JP2000143909A - Ionomer composition and use thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an ionomer composition capable of reducing the electricity storability possessed by an ionomer resin and attenuating electrostatic charges in a short time without causing a spark phenomenon, sticking, etc., of mutual films and suitable for the films or laminating materials. SOLUTION: This ionomer composition is obtained by compounding 100 pts.wt. of an ionomer containing two groups of metal ion species of (A) Li, Na or a polyvalent metal ion and (B) K, Rb or Cs ion in 0.05-1.0 gram equivalent ratio (A)/(B) and having 10-90% average degree of neutralization with 0.1-10 pts.wt. of a polyhydric alcoholic hydroxy group-containing compound. A film comprises the ionomer composition and a laminated film is prepared by laminating the above ionomer composition onto a substrate film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a general-purpose ethylene copolymer ionomer having an antistatic property.

[0002]

2. Description of the Related Art Ionomers of ethylene / unsaturated carboxylic acid copolymers have been known for a long time, and among them, ionomers using sodium or zinc as ionic species have been widely used. Such ionomers have been widely used as packaging materials because of their excellent transparency, oil resistance, chemical resistance, cold resistance, pinhole resistance, adhesion to metals, heat sealability, and the like. On the other hand, the above-mentioned ionomer is known to be a polymer electret material having a small surface charge decay as proposed in Japanese Patent Publication No. 51-48278. Further, when the ionomer is an alkaline earth metal ion species, the present inventors have found that this tendency is even stronger than those using sodium or zinc as the ion species, and that the resulting polymer electrets are more excellent. Japanese Patent Application No. 9-129
No. 172.

[0003] As described above, ionomer resins have strong electric storage properties that can be used also as polymer electrets. On the other hand, when ionomers are formed into a film or laminated on a base film, they are easily charged. This indicates that the film is hardly attenuated when charged, and in an extreme case, a problem such as sparking of the wound film or adhesion of the film molded products may be caused.

Although there is a method of blending a general-purpose antistatic agent to improve such a defect, it is necessary to blend a large amount of the antistatic agent in order to obtain a sufficient effect. In some cases, excellent characteristics were sacrificed. In addition, it was difficult to suppress the tendency to store electricity by adding a small amount of an antistatic agent.

On the other hand, among ionomers, potassium,
Those containing a large amount of rubidium, cesium, etc. as ionic species are excellent as resins having an excellent antistatic effect, but these are not always easy to produce and process,
Also, because of high water absorption, there are problems such as foaming and delamination during processing, so there is a restriction on use as a packaging material, and it can not be used as it is as a substitute for sodium ionomer or zinc ionomer There were many.

[0006]

In view of such circumstances, the present inventors have developed an ionomer which is easily charged and which does not attenuate once charged, without substantially impairing its excellent characteristics. A method to reduce the tendency was examined. As a result, it has been found that the purpose can be achieved by mixing a small amount of another group of ion species such as potassium as the ion species of such an ionomer and blending a specific additive. Accordingly, an object of the present invention is to provide an ionomer composition which is suitable as a film or a laminate material, and has improved spark phenomena due to storage of electricity and adhesion tendency between films.

[0007]

The present invention provides an ionomer obtained by neutralizing at least a part of the carboxyl group of an ethylene / unsaturated carboxylic acid copolymer with a metal ion, wherein the metal ion is lithium, It consists of a metal ion (A) selected from sodium and polyvalent metals and a metal ion (B) selected from potassium, rubidium and cesium, and (B) / (A) (gram equivalent ratio) is 0.05 to 1.
The present invention relates to an ionomer composition comprising 0.1 to 10 parts by weight of a polyhydric alcoholic hydroxyl group-containing compound per 100 parts by weight of the ionomer having a range of 0 and an average degree of neutralization of 10 to 90%.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION As the ionomer in the present invention, one containing a metal ion species selected from at least two groups at a specific ratio is used.

The ethylene / unsaturated carboxylic acid copolymer serving as the base polymer of the ionomer is not only a binary copolymer of ethylene and unsaturated carboxylic acid, but also a multi-component copolymer obtained by optionally copolymerizing other monomers. It may be united.

The unsaturated carboxylic acids include acrylic acid, methacrylic acid, ethacrylic acid, maleic acid, fumaric acid, itaconic acid, maleic anhydride, itaconic anhydride,
Examples thereof include monomethyl maleate and monoethyl maleate. Particularly preferred is acrylic acid or methacrylic acid.

