JPH0794158B2 - Polyolefin resin foam laminate - Google Patents

Description

TECHNICAL FIELD The present invention relates to a polyolefin resin foam laminate.
More specifically, the present invention relates to a polyolefin resin foam laminate that has excellent antistatic properties and can be suitably used as a household item such as a bath mat, a packing, a heat insulating material, an automobile interior material, and the like.

[Prior Art] Generally, a foam made of a polyolefin-based resin, particularly a polyethylene-based resin or a polypropylene-based resin has a large hydrophobicity, so that static electricity is remarkably generated, dust is attached to the foam, or static electricity is discharged. This causes a problem such as giving a shock to the human body.

Therefore, conventionally, in order to impart antistatic properties to the foam, a method of adding an anionic, cationic or amphoteric surfactant, or a polyolefin resin foam has been disclosed in Japanese Patent Laid-Open No.
The method of coating the resin described in JP-A-121717 or the resin described in JP-B-1-29820 is adopted.

However, in the method of adding the surfactant, since the surfactant has a relatively small molecular weight of about 500 to 600, it is volatilized during the production of the foam,
In addition, there is a problem that after foaming, it bleeds out over time, contaminates the surface of the foam, causes blocking, deteriorates adhesiveness, printability, vapor deposition, etc., and is inferior in durability of effect. is there. Further, in the method of coating the specific resin, since the resin is not a polyolefin-based resin, the adhesiveness with the polyolefin-based resin foam is poor, and thus the polyolefin-based resin foam laminate intended by the present invention is obtained. I can't get it. A method of adding such a resin to the foam is also conceivable, but in this case, since the compatibility with the polyolefin resin is poor, the transparency is deteriorated or voids are generated, and the surface property is poor. There is a problem.

In addition, when these resins and surfactants are included in the foam, the volume of the product increases, unlike sheets and films.As a result, unless a large amount of the resins and surfactants as described above is added, charging There is a problem that it is difficult to exert preventive properties.

[Problems to be Solved by the Invention] The present invention has been made in view of the above-mentioned prior art,
In addition to being excellent in antistatic property, it is intended to provide a polyolefin resin foam laminate excellent in adhesiveness, printability and vapor deposition property without occurrence of bleeding or blocking. is there.

[Means for Solving the Problems] The present invention provides an ethylene structural unit represented by the formula: CH ₂ —CH _2.
65-99 mol%, general formula: (In the formula, R ¹ represents an alkyl group having 1 to 4 carbon atoms), an acrylate structural unit of 0 to 15 mol% and a general formula: (In the formula, R ² is an alkylene group having 2 to 8 carbon atoms, R ³ and R ⁴
Are each an alkyl group having 1 to 4 carbon atoms, R ⁵ is 1 to 4 carbon atoms
An acrylamide structure represented by a 12 alkyl group, an arylalkyl group having 1 to 12 carbon atoms or an alicyclic alkyl group having 1 to 12 carbon atoms, X is a halogen atom, CH ₃ OSO ₃ or C ₂ H ₅ OSO ₃ ) The present invention relates to a polyolefin resin foam laminate comprising a polyolefin resin layer containing a polyolefin resin having a weight average molecular weight of 1000 to 50,000 linearly and irregularly arranged in a unit of 1 to 35 mol%.

Polyolefin resin foam laminate of the action and Examples] The present invention, as described above, wherein: CH ₂ -CH ₂ ethylene structural units 65-99 mol% represented by the general formula: (In the formula, R ¹ represents an alkyl group having 1 to 4 carbon atoms), an acrylate structural unit of 0 to 15 mol% and a general formula: (In the formula, R ² is an alkylene group having 2 to 8 carbon atoms, R ³ and R ⁴
Are each an alkyl group having 1 to 4 carbon atoms, R ⁵ is 1 to 4 carbon atoms
12 alkyl group, C 1-12 arylalkyl group or C 1-12 alicyclic alkyl group, X is a halogen atom,
CH ₃ OSO ₃ or C ₂ H ₅ OSO ₃ ), a polyolefin-based resin containing a polyolefin-based resin having a weight-average molecular weight of 1000 to 50,000 and linearly irregularly arranged and composed of 1 to 35 mol% of an acrylamide structural unit The resin is provided as the resin for the resin layer.

The ratio of ethylene structural units represented by the formula: CH ₂ —CH ₂ in the polyolefin resin is 65
~ 99 mol%. When the proportion of the ethylene structural unit is less than 65 mol%, the softening point of the polyolefin-based resin becomes low to cause tack and stickiness, and when it exceeds 99 mol%, the polyolefin-based resin is The antistatic property of becomes too small. In the present invention, the proportion of the ethylene structural unit is particularly preferably 85 to 97 mol% from the viewpoint of the balance between the softening point and the antistatic property.

The general formula in the polyolefin resin: The ratio of the acrylate structural unit represented by the formula (wherein R ¹ is the same as above) is 0 to 15 mol%. When the proportion of the acrylate structural unit exceeds 15 mol%, the softening point of the polyolefin resin becomes low and tack or stickiness occurs. In the present invention, the presence of the acrylate structural unit is preferable because it imparts toughness and impact resistance. In the present invention, the proportion of the acrylate structural unit is particularly preferably 1 to 15 mol%, especially 3 to 7 mol% from the viewpoint of the balance between the softening point and the toughness and impact resistance.

