JPS60152577A - Adhesive composition, film laminate and pouch or tube therefrom - 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 relates to adhesive compositions, film laminates, and pouches or tubes for retort foods or products made therefrom.

Certain packaging applications, such as retort packaging, require that the packaging material constitute a good barrier to the passage of oxygen and moisture vapors. Further (/C1 The packaging of some foods requires that a minimum amount of oxygen or air be transmitted to the contents.g Cheese is one food product that should be packaged to exclude oxygen. .

Stretched polyacrylonitrile (PAN) films have excellent oxygen barrier properties. However, its moisture barrier properties are worse than desired for retort packaging. Moreover, it is not heat sealable by itself. Both deficiencies can be overcome by applying a layer of thermoplastic material with good moisture barrier properties to the PAN surface. However, due to the significant chemical dissimilarity between PAN and thermoplastic moisture barrier polymers such as polyolefins, adhesion between the two is poor and packaging integrity is problematic. Therefore, for both of these questions, P
It is necessary to consider interposing it between the AN and the thermoplastic moisture barrier. However, it has been discovered that materials that exhibit good adhesion to I)AN generally do not exhibit good adhesion to other polymeric materials such as polyolefin films.

Previous practice of providing an adhesive bridge between a PAN and an effective moisture barrier film has involved the application of an adhesive such as polyurethane or polynisdel in a liquid vehicle. By this means, an adhesive is applied to the PAN and then a moisture barrier film is laminated through the adhesive to the PAN. Such a method, despite the use of a single layer of expensive adhesive, would provide the industry with a fusible film laminate that is economical and effective for retort food pouch applications. Ta.

In recent years, the food packaging industry has shown strong interest in the concept of pouch-packaged foods, which eliminate the need for refrigeration for preservation and therefore avoid costly and energy-intensive frozen transport, among other advantages. and storage facilities can be omitted. Legible retort food using materials that are not only able to withstand the rigors of disinfection and subsequent reheating and provide barrier properties sufficient to adequately preserve the contents during storage, but also are toxicologically safe. Significant efforts have been made to develop pouches or pressure cooker food pouches.

According to U.S. Pat. No. 3,453,173, a polyolefin-polyacrylonitrile laminate is said to have excellent heat-sealing strength, excellent barrier properties against gas permeation, and is compatible with food container construction. It is created by crosslinking a polyolefin surface and a polyacrylonitrile surface together and adhering their adjacent surfaces. In order to make one or both of these surfaces more adhesive, e.g. British Patent No. 834,19
6, or by treatment with a corona discharge as described in U.S. Pat. No. 2,632,921. Among the adhesives used in the production of are the ethylene-vinyl acetate copolymers described in U.S. Pat. No. 2,200,1129. Since the manufacturing conditions and the intended adhesive do not contribute to primary valence bonds,
Interlayer adhesion in boiling water is not expected to be strong.

In order to use the metal layer as an active surface, steps have also been taken to metal plate the PAN filter and bond through this metal layer to the water vapor barrier film.

This is also a somewhat expensive compromise.

One object of the present invention is to provide a new and effective adhesive composition that has particular utility in bonding together surfaces, particularly high quality film surfaces. It is.

Another objective of the present invention is to provide a film laminate using the IH'4 agent composition of the present invention.

Yet another object of the invention is to provide a product or food product pouch or tube that is effective in withstanding the rigors of hot or boiling water. According to the invention, polymeric surfaces are bonded together. Adhesive for use in…
A parabola is provided, but the glue is.

((I) 1 to 3:: Monomer reach ratio of styrene-butadiene to 1: styrene-butadiene polymer 9 (
b) about 12 to 1:4 monomer concentration erB, respectively;
Hiwomotsu 7 Clobentadiene Style” (fill
and (c) the monomers in a ratio of about 3 to 11:3 to 71:2.5 to 350 parts by weight, respectively (DI,
3-pentadiene, (2) monocyclic terpene, and U'(
3) a random terpolymer of alpha methyl styrene; consisting of an a1 combination of about 7-10 (a).

