JPS58199144A - Laminating method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses an improved ethylene copolymer composition as a laminate material to improve the spreadability when producing a laminate and the low temperature heat sealability of the resulting laminate. The present invention also relates to a method for laminating a laminate having good lamination adhesive strength.

A copolymer of ethylene and an organic acid such as acrylic acid or methacrylic acid (hereinafter referred to as a carboxylic acid group-containing ethylene copolymer) has a polar group in its molecular structure, so it cannot be used without an anchor coating agent. It shows relatively good forgeability with many materials, and has recently been used as a material for various laminations.

However, the current carboxylic acid group-containing ethylene copolymers cannot be said to have satisfactory processability and quality, especially when used as extrusion lamination materials.

In terms of workability, the aim of cutting costs was to
7. High-speed spreadability that can counter the thinning of layered materials is particularly required.9. Also, in terms of quality, good low-temperature heat-sealability that can support high-speed filling for the purpose of increasing productivity is required. is particularly sought after.

Up until now, in order to improve the spreadability during extrusion lamination, methods have been proposed to increase the fluidity of the paper itself when it is melted by adjusting it during polymerization, or methods to increase the processing temperature during extrusion lamination. is commonly attempted, but the former method is a simultaneous vc@
There is a disadvantage that the neck-in (ear loss) of m tends to increase, and as a result, the loss as a product increases. In the latter method, the upper limit temperature that can be laminated is determined by the thermal stability of the resin itself, and the temperature cannot be increased without limit.

In addition, as a method for improving the low-temperature heat sealability of the laminate, for example, increasing the comonomer content in the carboxylic acid group-containing ethylene copolymer to lower the melting point of the copolymer can be used to some extent. Copolymers with increased comonomer content have significantly lower thermal stability during extrusion lamination, and foaming occurs on the extruded film surface.

In addition, in order to avoid this phenomenon and obtain a good-quality laminate, it is necessary to process the laminate at a low temperature, which results in an increase in the melt viscosity of the copolymer and lacks sufficient fluidity. It is very difficult to obtain a thin laminate.

These drawbacks are particularly noticeable in copolymers of acrylic acid and/or methacrylic acid and ethylene.

On the other hand, although it is not a carboxylic acid group-containing ethylene copolymer,
Ionically crosslinked copolymers (hereinafter referred to as ionic copolymers) obtained by reacting the above carboxylic acid group-containing ethylene copolymers with ionic metal compounds are also used as various laminating materials. .

However, conventional ionic copolymers are hygroscopic due to the high degree of neutralization by ionic metal compounds, making storage difficult such as storing them in moisture-impermeable bags, and once they have absorbed moisture, they cannot be laminated. In addition to the disadvantage that it foams during molding and loses its commercial value, it also has the disadvantage that the strength of aluminum bonding is not as high as on the left.

Well, some ionic copolymers have a low degree of neutralization,
This has the disadvantage of not exhibiting good spreadability.

In particular, the present invention maintains the excellent physical properties of a copolymer of acrylic acid and/or methacrylic acid and ethylene, while
This material was completed as a result of intensive research aimed at creating a laminated material that does not have the above-mentioned drawbacks, that is, has excellent ductility and low-temperature heat resistance, and has good lamination adhesive strength.

By blending a small amount of a specific ionic copolymer with a specific copolymer of acrylic acid and/or methacrylic acid and ethylene, the spreadability during extrusion lamination is surprisingly improved, and the lamination and It was found that the low-temperature heat sealability of

That is, the present invention uses ethylene copolymer 14100 containing 5 to 10% by weight of acrylic acid and/or methacrylic acid.
1 to 5 parts by weight of an ethylene copolymer 0 containing 5 to 20 ji of unsaturated carboxylic acid and having at least one layer of the acid neutralized with an ionic metal compound. This is a lamination method characterized in that the composition is used in at least one layer of laminated materials.

The single layer lamination method of the present invention has the above-mentioned advantages and can be applied to various fields.

In the ethylene copolymer containing acrylic acid and/or methacrylic acid t-5 to 1O used in the present invention, if necessary, other monomers may be used as comonomers, preferably acrylic acid and/or methacrylic acid. It also includes those containing less than the specified amount. Other suitable monomers that may be used as co-imers include propylene and butene-1,4-methylpentene-
Examples include mono-olefins such as 1 and hexene-1; unsaturated carboxylic esters such as acrylic esters and methacrylic esters; vinyl esters such as vinyl acetate.

The bath melting index in this ethylene copolymer is 67 to JI8-
Melt flow rate at 60-1971 is 1 to 50C1
/1G worth is preferable.

Copolymers with an acrylic acid and/or methacrylic acid content of less than 5% by weight have very little effect on improving spreadability and low-temperature heat-sealing properties, while copolymers with a content exceeding 1011% have poor hygroscopicity and spreadability. Undesirable in terms of sex.