Other monomers which may optionally be copolymerized include vinyl esters such as vinyl acetate and vinyl propionate, methyl acrylate, ethyl acrylate, isopropyl acrylate, isobutyl acrylate, and the like.
Unsaturated carboxylic esters such as n-butyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, isobutyl methacrylate, dimethyl maleate, diethyl maleate, carbon monoxide, sulfur dioxide, etc. Can be exemplified.

The ethylene / unsaturated carboxylic acid copolymer also has a melt flow rate at 190 ° C. and a load of 2160 g of 1 to 2000 g / 10 min, preferably 2 to 2000 g / 10 min.
It is desirable to use a material of about 1000 g / 10 minutes. These ethylene copolymers can be obtained by copolymerizing the constituting monomers by a high-pressure radical polymerization method.

According to the present invention, there is provided an ionomer in which the above-mentioned ethylene / unsaturated carboxylic acid copolymer is used as a base polymer, and at least a part of the carboxyl group is neutralized with a metal ion. , A metal ion (A) selected from sodium and polyvalent metals and a metal ion (B) selected from potassium, rubidium and cesium as essential components, and those containing both at a specific ratio are used. You. Such an ionomer can be obtained by co-ionizing an ethylene / unsaturated carboxylic acid copolymer as a raw material using a metal compound as a supply source of a metal ion species selected from the above two groups. Can be. Alternatively, it can also be obtained by separately preparing ionomers of the metal ion species of each group and mixing and using them. Generally, the latter method is preferred because quality design is easier.

Among the metal ions (A), ionomers having lithium, sodium or the like as an ion species are obtained by reacting the above copolymer with hydroxides, carbonates, bicarbonates, fatty acids or the like of these metals. Obtainable.
Examples of the polyvalent metal include zinc, magnesium, calcium, barium, and the like, and ionomers containing these as ionic species include oxides, hydroxides, and carbonates of the above-described copolymer and polyvalent metal. And can be obtained by reacting An ionomer having metal ions (B), such as potassium, rubidium, and cesium, as the ion species can be produced in the same manner as an ionomer having lithium, sodium, or the like as the ion species.

When the ionomer of the present invention is produced by blending the ionomer containing the metal ion (A) with the ionomer containing the metal ion (B), the ionomer containing the metal ion (A) may be an unsaturated carboxylic acid. The content is 1 to 30% by weight, preferably 2 to 30% by weight, and the other monomer is 0 to 30% by weight, preferably 0 to 30% by weight.
It is preferable to use an ionomer having a degree of neutralization of 5 to 90%, particularly about 10 to 80%, using a base polymer containing 20% by weight. In other words, when a substance having a very low unsaturated carboxylic acid content or a substance having a very low degree of neutralization is used, it is not possible to exhibit excellent characteristics unique to ionomers, while a substance having a very high unsaturated carboxylic acid content is used. Then, it is not suitable as a film material or a laminate material.

The ionomer containing the metal ion (B) has an unsaturated carboxylic acid content of 8 to 30% by weight, preferably 10 to 20% by weight, and another monomer of 0 to 30% by weight.
%, Preferably from 0 to 20% by weight, having a degree of neutralization of from 10 to 100%, in particular from 60 to
It is preferable to use one having about 95%. That is, if an unsaturated carboxylic acid content is low or an ionomer having a low neutralization degree is used, it is not efficient because a large amount needs to be blended.

Of course, the base polymer in both ionomers may be the same or different. For each ionomer, 190 ° C,
The melt flow rate at a 2160 g load is 0.0
It is preferable to use one having a viscosity of 1 to 100 g / 10 min, particularly about 0.1 to 50 g / 10 min.

The blend ratio of the two is as follows: metal ion (B) /
Metal ion (A) (gram equivalent ratio) is 0.05-1.
0, preferably 0.1 to 0.6, and an average degree of neutralization of 10
To 90%, preferably 15 to 80%. If the proportion of the metal ion (B) is higher than the above range, problems such as water absorption and foaming in the ionomer of the metal ion (B) become more unfavorable than the characteristics of the ionomer due to the metal ion (A). In order to improve the problem of electric storage without losing the characteristics of the ionomer having the metal ion (A), it is preferable to adjust the ratio of the metal ion as described above. The required amount of the metal ion (B) varies depending on the type of the metal ion (A). For example, when (A) is sodium, lithium, or the like, (B) is effective in a relatively small amount, while zinc or magnesium is effective. In the case of the polyvalent metal, it is necessary to mix (B) in a slightly large amount.

