JPH05193034A - Laminated polyolefin resin foam - Google Patents

Abstract

PURPOSE:To provide a laminated polyolefin resin foam, which has excellent charging properties and in which no bleeding, blocking, etc., is generated. CONSTITUTION:In a laminated polyolefin resin foam, a polyolefin resin foam layer containing at least one kind of polyolefin resins which is composed of a 45-98.5mol% olefin structural unit shown in general formula (I) (in formula, R<1> represents a hydrogen atom or a methyl group), a 0-15mol% acrylate structural unit shown in general formula (II) (in formula, R<2> represents a 1-4C alkyl group) and a 0.5-5mol% alkyl maleimide structural unit and a 1-35mol% cation- changed maleimide structural unit shown in general formula (III) (in formula, R<3> represents a 8-18C alkyl group or a 8-18C aryl group), is arrayed linearly and irregularly and having weight-average molecular weight of 1000-50000, is formed.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a laminated polyolefin resin foam. More specifically, the present invention relates to a laminated polyolefin resin foam which has excellent antistatic properties and can be suitably used as materials such as daily necessities such as bath mats, packings, heat insulating materials, automobile interior materials and the like.

[0002]

2. Description of the Related Art Generally, a foam made of a polyolefin resin, particularly a polyethylene resin or a polypropylene resin, has a large hydrophobicity, so that static electricity is remarkably generated, dust is attached to the foam, or static electricity is discharged. As a result, there are problems such as shock to the human body and ignition in the process of using a flammable organic solvent.

As a conventional method for solving the above problems,
In order to impart antistatic properties to the foam, a method of adding an anionic, cationic or amphoteric surfactant has been adopted.In such a method, the surfactant has a molecular weight of at most 500-600. Since it is relatively small, it volatilizes during the production of the foam, and after being foamed, it bleeds out over time, contaminating the surface of the foam, causing blocking, adhesiveness, There is a problem of deteriorating printability and vapor deposition.

Therefore, a laminated polyolefin-based foam having a polyolefin-based resin foam layer excellent in antistatic property is a resin having one or more specific functional groups in the polyolefin-based resin foam layer, or a special modified resin ( For example, JP-A-62-121717), it is obtained by laminating a polyolefin resin foam to which an additive having a relatively small molecular weight is added, or by subjecting these to a corona discharge treatment.

However, in the method of adding the above-mentioned specific resin, since none of the above-mentioned resins is a polyolefin-based resin, the adhesiveness to the polyolefin-based resin foam is poor, and the polyolefin-based resin foam intended by the present invention is Cannot be obtained, and further, since such a resin has poor compatibility with the polyolefin resin, there are problems that voids are generated and the surface property is reduced.

Further, when these resins and surfactants are contained in the foam, the volume of the product increases unlike sheets and films, and as a result, a large amount of the resins and surfactants as described above is added. Otherwise, there is a problem that the antistatic property is hard to be exhibited.

[0007]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned prior art, and it is of course excellent in antistatic property, and is a laminated polyolefin resin foam which does not cause bleeding or blocking. It is intended to provide the body.

[0008]

The present invention has the general formula (I):

[0009]

[Chemical 9]

(In the formula, R ¹ represents a hydrogen atom or a methyl group) 45 to 98.5 mol% of an olefin structural unit represented by the general formula (II):

[0011]

[Chemical 10]

An acrylate structural unit represented by the formula (wherein R ² represents an alkyl group having 1 to 4 carbon atoms) in an amount of 0 to 15 mol%, a general formula (III):

[0013]

[Chemical 11]

(Wherein R ³ represents an alkyl group having 8 to 18 carbon atoms or an aryl group having 8 to 18 carbon atoms), and 0.5 to 5 mol% of an alkylmaleimide structural unit and the general formula (IV):

[0015]

[Chemical 12]

(In the formula, R ⁴ is an alkylene group having 2 to 8 carbon atoms, R ⁵ and R ⁶ are each an alkyl group having 1 to 4 carbon atoms, R ⁷ is an alkyl group having 1 to 12 carbon atoms, and 6 carbon atoms. 12 arylalkyl group, alicyclic alkyl group of the epoxy group or C6-12 2 to 4 carbon atoms which may be substituted by an alkyl group, X is a halogen atom, CH ₃ OSO ₃ or C ₂ H ₅ Of the cationized maleimide structural unit represented by OSO ₃ ) having a weight average molecular weight of 1000 to 50000 and having a weight average molecular weight of 1000 to 50000, and the general formula (I):

[0017]

[Chemical 13]

(In the formula, R ¹ is the same as above) 45 to 98.5 mol% of an olefin structural unit represented by the general formula (II):

[0019]

[Chemical 14]

(Wherein R ² is the same as above) 0 to 15 mol% of an acrylate structural unit represented by the general formula (V):

[0021]

[Chemical 15]

(Wherein R ¹ and R ³ are the same as above, m
Represents 0 or 1) 0.5 to 5 mol% of an alkyl maleimide structural unit represented by the general formula (VI):

[0023]

[Chemical 16]

(Wherein R ¹ , R ⁴ , R ⁵ , R ⁶ , R ⁷ ,
X and m are the same as those described above), and contain at least one polyolefin resin having a weight average molecular weight of 1000 to 50,000 linearly irregularly arranged and composed of 1 to 35 mol% of a cationized maleimide structural unit. The present invention relates to a laminated polyolefin resin foam which is provided with a polyolefin resin foam layer.