In such an ethylene copolymer, for example,
Child 3341. It is manufactured by the method described in Publication No. 38-23494.

Next, the ethylene copolymer ◎ containing 5 to 20 weight units of unsaturated carboxylic acid used in the present invention and in which one or more portions of the acid are neutralized with an ionic metal compound is an unsaturated A copolymer of carboxylic acid such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, maleic anhydride, etc., and ethylene, and optionally other monomers mentioned above, neutralized with an ionic metal compound. It is.

As a way to neutralize it, for example,
Examples include methods described in O1 Publications No. 42-15768 and No. 49-31556.

If the above-mentioned ethylene copolymer does not meet the criteria of 0, the effects of the present invention cannot be expected.

The carboxylic acid used in the production of Copolymer 0 is particularly preferably acrylic acid and/or methacrylic acid.

The degree of neutralization is expressed as the molar ratio of the carboxylic acid metal base to the sum of the carboxylic acid group and the carboxylic acid metal base in copolymer 0. This value can also be obtained by the commonly practiced neutralization titration method.

The above ethylene copolymer 0 is 10 in the ethylene copolymer.
A composition is prepared by adding 1 to 5 parts by weight to 0 parts by weight. As for this blending method, the components may be tri-blended and directly subjected to extrusion lamination, or may be melt-kneaded using a mixer such as an extruder.

If the amount of ethylene copolymer 0 is less than 1 part by weight, there will be no effect on extensibility during extrusion lamination, while if it exceeds 5 parts by weight, it is unfavorable in terms of adhesiveness. The preferred range is 2 to 4 parts by weight.

The base material constituting the composition and the laminate may be any material commonly used in extrusion lamination, such as paper, plastics such as polyethylene, polypropylene, and nylon, and metal layers such as aluminum foil.

These base materials and the composition of the present invention (represented by (A + B))
The following are examples of the structure of a laminate consisting of:

Nylon 7IA+B), polyethylene/(A+B), -
)-4a y / (A + B) / yt! I
J ethylene, ethylene-vinyl acetate copolymer/(λ0B
), nylon/(A+B)/polyester, vinylidene chloride/(A+B)/polyethylene, polypropylene/
(A+B), nylon/(A+B)/polypropylene, paper/(A+B), paper/(A+B)/polyethylene, (
A+B)/Aluminum foil, paper/(A+B)/Aluminum foil, nylon/(A+B)/Aluminum foil, paper/(A+B)/Aluminum foil/(A+B), polymethyl methacrylate/(A+B)
/ Aluminum foil, AB8 tree @ / (A + B) / Polypropylene, Polycarbonate) / (A + B) / Polyethylene, (A
+B)/Polyvinyl chloride/Polyvinylidene chloride, Polyethylene/Paper/Polyethylene/Aluminum i/(A+B),
Examples include laminates with a two-layer or multilayer structure such as cellophane/polyethylene/aluminum 4/(A+J nylon/(A+B)/polyester/(A+B)).

These laminates can be combined in various ways depending on the need.

As a lamination method for obtaining the laminate of the present invention, extrusion coating method, dry lamination method, coextrusion molding method, etc. can be applied.

In particular, the composition of the present invention exhibits excellent spreadability in extrusion coating methods.

The processing temperature in this case is generally JIc 200-350t:.

If necessary, stabilizers, plasticizers, lubricants, fillers, colorants such as pigments, and other additives may be mixed into the composition and base material used in the present invention.

Examples are shown below.

In addition, the spreadability during extrusion lamination of the cough composition and the base material, the low-temperature heat sealability of the laminate, and the adhesion between the composition and aluminum foil were evaluated by the following methods.

(1) Expandability evaluation conditions during extrusion lamination Molding machine: 40-
Diameter laminator (L/D=26) Die: Inner deck die Effective width: 38.0 layer m Die slip width = IM Air gap: 110ag Molding temperature: 2801 Screw speed: 20 rpm Base material: Polyester film (20μ ) on which low-density polyethylene (15 .mu.m) is laminated.The base material is sent out from one side under the above conditions, and the molten evaluation resin is extruded and laminated thereon in the form of a film to obtain a laminate.

The spreadability is determined by the take-up speed t- at which the evaluation resin does not break off when the base material is increased in speed.
S was determined.

Q) Evaluation conditions for low temperature heat keel property The heat seal strength at each temperature was measured for the laminate in which the base material was coated with me for evaluation to a thickness of 40p under the conditions α).

The heat sealing strength was determined by heat sealing using a Type 11 heat cooler at each temperature with a sealing width of 5 -, a sealing pressure of 2if/j, and a sealing time of ゛, and this specimen was adjusted to a Vt width of 20 m.

