of short-chain branches per 1000 carbon atoms in the main chain is less than the lower limit or exceeds the upper limit, the uniformity of the composition of the present invention is unsatisfactory. That is, when L-LDPE out of the above range is used, especially when the fuel oil resistance in the long term is evaluated, not only the decrease in tensile elongation is large but also the heat resistance (specifically, in an atmosphere of 100 ° C. or more, Under the conditions to which the (durability test) is added, the physical properties further decrease, but all of these are considered to be due to the non-uniformity of the dispersibility of the components of the composition.

[0017] Further, the MFR is 0.1% from the viewpoint of moldability.
1 to 50 g / 10 min, preferably 0.2 to 40 g / 10 min, and particularly preferably 0.2 to 30 g / 10 min.
Further, the melting point by the DSC method (the measuring method will be described later) is 115 to 130 ° C, preferably 118 to 130 ° C, and particularly preferably 118 to 125 ° C. When the melting point is less than 115 ° C., the long-term fuel oil resistance at high temperatures is not good. On the other hand, if it exceeds 130 ° C., it is not preferable in terms of impact resistance.

The L-LDPE is manufactured industrially and its manufacturing method is well known. In particular, they are widely used because of their excellent environmental stress crack resistance, transparency, heat sealability, low-temperature properties, and the like (for example, packaging materials such as films and industrial materials such as pipes). This L-LDPE is usually produced by copolymerizing ethylene and the above-mentioned α-olefin by a gas phase method, a solution method or a slurry (suspension) method using a Ziegler catalyst. is there. The short chain is substantially composed of an alkyl group having 1 to 10 (preferably 1 to 6) carbon atoms.

(3) L-VLDPE (Resin D) The method for producing L-VLDPE used in the present invention is widely known. It is manufactured and widely used. Thus those obtained conventionally known crystallinity obtained by the polymerization with the use of a vanadium catalyst system and is a few percent to about 10 a few percent low-crystalline ethylene -α-- olefin random Copolymer (density 0.86-0.91 g / cm
³ ) Unlike Japanese Unexamined Patent Publication No. 57-68306,
L-VLDPE produced by a slurry method or a gas phase method using a stereoregular catalyst (so-called Ziegler catalyst) as described in JP-A-59-23011 and JP-A-62-109805.

The L-VLDPE of the present invention has a density of 0.890 to 0.910 g / cm ³ and an MFR of 0.1 to 3
0g / 10 min, and the melting point by DSC is 110
L-LDPE having a temperature of 125 ° C. and a number of short-chain branches of 18 to 60 per 1000 carbon atoms in the main chain.

In the present invention, if the density of the polyethylene resin is less than 0.890 g / cm ³ , there is a problem in the fuel oil resistance of the obtained composition. On the other hand, 0.910 g / cm
^If it exceeds ³ , the resulting composition is insufficient in impact resistance. From these, the density is 0.892 to 0.91.
0 g / cm ³ is preferred. If the MFR of the resin is less than 0.1 g / 10 minutes, it is not preferable in terms of moldability and workability. On the other hand, if it exceeds 30 g / 10 minutes, there is a problem in terms of impact resistance. From these facts, it is desirable that the MFR is 0.1 to 10 g / 10 min, especially 0.2 to 10 g / 10 min.
8.0 g / 10 min is preferred.

Further, DSC (about 5 mg of a sample was weighed, set in a DSC measuring apparatus, heated to 200 ° C. from room temperature at a rate of 10 ° C./min, and kept at that temperature for 5 minutes. , then allowed to cool to room temperature at a of 10 ° C. / min cooling rate, and the melting point with a further temperature peak maximum endothermic region when the temperature was raised at a heating rate of the following Tmp
Melting point represented by that) are those having 110-125 ° C.. Particularly, those having a temperature of 112 to 125 ° C are preferable. If the melting point is lower than 110 ° C., the resulting composition is insufficient in heat resistance. On the other hand, if it is higher than 125 ° C., the effect of improving impact resistance is poor.

Furthermore, the number of short-chain branches per 1000 carbon atoms in the main chain of the polyethylene resin is 18 to 60, preferably 18 to 50, and particularly preferably 20 to 50. If the number of short-chain branches per 1000 carbon atoms in the main chain is less than 18, there is a problem in the resulting impact resistance. On the other hand, when the number exceeds 60, the fuel oil resistance is significantly poor. Here, the short chain substantially has 1 to 10 carbon atoms.
(Preferably 1 to 6) alkyl groups. In addition, in view of the effect of improving impact resistance, the initial tensile modulus of the polyethylene resin is 2 × 10 ³ kgf / cm.
² or less (preferably, 1.5 × 10 ³ kgf / cm ² or less)
Are preferred.