[0025]

ACTION AND EXAMPLE As described above, the present invention provides (A)
General formula (I):

[0026]

[Chemical 17]

(In the formula, R ¹ represents a hydrogen atom or a methyl group) 45 to 98.5 mol% of an olefin structural unit represented by the general formula (II):

[0028]

[Chemical 18]

An acrylate structural unit represented by the formula (wherein R ² represents an alkyl group having 1 to 4 carbon atoms) of 0 to 15 mol%, and a general formula (III):

[0030]

[Chemical 19]

(Wherein R ³ represents an alkyl group or an aryl group having 8 to 18 carbon atoms), and 0.5 to 5 mol% of an alkylmaleimide structural unit and the general formula (IV):

[0032]

[Chemical 20]

(In the formula, R ⁴ is an alkylene group having 2 to 8 carbon atoms, R ⁵ and R ⁶ are each an alkyl group having 1 to 4 carbon atoms, R ⁷ is an alkyl group having 1 to 12 carbon atoms, and 6 carbon atoms. 12 arylalkyl group, alicyclic alkyl group of the epoxy group or C6-12 2 to 4 carbon atoms which may be substituted by an alkyl group, X is a halogen atom, CH ₃ OSO ₃ or C ₂ H ₅ OSO ₃ consisting cationized maleimide structural units to 35 mole% represented by the illustrated) linearly arranged irregularly with weight-average molecular weight from 1,000 to 50,000 polyolefin resin (hereinafter, referred to as the polyolefin resin a), and
(B) the olefin structural unit represented by the general formula (I) 45
~ 98.5 mol%, the acrylate structural unit represented by the general formula (II) 0 to 15 mol%, the general formula (V):

[0034]

[Chemical 21]

(Wherein R ¹ and R ³ are the same as above, m
Represents 0 or 1) and an alkylmaleimide structural unit represented by formula (VI): 0.5 to 5 mol%;

[0036]

[Chemical formula 22]

(Wherein R ¹ , R ⁴ , R ⁵ , R ⁶ , R ⁷ ,
X and m are the same as the above), and a polyolefin resin having a weight average molecular weight of 1000 to 50,000 and linearly irregularly arranged of 1 to 35 mol% of a cationized maleimide structural unit (hereinafter referred to as polyolefin resin B) A laminated polyolefin-based resin foam comprising a polyolefin-based resin foam layer containing at least one of the above.

First, the polyolefin resin A and its intermediate will be described.

The proportion of the olefin structural unit represented by the general formula (I) in the polyolefin resin A is 45 to 9
It is 8.5 mol%. When the proportion of the olefin structural unit is less than 45 mol%, the glass transition point of the polyolefin resin A becomes high, and not only the original flexibility of the polyolefin resin is impaired, but also the chaotic group is added. The antistatic property is not so good in spite of the existence of many, and when it exceeds 98.5 mol%, the antistatic property of the polyolefin resin A becomes too small.

In the above olefin structural unit, R ¹ is a hydrogen atom or a methyl group, and these groups may be mixed in one molecule. The proportion of the olefin structural unit is preferably 85 to 97 mol% from the viewpoint of antistatic property and balance of glass transition point.

The proportion of the acrylate structural unit represented by the general formula (II) in the polyolefin resin A is 0 to 15 mol%. The ratio of the acrylate structural unit is
When it exceeds 15 mol%, the softening point of the polyolefin resin A becomes low and tack and stickiness occur.
In the present invention, when the acrylate structural unit is contained, toughness and impact resistance are imparted, which is preferable. In the present invention, the proportion of the acrylate structural unit is 1 to 15 mol%, especially 3 to 7 from the viewpoint of the balance between the softening point and the toughness and impact resistance.
It is particularly preferable that the content is mol%.

In the acrylate structural unit, R ²
Is an alkyl group having 1 to 4 carbon atoms. Specific examples of R ² include, for example, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group and the like, and these groups are mixed in one molecule. May be. Among these groups, the methyl group and the ethyl group are particularly preferable in maintaining the softening point of the polyolefin resin A.

The proportion of the alkylmaleimide structural unit represented by the general formula (III) in the polyolefin resin A is 0.5 to 5 mol%. The alkylmaleimide structural unit has the property of improving the compatibility with other polyolefin resins, improves the flexibility of the polyolefin resin A, and imparts the property of making the antistatic property less dependent on the environmental humidity. It is a thing. When the proportion of the alkylmaleimide structural unit is less than 0.5 mol%, the compatibility with other polyolefin resins becomes poor, and when it exceeds 5 mol%, the antistatic property becomes poor. Therefore, the proportion of the alkylmaleimide structural unit is preferably 1 to 3 mol% in terms of the compatibility and antistatic property.

In the alkylmaleimide structural unit represented by the general formula (III), R ³ is an alkyl group having 8 to 18 carbon atoms or an aryl group having 8 to 18 carbon atoms. From the viewpoint of compatibility with other olefin resins, a long-chain alkyl group having 16 to 18 carbon atoms is preferable.

The proportion of the cationized maleimide structural unit represented by the general formula (IV) in the polyolefin resin A is 1 to 35 mol%. When the ratio of the cationized maleimide structural unit is less than 1 mol%, the antistatic property becomes too small, and when it exceeds 35 mol%, the polyolefin resin A is blended with other polyolefin resin. When this occurs, hygroscopicity occurs and the compatibility with the polyolefin resin becomes poor. A preferable ratio of the cationized maleimide structural unit is 3 to 15 mol%.

In the cationized maleimide structural unit represented by the general formula (IV), specific examples of R ⁴ include ethylene group, propylene group, hexamethylene group, neopentylene group, and the like. They may be mixed in one molecule. Among these groups, ethylene group and propylene group are preferable from the viewpoint of easiness of production of the polyolefin resin A, economy, and the like. R ⁵ and R ⁶ are alkyl groups having 1 to 4 carbon atoms, and specific examples of R ⁵ and R ⁶ include, for example, a methyl group, an ethyl group, a propyl group, and a butyl group. They may be mixed in one molecule. Among these groups, a methyl group and an ethyl group are preferable in order to impart sufficient antistatic properties. R ⁷ is an alkyl group having 1 to 12 carbon atoms, an arylalkyl group having 6 to 12 carbon atoms, or 2 to 2 carbon atoms which may be substituted with an alkyl group.
It is an epoxy group having 4 or an alicyclic alkyl group having 6 to 12 carbon atoms. Among the above R ⁷ , in order to improve the heat resistance of the polyolefin resin A, a linear alkyl group or an arylalkyl group is preferable. Particularly preferred R ⁷ includes a methyl group and an ethyl group. The X
Is a halogen atom such as Cl, Br or I, CH
₃ OSO ₃ or C ₂ H ₅ OSO ₃ , which are 1
It may be mixed in the molecule. Among these, Cl, CH ₃ OSO ₃ and C from the viewpoint of antistatic property.
₂ H ₅ OSO ₃ is preferred.