In the acrylate structural unit, R ¹ has 1 to 4 carbon atoms.
Is an alkyl group. Specific examples of R ¹ include methyl group, ethyl group, n-propyl group, i-propyl group, n
-Butyl group and i-butyl group are mentioned, and these groups are 1
It may be mixed in the molecule. Among these groups, a methyl group and an ethyl group are preferable for maintaining the softening point of the polyolefin resin.

The general formula in the polyolefin resin: The ratio of the acrylamide structural unit represented by the formula (wherein R ² , R ³ , R ⁴ and ⁵ are the same as above) is 1 to 35 mol%.
When the proportion of the acrylamide structural unit is less than 1 mol%, the antistatic property becomes too small, and when it exceeds 35 mol%, the polyolefin resin becomes hygroscopic. In the present invention, the proportion of the acrylamide structural unit is particularly preferably 3 to 15 mol% in terms of antistatic property and hygroscopic property.

In the acrylamide structural unit, R ² has 2 to 2 carbon atoms.
8 is an alkylene group. Specific examples of R ² include:
Examples thereof include ethylene group, propylene group, hexamethylene group, neopentylene group, and the like.
It may be mixed in the molecule. Among these groups, an ethylene group and a propylene group are preferable, and a propylene group is particularly preferable, from the viewpoint of ease of production and economy.

R ³ and R ⁴ are each an alkyl group having 1 to 4 carbon atoms. Specific examples of R ³ and R ⁴ include a methyl group,
Examples thereof include an ethyl group, a propyl group, and a butyl group, and these groups may be mixed in one molecule. Among these groups, a methyl group and an ethyl group are preferable from the viewpoint of antistatic property.

R ⁵ is an alkyl group having 1 to 12 carbon atoms, an arylalkyl group having 1 to 12 carbon atoms, or an alicyclic alkyl group having 1 to 12 carbon atoms. Specific examples of R ⁵ include, for example, a methyl group,
Alkyl groups such as ethyl group, n-propyl group, i-propyl group, n-butyl group, sec-butyl, n-octyl group and n-lauryl group; arylalkyl groups such as benzyl group and 4-methylbenzyl group; Examples thereof include alicyclic alkyl groups such as a cyclohexyl group and a methylcyclohexyl group, and these groups may be mixed in one molecule. In addition, the above
As R ⁵ , a linear alkyl group and an arylalkyl group are preferable from the viewpoint of heat resistance, and a lower alkyl group is preferable from the viewpoint of antistatic properties. Particularly preferred R ⁵ includes a methyl group and an ethyl group.

The X is, for example, a halogen atom such as Cl, Br or I, CH
₃ OSO ₃ or C ₂ H ₅ OCO ₃ , which may be mixed in one molecule. Among these, Cl, CH ₃ OSO ₃ and C ₂ H ₅ OSO ₃ are preferable from the viewpoint of antistatic property.

The weight average molecular weight of the polyolefin resin is 1000 to
It is 50,000. When the weight average molecular weight is less than 1000, the molecular weight becomes too small to volatilize when heated, and when it exceeds 5000, the viscosity when melted becomes too large, resulting in poor workability. Become. The preferred weight average molecular weight is 3000 to 30,000.

In addition, in this specification, a weight average molecular weight means the monodisperse polystyrene conversion weight average molecular weight measured by gel permeation chromatograph (GPC).

The polyolefin-based resin used in the present invention is hardly soluble in a normal gel permeation eluent such as tetrahydrofuran (THF) or xylene, so its weight average molecular weight cannot be easily measured. (Kinukawa, Journal of Polymer Science, Vol. 44, No. 2, pp. 139-141 (1987)
Year)).

An ethylene structural unit represented by the formula: CH ₂ —CH ₂ which is an intermediate of the polyolefin resin, a general formula: (Wherein R ¹ is the same as above) and a general formula: (In the formula, R ² , R ³ and R ⁴ are the same as described above) The olefinic copolymer having a weight average molecular weight of 1000 to 50000 linearly and irregularly arranged consisting of an acrylamide structural unit is, for example, Obtained by the method.

First, the raw material of the olefin-based copolymer is not particularly limited, but more advantageously ethylene (C ₂ H ₄ ) and the general formula: CH ₂ CHCOOR ¹ (wherein R ¹ is the same as above). A (partial) hydrolyzate of a copolymer with the acrylate represented is used. Such a copolymer can be easily obtained by copolymerizing ethylene and the acrylate by a high pressure polymerization method.

The ratio of the ethylene structural unit derived from ethylene to the acrylate structural unit derived from the acrylate determines the ratio of the ethylene structural unit, the acrylate structural unit and the acrylamide structural unit of the obtained olefinic copolymer.

Since the copolymer usually has a high molecular weight of about 5 to 300 as a melt index, it is reduced in molecular weight by, for example, a degradation method in which hydrolysis and thermal decomposition are simultaneously performed under high temperature and high pressure in the presence of water. It is preferable.

At this time, the general formula derived from acrylate: (In the formula, R ¹ is the same as above), all or part of the acrylate structural unit is hydrolyzed to form the formula: It becomes an acrylic acid structural unit represented by.

In order to prepare a copolymer having a molecular weight of 50 to 600 by thermal decomposition of the copolymer, the copolymer is reacted in the presence of water at a reaction temperature of 150 to 500 ° C. and a pressure of 3 ~ 50
The molecules may be cut by heating at 0 kg / cm ² .