0,5'-tl+ of 1,5), and (c) of 2-4
, consisting of a heavy arsenal ratio.

Also according to the invention, among other uses.

Suitable for use in the production of product pouches or tubes or other products for food packaging. J flexible film laminates are provided, which laminates are comprised of two or more than two polymeric films bonded together by the adhesive composition of the present invention.

Further, according to the present invention, the laminate according to Specification 1 has a
A product pouch or tube made from either is provided.

As noted above, the adhesive composition of the present invention is a combination of the three materials broadly mentioned above. The first substance of this combination,
Thus, styrene-butane emboss copolymers are commercially available, for example, as Kraton 1000, a Norriez product (Mechanical Company, Polymer Division). One material, Kraton I 102, is a styrene-butane polymer copolymer containing about 28 parts by weight styrene and about 72 parts by weight I,=1-butadiene, 75. (100 and 150
,000.

The second material of the adhesive composition as defined above is a cyclopentadiene-styrene resin in which the weight ratio of cyclopentadiene to styrene is from about 1=2 to about 1=4. Its molecular weight ranges from about 350 to about 2,500, and its specific gravity ranges from 1 to 13.
It is truly within the range of. This material is also commercially available. For example, a product known as Nebu LX685-180 is available from Nebu Chemical Company. This substance is 3
02°J? Softening point (ASTM F18 58T)
, molecular weight of about 890, specific gravity of 1095, 4? As a sign,
This resin contains 899% carbon, 91% hydrogen, and the remainder is oxygen and sulfur.

The third substance of the adhesive composition defined in item 1 is about 30 to about 4
0 parts by weight of 1.3-pentadiene, from about 30 to about 10
Parts by weight of monocyclic terpenes, and about 25 or! ”) approx. 35
Parts by weight of alpha methylstyrene, lanthanum, terpolymer. Although the preferred monocyclic terpene for use in the present random terpolymer medium pressure is beta-phellandrene, other monocyclic terpenes/or mixtures thereof may be used.

These are dibe/ten, alphadelpinene, betaterpinene, alphaphelandrene, gammaterpinene, terpinolene, silvestrene, origanene,
Including Vironen, etc.

Preferably, the polymer additive exhibits the following properties:
Melting point range (ring and ball), 75-125°C; ratio L 1.0
8-0.90 i bromine number, 614 l iodine rIIJ%7
9: acid value, 1 or less; saponifier, 1 or less; decomposition temperature (in air), 3008C; color (as a 50% toluene solution), Gardner 6; and viscosity (in toluene), 70%.

A particularly preferred random φ terpolymer is a feed stream containing 37.5 wt% 1.3-pentadiene, 37.5 wtffi% betanoelandrene, and 255 wt% alpha-methylstyrene in a toluene diluent. Produced by polymerization in the presence of an aluminum chloride catalyst. The resulting Turbo IJ mer μ contained 34.0 parts by weight of 1,3-pentadiene, 365 parts by weight of beta-phellandrene, 29.5 parts by weight [4 parts of alpha-methylstyrene].

This material has a molecular weight (average weight) of 188o, a bromine number of 14, an iodine number of 79, a glass transition temperature of 38°C, and a glass transition temperature of 70°C.
It has a toluene viscosity of f to g and a decomposition degree (in air) of 300°C. When formulating the adhesive compositions of the present invention, the preferred weight part ratios of the components are as follows: about 7-10 parts by weight styrene-butadiene;
block copolymer, about 0.5-1.5 parts by weight of 7-clopentadiene-styrene resin, and about 2-4 parts by weight of random terpolymer.

The method of kneading these three materials in part is not critical and does not form part of the present invention. Preferably, these three components are physically pressure mixed by any mechanical mixing device conventionally used to mix viscous adhesives or plastics, such as an extruder, a Banbury mixer, or a differential roll mill. To aid thorough mixing of the polymers and develop the desired improved combination of physical properties, this mechanical kneading is carried out at a high enough temperature to soften the polymers so that they are completely dispersed and intermixed. do. Alternatively, these components may be solution mixed by dissolving the polymer in a solvent such as toluene. Adhesive can be applied from this solution to any surface desired to be adhesively bonded to another mj. It should be understood that the adhesive mixture of the present invention may also contain other additives for plasticizing, warming, dyeing, coloring, antioxidant, flame retardant, etc. the resin adhesive mixture. .

