JPS6337146A - Aqueous dispersion composition of resin - Google Patents

Abstract

PURPOSE:To provide a composition obtained by compounding an aqueous dispersion of a specific thermoplastic polyurethane resin with an aqueous dispersion of an ethylenic resin, forming an easily peelable coating layer on a plastic and giving an easy-peel bag when used as a sealing material for an opening part of a bag. CONSTITUTION:(A) 5-95wt% (in terms of solid resin content) aqueous dispersion of a thermoplastic polyurethane resin having a softening point of 90-140 deg.C is compounded with (B) 95-5wt% (in terms of solid resin content) aqueous dispersion of an ethylenic resin. The component B is an aqueous dispersion of an ethylene-vinyl acetate copolymer resin. The component A is preferably a dispersion produced from a polyol of 1 mol of a dioxy compound having an average molecular weight of 500-5,000 and <=10mol of a 2-8C saturated aliphatic unsubstituted glycol and an organic diisocyanate of a molar number equal to the sum of the above two components.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an aqueous resin dispersion composition that provides an easily peelable film to plastics. A container whose main body and lid are sealed using the composition of the present invention, or a bag container whose opening is sealed, has the advantage that it can be easily opened with fingers (easy beer).

[Prior art]

polyvinyl chloride, polyvinylidene chloride, polyester,
Polycarbonate and rubber-modified acrylonitrile copolymers are widely used as resin containers either alone or in combination with other resins. These resin containers are used for cups and trays for foods such as pickles, tsukudani (tsukudani), margarine, miso, solid curry, cream puffs, and dried whitebait by taking advantage of the characteristics of the resin.

In recent years, consumers have been demanding so-called easily peelable containers that can be peeled off by hand, whereas in the past, the lid and container were completely welded together and were difficult to peel off. In order to provide easy peelability, it is common to provide an easily peelable film on at least one of the lid material or the container, and apply an adhesive (anchor coating agent, dry laminating agent) to the surface of the base material. Through,
Laminated by extrusion lamination or dry lamination.

In these conventional technologies, as an easily peelable film,
Those whose main component is ethylene/vinyl acetate copolymer are widely used. When trying to provide an easily peelable resin layer mainly composed of this ethylene/vinyl acetate copolymer on a polyester film layer by extrusion lamination, for example,
First, an anchor coating agent is applied to the polyester film layer and dried, and then low density polyethylene is extruded and laminated at a temperature of 300°C or higher, and then an easily peelable resin layer, ethylene/vinyl acetate copolymer resin, is extruded and laminated.
Alternatively, the film may need to be heat laminated. (The reason for this is that the thermal decomposition temperature of the ethylene/vinyl acetate copolymer resin is low and extrusion lamination cannot be performed at high temperatures, so the effect of the anchor coating agent is low.) Therefore,
In terms of easy peelability, a low-density polyethylene layer that has no effect can be said to be a complete waste. In addition, in the case of extrusion lamination, arranging, and film covering, from the viewpoint of molding technology, 1.
It is nearly impossible to form a continuous film with a thickness of 0μ or less, and there is a possibility that the film thickness is greater than necessary. Furthermore, although it would be sufficient to provide an easily peelable resin layer only in the heat-sealed area, applying extrusion lamination or dry lamination on the entire surface of the film is wasteful because unnecessary areas are laminated. There are also difficulties in recyclability such as loss of the ears and separation after trimming, making it uneconomical.

In order to improve the above-mentioned drawbacks, the present inventors have proposed a method for manufacturing easily peelable containers and a liquid adhesive composition that are more economical than conventional methods by applying a liquid adhesive to the heat-sealable portion. (Japanese Patent Application Laid-Open No. 59-78278, 60-154)
No. 054, No. 60-173 (B) 0).

Since these contain a small amount of organic solvent, they remain in the dried film of the heat-sealed portion of the container body, and have the disadvantage that their odor is transferred to the food product when the lid is heat-sealed.

[Problem that the invention seeks to solve]

The present invention provides an aqueous resin fraction liquid composition that does not contain plasticizers or organic solvents, and the adhesive film obtained from this composition can be easily peeled off by hand (beer strength 750-2.Q). OOt/1s width).

That is, the present invention provides the following components: (4) Component: 5 to 95% by weight of an aqueous fraction liquid resin of thermoplastic polycrethane resin with a softening point of 90 to 140°C (B) Component: Aqueous fraction liquid resin of an ethylene resin 95 to 5 C in solid dispersion! % A resin aqueous dispersion of the above-mentioned active ingredient and component (1B) is blended in the above-mentioned proportions to provide a fat-water dispersing liquid composition.

Thermoplastic polyurethane resin aqueous dispersion as a prison component: (4)
The thermoplastic polyurethane resin of the aqueous dispersion of the components has a softening point of 90 to 140°C, and has an average molecular weight of, for example, 500°C.
A polyol obtained from ~5,000 dioxy compound (a) and an aliphatic unsubstituted glycol having 2 to 8 carbon atoms in an amount of 10 moles or less per 1 mole of (a), and (a)
), and organic diisocyanate (c) in a molar number equal to the sum of (b).