The ratio of the alkylmaleimide structural unit represented by the general formula (III) to the cationized maleimide structural unit represented by the general formula (IV) (alkylmaleimide structural unit / cationized maleimide structural unit: molar ratio) Is 1/70 to 1/2, especially 1/70 to impart sufficient antistatic properties to the polyolefin resin A.
It is preferably 70 to 1/43.

The polyolefin resin A has a weight average molecular weight of 1,000 to 50,000. The weight average molecular weight is 1000
When it is less than the above range, the molecular weight becomes too small to be volatilized when heated, and when it exceeds 50,000, the viscosity at the time of melting becomes too large, resulting in poor workability. The preferred weight average molecular weight is 3000 to 35000.

The term "weight average molecular weight" as used herein means gel permeation chromatography (GP).
The monodisperse polystyrene-equivalent weight average molecular weight measured in C).

The above-mentioned polyolefin resin A cannot be easily measured because it is hardly soluble in an eluent for normal gel permeation such as tetrahydrofuran (THF) or xylene, but it cannot be easily measured. It can be measured in accordance with Molecular Papers, Vol. 44, No. 2, pp. 139-141 (1987)).

The polyolefin resin A and an olefin structural unit represented by the general formula (I) which is an intermediate thereof.
45-98.5 mol%, acrylate structural unit represented by general formula (II) 0-15 mol%, alkylmaleimide structural unit represented by general formula (III) 0.5-5 mol% and general formula (VI
I):

[0052]

[Chemical formula 23]

(Wherein R ⁴ , R ⁵ and R ⁶ are the same as above), the linearly irregularly arranged weight average molecular weight of 1000 to 50000 consisting of 1 to 35 mol% of a dialkylaminomaleimide structural unit The copolymer (hereinafter referred to as intermediate A) can be obtained, for example, by the following method.

First, the raw material of the intermediate A is not particularly limited, and for example, benzene in an autoclave,
Using toluene or the like as a solvent, a radical polymerization initiator such as acrylate, maleic anhydride and benzoyl peroxide is dissolved, a predetermined amount of olefin is blown into the solution, and the mixture is reacted at 50 to 80 ° C. for 8 to 12 hours, and then autoclaved. Examples thereof include an olefin-acrylate-maleic anhydride copolymer obtained by a known method such as adding a large amount of the content in a solvent such as ether. Here, the charged molar ratio of each monomer is
It is almost equal to the ratio of structural units of the target copolymer.

From the raw materials, the polyolefin resin A
The method for producing the intermediate A and the intermediate A is not particularly limited, but one example thereof will be described below.

For example, benzene, toluene,
It is dissolved in an aromatic or aliphatic hydrocarbon such as xylene, cyclohexanone, decane, cumene or cymene, or an inert solvent such as a ketone, and first, an alkyl group having 8 to 18 carbon atoms is obtained to obtain a maleimide structure corresponding to the general formula (III) An amine is added and reacted at 130 to 180 ° C. to convert the acid anhydride group contained in the maleic anhydride structural unit into an alkylimide group.
Then add dialkylaminoalkylamine,
All of the remaining maleic anhydride structural units are converted to dialkylaminoalkylmaleimide structural units by reaction at ˜180 ° C. to give Intermediate A. The amount of the alkylamine used is 0.5 to 5 mol% of the alkylmaleimide unit so that the amount of the alkylamine may be adjusted to the acid anhydride group of the maleic anhydride structural unit.
It is 1.4 to 83 mol%, preferably 1.4 to 30 mol%. The dialkylaminoalkylamine is used in an amount of 100 to 150 mol%, preferably 100 to 110 mol%, based on the remaining maleic anhydride structural unit in order to adjust the amount of the dialkylaminoalkylmaleimide structural unit to 1 to 35 mol%. Is.

The resulting intermediate A is further cation-modified with a known quaternizing agent such as alkyl halide, dialkyl sulfuric acid and epichlorohydrin to convert the dialkylaminoalkylmaleimide structural unit into a cationized maleimide structural unit. It is converted to obtain the polyolefin resin A.

Next, the polyolefin resin B and its intermediate will be described.

As described above, the polyolefin resin B is an olefin structural unit 45 represented by the general formula (I).
To 98.5 mol%, an acrylate structural unit represented by the general formula (II) 0 to 15 mol%, an alkylmaleimide structural unit represented by the general formula (V) 0.5 to 5 mol%, and a general formula (VI)
A cationized maleimide structural unit represented by 1 to 35 mol% of linearly irregularly arranged weight average molecular weight of 1000
It is a polyolefin resin of up to 50,000.

The proportion of the olefin structural unit represented by the general formula (I) in the polyolefin resin B is 45 to 9
It is 8.5 mol%. When the proportion of the olefin structural unit is less than 45 mol%, the glass transition point of the polyolefin resin B becomes high, and the flexibility inherent to the resin is not only deteriorated when blended with the polyolefin resin. Without
Despite the large amount of cationic groups, the antistatic property is not so good, and when it exceeds 98.5 mol%, the antistatic property of the polyolefin resin B becomes too small. In the olefin structural unit, R ¹ is a hydrogen atom or a methyl group, and these groups may be mixed in one molecule. The proportion of the olefin structural unit is preferably 85 to 97 mol% from the viewpoint of antistatic property and balance of glass transition point.

The proportion of the acrylate structural unit represented by the general formula (II) in the polyolefin resin B is 0 to 15 mol%. The ratio of the acrylate structural unit is
When it exceeds 15 mol%, the softening point of the polyolefin resin B becomes low, and tackiness or stickiness occurs when blended with the polyolefin resin. In the present invention, when the acrylate structural unit is contained, it is preferable because it is imparted with toughness and impact resistance when blended with the polyolefin resin. In the present invention, the ratio of the acrylate structural unit is 1 to 15 from the viewpoint of the balance between the softening point and the toughness and impact resistance.
It is particularly preferable that it is mol%, especially 3 to 7 mol%.

In the acrylate structural unit, R ²
Is an alkyl group having 1 to 4 carbon atoms. Specific examples of R ² include the same as the acrylate structural unit of the polyolefin resin A.