Further, in the present invention, the proportion of the acrylic acid structural unit can be appropriately adjusted by adjusting the charged amount of water, the reaction temperature, the pressure, and the reaction time.

Specific examples of the degradation method include, for example, JP-A-53-57.
295, JP 53-65389, JP 60-79008
The methods described in JP-A No. 60-79015 and the like.

The polyolefin resin used in the present invention may impair its commercial value if it is colored, so that the raw material used in the present invention is, for example, JP-A-60-
It is preferable to use the product of the method exemplified in 79008.

The polyolefin resin used in the present invention can be obtained by using the thus obtained intermediate of the polyolefin resin.

The method for producing the polyolefin resin used in the present invention from the intermediate is not particularly limited. An example thereof will be described below.

Examples of the intermediate include benzene, toluene, xylene,
Soluble in an inert solvent such as cyclohexanone, dencan, cumene, cymene or other aromatic or aliphatic hydrocarbons,
To this, 100 to 150 mol% of a dialkylamine-based monomer such as dialkylaminoalkylamine with respect to the carboxyl group of the intermediate is added, and reacted at 130 to 220 ° C. to remove the carboxyl group contained in the acrylic acid structural unit. After conversion to a dialkylaminoalkylamide group to give an intermediate, cation modification with a known quaternizing agent such as an alkyl halide or dialkyl sulfate gives a linear random copolymer used in the present invention. A polyolefin resin can be obtained.

The polyolefin resin thus obtained has excellent charging.
Exhibits preventive properties. The reason why the antistatic property is exhibited is
Although it is not certain, the accompaniment contained in polyolefin resin
Lilamide structural unit takes in the water contained in the air
See, x Is ionized and exhibits electrical conductivity,
It is considered that this is due to the fact that it exhibits a low electric resistance.

Further, in the present invention, the acrylamide structural unit does not exhibit volatility even at high temperatures, and since it is chemically incorporated in the polyolefin resin used in the present invention, there is no volatilization during processing, It is considered that blocking does not occur after processing.

The polyolefin resin foam laminate of the present invention is provided with a resin layer resin containing the polyolefin resin, and the resin layer resin may be a polyolefin resin alone or the resin and other polyolefin resin. A mixture of and is used.

Examples of the other polyolefin resins include ethylene-propylene copolymers having an ethylene content of 2 to 30% by weight, butene-propylene copolymers containing butene-
Terpolymer further copolymerized with 1, high-pressure low-density polyethylene, linear low-density polyethylene, linear ultra-low-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, the above-mentioned ethylene-vinyl acetate Saponified copolymer, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester copolymer, ethylene- (meth) acrylic acid-maleic anhydride terpolymer,
Examples thereof include ethylene- (meth) acrylic acid ester-maleic anhydride terpolymer, and these resins may be used alone or in combination of two or more.

When the polyolefin-based resin and the other polyolefin-based resin are used in combination, the amount of the polyolefin-based resin used is 0.1 part with respect to 100 parts of the resin layer resin (weight part, the same applies hereinafter). Or more, preferably 1
It is desirable that the content is 0 part or more in order to impart antistatic properties.

The resin composition of the polyolefin-based 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 obtained polyolefin-based resin foam laminate. Examples of the resin that can be used for the polyolefin resin foam include polypropylene,
The ethylene-propylene copolymer having an ethylene content of 2 to 30% by weight and the butene-containing ethylene-propylene copolymer
Various copolymers of propylene and other olefins such as terpolymers obtained by further copolymerizing 1 with, high-pressure low-density polyethylene, low-pressure high-density polyethylene, linear low-density polyethylene, linear ultra-low Density polyethylene, ethylene-vinyl acetate copolymer, saponified ethylene-vinyl acetate copolymer, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester, ethylene- (meth) acrylic Acid-maleic anhydride terpolymer,
Examples thereof include ethylene- (meth) acrylic acid ester-maleic anhydride terpolymer, and these resins may be used alone or in combination of two or more.

The method for producing the polyolefin resin foam used in the present invention is not particularly limited, and known production methods can be applied. As specific examples thereof, for example, a decomposable foaming agent is mixed with an expandable resin composition and introduced into an extruder, a method of decomposing the foaming agent to foam, and an expandable resin composition is introduced into the extruder, A so-called extrusion foaming method in which an evaporative solvent is pressed into an extruder for foaming, a foamable resin composition is charged into a mold together with a mixture of a decomposable foaming agent and a peroxide compound and heated under pressure to decompose the peroxide compound. Then, it is crosslinked, and the decomposable foaming agent is decomposed to release the pressure at the same time to form a foam, which is a so-called block foaming method, in which a foamable resin composition is introduced into an extruder and molded into a sheet, and then irradiated with electron beams. Alternatively, an atmospheric pressure cross-linking foaming method in which a peroxide compound is added to cross-link and heat-foaming may be used.

The expansion ratio and the thickness of the polyolefin resin foam are not particularly limited and may be appropriately selected depending on the application of the obtained polyolefin resin foam laminate.

In the present invention, as long as the object of the present invention is not hindered, for example, calcium carbonate, talc, inorganic filler such as glass single fiber, antioxidant, flame retardant, colorant,
Various auxiliaries such as polyfunctional monomers may be contained in the resin for resin layer and the foam.