When the ionomer of the present invention is produced by co-ionization, the content of unsaturated carboxylic acid as a base polymer is 1 to 30% by weight, preferably 5 to 20% by weight, and the content of other monomers is 0 to 30%. % By weight, preferably 0 to
It can be produced by the same method as described above, using 20% by weight and using a metal compound in a predetermined ratio.
In this case, the ionomer has a degree of neutralization of 10
It is preferably set to about 90%, especially about 15 to 80%.

In the present invention, a polyhydric alcoholic hydroxyl group-containing compound is used together with the ionomer containing the two kinds of metal ions. Here, the polyhydric alcoholic hydroxyl group-containing compound means polyhydric alcohol, partial ester of polyhydric alcohol, partial ether of polyhydric alcohol, alkylene oxide adduct thereof, alkylamine alkylene oxide adduct, alkylamide alkylene oxide And additional materials.

Preferred polyhydric alcohols have a molecular weight of about 60 to 2,000, and specific examples include glycerin, propanetriol, hexanetriol, pentaerythritol, sorbitol, diglycerin, triglycerin and the like. However, it is particularly preferable to use one having 3 or more hydroxyl groups and having about 3 to 6 carbon atoms.

As the partial ester of the polyhydric alcohol,
Examples thereof include glycerin monofatty acid ester, sorbitan mono- or difatty acid ester, glycerin monofatty acid ester monoborate, and diglycerin monofatty acid ester monoborate. The fatty acid component constituting such a partial ester includes one having 1 carbon atom.
About 2 to 22, especially about 14 to 20 are preferable. Specific examples include lauric acid, myristic acid, palmitic acid, stearic acid, arachiic acid, behenic acid, oleic acid, and hydroxystearic acid.

Examples of the alkylene oxide adduct of the polyhydric alcohol include polyethylene glycol, polypropylene glycol, polyoxyethylene / polyoxypropylene glycol, and the like.

Examples of the alkylamine oxide adduct of an alkylamine include compounds represented by formula (1)

Embedded image (Wherein, R is a hydrocarbon group having about 1 to 22 carbon atoms, m, n
Is an arbitrary integer of 1 or more).

As the alkylene oxide adduct of alkylamide, for example, a compound represented by the formula (2)

Embedded image (Wherein R and m and n are the same as those in the formula (1)) can be mentioned as typical examples.

The compounding ratio of the polyhydric alcoholic hydroxyl group-containing compound is 0.1 to 1 per 100 parts by weight of the ionomer.
0 parts by weight, preferably 0.2 to 3 parts by weight. If the compounding ratio is too small, the effect of preventing electricity storage is not sufficient, and if the compounding ratio is excessive, the excellent properties of the ionomer may be impaired.

[0027] The ionomer composition of the present invention may contain other polymers and additives as long as the object is not impaired. Examples of such additives include, for example, antioxidants, weathering stabilizers, light stabilizers, ultraviolet absorbers, lubricants, antiblocking agents, pigments, dyes, inorganic fillers, foaming agents, foaming aids, crosslinking agents. And flame retardants.

Thus, the ionomer composition of the present invention comprises
As shown in Examples below, the time required for the initial maximum charged voltage to be attenuated by 10% when charged at 5 kV is such that there is no ion in Group (B) and no polyhydric alcoholic hydroxyl group-containing compound is used. Can be at least １ ／ or less, and can be 15 minutes or less, preferably 10 minutes or less. In particular, when the above-described formulation is applied to a polyvalent metal ionomer having a large tendency to store electricity, such an effect is more remarkably exhibited.

Since the ionomer composition of the present invention has a reduced tendency to charge electricity, there are few troubles during molding, and it is possible to use extrusion molding, injection molding, blow molding, compression molding, vacuum molding, or the like.
It can be formed into films, sheets, hollow containers, trays, tubes, tubes, and molded articles of various shapes by molding such as air pressure molding. In particular, it is a material suitable for single-layer or multi-layer film molding or laminate molding, and can be suitably used for packaging materials, lid materials, and the like.