The dioxy compounds with an average molecular weight of 500 to 5,000 mentioned here include, for example, poly(tetramethylcarbonyloxy) glycol manufactured from butanediol and adipic acid, poly(ethylenetetramethylene) glycol manufactured from ethylene glycol and adipic acid, etc. Dihydroxy polyesters produced from aliphatic dihydroxy compounds such as carbonyloxy) glycol and alkylene dicarboxylic acids, or ring-opening polymerization of alkyl-substituted lactones such as poly(pentamethylenecarbonyloxy) glycol produced from 8-caprolactone. Examples include polylactone glycol, which is produced from various sources, and polytetramethylene ether glycol, which is produced from tetrahydrofuran.

In addition, saturated aliphatic non-+rt substituted glycols having 2 to 8 carbon atoms and q, t, ethylene glycol, propylene glycol, 1,4-butanediol, diethylene glycol, 1,6-hexamethylene Examples include Krikor and the like.

Examples of organic diincyanates include aromatic isocyanates such as toluene diisocyanate, 4,4'-diphenylmethane diisocyanate (MDI), and hydrogenated MDL xylene diisocyanate, and aliphatic incyanates such as hexamethylene diisocyanate.

If the degree of softening of the polyurethane resin is less than 90°C, the film after coating and drying will be sticky and blocking will occur on the coated substrate, which is not preferable.

Dad, if the temperature exceeds 140℃, the heat sealing temperature is too high and is not practical.

The aqueous dispersion of thermo-OT plastic polyurethane resin as component (c) is Hytran 301, 310, 311, 312B, AP-10, and AP from Dainippon Ink Chemical.
-It is sold under 20 product names.

(2) Aqueous dispersion of ethylene resin as component: The ethylene copolymer in the aqueous dispersion as component (B) is an ethylene homopolymer, 50% or more of ethylene, and other covalent monomers. It is a copolymer with the same substance and has a softening point of 60 to 150°C.

Other copolymerizable monomers include unsaturated carboxylic acids such as acrylic acid and methacrylic acid, acrylic esters and methacrylic esters, monoolefins such as propylene and butene, and vinyl acetate. can give. Among these, the most preferred is an ethylene-vinyl acetate copolymer with a vinyl acetate content of 20 to 451,
It is advantageous in terms of heat sealability and economy for the base material.

Manufacturing method of ethylene resin aqueous dispersion! d1 opening Showa 56-
No. 2149, No. 59-78278, No. 56-1276
No. 44 and No. 56-106940.

If the softening point of this ethylene resin is less than 60° C., the film is likely to cause blocking. Moreover, if it exceeds 1rO<0>C, the drying temperature of the fraction liquid composition is high, making it uneconomical.

The proportion of the prison component and the component (B) for use is 5 to 95% by weight based on the total weight of the prison component and the component (B).

If it is less than 5% by weight, the heat sealing strength of the film will be low.

Moreover, if it exceeds 95 weight Wk%, the heat sealing strength of the film will be too high (2,00 Q r/15 m+width or more) and it will not be easy to peel.

Adherent material: Resins for containers and lids to which the aqueous resin dispersion of the present invention is applied include highly rigid resins such as polyvinyl chloride, polycarbonate, polyethylene terephthalate, rubber-modified acrylonitrile copolymers, and polyvinylidene chloride. mosquito,
Those with a high melting point of 160°C or higher are used.

Manufacture of containers and bags: Container forming sheets are formed by pressure forming, vacuum forming, etc.
The aqueous resin dispersion of the present invention is applied to the brim of the container body formed in large numbers on a sheet, and dried to form a heat-sealing film having a thickness of 1 to 20 microns.

Next, the container is filled with food, mechanical parts, fancy toys, etc., a sheet of lidding material is placed on top of the container, the sheet is pressurized with a hot roll or press to thermally bond it, and then trimmed to seal the container. get.

In addition, the aqueous resin dispersion composition of the present invention is applied to the entire surface of the extrusion-molded lidding sheet or a necessary sealing part, and after drying, the container is filled with the contents. may be covered with this lid material, followed by thermal bonding and trimming.

The lid material may be the aforementioned single resin sheet, a laminate sheet of these materials, a laminate of aluminum foil and polyethylene or ethylene/vinyl acetate copolymer film, or a urethane resin primer or urethane resin primer or aluminum foil. It may be coated with a polyester brimer.

The thickness of the film is selected so that the resulting adhesive film has a binding strength (beer strength) of 750 to 2.000 y/15 mm. Generally, the thicker the coating, the higher the beer strength.

〔effect〕

Since the aqueous resin dispersion composition of the present invention does not contain an organic solvent or a plasticizing agent, there is no hygienic problem when it is used in food containers.

Furthermore, since the resulting film does not cause blocking, it can be applied to containers or lids, and the dried semi-finished products can be stacked and stored.

Furthermore, it is economical because it coats only the areas necessary for adhesion, and because it is an aqueous dispersion, it can be made into a thin film.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples. In addition, parts and percentages in the examples are based on weight unless otherwise specified.