Among the advantages afforded by the adhesive formulation of the present invention is its remarkable resistance to weakening or failure of its adhesive strength upon exposure to boiling water. The decoctions of the invention find exceptional utility in organic films and laminated bonding with one another. These films 1 may be made by joining together parts of individual films of the same kind, or may be made by laminating different kinds of polymers to take advantage of the unique properties of each film. Preferred organic polymer films include polyacrylonitrile films and polyolefin films. However, as mentioned above, the invention is not limited to laminating these two types of films.

Contemplated PAN films include homopolymer polyacrylonitrile. This film is heated to 100°F (
38℃) vc#,,IrL approx. 10"5' 100
Square indiff 24 hours/atmosphere or less, more preferably 2
Oxygen transmission rate of less than about 0.1 CC/100 square inches/24 hours/atmosphere at 3°C, and preferably 10
Approximately 109 at 0”F (38°C) and 90% relative humidity
/100 square inches/24 hours or less, more preferably 1
It should have a water vapor transmission rate of less than about 109/100 square inches/24 hours at 00°F (38°C) trapping.

The double oxygen and water vapor transmission rates can be measured by various known methods. For example, oxygen permeability can be easily measured using Dollman's Polymeric Permeability Analyzer, PPA-1 (Dollman Enpirochik Corporation, (Mountain View 〇A)).
You can measure it. Dow Cell also meets ASTM D-1434
can be used for this purpose according to Preferably, a biaxially oriented film of acrylonitrile homopolymer made by the polymerization and film forming method described in US Pat. No. 4,066,731 is used.

Polyolefins useful herein are those formed by the polymerization of one or more alpha olefins, such as ethylene, propylene, butene-1, pentene-1, hegysene-1, heptene-11 octene-1, etc. Includes film-forming homopolymers and copolymers. Useful polyolefins also include one or more copolymerizable alpha olefins that may be copolymerized with one or more of the alpha olefins up to about 20% by weight of the total, preferably up to about 5% by weight of the total. Film formation fi-1ho IJ copolymerized with monomer
Including mar. These include carbon mono-7-bt-112, sulfur dioxide, acrylic acid, or acrylic esters such as methyl acrylate, amyl acrylate, hexyl acrylate, cyclohexyl acrylate, and the like. Additionally, alpha olefins may include methacrylic acid or methacrylic esters such as methyl methacrylate,
It can be copolymerized with ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, etc. They may also include vinyl acetates or vinyl esters such as vinyl C fumemate, vinyl acedate, vinyl propionate, vinyl butyrate, vinyl benzonite, inogropylacetate.
, etc. may be copolymerized.

Polyolefin films contemplated herein include mixtures and blends of polyolefins and one or more other polymers compatible therewith. Thus, for example, a polyolefin film can be made from a blend of about 80% by weight polypropylene and about 20% polyethylene. The polymers herein may also include other ingredients such as processing aids, plasticizers, antioxidants, reinforcing agents, fillers, pigments, etc. in conventional amounts.

Although the adhesive composition of the present invention can be applied to the desired surface in a variety of ways, a particularly convenient way is to apply the composition from a dispersion or solution in a suitable organic solvent such as toluene. . this solution.

Alternatively, after applying the dispersion, the solvent is removed by drying to obtain a pressure-sensitive adhesive film. The surface to be contacted with the adhesive can be compressed into even contact with the adhesive coating. Obviously the image surface may be coated with a thin layer of adhesive.

The individual fills l, constituting the laminate in question here, have various thicknesses, for example approximately 0.1 mil (0.0025111
π) to about 10 mils (0,25+ni) preferably about 0
5 mils (0,'0125mm) to approximately 5 mils (012mm)
It can be made with a thickness of 5mm, ). These films may be processed by any one or more of several 111 methods, such as those described in U.S. Pat. No. 3,453,173, which is incorporated herein by reference. It can be used to assemble into a laminate.