Further, in the present invention, a known low molecular weight surfactant may be used in the resin for resin layer and the foam within a range not exceeding 30 parts with respect to 100 parts of the polyolefin resin. Bleed is not observed when the surfactant is used within the range not exceeding 30 parts.

The method for laminating the resin layer resin on the polyolefin resin foam is not particularly limited, and examples thereof include a method for laminating a resin layer resin by the extrusion lamination method, and a polyolefin resin. A method of directly laminating a resin layer resin during the production of a foam,
Specifically, it includes a method in which the resin for resin is laminated on one or both sides of the molten resin that becomes a foam and then foamed. Roll coating method,
There is a method of coating the surface of the foam by a gravure coating method, a bar coating method or the like.

The thickness of the polyolefin resin layer may be in the range of 1 to 150 μm, preferably 3 to 100 μm, and more preferably 5 to 50 μm when the final product is used. If the thickness is less than 1 μm, cohesive failure occurs at the interface between the resin layer and the foam, resulting in poor adhesiveness and vapor deposition properties. The flexibility of the layer becomes remarkable, and a phenomenon such as blocking occurs.

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

Next, the polyolefin resin foam laminate of the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

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

Further, as the resin for resin layer, the ethylene structural unit represented by the formula: CH ₂ —CH ₂ is 85 mol%, and the formula: An acrylate structural unit represented by 5 mol% and a formula: A polyolefin resin having a weight average molecular weight of 21000, which was linearly and irregularly arranged and consisted of 10 mol% of the acrylamide structural unit represented by, was pulverized into 32 mesh paths.

Next, two extruders were prepared, and after introducing the foamable resin composition and the resin for resin layer into each of them,
Melted and kneaded by being introduced into a laminating machine equipped with a die complex facility, the resin layer has a thickness of 500 μm, the foamable resin layer part that becomes the foam has a thickness of 1.5 mm and a width of 500 mm. Was molded.

This sheet was irradiated with an electron beam of 5 Mrad by an electron beam irradiator to be 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 foam laminate. This foam laminate has an overall thickness of 3.3 mm and an overall width of 1
170 mm, apparent expansion ratio 20 times, resin layer thickness 43 μm
It was the one.

When the surface resistivity of the obtained foam laminate was examined according to the following method, it was found to be extremely small, 3.2 × 10 ⁸ Ω, and it was found to have excellent antistatic properties.

Next, after leaving the obtained foam laminate in an atmosphere of 40 ° C. and 80% RH (relative humidity) for 7 days, the surface of the resin layer of the foam laminate was observed, but stickiness due to bleeding out occurred. Moreover, printing was performed using a printing ink for polypropylene on the surface of the resin layer of the obtained foam laminate, but there was no printing failure due to bleed-out.

Next, one surface of the obtained foam laminate was subjected to corona discharge treatment to have a surface wetting tension of 45 dyne / cm or more, and the adhesiveness with various coating agents could be improved.

In addition, after providing a coating agent layer and laminating various skin materials, films, sheets, other foams, metal foils, papers, non-woven fabrics or synthetic leathers made of natural fibers or synthetic fibers into a composite, various methods are used. Then, it could be molded into a desired shape.

(Surface specific resistance) A foam laminate is cut into a size of 10 cm x 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 the aging, the surface resistivity is measured in the atmosphere.

Measuring instrument: Super Insulator (VE-40 manufactured by Kawaguchi Electric Co., Ltd.)
Type) with a room temperature measurement box (type RC-02) connected Measurement conditions: Applied voltage 100V The value measured with this unit is used.

The surface resistivity of 1 × 10 ¹³ Ω or less and the half-life of the charge of 3 minutes or less are considered to have antistatic properties.

Example 2 As a foamable resin composition, low-density polyethylene (density:
0.923g / cm ³ , melt index: 1.2g / 10min, particle size: 3
(2 mesh pass) 10 parts of azodicarbonamide was added as a foaming agent to 100 parts of the mixture and mixed.

Further, as the resin for the resin layer, an ethylene structural unit represented by the formula: CH ₂ —CH ₂ 85%, the formula: An acrylate structural unit represented by 5 mol% and a formula: A polyolefin resin having a weight average molecular weight of 30,000, which was linearly and irregularly arranged and was composed of 10 mol% of the acrylamide structural unit represented by

Next, using the foamable resin composition and the resin for resin layer, a foam laminate was obtained in the same manner as in Example 1. This foam laminate had an overall thickness of 1.9 mm, an overall width of 1170 mm, an apparent expansion ratio of 15 times, and a resin layer thickness of 50 μm.

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

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

(Bleed out) An additive-free biaxially oriented polypropylene film was laid on the surface of the foam laminate and placed in an atmosphere of 40 ° C, 80% RH for 7 days, then taken out and the film was peeled from the foam to remove the film surface. Check for any deposits.

(Blocking shearing force) Two foam laminates were stacked over a width of 3 cm and a length of 4 cm, and a weight of 550 g was placed on the foam laminate, which was placed in an atmosphere of 40 ° C. and 80% RH for 7 days, and then two sheets. The shear peeling force of the foam is measured by a Shopper type tensile tester.

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

Example 3 Low density polyethylene (density: 0.9
21 g / cm ³ , melt index: 3.2 g / 10 min) 100 parts of the mixture to which 13 parts of azodicarbonamide and 1 part of dicumyl peroxide were added as a foaming agent were used.