(4) Modified L-LDPE (Resin C) The modified L-LDPE used in the present invention is the aforementioned L-LDPE.
It can be obtained by treating LDPE with an unsaturated carboxylic acid and / or a derivative thereof described below in the presence of a radical initiator, respectively. At this time, a synthetic resin or an elastomer (rubber) described later, which has affinity with the L-LDPE to be grafted, may be allowed to coexist.

(4-1) Unsaturated carboxylic acids and derivatives thereof The unsaturated carboxylic acids and derivatives thereof for producing modified L-LDPE (for grafting) used in the present invention include monobasic unsaturated carboxylic acids and dicarboxylic acids. Base unsaturated carboxylic acids and their metal salts, amides, imides, esters and anhydrides. Among 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 carbon number of 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 are described in JP-A-62-10107, page 3, lower right column, line 8 to page 4, upper right column, line 12.

Among these unsaturated carboxylic acids and derivatives thereof, acrylic acid, methacrylic acid, maleic acid and anhydride thereof, 5-norbornene-2,3-dicarboxylic acid and anhydride thereof, and glycidyl methacrylate are preferred. Particularly, maleic anhydride and 5-norbornene anhydride are preferred.

(4-2) Radical Initiator Further, the radical initiator for grafting according to the composition of the present invention usually has a decomposition temperature of 1 minute half life of 10 minutes.
The temperature is 0 ° C. or higher, preferably 103 ° C. or higher, particularly preferably 105 ° C. or higher. Suitable radical initiators include dicumyl peroxide, benzoyl peroxide, di-tert-butyl peroxide,
2,5-dimethyl-2,5-di (tert-butylperoxy) hexane, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexine- 3, lauroyl peroxide And organic peroxides such as tertiary-butyl peroxybenzoate.

(4-3) Synthetic Resin and Elastomer In producing the modified L-LDPE according to the composition of the present invention, the synthetic resin and the elastomer coexisting with the L-LDPE to be grafted have an affinity with L-LDPE. There is something. Among these, synthetic resins include high-pressure low-density polyethylene resin, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-methyl acrylate copolymer, ethylene- Copolymers of ethylene and other vinyl monomers, such as an ethyl acrylate copolymer, an ethylene-butyl acrylate copolymer, and an ethylene-methyl methacrylate copolymer.

As the elastomer, ethylene-
Propylene copolymer rubber, ethylene-propylene-diene terpolymer rubber, ethylene-butene-1 copolymer elastomer
Ethylene -α- olefin copolymers such as Tomah gills
Stomer , polyisobutylene rubber, polyurethane rubber,
Synthetic rubber such as styrene-butadiene copolymer rubber and polybutadiene rubber, and natural rubber are exemplified.

(4-4) Ratio In producing the composition of the present invention, the grafted L
-The ratio of the unsaturated carboxylic acid and / or its derivative and the radical initiator to 100 parts by weight of LDPE is as follows. Unsaturated carboxylic acids and their derivatives are generally present in a total amount of from 0.01 to 5.0.
Parts by weight, preferably from 0.01 to 3.0 parts by weight, particularly preferably from 0.02 to 2.0 parts by weight. When the proportion of the unsaturated carboxylic acid and its derivative is less than 0.01 parts by weight as the total amount thereof, graft modification becomes insufficient, and there is a problem in the affinity or adhesive property aimed at by the present invention. On the other hand, if it exceeds 5.0 parts by weight, the resulting modified L-LDPE may gel, cause coloring or deterioration, and the improvement of the performance intended for the present invention cannot be recognized.

The proportion of the radical initiator is usually from 0.001 to 1.0 part by weight, preferably from 0.005 to 1.0 part by weight, more preferably from 0.005 to 1.0 part by weight based on 100 parts by weight of the resin. ~ 0.5 parts by weight is preferred. When the ratio of the radical initiator is less than 0.001 part by weight, the effect of the graft modification is poorly exhibited, 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, an excessive decomposition or a crosslinking reaction is caused, which is not preferable.

Further, when the above-mentioned synthetic resin or elastomer is used, its proportion in the total amount with L-LDPE is generally at most 10% by weight, particularly preferably 5.0% by weight or less. The ratio of the synthetic resin and / or the elastomer to the total amount with L-LDPE is 1 as a total amount.
If it exceeds 0% by weight, the basic properties of L-LDPE may be impaired.