The laminate of the present invention can be processed into tort food pouches or tubes using known methods. According to one such method, two superimposed layers of the laminate, with the heat-healing olefin surfaces facing each other, can be edge sealed between hot plates. This pouch or tube can then be filled with food and heat sealed at both or one end to complete the packaging.

Example 1 An adhesive within the scope of the present invention was made as follows: 30.8 g of styrene-butadiene brosoxypolymer containing 28 weight parts of styrene and 72 weight parts of 1,4-butadiene. (Sold as Clayton 1101. Ner Chemical Company, Holima division) 'fE 33% cyclopentadiene, 66% styrene and 36g of 7-chloropentadiene-styrene (January 2015) (Nebuko Chemical Chikara Tsubani to Nebu LX6
85-180); 106 g of a random terpolymer (available as Startac 100) was dissolved in 2557+4 l luene.

Example 2 A 7×12 inch (17.8×
30,5 on) piece was coated with adhesive R-j solution in Example ■ using ≠8 fire lot, and solvent was applied with 1'' of solvent.
Remove by drying at 00G for 5 minutes. This coated polyacrylonitrile film was coated with a 3 mil (0.07
27 with polyglobulylene film of 5++++π)
'rjlXM in a plate plain at 0°F (132°C)
Shilko.

Ten-half of these trials were exposed to boiling water for 0 minutes.

Boiled Seishin] and non-boiled Q+i samples were both tested for peel strength. Both samples were 15 bonds/inch (o26Kq
/cm), which indicates that the adhesion is unaffected by boiling water.
The adhesive of the present invention is highly resistant to boiling water and can be used as a pressure sensitive adhesive for various polymers in addition to those listed above.

Claims (1)

[Claims] 1. Adhesive, Vi composition comprising (0,) a styrene-butadiene block copolymer having monomer parts in a weight ratio of about 1 to 3:3 to 10: (b) about 1:2 cyclopentadiene-styrene resin i and (c) (1) 1,3-pentadiene, (2) monocyclic terpene, and (3) alpha-methylstyrene in a weight ratio of 1 to 4. A random terpolymer consisting of a homogeneous combination of these monomers in a weight ratio of about 3 to 4:3 to 4:25 to 3.50, respectively, and the combination is at a temperature of about 7°C.
・10(a), 0.5 to 15(b) and 2
An adhesive composition comprising (c) in a weight part ratio of 4 to 4 parts by weight. 2. The j* adhesive according to claim 1, wherein the monocyclic terpene is betaphellandrene. 3. The adhesive according to item 1 of the 1.α-tetrasaccharide of the patent, which is dissolved or dispersed in the PIka form. 4, (α) each have a styrene-butadiene weight ratio of about 1:25, (b) each have a cyclobentadiene-styrene weight ratio of about 1=2; (c) each have a weight ratio of about 3.5. :35:3 (1) : (2) : (
The capping agent according to claim 1, having a weight to weight ratio of 3). 5, ap total is about 8M: fitf[i's (a″), I
Claim 4 consisting of (b>. of M measuring parts and (c) of 3 parts by weight)
Adhesives listed in section. 6 Scope of claims? A film fastener comprising two or more polymer films bonded together with an adhesive combination as described in JT, 1 to 5rIA. 7 Ta, Kuζ4・5 One film is polyacrylonyl
The laminate according to claim 6, which is an Il film. 8. - The laminate according to claim 7, wherein the polyacrylonitrile film is a homopolymer. 9. At least one film is a polyolefin,
A laminate according to claim 6. 10 The polyolefin is a C2-cs polymer or copolymer. A laminate according to claim 9. 11. The laminate according to claim 10, wherein the polyolefin is a heat-based polyolefin. 12. The film laminate of claim 6, wherein the thickness of the individual layers is in the range of about 10 mils (from about 0.0025 to about 0.25+am). 13. Claims A retortable food pouch made from any of the laminates according to items 6-12.