Further, as the resin for the resin layer, an ethylene structural unit represented by the formula: CH ₂ —CH ₂ of 80 mol% and the formula: A linearly irregularly arranged polyolefin resin having a weight average molecular weight of 31,000 consisting of 20 mol% of acrylamide structural units represented by is crushed into 32 mesh pass 80 parts and low density polyethylene (density: 0.921 g / cm ³ , melt index: 3.2 g / 10 minutes, particle size: 32 mesh pass) 20 parts were mixed and used.

Example 1 was repeated except that dicumyl peroxide was decomposed and crosslinked by using the foamable resin composition and the resin for resin layer thus obtained, that is, no electron beam was irradiated.
A foam laminate was obtained in the same manner as in. This foam laminate had an overall thickness of 3.03 mm, an overall width of 1170 mm, an apparent expansion ratio of 25 times, and a resin layer thickness of 30 μm.

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

Example 4 Linear low-density polyethylene (density: 0.925 g / cm ³ , melt index: 2 g / 10 minutes) and low-density polyethylene (density: 0.923 g / cm ³ , melt index: 1.5 g) as a foamable resin composition / 10 minutes) was mixed at a weight ratio of 30/70 to 100 parts and 10 parts of azodicarbonamide was added as a foaming agent.

Further, as the resin for the resin layer, the ethylene structural unit represented by the formula: CH ₂ —CH ₂ is 80 mol%, and the formula: An acrylate structural unit represented by 1 mol% and a formula: Was used. 80 parts of a polyolefin resin having a weight average molecular weight of 27,000 and having a linearly irregular arrangement of 19 mol% of an acrylamide structural unit represented by the following formula and 20 parts of the same linear low-density polyethylene as used in Example 3 were used. .

A foam laminate was obtained in the same manner as in Example 1 using the foamable resin composition and the resin for the resin layer. This foam-to-laminate had an overall thickness of 4.35 mm, a total width of 1170 mm, an apparent expansion ratio of 20 and a resin layer thickness of 50 μm.

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

Example 5 As an expandable resin composition, an ethylene-propylene copolymer (ethylene content: 8% by weight, melt index: 2.3 g / 10
Min) 100 parts of which 4 parts of azodicarbonamide was added as a foaming agent was used.

Further, as the resin for resin layer, the ethylene structural unit represented by the formula: CH ₂ —CH ₂ is 88 mol%, and the formula: An acrylate structural unit represented by 3 mol% and a formula: The linearly irregularly arranged polyolefin resin having a weight average molecular weight of 33000 and consisting of 9 mol% of the acrylamide structural unit represented by is crushed to have a 32 mesh path. 10 parts of polypropylene (melt index: 2.5 g /
10 minutes, particle size: 32 mesh pass) 90 parts added were used.

Next, using the obtained foamable composition and resin for resin layer, a foam laminate was obtained in the same manner as in Example 1. The resulting foam laminate has a total thickness of 4.2 mm and a total width of 1170 m.
m, the apparent expansion ratio was 9, and the thickness of the resin layer was 150 μm.

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

Comparative Example 1 A resin for resin layer was obtained by mixing 99 parts of polypropylene (melt index: 2.5 g / 10 minutes, particle size: 32 mesh pass) and 1 part of stearic acid monoglyceride as an antistatic agent.

A foamable composition was prepared by mixing 100 parts of an ethylene-propylene copolymer (ethylene content: 5% by weight, melt index: 1.2 g / 10 minutes) with 3.5 parts of azodicarbonamide as a foaming agent and 1 part of dicumyl peroxide. I got it.

Next, using the obtained foamable composition and resin for resin layer, a foam laminate was obtained in the same manner as in Example 3.

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

Comparative Example 2 99.2 parts of polypropylene (melt index: 2.5 g / 10 minutes, particles: 32 mesh pass) and the formula as an antistatic agent: A betaine-type amphoteric surfactant represented by the following formula (0.8 parts) was mixed to obtain a resin for resin layer.

100 parts of the same ethylene-propylene copolymer as used in Comparative Example 1 and azodicarbonamide 2 as a blowing agent
Parts and 2 parts of divinylbenzene were mixed to obtain a foamable composition.

Next, using the obtained foamable composition and resin for resin layer, a foam laminate was obtained in the same manner as in Example 1.

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

Comparative Example 3 Linear low-density polyethylene (density: 0.921 g / cm ³ , melt index: 3.2 g / 10 minutes, particle size: 32 mesh pass) 98.
Formula with 5 parts and stearic acid monoglyceride as antistatic agent: The 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 resin for resin layer.
A foamable composition was obtained by mixing 100 parts of the same low-density polyethylene used in Example 4 and 15 parts of azodicarbonamide as a foaming agent.

A foam was obtained in the same manner as in Example 1 using the foamable composition and the resin for resin layer thus obtained.

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

Comparative Example 4 95 parts of an ethylene-propylene copolymer having an ethylene content of 5% by weight (melt index: 1.2 g / 10 minutes, particle size: 32 mesh pass) and sodium dodecylbenzene sulfonate as a antistatic agent and polyethylene glycol 1: The resin for resin layer was obtained by mixing 5 parts of the mixture in a weight ratio of 1.