As the substrate to be laminated in the above-mentioned multilayer film or laminate molding, various types of polyethylene, polypropylene, poly-4-methyl-1-pentene, ethylene
Olefin polymers such as vinyl acetate copolymers, ethylene / unsaturated carboxylic acid copolymers, ethylene / unsaturated carboxylic acid ester copolymers, polystyrene, high impact polystyrene, styrene polymers such as ABS type resins, Polyester such as polyethylene terephthalate and polyethylene naphthalate, nylon 6, nylon 6
6, single-layer or multi-layer base materials such as polyamide, such as nylon 12, nylon 612, polycarbonate, polyvinyl chloride, aluminum foil, metal or silica, vapor-deposited films on which oxides such as alumina are vapor-deposited, and paper. be able to.

[0031]

The ionomer composition of the present invention is less likely to be charged than conventional general-purpose ionomers and attenuates in a short time even if charged, so that the film wound up in film molding, lamination molding, etc. There is no problem such as sparking. Also, in various molded products such as a single-layer or multilayer film, the tendency of adhesion between the molded products and adhesion of dust is reduced.

[0032]

Next, the present invention will be described with reference to examples and comparative examples. The types of raw material components used in the following Examples and Comparative Examples and methods for measuring physical properties of the obtained compositions are as follows.

1. Raw materials (1) Ionomer resin Ionomer of ethylene-methacrylic acid copolymer, different in base polymer composition, ionic species and degree of neutralization Table 1
The various ionomers described were used.

[0034]

[Table 1]

(2) Polyhydric alcoholic hydroxyl group-containing compound (1) Glycerin (2) PEG: polyethylene glycol (molecular weight: 60)
0)

2. Physical property measurement method (1) MFR JIS K6760 compliant 190 ° C, 2160g load

(2) Initial maximum charged voltage and charged voltage decay time JIS L1094 compliant Equipment used: Static Honest Meter (Shishido Electrostatic Co., Ltd.) Measurement sample: An ionomer composition sample was pressed into a 1 mm thick sheet and heated at 23 ° C. / Aged for 24 hours under 50% RH was used. Measurement method: A measurement sample was set on a static honest meter, charged at a voltage of 5 kV, and the initial maximum charged voltage was read. After that, the charge switch is turned off and the charge voltage becomes 10
The time required for the% to decay was measured.

[Examples 1 to 5] Ionomer resin having a metal ion belonging to group (A), ionomer resin having a metal ion belonging to group (B), and glycerin or polyethylene glycol which is a compound containing a polyhydric alcoholic hydroxyl group ( The three components having a molecular weight of 600) were blended at the compounding ratio shown in Table 2, and the charge decay time was measured. Table 2 shows the results.

[Comparative Examples 1 to 4] The decay time of the ionomer resin having the metal ion of the group (A) alone was measured. Table 3 shows the results.

Comparative Example 5 The decay time of an ionomer and a mixture of the ionomer alone was measured without adding glycerin or PEG. Table 3 shows the results.

[0041]

[Table 2]

[0042]

[Table 3]

As is evident from the results in Tables 2 and 3, the ionomer compositions of Examples in which the potassium ionomer and the polyhydric alcohol were blended were all lower in initial charging voltage than the ionomers in which these were not blended. Although there is almost no change, the decay time is significantly reduced. In contrast, ionomers-alone,
Alternatively, it can be seen that even if the composition is from an ionomer to a composition, the composition without polyhydric alcohol requires a long time for attenuation.

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (Reference) C09K 3/16 102 C09K 3/16 102E F term (Reference) 4F071 AA15X AA32X AA36X AA51 AA78 AC05 AC06 AC10 AE16 AF38 AH04 AH05 BC01 4F100 AH02A AK70A AL05A AT00B BA02 JG10 4J002 BB231 CH022 CH052 EC056 ED026 EH056 FD102 FD106 GF00 GG01 GG02

Claims (3)

[Claims] 1. An ionomer obtained by neutralizing at least a part of a carboxyl group of an ethylene / unsaturated carboxylic acid copolymer with a metal ion, wherein the metal ion is selected from lithium, sodium and polyvalent metals. A metal ion (A) and a metal ion (B) selected from potassium, rubidium and cesium, wherein (B) / (A) (gram equivalent ratio) is in the range of 0.05 to 1.0 and average The polyhydric alcoholic hydroxyl group-containing compound is used in an amount of 0.1 per 100 parts by weight of the ionomer having a degree of neutralization of 10 to 90%.
An ionomer composition comprising 10 to 10 parts by weight. 2. A film comprising the ionomer composition of claim 1. 3. A laminated film obtained by laminating the ionomer composition according to claim 1 on a base film.