The proportion of the alkylmaleimide structural unit represented by the general formula (V) in the polyolefin resin B is 0.5 to 5 mol%. The alkylmaleimide structural unit has the property of improving the compatibility with the polyolefin resin, improves the flexibility of the polyolefin resin B, and imparts the property of making the antistatic property less dependent on the environmental humidity. Is. When the proportion of the alkylmaleimide structural unit is less than 0.5 mol%, the compatibility with the polyolefin resin becomes poor, and when it exceeds 5 mol%, the antistatic property becomes poor. Therefore, the proportion of the alkylmaleimide structural unit is preferably 1 to 3 mol% in terms of the compatibility and antistatic property.

In the alkylmaleimide structural unit represented by the general formula (V), R ³ is an alkyl group having 8 to 18 carbon atoms or an aryl group having 8 to 18 carbon atoms. A long-chain alkyl group having 16 to 18 carbon atoms is preferable from the viewpoint of compatibility with other polyolefin resins.

The proportion of the cationized maleimide structural unit represented by the general formula (VI) in the polyolefin resin B is 1 to 35 mol%. When the ratio of the cationized maleimide structural unit is less than 1 mol%, the antistatic property becomes too small, and when it exceeds 35 mol%, hygroscopicity occurs and the compatibility with the polyolefin resin is low. become bad. A preferable ratio of the cationized maleimide structural unit is 3 to 15 mol%.

In the cationized maleimide structural unit represented by the general formula (VI), R ⁴ , R ⁵ , R ⁶ and R
Specific examples of ⁷ and X include the same as the cationized maleimide structural unit represented by the general formula (IV) of the polyolefin resin A.

The ratio of the alkylmaleimide structural unit represented by the general formula (V) to the cationized maleimide structural unit represented by the general formula (VI) (alkylmaleimide structural unit / cationized maleimide structural unit: molar ratio)
Is 1/70 to 1/2, especially 1/70 to 1 in order to impart sufficient antistatic property to the polyolefin resin B.
It is preferably 1/43.

The weight average molecular weight of the polyolefin resin B is 1,000 to 50,000. The weight average molecular weight is 1000
If it is less than the above, the molecular weight becomes too small and the polyolefin resin B is blended with the polyolefin resin, and volatilizes when heated, and if it exceeds 50,000, the polyolefin resin B is melted. When it is done, the viscosity becomes too high and the workability becomes poor. The preferred weight average molecular weight is 3000 to 35000.

The weight average molecular weight of the polyolefin resin B can be measured in the same manner as the polyolefin resin A.

The polyolefin resin B and its intermediate (hereinafter referred to as intermediate B) can be obtained, for example, by the following method.

The method for producing the maleic anhydride graft-olefin-acrylate copolymer, which is a raw material of the intermediate B, is not particularly limited. For example, a commercially available low molecular weight polypropylene-ethyl acrylate copolymer is used. Obtained by graft polymerization of maleic anhydride in the presence of an organic peroxide such as benzoyl peroxide.

The olefin-acrylate copolymer grafted with maleic anhydride thus obtained is reacted with an alkylamine and a dialkylaminoalkylamine in the same manner as in the case of the above-mentioned polyolefin resin A. 45 to 98.5 mol% of olefin structural unit represented by formula (I), 0 to 15 mol% of acrylate structural unit represented by general formula (II), 0.5 to 5 mol% of alkylmaleimide structural unit represented by general formula (V) And general formula (VIII):

[0073]

[Chemical formula 24]

(Wherein R ¹ , R ⁴ , R ⁵ , R ⁶ and m
Is the same as the above), and an intermediate B having a weight average molecular weight of 1000 to 50,000 and linearly and irregularly arranged and composed of 1 to 35 mol% of a dialkylaminomaleimide structural unit is obtained.

The amount of the alkylamine used is 1.4 to 83 relative to the grafted maleic anhydride structural unit so that the amount of the alkylmaleimide structural unit is 0.5 to 5 mol%.
Mol%, preferably 1.4 to 30 mol%. The dialkylamine is used in an amount of 100 to 150 mol%, preferably 100 to 110 mol%, based on the remaining maleic anhydride structural unit in order to adjust the dialkylaminoalkylmaleimide structural unit to 1 to 35 mol%. is there.

Then, by reacting with the same quaternizing agent as in the production of the polyolefin resin A, the polyolefin containing the grafted cationized maleimide structural unit represented by the general formula (VI) is used. A system resin B is obtained.

The polyolefin resins A and B thus obtained each have an excellent antistatic property,
Moreover, it has an excellent property that the antistatic property is not so much influenced by the environmental humidity. Although the reason why the polyolefin resin has excellent properties is not clear, the cationized maleimide structural units contained in the polyolefin resins A and B take in water in the air, and X ⁻ is ionized. Since it exhibits electrical conductivity, it is considered to be due to its low electrical resistance. On the other hand, since the alkylmaleimide structural units in the polyolefin resins A and B also have long alkyl groups in their side chains, flexibility is improved, and antistatic properties are excellently independent of environmental humidity. It is speculated that this is a factor.

Further, in the present invention, since the cationized maleimide structural unit does not exhibit volatility even at high temperature and is chemically incorporated in the polyolefin resin, no volatilization occurs during processing. It is considered that blocking does not occur after processing.

The polyolefin resin foam layer used in the present invention contains at least one of the polyolefin resins A and B, and the polyolefin resins A and / or B are combined with other polyolefin resins. It can be mixed and used.

Examples of the other polyolefin resins include ethylene-containing ethylene having an ethylene content of 2 to 30% by weight.
Propylene copolymer, terpolymer obtained by further copolymerizing butene-1 with the ethylene-propylene copolymer, high-pressure low-density polyethylene, linear low-density polyethylene, linear ultra-low-density polyethylene, high density Polyethylene, ethylene-vinyl acetate copolymer, saponified ethylene-vinyl acetate copolymer, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester copolymer, ethylene- (meth) Acrylic acid-maleic anhydride terpolymer, ethylene- (meth) acrylic acid ester-maleic anhydride terpolymer, etc. may be mentioned. These resins may be used alone or in combination of two or more. Be done.

When at least one of the polyolefin resins A and B is used in combination with the other polyolefin resin, the polyolefin resin A is used.
The use amount of at least one of B and B is 100 parts by weight of the resin component contained in the obtained polyolefin resin layer (parts by weight,
The same shall apply hereinafter) is 0.1 part or more, preferably 20 parts or more in order to impart antistatic properties.