A foamable composition was obtained by mixing 100 parts of the same polypropylene as used in Example 5, 12 parts of azodicarbonamide as a foaming agent, 1 part of dicumyl peroxide and 2 parts of divinylbenzene.

The resulting foamable composition and resin for resin layer were treated in the same manner as in Example 1 to obtain a foam laminate.

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

Comparative Example 5 A resin for resin layer was obtained by mixing 99.2 parts of polypropylene (melt index: 2.5 g / 10 minutes, particle diameter: 32 mesh pass) and 0.8 part of stearyldiethanolamine as an antistatic agent.

Further, 100 parts of the polypropylene and 2 parts of azodicarbonamide and 2 parts of divinylbenzene as a foaming agent were mixed to obtain a foamable composition.

Next, using the obtained foamable composition and resin for resin layer, a foam laminate was obtained in the same manner as in Example 1.

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

From the results shown in Table 1, the polyolefin resin foam laminate of the present invention is excellent in that the surface resistivity, which is an index of antistatic property, is 1 × 10 ¹³ Ω or less and the charge half-life is 180 seconds or less. In addition, the foam laminate of the antistatic component does not bleed out from the resin layer of the foam laminate, and therefore it is a foam laminate excellent in antistatic property without blocking.

On the other hand, the foam laminates obtained in Comparative Examples 1 to 5 were those in which the conventional comparatively low molecular weight surfactant type antistatic agent was used, and from the results shown in Table 2, the antistatic It is understood that if the properties are to be satisfied, the antistatic agent bleeds out from the foam, which causes blocking.

Example 6 The same polyolefin-based resin as used in Example 1 was prepared, and the polyolefin-based resin was poured into ion-exchanged pure water heated to 60 ° C., and the mixture was stirred and dispersed at high temperature with a homolyzer,
The emulsion was cooled to room temperature to obtain an emulsion containing 24% by weight of the resin.

Next, using low-density polyethylene (density: 0.923 g / cm ³ , melt index: 3.2 g / 10 minutes), a foam obtained by the atmospheric cross-linking foaming method (foaming ratio: 20 times, thickness: 3 mm) The emulsion was applied onto the surface of the above by a roll coating method so that the resin layer had a thickness of 5 μm, and then supplied to a hot air drying oven at 120 ° C., dried and wound. The resin layer after drying had a thickness of 2 μm.

When the surface resistivity of the obtained foam laminate was examined in the same manner as in Example 1, it was found to be extremely small at 3.2 × 10 ⁸ Ω and excellent in antistatic property.

Next, prepare two pieces of the obtained foam laminate, overlap the coated surface and the uncoated surface, and
After being placed in an atmosphere of 80 ° C. and 80% RH for 24 hours, the surface was peeled off and the surface of the foam laminate was observed, but no stickiness due to bleeding out occurred, and no blocking occurred. Printing was performed on the resin layer surface of the obtained foam laminate using a printing ink for polypropylene and a printing ink for cellophane, but there was no printing failure due to bleed-out.

Next, the resin layer surface of the obtained foam laminate has a thickness of 20 ~
Aluminum was vapor-deposited so as to have a thickness of about 50 μm, but the adhesiveness of the vapor-deposited film was extremely good, and whitening phenomenon of the vapor-deposited film due to bleed-out, peeling, and falling off were not observed.

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

In addition, a coating layer can be provided on the resin layer and laminated with other films or sheets, or a heat sealant layer can be provided to be used as various packaging materials and packaging materials.

Example 7 Polypropylene (melt index: 2.3 g / 10 minutes) 100
Parts and 5 parts of azodicarbonamide as a foaming agent and 2 parts of divinylbenzene were mixed to obtain a foamable resin composition.

Using the obtained foamable resin composition, introduced into an extruder heated to 170 to 180 ° C., and melted so that the foaming agent does not decompose,
The mixture was kneaded to obtain a foaming sheet having a thickness of 2.0 mm. further,
This product was irradiated with an electron beam of 2.8 Mrad to be crosslinked, then introduced into a silicone bath heated to 230 ° C., and foamed to obtain a foam having a thickness of 2.5 mm and a foaming ratio of 10 times.

The same polyolefin resin as used in Example 2 and an ethylene-vinyl acetate copolymer (vinyl acetate content: 45% by weight) emulsion (resin solid content: 20% by weight) were mixed at 10:90.
The mixture mixed in the weight ratio of 1 was coated with a roll coater type coating device to obtain a foam laminate.

The thickness of the resin layer of the obtained foam laminate was 0.5 mm.

The surface resistivity of the resulting foam laminate was set to be the same as in Example 1, and the charge half-life, bleed-out and blocking shearing force were set to be the same as in Example 2 to further improve printability and vapor deposition property. It measured according to the following method.
The results are shown in Table 3.

(Printability) Printing ink for polypropylene (PPST), cellophane (CC
ST: Toyo Ink Mfg. Co., Ltd. was applied using a # 50 bar coater, dried with a hot air dryer at 80 ° C, and then printed with cellophane adhesive tape (Nichiban Co., Ltd .: width) 24mm) is cut out to a length of 20cm, of which 15
cm was pasted and rubbed several times to firmly attach the cellophane adhesive tape. The remaining tape portion was held by the hand and the tape was rapidly peeled off, and the printability was examined by observing the state of the peeled ink portion remaining on the foam.

The printability was judged according to the following five-step evaluation standard by obtaining the remaining amount of the foam ink on the peeled surface of the tape.