Heat seal strength of specimen with t23℃, tensile speed 500
Measured in M/min.

(3) Evaluation conditions for adhesion to aluminum foil (
Polyester film (20p) was used as the base material under the conditions of 1).
) was laminated with low-density polyethylene (15μ), and then aluminum foil (7μ) was laminated on top of that, and the evaluation resin was coated on the aluminum foil with a thickness of t-40μ. did.

This linear laminate with strong adhesion between the resin and aluminum foil of the laminate was adjusted to a specimen with a width of 205 g and a length of 100 as,
The maximum value when 180° beer was applied at room temperature and a tensile rate of 5θQs/min was measured.

Implementation 11i As an extrusion coating resin, a copolymer of ethylene and acrylic acid (ethylene 93'
! ! Ionic crosslinked copolymer of ethylene and methacrylic acid with a melting index of 5f/1G in 100 parts by weight (
Extrusion lamination using a tri-blend of 2 parts by weight of neutralized metal species (Zn) with a degree of ion neutralization of 10% and a laminated film of polyester (20 μ) and low density polyethylene (15/J) as the base material. I did it.

Table 1 shows the results of measuring the spreadability during extrusion lamination and the low-temperature heat sealability of the laminate.

Comparative Examples 1 to 4 In Comparative Example 1, the composition ratio of the ethylene and acid copolymer, in Comparative Example 2, the ion neutralization tL of ionically crosslinked ethylene copolymer 0, and in Comparative Examples 3 and 4, Extrusion lamination was carried out in the same manner as in Example 1, except that the amount of ionically crosslinked ethylene copolymer 0 was changed. Table 1 shows the results of measuring the spreadability during extrusion lamination and the low-temperature heat sealability of the laminate.

As is clear from Table 1, the laminates of the present invention are
It can be seen that it has significantly better ductility and low-temperature heat-sealing strength than any of those shown in No. 4.

Examples 2 to 9 In Example 2, when a copolymer of ethylene and methacrylic acid was used as a copolymer of ethylene and acid, in Example 3, the composition was as an ionically crosslinked ethylene copolymer. When a copolymer of ethylene and acrylic acid was used, in Example 4, ethylene, acrylic acid and acrylic 1ln-7' chill ternary copolymer valley body was used as the copolymer, and in Example 5, ionic crosslinking was performed. Example 6 When Na+ was used as the type of neutralizing metal for friend ethylene copolymer 0,
In Example 7, when ionically crosslinked ethylene copolymer 0 was used with an ion neutralization degree of 20, the melting index of ionically crosslinked ethylene copolymer 0 was 10F71.
In addition, in Examples 8 and 9, when the amount of ionically crosslinked ethylene copolymer 0 was 5 parts by weight and the degree of ion neutralization was 60 parts. For each, extrusion lamination was carried out in the same manner as in Example 1.

Table 1 shows the results of measuring the spreadability during extrusion lamination and the low-temperature heat sealability of the laminate.

In any case, compared to the results shown in Comparative Examples 1 to 4, it can be seen that the spreadability during extrusion lamination and the low-temperature heat sealability of the laminate are significantly improved.

Comparative Examples 5 to 8 In Comparative Examples 5 to 8, ionically crosslinked ethylene copolymers (average blending amounts of 10, 15, 20 and 30 parts) were used, and polyester/low density polyethylene/ Except for 9, which uses aluminum bonded,
9. Extrusion lamination was performed in the same manner as in Example 1. The adhesive strength between each evaluation resin and aluminum foil was measured and the results are shown in Table 1.

Example 1O111 In Examples 1O and 11, evaluations were made in the same manner as in Example 1, except that ethylene copolymers with different composition ratios were used. The results are shown in Table 1.

Comparative Example 9 Using the copolymer of ethylene and acrylic acid in Example 1, zinc acetate (CHsCOU)zZn.2H was used as a neutralizing agent.
*Second ion crosslinking using Ot in a vented extruder at 250°C, MFR 9.3f/10min, degree of ion neutralization 3%
and MFR is 5g/10) with degree of ion neutralization 2
Two types of polymers of G'j were obtained.

The spreadability of these was evaluated in the same manner as in Example 1, and the results were 60 explosions/min for the one with a degree of ion neutralization of 3, and 100111/min for the other.

(Margin below)

Claims (1)

[Claims] (1) Acrylic acid and /l or methacrylic acid
An ethylene copolymer containing 5 to 20% by weight of an unsaturated carboxylic acid in 100 parts by weight of an ethylene copolymer containing ~10% by weight, with at least 101 parts of the acid being neutralized with an ionic metal compound. A lamination method characterized in that a composition containing 1 to 5 parts by weight of a polymer 0 is used in at least one layer of a laminated material. body) Unsaturated carboxylic acid contained in ethylene copolymer.