(4-5) Graft modification of L-LDPE The modified L-LDPE used in the composition of the present invention is L-LDPE.
It can be produced by reacting LDPE (optionally containing a synthetic resin and / or elastomer), unsaturated carboxylic acid and / or derivative thereof and a radical initiator within the above-mentioned ratio. The processing method is a known method as described in JP-A-62-10107, page 4, lower left column, line 13 and after, and JP-A 61-132345, page 7, upper column left column, line 14 and after. Adopt it.

Examples of the treatment method include a method in which L-LDPE is kneaded in a molten state using an extruder, a Banbury mixer, a kneader, or the like; a solution method in which L-LDPE is dissolved in an appropriate solvent; A slurry method in which particles are suspended, or a so-called gas-phase grafting method may be used. The treatment temperature is appropriately selected in consideration of the degradation of the L-LDPE polymer, the decomposition of the unsaturated carboxylic acid and its derivatives, the decomposition temperature of the radical initiator used, and the like. For example, the temperature is usually 100 to 350 ° C., preferably 150 to 300 ° C., and particularly preferably 180 to 300 ° C.

(5) Composition ratio The above-mentioned LV in the polyethylene resin composition according to the present invention.
The composition ratio of LDPE is 5.0 to 40% by weight,
0 to 37.5% by weight, especially 7.0 to 3% by weight.
7.5% by weight is preferred. When the composition ratio of L-VLDPE in the polyethylene-based resin composition is less than 5.0% by weight, the obtained composition is inferior in impact resistance. On the other hand, 40
When the content is more than 10% by weight, the fuel oil resistance (particularly, the fuel oil resistance at 40 ° C.) is remarkably reduced, which is not preferable.

Similarly, the L-LDPE and the modified LL
L-LDPE and modified LL in total amount of DPE
The composition ratio of DPE is at least 0.1% by weight, preferably 1.0% by weight or more, and particularly preferably 2.5% by weight. When the modified L-LDPE content is less than 0.1% by weight, the affinity and the adhesiveness with a resin material such as a polyamide resin, a saponified ethylene-vinyl acetate copolymer or a metal material are not satisfied. HDPE in the total amount of HDPE, L-LDPE and modified L-LDPE is 5% by weight.
Not less than 75% by weight. If it is less than 5% by weight, the fuel oil resistance is insufficient, and if it exceeds 75% by weight, the adhesion durability at high temperatures is insufficient.

(6) Method for Producing Composition The resin composition of the present invention comprises HDPE, L-LDPE, modified L
-LDPE and L-VLDPE are each in the range of the above composition ratio. In general, when a monomer (in the case of the present invention, an unsaturated carboxylic acid or a derivative thereof) is graft-modified to a polymer (in the case of the present invention, L-LDPE), it is difficult to graft the monomer to all polymers, Some of the polymers are not grafted. In the present invention, ungrafted L-LDPE may be used as it is without separation. HDPE, L-LDPE and L
-VLDPE may be mixed in advance, and the resulting mixture may be mixed with the modified L-LDPE, or all components may be mixed simultaneously.

In producing the resin composition of the present invention,
Addition of antioxidants, heat stabilizers, ultraviolet absorbers, lubricants, antistatic agents, pigments (colorants) and the like generally used in the field of polyolefin resins within a range that does not substantially impair the effect of the composition. An agent can be compounded.

As a mixing method for producing the composition, various mixing methods generally used 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, a Banbury mixer, and a method of melt-kneading using a kneader such as a roll. At this time, a more uniform composition can be obtained by performing two or more of these mixing methods (for example, a method of dry blending in advance and further melting and kneading the resulting mixture).

(7) Processing Method, etc. The resin composition of the present invention thus obtained can be applied to containers such as industrial chemical cans and fuel oil tanks such as gasoline, and is generally used as a molding method. It is possible to easily form into a desired shape by the conventional hollow forming method, and it is possible to obtain an article having an unprecedented impact resistance. In addition to the hollow molding method, various parts can be easily obtained by injection molding, compression molding, and the like as caps and various industrial members.

Further, in recent years, polyethylene resins have been used for fuel oil tanks of automobiles and the like, and PA has been developed as one of means for preventing permeation of fuel oil from these tanks. The resin composition of the present invention has excellent impact resistance (particularly low-temperature impact resistance) and fuel oil resistance as an adhesive layer between a barrier material and a main material (mainly, HDPE) in a multilayer fuel oil tank having a barrier layer of It is particularly useful for having both. In this case, the multilayer structure is A / C / B, A / C / B / C / A, where A is the main material, B is the barrier material, and C is the composition of the present invention.
A, A / C / B / C, C / B / C / A, etc., three layers or more (of course, in these configurations, between the A and C layers,
For example, a layer formed of a resin mixture by recycling a burr layer generated by hollow molding may be provided).