Example of manufacturing a protective colloid agent A mixture of 10 parts of acrylic acid, 30 parts of methacrylic acid, 50 parts of n-butyl methacrylate, and 20 parts of stearyl methacrylate was mixed with 150 parts of isopropyl alcohol. The mixture was charged into a four-hole flask equipped with a meter and a dropping funnel, and after purging with nitrogen gas, polymerization was carried out at 80° C. for 3 hours using 0.6 part of 2,2-azobisisobutyronitrile as an initiator.

Then, after neutralizing with 25 parts of 28% aqueous ammonia solution,
Add water while distilling off inglobil alcohol.
After 4 conversions, a viscous aqueous solution of neutralized acrylic copolymer having a solid content of 30% was finally obtained.

Production of aqueous dispersion of ethylene resin 1 Ethylene/vinyl acetate copolymer (vinyl acetate containing Wk4
0%, softening point 100℃ (4-ball method), melt index at 190℃ ssr/lo min) for 10,000 hours using a co-rotating intermeshing twin screw extruder (Ikegai Tekko Co., Ltd. product name PCM45, triple thread screw) Shallow groove type, L/D=
30) was continuously supplied from the hopper.

In addition, from the supply port provided in the first vent part of the same extruder, 20 parts (6 parts as solid content) of the above acrylic copolymer aqueous solution was pumped into the gear pump (discharge) at a rate of 7 hours. It is pressurized at a pressure of 3#/+!G) and supplied continuously, and
While supplying 80°C hot water at a rate of 80 parts/hour from the supply port provided in the second vent part closer to the extrusion die side, extrude continuously at a heating temperature (cylinder ff1e) of 110°C. (250 rpm) to obtain a milky white aqueous dispersion (pH 8) with a solids content of approximately 53%.

The average particle size of this aqueous polymer dispersion was determined using a microscope and was approximately 1 μm.

Example 2 Same as Example 1 except that an ethylene/vinyl acetate copolymer with a vinyl acetate absorption of 28%, a melting point of 74°C (differential thermal analysis), and a melt index of ssy/lo is used as the ethylene/vinyl acetate copolymer. An aqueous dispersion having a solids content of about 53% was obtained.

Examples 1-4, Comparative Examples 1-2, Reference Examples 1-2 The adhesive compositions shown in Table 1 were applied to a hard vinyl chloride resin sheet (thickness 0
．． 18 m) using a gravure printing roll so that the film thickness after drying was as shown in Attached Table 1, and then dried with a hot air dryer.

This coated base sheet and an uncoated hard vinyl chloride resin sheet (depth 0.25 m) were heat-sealed for 1.5 seconds at a temperature of 190°C and a pressure of 2 Al$l/- using a hot plate type heat sealer.

This heat-sealed sample was cut into strips 15 m wide, and a beer speed of 300, / min.
0° Beer wiping experiment was conducted.

The results are shown in Table-1. However, regarding blocking, the following method was used.

Overlap the coated side and non-coated side and apply 10
A metal weight with a load of 5H is placed on a glass plate with an area of - and kept at 40°C in a 90% atmosphere for 24 hours.

After a predetermined period of time, the sample was returned to room temperature and the coated and uncoated surfaces easily peeled off as 0), and the others were graded as poor (x).

Examples 5 to 7 Instead of the vinyl chloride resin sheet used in Example-1, polycarbonate (thickness: 50μ) or coextruded film of polycarbonate and polyester (width: 50μ)
(For coextrusion, apply to the polyester surface)
Polycarbonate (thickness 1
30μ) was used.

In addition, as a resin aqueous dispersion composition, Dainippon Ink & Chemicals (Ionomer type polyester urethane resin aqueous emulsion - AP-10'' (trade name, softening point 90
~95°C, non-volatile content: 30%) and the aqueous dispersion of the ethylene/vinyl acetate copolymer obtained in Example 2 were blended in the proportions shown in Table 2.

Except for this, the composition was evaluated in the same manner as in Example-1.

The results are shown in Table-2.

(Margins below) Actual ffmM-8 The dispersion composition of Actual Example-7 was applied to an aluminum foil with a wall thickness of 40 μm to form a dry film of 8 μm, and a styrene-acrylonitrile copolymer resin sheet (thickness 0.5 μm) was applied. 25m
+: When heat-sealed with product name Zekron (manufactured by Mitsui Toatsu) under the above-mentioned conditions and evaluated under the same conditions, the beer strength was 1, (B) 0 P/l 5-width, and the anti-blocking property was good. .

Claims (1)

[Claims] 1), Component (A): Aqueous dispersion of thermoplastic polyurethane resin with a softening point of 90 to 140°C, 5 to 95% by weight of resin solids (B) Component: Aqueous ethylene resin Dispersion resin solid content: 95 to 5% by weight An aqueous resin dispersion composition in which the aqueous resin dispersions of component (A) and component (B) are blended in the above ratio. 2) The composition according to claim 1, wherein component (B) is an aqueous resin dispersion of an ethylene/vinyl acetate copolymer.