The resin composition of the polyolefin resin foam used as the substrate in the present invention is not particularly limited, and may be appropriately selected and used according to the application of the laminated polyolefin resin foam obtained. Examples of the resin that can be used for the polyolefin-based resin foam include polypropylene, an ethylene-propylene copolymer having an ethylene content of 2 to 30% by weight, and a terpolymer obtained by further copolymerizing butene-1 with the ethylene-propylene copolymer. Various copolymers of propylene and other olefins such as copolymers, high pressure low density polyethylene, linear low density polyethylene, linear ultra low density polyethylene, high density polyethylene and ethylene
-Vinyl acetate copolymer, saponified ethylene-vinyl acetate copolymer, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester, ethylene-
Examples include (meth) acrylic acid-maleic anhydride terpolymer, ethylene- (meth) acrylic acid ester-maleic anhydride terpolymer, etc. These resins may be used alone or in combination of two or more. Used.

The method for producing the polyolefin resin foam used in the present invention is not particularly limited, and known production methods can be applied. Specific examples thereof include, for example, a method of mixing a decomposable foaming agent with a foamable resin composition containing the polyolefin resin, introducing the mixture into an extruder, and decomposing the foaming agent to foam, and the foamable resin composition. Is introduced into an extruder, and a so-called extrusion foaming method in which an evaporative solvent is further pressed into the extruder to foam, a foamable resin composition is charged into a mold together with a mixture of a decomposable foaming agent and a peroxide compound and pressurized. By heating, decomposing the peroxide compound to crosslink, further decomposing the decomposition type foaming agent and simultaneously releasing the pressure to form a foam, the so-called block foaming method, introducing the foamable resin composition into the extruder, and forming it into a sheet form. After molding, a method of irradiating with an electron beam or adding a peroxide compound to crosslink and heat foaming may be mentioned.

The expansion ratio and thickness of the polyolefin resin foam and the foam layer are not particularly limited and may be appropriately selected depending on the intended use of the laminated polyolefin resin foam obtained.

In the present invention, as long as the object of the present invention is not impaired, for example, inorganic fillers such as calcium carbonate, talc, glass single fiber, antioxidants, flame retardants, colorants, polyfunctional monomers, etc. The various auxiliaries and the like may be included in the polyolefin resin foam layer and the polyolefin resin foam.

In the present invention, a known low molecular weight surfactant may be used in the polyolefin resin within a range not exceeding 30 parts with respect to 100 parts of the polyolefin resin. When the surfactant is used within the range of not more than 30 parts, no bleeding is observed from the obtained foam or foam layer.

The method for laminating the polyolefin resin foam layer on the polyolefin resin foam is not particularly limited. For example, a polyolefin resin foam to be used as a base material is manufactured in advance. Then, a method of heating both surfaces of the polyolefin resin foam containing the polyolefin resin with hot air to a temperature equal to or higher than the melting temperature and fusing and laminating the polyolefin resin foam, or including the polyolefin resin during the production of the polyolefin resin foam A method of directly laminating a polyolefin-based resin foam layer, specifically, a polyolefin-based resin foam layer having a thickness of 0.5 to 2 mm on one or both sides of a portion of a molten base resin to be a foam resin. Examples include a method of foaming after composite lamination.

The laminated polyolefin resin foam of the present invention thus obtained can be further subjected to corona discharge treatment on at least one side thereof to increase the surface wetting tension and improve the adhesiveness with various water-soluble coating agents. it can. In addition, after providing a coating agent layer, various skin materials, films, sheets, other foams, metal foils, papers, non-woven fabrics made of natural fibers or synthetic fibers or synthetic leathers are laminated to form a composite, and then these It can be molded by any method.

Next, the laminated polyolefin resin foam of the present invention will be described in more detail with reference to Examples.
The invention is not limited to only such embodiments.

Example 1 As a foamable resin composition (A) for a polyolefin resin foam as a base material, a high-pressure low-density polyethylene (density:
0.921 g / cm ³ , melt index: 3.7 g / 10 minutes,
Particle size: 32 mesh pass) 10 parts of azodicarbonamide as a foaming agent was added to 100 parts of the mixture and mixed.

Further, as the resin for the foam layer, the formula:

[0092]

[Chemical 25]

85 mol% of olefin structural unit represented by the formula:

[0094]

[Chemical formula 26]

5 mol% of an acrylate structural unit represented by the formula:

[0096]

[Chemical 27]

1 mol% of an alkylmaleimide structural unit represented by the formula:

[0098]

[Chemical 28]

20 parts of a polyolefin resin having a weight-average molecular weight of 39400 linearly and irregularly composed of 9 mol% of a cationized maleimide structural unit represented by: 100 parts of the same high-pressure low-density polyethylene resin as described above and a blowing agent A foamable resin composition (B) was used in which 6 parts of azodicarbonamide was added and mixed.

Next, two extruders were prepared, and the above-mentioned expandable resin compositions (A) and (B) were introduced into each of them, and then introduced into a laminating apparatus equipped with a die-composite facility, and melted and kneaded. The thickness of the polyolefin resin foam layer is 1 mm,
The thickness of the foamable resin layer part that becomes the foam of the base material is 1.5 mm,
A molten composite continuous sheet having a width of 500 mm was formed.

This sheet is irradiated with an electron beam of 5 Mrad with an electron beam irradiator.
Was irradiated and crosslinked to obtain a crosslinked foamable laminated sheet.

The crosslinked foamable laminated sheet thus obtained was continuously introduced into a vertical hot air foaming machine in a heating atmosphere of 230 ° C. to obtain a laminated foam. This laminated foam has an overall thickness of 4.2 mm,
The overall width is 1170 mm, and the apparent expansion ratio is 20
The foam layer had an apparent expansion ratio of 13 times and the foam layer had a thickness of 1.7 mm.

When the surface resistivity of the obtained laminated foam was examined according to the method described below, it was found to be extremely small at 3.6 × 10 ¹¹ Ω and excellent in antistatic property.

Next, the obtained laminated foam was subjected to 80% at 40 ° C.
The surface of the resin layer of the laminated foam was observed after being left in an atmosphere of RH (relative humidity) for 7 days. No stickiness due to bleed-out was observed, and the polypropylene resin was not formed on the surface of the resin layer of the obtained laminated foam. Printing was performed using the printing ink for printing, but there were no printing defects due to bleed-out.