Further, since the resin composition of the present invention has an affinity and an adhesive property with a barrier resin such as PA, two types of C / B or C / B / C two-layer or It can be used as a laminate comprising three seed layers.

[0043]

The present invention will be described in more detail with reference to the following examples. In Examples and Comparative Examples, impact resistance was measured according to JIS.
According to the K7110 method, using a 3 mm thick press plate,
Notched Izod impact strength at 23 ° C. and −35 ° C. was measured. In addition, heat resistance and fuel oil resistance (durability test) were measured according to JIS2
The test specimen was allowed to stand in a gear oven at 100 ° C. for 96 hours, then immersed in commercial regular gasoline at 40 ° C. for 1500 hours, and then measured for tensile elongation at break (E ₁ ) in accordance with JIS K7113. The evaluation was made by comparing the tensile elongation at break (E ₀ ) of the untested specimen.
The adhesive strength (kg / cm) with PA6 was determined using a multi-layer coextrusion apparatus equipped with a two-unit extruder having a diameter of 40 mm for the inner layer and the outer layer and 30 mm for the intermediate layer, and a two-type three-layer multi-layer T die. Nylon 6 (manufactured by Toray Industries, trade name: Amilan CM1041) is an intermediate layer having a thickness of 0.10 mm, and a resin composition prepared in Examples or Comparative Examples is an inner and outer layer having a thickness of 0.20 mm. And a three-layer sheet having a molding temperature of 230 ° C. With respect to the specimen (width 10 mm, length 150 mm) of each of the obtained sheets, the peeling speed was 50 at the interface of nylon 6 using a Tensilon type tensile tester.
T-peeling was performed at a rate of mm / min to determine the adhesive strength (kg / cm width) before the treatment. Further, as evaluation of heat resistance and fuel oil resistance with respect to adhesiveness, each of the same multilayer sections as above was evaluated for 10 minutes.
After standing in an oven at 0 ° C. for 96 hours, it was immersed in commercial regular gasoline at 40 ° C. for 1500 hours, and the adhesive strength to nylon 6 was similarly determined as a value after the treatment. Table 1 shows the results.

(Examples 1 to 10, Comparative Examples 1 to 6) The modified L-LDPE used in Examples and Comparative Examples was produced as described below. The properties of the unmodified HDPE and L-LVLDPE used in the resin composition are also shown below. Compositions using these various polyethylenes were prepared by subjecting a mixture previously dry-blended at the ratios shown in Table 1 to 21% with a 40 mm extruder equipped with a dalmage type screw.
The mixture was melt-kneaded at a temperature of 5 ° C. to form pellets.

[0045] (i) modified L-LDPE (indicated as g-C ₁₎ Density 0.925g / cm ^3, MFR0.70g / 10 min,
L-LDPE (B ₁ ) having 11 short-chain branches per 1000 C and Tmp = 121 ° C. was added with 2,5-dimethyl-2,5-
0.01 phr of t-butyl peroxyhexane was added,
After dry blending with a Henschel mixer for 2 minutes, 0.350 phr of maleic anhydride was added thereto, and after dry blending for further 2 minutes, the mixture was melt-kneaded at a resin temperature of 255 ° C. and pelletized. The amount of the grafted maleic anhydride was measured by an infrared absorption spectrum method (hereinafter, referred to as an IR method), and as a result, was 0.29% by weight.

(Ii) Modified L-LDPE (g-C ₂ ) density, 0.920 g / cm ³ , 1.9 g / 10 min MFR,
Except for using L-LDPE (B ₂₎ powder short chain branches per 1000C number 15, Tmp = 120 ℃ created a (i) above and by modifying similarly modified _{L-LDPE (g-C 2} ) . The grafted amount of maleic anhydride was 0.28% by weight.

(Iii) Modified L-LDPE (g-C ₃ ) Density 0.916 g / cm ³ , MFR 3.0 g / 10 min, T
mp 119 ° C, number of branches 21 / main chain C1000 L-
Except for using LDPE (B ₃ ), the same treatment as in (i) above was performed to obtain a modified L-LDPE (g-C ₃ ). The grafted amount of maleic anhydride was 0.28% by weight.

(Iv) HDPE (A ₁ ) having a density of 0.935 g / cm ³ and an MFR of 0.70 g / 10 minutes was used.

(V) HDPE (A ₂ ) having a density of 0.946 g / cm ³ and an MFR of 1.1 g / 10 minutes was used.

(Vi) L-VLDPE (D ₁ ) density, 0.903 g / cm ³ , MFR 0.95 g / 10
L-VLDPE having a Tmp of 120 ° C. and a number of branches of 26 / main chain C of 1,000.