 (Evaluation Criteria) Less than 50% Index 1 50% or more-less than 75% Index 2 75% or more-less than 90% Index 3 90% or more-less than 100% Index 4 100% Index 5 In addition, pass is index 4 or more.

(Vapor deposition property) Cellophane adhesive tape (Nichiban Co., Ltd., width
24 mm) was adhered, and then peeled at 180 ° C. at a speed of 50 mm / min.

 (Evaluation criteria) Deposition area after peeling Index 100% Index 5 90% or more and less than 100% Index 4 70% or more and less than 90% Index 3 50% or more and less than 70% Index 2 less than 50% Index 1 In addition, pass The index is 4 or more.

Example 8 13 parts of azodicarbamide as a foaming agent was added to 100 parts of low-density polyethylene (density: 0.921 g / cm ³ , melt index: 3.2 g / 10 minutes) and mixed to obtain a foamable resin composition. I got a thing.

The resulting foamable resin composition was introduced into an extruder heated to 120 to 130 ° C. and melted so that the foaming agent would not decompose,
After kneading, a foaming sheet having a thickness of 1.5 mm was obtained. Furthermore, this product was irradiated with an electron beam of 3.2 Mrad to crosslink it, and then foamed with a vertical hot air foaming device heated to 250 ° C to a thickness of 3
A foam having an expansion ratio of 25 mm and an expansion ratio of 25 was obtained.

Next, the same polyolefin resin as used in Example 3 and the same ethylene-vinyl acetate copolymer emulsion as used in Example 7 were mixed in a weight ratio of 30:70. A foam laminate was obtained in the same manner as in 7.

The thickness of the resin layer of the obtained foam laminate was 0.02 mm.

The physical properties of the resulting foam laminate were examined in the same manner as in Example 7. The results are shown in Table 3.

Example 9 Linear low-density polyethylene (density: 0.925 g / cm ³ , melt index: 5 g / 10 minutes) and low-density polyethylene (density:
0.923 g / cm ³ , melt index: 3 g / 10 min) was mixed at a weight ratio of 30/70 to 100 parts, and 15 parts of azodicarbonamide and dicumyl peroxide as a foaming agent 1.
5 parts were added and mixed to obtain a foamable resin composition.

The foamable resin composition obtained below is introduced into an extruder heated to 120 to 130 ° C., so that the foaming agent is not decomposed, and dicumyl peroxide is decomposed so that crosslinking does not proceed significantly during kneading. After being melted and kneaded as described above, a cross-linking degree suitable for foaming was prepared, and then a foaming sheet was formed. This was equipped with a floating device and foamed with a horizontal hot air foaming device heated to 250 ° C. to obtain a foam having a thickness of 4 mm and a foaming ratio of 35 times.

The same polyleophine resin as used in Example 4 and an ethylene-acrylic acid copolymer (acrylic acid content: 25% by weight) emulsion (resin solid content: 30% by weight) were mixed at 20:80.
The mixture mixed in the weight ratio of was coated in the same manner as in Example 8 to obtain a foam laminate.

The thickness of the resin layer of the obtained foam laminate was 0.02 mm.

The physical properties of the resulting foam laminate were examined in the same manner as in Example 7. The results are shown in Table 3.

Example 10 To 100 parts of an ethylene-propylene copolymer (ethylene content: 8% by weight, melt index: 2.3 g / 10 minutes), 15 parts of azodicarbonamide as a foaming agent and 2 parts of divinylbenze were added and mixed, A foamable resin composition was obtained.

The resulting expandable resin composition was introduced into an extruder heated to 170 to 180 ° C. and melted so that the foaming agent would not decompose,
The mixture was kneaded to obtain a foaming sheet having a thickness of 2.6 mm. Further, this was irradiated with an electron beam of 2.8 Mrad to be crosslinked, then introduced into a silicone bath heated to 230 ° C., and foamed to obtain a foam having a thickness of 5 mm and a foaming ratio of 30 times.

Formula: ethylene structural unit represented by CH ₂ —CH ₂ 88 mol%, formula: An acrylate structural unit represented by 3 mol% and a formula: Of the polyolefin resin having a weight average molecular weight of 31300, which is linearly irregularly arranged and composed of 9 mol% of acrylamide structural units represented by A foam laminate was obtained by coating in the same manner as in Example 8 using a mixture of a 20% solution of an acrylic acid copolymer in toluene at a weight ratio of 50:50.

The thickness of the resin layer of the obtained foam laminate was 0.03 mm.

The physical properties of the resulting foam laminate were examined in the same manner as in Example 7. The results are shown in Table 3.

Example 11 100 parts of the same ethylene-propylene copolymer as used in Example 10 was used as a blowing agent for azodicarbonamide 4
And 2 parts of divinylbenzene were mixed to obtain a foamable resin composition.

Using the foamable resin composition thus obtained, a foam was obtained in the same manner as in Example 7. The obtained foam had an expansion ratio of 8 and a thickness of 3 mm.

The same polyolefin resin as that used in Example 5 and the same ethylene-acrylic acid copolymer emulsion as that used in Example 7 were mixed in a weight ratio of 30:70, and the same as in Example 8. To obtain a foam laminate.

The thickness of the resin layer of the obtained foam laminate was 0.08 mm.