Next, one surface of the obtained laminated foam was subjected to corona discharge treatment so that the surface wetting tension was 37 dyne / cm or more, and the adhesiveness with various coating agents could be improved.

Further, by providing a coating agent layer, various skin materials, films, sheets, other foams, metal foils, papers,
Nonwoven fabrics or synthetic leathers made of natural fibers or synthetic fibers were laminated to form a composite, which was then formed into a desired shape by various methods.

(Surface Resistivity) The laminated foam was cut into a size of 10 cm × 10 cm, and left in a constant temperature and constant temperature room controlled at 20 ° C. and 60% RH for 48 hours for aging.

After completion of aging, the surface resistivity is measured in the atmosphere.

Measuring instrument: Ultra-insulator (VE-40 type) manufactured by Kawaguchi Electric Co., Ltd. and room temperature measuring box (RC-02 type) connected Measuring condition: Applied voltage 100 V Value measured by this instrument To adopt.

The surface resistivity is 1 × 10 ¹³ Ω.
Hereinafter, the one having a charge half-life of 3 minutes or less is assumed to have antistatic properties.

Example 2 A low-density polyethylene (density: 0.923) was used as a foamable resin composition (A) for a polyolefin resin foam as a base material.
g / cm ³ , melt index: 1.2 g / 10 min, particle diameter: 32 mesh pass) 10 parts of azodicarbonamide as a foaming agent was added to 100 parts and mixed.

The resin for the foam layer has the formula:

[0113]

[Chemical 29]

85 mol% of the olefin structural unit represented by the formula:

[0115]

[Chemical 30]

5 mol% of an acrylate structural unit represented by the formula:

[0117]

[Chemical 31]

9 mol% of an alkylmaleimide structural unit represented by the formula:

[0119]

[Chemical 32]

A polyolefin resin having a weight average molecular weight of 39400 and having a linearly irregular arrangement of 9 mol% of a cationized maleimide structural unit represented by: The composition (B) was used.

Next, the foamable resin composition (A) and
Using (B), a laminated foam was obtained in the same manner as in Example 1.
This laminated foam has an overall thickness of 3.0 mm and an overall width of 1170 m.
m, the apparent expansion ratio of the foam of the base material was 20 times, the apparent expansion ratio of the foam layer was 6 times, and the thickness of the foam layer was 0.8 mm.

The surface properties of the obtained laminated foam were examined in the same manner as in Example 1, and the half-life of charge, bleed-out and blocking shearing force were examined according to the following methods. The results are shown in Table 1.

(Half-life of charge) A voltage of 10 KV was applied to the sample in the same atmosphere as when the surface resistivity was measured, using a static Honest meter (manufactured by Shishido Shokai Co., Ltd.) to measure the applied charge. Determine the decay rate as the half-life.

(Bleed out) An additive-free biaxially oriented polypropylene film was laminated on the surface of the foam, and the temperature was 40% at 80 ° C.
After putting in the atmosphere of H for 7 days, it is taken out, the film is peeled from the foam, and the presence or absence of the deposit on the surface of the film is examined.

(Blocking Shearing Force) Two foams were superposed on each other over a width of 3 cm and a length of 4 cm, and 550 g of the foam was superposed thereon.
After placing it for 7 days in an atmosphere of 40 ° C. and 80% RH, the shear peeling force of the two foams is determined by a Shopper-type tensile tester.

A shear peeling force of 1000 g or less is regarded as acceptable. The amount is preferably 500 g or less.

Example 3 Low-density polyethylene (density: 0.921 g / cm ³ , melt index: as the foamable resin composition (A) which is a base material)
3.2 g / 10 minutes) A azodicarbonamide (10 parts) was added as a foaming agent to 100 parts.

The resin for the foam layer has the formula:

[0129]

[Chemical 33]

80 mol% of an olefin structural unit represented by the formula:

[0131]

[Chemical 34]

1 mol% of an alkylmaleimide structural unit represented by the formula:

[0133]

[Chemical 35]

30 parts of a polyolefin resin having a weight average molecular weight of 29800 and having a linearly irregular arrangement of 19 mol% of cationized maleimide structural units represented by: low density polyethylene (density: 0.921 g / cm ³ , melt index:
A foamable composition (B) obtained by adding 70 parts of 3.2 g / 10 minutes, particle size: 32 mesh pass) and 6 parts of azodicarbonamide as a foaming agent and mixing was used.

Using the foamable resin compositions (A) and (B) thus obtained, two extruders heated to 110 to 170 ° C. were prepared, and the foamable resin compositions (A) and (B)
Was introduced, the foaming agent was gradually decomposed and kneaded until the foaming gas was uniformly dispersed, and the temperature was adjusted so that the viscosity was suitable for foaming, and then the mixture was introduced into a device equipped with a die complex facility and laminated. Then, it was extruded from the die under atmospheric pressure and expanded to obtain a laminated foam. This laminated foam has an overall thickness of 4.0 mm
The total expansion width was 1170 mm, the apparent expansion ratio of the foam as the base material was 25 times, the apparent expansion ratio of the foam layer was 13 times, and the thickness of the foam layer was 1.0 mm.

The physical properties of the obtained laminated foam were examined in the same manner as in Example 2. The results are shown in Table 1.

Example 4 A linear low-density polyethylene (density: 0.925 g / cm ³ , melt index: 2 g / 10 minutes) and a low-density polyethylene (density: as a foamable resin composition (A) as a base material) 0.923
(g / cm ³ , melt index: 1.5 g / 10 min) were mixed at a weight ratio of 30:70.