(Vii) L-VLDPE (D ₂ ) density 0.898 g / cm ³ , MFR 3.0 g / 10 min, T
L- of mp116 ° C, number of branches 38 / main chain C1000
VLDPE.

(Viii) L-VLDPE (D ₃ ) This D ₃ is different from the above and is obtained by a conventional vanadium catalyst system and has a density of 0.900 g / cm ³ and MFR
L-VLDPE having 2.0 g / 10 min, Tmp of 100.5 ° C. and 75 branches / 1000 main chains.

(Ix) Modified L-VLDPE (g · D ₃ ) A modified L-VLDPE (g · D ₃ ) was obtained in the same manner as in the above (i) except that D ₃ was used as the polyethylene. .27% by weight.

(X) L-LDPE (B ₁ , B ₂ , B ₃ ) L-LDPE used for producing modified L-LDPE (C ₁ , C ₂ , C ₃ ).

[0055]

[Table 1]

(Example 11, Comparative Example 7) A two-type, three-layer sheet with nylon 6 (three layers of nylon 6) prepared using the resin composition obtained in Example 4 was cut using a sheet cutter. After being cut into pellets, 5% by weight, 95% by weight of high-density polyethylene (A ₃ ) having a density of 0.945 and HLMFR = 5 were mixed at a resin temperature of 260 ° C. using a 40φ coaxial twin-screw extruder. To prepare a composition. The dispersion state of nylon 6 in the composition was examined by dyeing the nylon particles with a red acid dye and examining the dispersion with an optical microscope. As a result, the maximum particle size was 85 μm and the average particle size was 50 μm. Further, the impact resistance (Izod impact strength) of the composition is 23 ° C.
And at −35 ° C., respectively, 58 and 55 kg · cm /
cm and the value of high-density polyethylene (A ₃ ) alone is 6
0, almost equal to 57 kg · cm / cm. On the other hand, the adhesive resin composition similarly used in Comparative Example 3 was used in Example 11
As a result of preparing a composition in the same manner as above and examining the same,
Izod impact strength at 23 ° C and -35 ° C is 5
In addition to inferior compared to 3,45kg · cm / cm and A _3, the reduction rate in the heat-resistance to fuel oil test in (A ₃ alone 0
%) Was as large as 18%.

[0057]

The resin composition of the present invention exhibits the following effects. (1) Not only the impact resistance at normal temperature is excellent, but also the impact resistance at low temperature (for example, -35 ° C) is very good. (2) Excellent heat and fuel oil resistance over a long period of time. (3) polyethylene resin, polyamide resin, EVOH,
It has good affinity and adhesion to various resin materials such as thermoplastic polyester resin and various metals, and especially, it is also possible to produce a laminate in which the composition of the present invention is interposed between a polyethylene resin and a polyamide resin. it can. The laminate has excellent heat and oil resistance. The resin composition of the present invention can be used in various fields to exhibit the above effects. In particular, typical applications that can be used in various fields by bonding to or intervening between the various resin materials and various metal materials described above are shown below. (1) A container for fuel oil such as a gasoline tank or various industrial chemicals. (2) Various packaging materials. (3) Various industrial materials.

Claims (1)

(57) [Claims] (1) a high-density polyethylene resin (resin A) having a density (g / cm ³ ) of 0.935 or more and a melt flow rate (g / 10 minutes) of 0.01 g or more; 5 to 30 branches / [C number of main chain 10]
00 pieces], density (g / cm ³ ) exceeding 0.910 and 0.9
Less than 35, melt flow rate (g / 10 min) 0.1 to
50, melting point of 115 to 13 by differential scanning calorimetry
(C) a modified linear low-density polyethylene resin obtained by grafting at least one monomer selected from the group consisting of unsaturated carboxylic acids and derivatives thereof onto resin B (resin B); Resin C) (d) [Number of branched short chains 18 to 60] / [Number of C in main chain 1]
000 pieces], density (g / cm ³ ) 0.890-0.91
0, melt flow rate (g / 10 min) 0.1-30,
Further, it is a composition comprising a linear ultra-low density polyethylene resin (resin D) having a melting point of 110 to 125 ° C. by differential scanning calorimetry, wherein resin B / (resin B + resin C) is 0.1 to
99.9% by weight, resin A / (resin A + resin B + resin C)
Is 5 to 75% by weight, resin D / (resin A + resin B + resin C
+ Resin D) is 5 to 40% by weight, occupying in the total composition, and the total of grafted monomers is 0.001 to 5.
0% by weight of the resin composition.