The physical properties of the resulting foam laminate were examined in the same manner as in Example 7. The results are shown in Table 3.

Comparative Example 6 A polypropylene was used in the same manner as in Example 7 except that polypropylene having a melt index of 2.8 g / 10 minutes was used. The obtained foam had a foaming ratio of 6 and a thickness of 2.5 mm.

A mixture of ethylene-vinyl acetate copolymer (vinyl acetate content: 45% by weight) and chlorinated polyethylene (chlorination degree: 34% by weight) at a ratio of 70/30 was used, and a 15% toluene solution was used. A coating was obtained in the same manner as above to obtain a foam laminate.

The thickness of the resin layer of the obtained foam laminate was 0.02 mm.

The physical properties of the resulting foam laminate were examined in the same manner as in Example 7. The results are shown in Table 4.

Comparative Example 7 Using the same low density polyethylene as used in Example 8, the expansion ratio was 20 times and the thickness was 4 mm in the same manner as in Example 8.
I got a foam.

Next, a foam laminate was obtained in the same manner as in Example 8 using the same ethylene-vinyl acetate emulsion as used in Example 8.

The thickness of the resin layer of the obtained foam laminate was 0.05 mm.

The physical properties of the resulting foam laminate were examined in the same manner as in Example 7. The results are shown in Table 4.

Comparative Example 8 Using the same mixture of linear low-density polyethylene and low-density polyethylene as used in Example 9, a foam having an expansion ratio of 30 times and a thickness of 5 mm was obtained in the same manner as in Example 9.

Next, an ethylene-acrylic acid copolymer (acrylic acid content: 25% by weight) neutralized with caustic soda emulsion (resin solid content: 30% by weight) was used, and the foam obtained above was treated as in Example 9. A similar coating was applied to obtain a foam laminate.

The thickness of the resin layer of the obtained foam laminate was 0.01 mm.

The physical properties of the resulting foam laminate were examined in the same manner as in Example 7. The results are shown in Table 4.

Comparative Example 9 Using the same ethylene-propylene copolymer as that used in Example 9, a foam having a foaming ratio of 35 times and a thickness of 3 mm was obtained in the same manner as in Example 9.

Next, using the 18% toluene solution of ethylene-acrylic acid copolymer (acrylic acid content: 25% by weight), the foam obtained above was coated in the same manner as in Example 9 to form a foam laminate. I got it.

The thickness of the resin layer of the obtained foam laminate was 0.009 mm.

The physical properties of the resulting foam laminate were examined in the same manner as in Example 7. The results are shown in Table 4.

Comparative Example 10 The same ethylene-propylene copolymer as used in Example 11 was used to obtain a foam having a foaming ratio of 10 times and a thickness of 3 mm.

Ethylene-acrylic acid copolymer (acrylic acid content: 25% by weight) and sodium dodecylbenzene sulfonate 90:10
Using the emulsion (resin solid content: 20% by weight) mixed in a weight ratio of 1, the foam obtained above was coated in the same manner as in Example 11 to obtain a foam laminate.

The thickness of the resin layer of the obtained foam laminate was 0.03 mm.

The physical properties of the resulting foam laminate were examined in the same manner as in Example 7. The results are shown in Table 4.

As is clear from the results shown in Table 3, the foam laminate of the present invention has a surface specific resistance of 1 × 10 ¹³ Ω or less and a charge half-life of 180 seconds or less, and at the same time, it has an antistatic component. It can be seen that there is no bleed-out, no blocking occurs, and the printability and vapor deposition are excellent.

On the other hand, as is clear from the results shown in Table 4, the conventional foam laminate is inferior in adhesiveness and vapor deposition even though the antistatic property is satisfied by the surfactant added as the antistatic agent. I know there is.

From the above, the polyolefin-based resin foam laminate of the present invention has excellent antistatic properties, and further there is no bleed-out of the antistatic agent and no blocking occurs,
For example, it can be seen that it can be suitably used in the fields where it is necessary to prevent the occurrence of troubles due to static electricity, in the fields of packaging and packaging that require printing and vapor deposition, and the like.

[Advantages of the Invention] The polyolefin resin foam laminate of the present invention has an excellent antistatic property without bleed-out, and therefore does not have dust adhesion and does not give a shock to a human body due to electrostatic discharge. Therefore, the foam laminate has excellent adhesiveness, printability, vapor deposition property, and handling property.

Claims (1)

[Claims] 1. An ethylene structural unit represented by the formula: CH ₂ —CH ₂ 65 to 99 mol%, a general formula: (In the formula, R ¹ represents an alkyl group having 1 to 4 carbon atoms), an acrylate structural unit of 0 to 15 mol% and a general formula: (In the formula, R ² is an alkylene group having 2 to 8 carbon atoms, R ³ and R ⁴
Are each an alkyl group having 1 to 4 carbon atoms, R ⁵ is 1 to 4 carbon atoms
An acrylamide structure represented by a 12 alkyl group, an arylalkyl group having 1 to 12 carbon atoms or an alicyclic alkyl group having 1 to 12 carbon atoms, X is a halogen atom, CH ₃ OSO ₃ or C ₂ H ₅ OSO ₃ ) A polyolefin-based resin foam laminate, comprising a polyolefin-based resin layer containing a polyolefin-based resin having a weight-average molecular weight of 1000 to 50,000 arranged linearly and irregularly and having a unit of 1 to 35 mol%.