The resin for the foam layer has the formula:

[0139]

[Chemical 36]

80 mol% of an olefin structural unit represented by the formula:

[0141]

[Chemical 37]

1 mol% of an acrylate structural unit represented by the formula:

[0143]

[Chemical 38]

1 mol% of an alkylmaleimide structural unit represented by the formula:

[0145]

[Chemical Formula 39]

20 parts by weight of a polyolefin resin having a weight average molecular weight of 27800 and having a weight average molecular weight of 27800, which was linearly and irregularly arranged, and which consisted of 18 mol% of a cationized maleimide structural unit represented by
80 parts of the same linear low density polyethylene as used in 1. was used. Next, prepare two extruders heated to 110 to 125 ° C, introduce the foamable compositions (A) and (B) into each extruder, melt them, and remove the volatile solvent from the middle of the barrel of each extruder. Blow in the state of addition, kneading until the volatile solvent is uniformly dispersed in the resin, after adjusting the temperature so as to have a viscosity suitable for foaming, then introduced into the manufacturing equipped with a die complex equipment, laminated A laminated foam was obtained by extruding from a die under atmospheric pressure and expanding. This laminated foam has an overall thickness of 4.5 m
m 2, the overall width was 1170 mm, the apparent expansion ratio was 15 times, the apparent expansion ratio was 9 times, and the thickness of the foam layer was 1.25 mm.

The physical properties of the obtained laminated foam were examined in the same manner as in Example 2. The results are shown in Table 1.

Example 5 As a foaming resin composition (A) which is a base material, an ethylene-propylene copolymer (ethylene content: 8% by weight, melt index: 2.3 g / 10 minutes) was used as a foaming agent for 100 parts. Azodicarbonamide 3 parts, dicumyl peroxide 1
And 2 parts of divinylbenzene were added.

The resin for the resin layer has the formula:

[0150]

[Chemical 40]

88 mol% of an olefin structural unit represented by the formula:

[0152]

[Chemical 41]

3 mol% of an acrylate structural unit represented by the formula:

[0154]

[Chemical 42]

1 mol% of an alkyl maleimide structural unit represented by the formula:

[0156]

[Chemical 43]

Polyolefin resin having a weight average molecular weight of 37,800, which is composed of 8 mol% of the cationized maleimide structural unit represented by the formula and has a weight average molecular weight of 37800, is crushed to have a size of 32 mesh, 60 parts, polypropylene (melt index). : 2.5 g / 10 minutes, particle size: 32 mesh pass) 40 parts and azodicarbonamide 2 as a foaming agent
Was used, and a foamable resin composition (B) was used in which 1 part of dicumyl peroxide and 2 parts of divinylbenzene were added and mixed.

Next, a laminated foam was obtained in the same manner as in Example 1 except that dicumyl peroxide was decomposed and crosslinked, that is, no electron beam was irradiated. The obtained laminated foam has an overall thickness of 4.5 mm, an overall width of 1170 mm,
The apparent expansion ratio of the foam as the base material was 5 times, the apparent expansion ratio of the foam layer was 3 times, and the thickness of the foam layer was 0.25 mm.

The physical properties of the obtained laminated foam were examined in the same manner as in Example 2. The results are shown in Table 1.

Example 6 A linear low-density polyethylene (density: 0.925 g / cm ³ , melt index: 2 g / 10 minutes) and a low-density polyethylene (density: 0.923
(g / cm ³ , melt index: 1.5 g / 10 min) were mixed at a weight ratio of 30:70.

The resin for the foam layer has the formula:

[0162]

[Chemical 44]

80 mol% of an olefin structural unit represented by the formula:

[0164]

[Chemical 45]

1 mol% of an acrylate structural unit represented by the formula:

[0166]

[Chemical 46]

1 mol% of an alkylmaleimide structural unit represented by the formula:

[0168]

[Chemical 47]

20 parts by weight of a polyolefin resin having a weight average molecular weight of 26900 and linearly irregularly arranged consisting of 19 mol% of a cationized maleimide structural unit represented by and Example 3
80 parts of the same linear low density polyethylene as used in 1. was used. Next, prepare two extruders heated to 110 to 125 ° C, introduce the foamable compositions (A) and (B) into each extruder, melt them, and remove the volatile solvent from the middle of the barrel of each extruder. Blow in the state of addition, kneading until the volatile solvent is uniformly dispersed in the resin, after adjusting the temperature so as to have a viscosity suitable for foaming, then introduced into the manufacturing equipped with a die complex equipment, laminated A laminated foam was obtained by extruding from a die under atmospheric pressure and expanding. This laminated foam has an overall thickness of 4.5 m
m 2, the overall width was 1170 mm, the apparent expansion ratio was 17 times, the apparent expansion ratio was 13 times, and the thickness of the foam layer was 1.25 mm.

The physical properties of the obtained laminated foam were examined in the same manner as in Example 2. The results are shown in Table 1.

Example 7 A laminated foam was obtained in the same manner as in Example 1 except that 10 parts of the 20 parts of the polyolefin resin used in Example 1 were replaced with the polyolefin resin used in Example 6. This laminated foam has an overall thickness of 4.5 mm, an overall width of 1170 mm, an apparent expansion ratio of 25 times as a base material, an apparent expansion ratio of 15 times, and a foam layer thickness of 15 times. It was 1.25 mm.

The physical properties of the obtained laminated foam were examined in the same manner as in Example 2. The results are shown in Table 1.

[0173]

[Table 1]

Comparative Example 1 Polypropylene (melt index: 2.5 g / 10 minutes,
Particle size: 32 mesh pass) 99 parts, 1 part of stearic acid monoglyceride as an antistatic agent, 5 parts of azodicarbonamide as a foaming agent, and 2 parts of divinylbenzene are mixed to obtain a foamable composition (B) for a foam layer. I got it.

Ethylene-propylene copolymer (ethylene content: 5% by weight, melt index: 1.2 g / 10 minutes)
By mixing 100 parts with 3 parts of azodicarbonamide as a foaming agent and 2 parts of divinylbenzene, a foamable composition (A) for a foam, which is a base material, was obtained.

Next, the obtained foamable composition (A) and
A laminated foam was obtained in the same manner as in Example 1 using (B).

The physical properties of the obtained laminated foam were examined in the same manner as in Example 2. The results are shown in Table 2.

Comparative Example 2 Polypropylene (melt index: 2.5 g / 10 minutes,
Particles: 32 mesh pass) 99.2 parts, formula as antistatic agent:

[0179]

[Chemical 48]

Betaine type amphoteric surfactant represented by:
8 parts, 3 parts of azodicarbonamide as a foaming agent, and 2 parts of divinylbenzene were mixed to obtain a foamable resin composition (B) for a foam layer.

A foaming composition for a foam, which is a base material by mixing 100 parts of the same ethylene-propylene copolymer as used in Comparative Example 1 and 1 part of azodicarbonamide as a foaming agent and 2 parts of divinylbenzene. I got (A).

Next, the obtained foamable composition (A) and
A laminated foam was obtained in the same manner as in Example 1 using (B).

The physical properties of the obtained laminated foam were examined in the same manner as in Example 2. The results are shown in Table 2.

Comparative Example 3 Low density polyethylene (density: 0.921 g / cm ³ , melt index: 3.2 g / 10 minutes, particle size: 32 mesh pass)
Formula with 98.5 parts stearic acid monoglyceride as antistatic agent:

[0185]

[Chemical 49]

A betaine type amphoteric surfactant represented by the formula (1) was mixed at a weight ratio of 1: 1 and 1.5 parts was mixed to obtain a foamable resin composition (B) for a foam layer.

A foamable resin composition for a foam, which is a base material using the same low-density polyethylene as that used in Example 3.
I got (A).

Using the foamable resin compositions (A) and (B) obtained below, a laminated foam was obtained in the same manner as in Example 4.

The physical properties of the obtained laminated foam were examined in the same manner as in Example 2. The results are shown in Table 2.

Comparative Example 4 95 parts of ethylene-propylene copolymer having an ethylene content of 5% by weight (melt index: 1.2 g / 10 minutes, particle size: 32 mesh pass), sodium dodecylbenzenesulfonate as an antistatic agent and polyethylene glycol 5 parts of 1: 1 by weight, 10 parts of azodicarbonamide as a foaming agent and 2 parts of divinylbenzene were mixed to obtain a foamable composition (B) for a foam layer.

The same polypropylene used in Example 5
100 parts and 8 parts of azodicarbonamide as a foaming agent,
Two parts of divinylbenzene were mixed to obtain a foamable composition (A) for a foam which was a base material.

The following foamable composition (A) and
(B) A laminated foam was obtained in the same manner as in Example 1.

The physical properties of the obtained laminated foam were examined in the same manner as in Example 2. The results are shown in Table 2.

Comparative Example 5 Polypropylene (melt index: 2.5 g / 10 minutes,
Particle size: 32 mesh pass) 99.2 parts, stearyldiethanolamine 0.8 part as an antistatic agent, and azodicarbonamide 3 parts as a foaming agent, dicumyl peroxide 1 part, and divinylbenzene 2 parts are mixed to form a foaming layer. The composition (B) was obtained.

Further, 100 parts of the polypropylene and 2 parts of azodicarbonamide as a foaming agent, 1 part of dicumyl peroxide and 2 parts of divinylbenzene were mixed to obtain a foamable composition (A) for a foam which was a base material. I got it.

Next, the obtained foamable composition (A) and
A laminated foam was obtained in the same manner as in Example 1 except that the dicumyl peroxide was decomposed and crosslinked using (B), that is, no electron beam was irradiated.

The physical properties of the obtained laminated foam were examined in the same manner as in Example 2. The results are shown in Table 2.

[0198]

[Table 2]

From the results shown in Table 1, the laminated polyolefin resin foam of the present invention has a surface resistivity of 1 × 10 ¹³ Ω or less, which is an index of antistatic property, and a charge half-life of 180 seconds or less. It can be seen that the laminated foam is excellent and has no bleed-out from the foam layer of the laminated foam of the antistatic component, and thus is excellent in antistatic property without blocking.

On the other hand, the laminated foams obtained in Comparative Examples 1 to 5 were those in which the conventional comparatively low molecular weight surfactant type antistatic agent was used. It can be seen that if the antistatic property is to be satisfied, the antistatic agent bleeds out from the foam, which causes blocking.

From the above, the laminated polyolefin resin foam of the present invention has excellent antistatic properties, and since there is no bleed-out of the antistatic agent and no blocking occurs, for example, the occurrence of damage due to static electricity is prevented. It can be seen that it can be suitably used in the field where it must be.

[0202]

EFFECT OF THE INVENTION The laminated polyolefin resin foam of the present invention has no bleed-out and has an excellent antistatic property, so that it is free of dust and does not give a shock to the human body due to the discharge of static electricity. Therefore, it is a laminated foam excellent in handleability.

Claims (1)

[Claims] 1. General formula (I): (In the formula, R ¹ represents a hydrogen atom or a methyl group) 45 to 98.5 mol% of an olefin structural unit represented by the general formula (II): (In the formula, R ² represents an alkyl group having 1 to 4 carbon atoms) 0 to 15 mol% of an acrylate structural unit represented by the general formula (III): (Wherein R ³ represents an alkyl group having 8 to 18 carbon atoms or an aryl group having 8 to 18 carbon atoms), and 0.5 to 5 mol% of an alkylmaleimide structural unit and a compound represented by the general formula (IV): (In the formula, R ⁴ is an alkylene group having 2 to 8 carbon atoms, R ⁵ and R ⁶ are respectively alkyl groups having 1 to 4 carbon atoms, R ⁷ is an alkyl group having 1 to 12 carbon atoms, and 6 to 12 carbon atoms. Arylalkyl group, 2 to 2 carbon atoms which may be substituted with an alkyl group
An epoxy group having 4 or an alicyclic alkyl group having 6 to 12 carbon atoms,
X is a halogen atom, CH ₃ OSO ₃ or C ₂ H ₅ OS
O ₃ ) and a polyolefin resin having a weight average molecular weight of 1000 to 50000 and having a weight average molecular weight of 1000 to 50000, which is composed of 1 to 35 mol% of a cationized maleimide structural unit represented by the general formula (I): (Wherein R ¹ is the same as above) 45 to 98.5 mol% of an olefin structural unit represented by the general formula (II): (Wherein R ² is the same as above) 0 to 15 mol% of an acrylate structural unit represented by the general formula (V): (In the formula, R ¹ and R ³ are the same as above, m is 0 or 1
Is represented by) and an alkylmaleimide structural unit represented by 0.5
~ 5 mol% and general formula (VI): (Wherein R ¹ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , X and m are the same as described above), and the cationized maleimide structural units represented by 1 to 35 mol% are linearly and irregularly arranged. A laminated polyolefin-based resin foam comprising a polyolefin-based resin foam layer containing at least one kind of polyolefin-based resin having a weight average molecular weight of 1,000 to 50,000.