CA1082090A

CA1082090A - Container for a fluid photographic processing material

Info

Publication number: CA1082090A
Application number: CA277,640A
Authority: CA
Inventors: John D. Cawley
Original assignee: Eastman Kodak Co
Current assignee: Eastman Kodak Co
Priority date: 1976-05-05
Filing date: 1977-05-04
Publication date: 1980-07-22
Also published as: JPS52134434A; JPS5942863B2; FR2350627A1; DE2720005C2; FR2350627B1; DE2720005A1

Abstract

ABSTRACT OF THE DISCLOSURE

A container (pod) is disclosed for photographic processing liquid which contains an aromatic alcohol in which a cavity-forming layer is provided for a strong seal at the edge areas of the container (2 to 3 lbs./in.). However, in selected edge areas of the cavity-forming layer an additional adhesive layer is located which provides for a more easily bursting seal. This differentially weaker seal/stronger seal effect is accomplished by the use of an adhesive layer comprising a a) crosslinked homopolymer of 2-acetoacetoxyethyl methacrylate or a crosslinked copolymer of this compound with specific norbornyl esters of methacrylic acid or b) crosslinked homopolymer of specific norbornene esters of methacrylic acid.
The cohesive strength of such a polymerized and cross-linked composition is such that it permits the bursting of the adhesive layer at a desired level of pressure (0.3 to 0.7 ??./in.).

Description

108;~090 CONTAINER FOR A FLUID PHOTOGRAPHIC PROCESSING MATERIAL

The invention relates to a container for a fluid photo-graphic processing material containing aromatic alcohol comprising a pair of opposed walls marginally sealed together over a substantial area to provide an internal cavity adapted to retain such material, at least one of said walls being flexible and deformable, the internal surfaces of said walls bounding said cavity comprising a polymer which resists deterioration by the action of such processing material, said opposed walls being marginally sealed together over a 10 first part of said area polymer-to-polymer, and a polymeric sealing composition interposed between said opposed walls over a second part of said area forming a seal of less strength than the seal over said first part of said area, whereby said container opens along said second part of said area upon the application of pressure to said container.
Homopolymers and copolymers suitable for forming the relatively weak burst seal in a pod have been known. Such seal materials are generally located along that edge of a pod which is intended to burst for releasing the photographic 20 developer, and are coated over an inner layer of the pod which is poly(vinyl chloride) or other polymer that resists the developer.
Reference is made to the following representative patents and a publication describing the named seal compositions and others:
: :

U.S. 3,056,491 describes plasticIzed and unplasticized polyvinyl butyral; also a composition comprising poly(vinylidene chloride), polyacrylonitrile - poly(vinyl chloride), and an acrylic ester resin.
U.S. 3,056,492 describes cellulose nitrate - acrylic ester resin composition.
U.S. 3,438,550 describes vinylidene chloride - nitrocellulose.
ethyl cellulose - acrylic ester resin.
U.S. 3,750,907 describes a mixture of cellulose nitrate or alcohol soluble cellulose acetate butyrate with styrene-methyl methacrylate copolymer or toluene soluble cellulose acetate butyrate or poly(vinyl butyral), and a mixture, with a plasticizer, of alcohol soluble cellulose acetate butyrate, or a copolymer of bisphenol A with epichlorohydrin, or toluene soluble cellulose acetate butyrate.
Research Disclosure, November 1974, Item 12713 describes poly(2-norbornylmethyl methacrylate);
poly[cyclohexyl methacrylate-co-5(6)-methyl-mercapto-

2-norbornylmethyl methacrylate];

polyhydroxy ether resulting from copolymerization of bisphenol A with epichlorohydrin;
poly(cyclohexyl methacrylate);
U.S. 2,634,886 teaches a pressure rupturable fluid container having a seal on one edge which is more easily rupturable than the seals of the other edges. The sealing composition proposed in this patent is ethyl cellulose or an ethyl cellulose and paraffin mixture. The problem underlying ' . .
. .

1(~8ZO9O

this prior art teaching is, however, quite different from the present teaching, because the prior art is not faced with the problem of holding photographic solutions, which contain an aromatic alcohol and the container of the mentioned U.S. 2,634,886 is not suited for such fluids.
U.S. 3,459,790 discloses monomeric acrylic ester materials of a very general formula which form a class of interpolymers and are useful in the photographic field, especially as substitutes of gelatin. There is, however, no hint whatsoever 10 that even if crosslinked these substances might be suited as sealing compositions, especially for solving the specific problem of holding photographic solutions containing an aromatic alcohol in a container. ~
U.S. 3,2~3,416 teaches 2-norbornylmethyl esters of acrylic and methacrylic acids and polymers thereof as being useful substances in the general field of synthetic polymers. Apart -~
from the fact that the reference does not at all refer to the specific problem underlying the present invention, the sub-stances disclosed therein could not even be crossiinked as 20 required in the present teaching due to the absence of a double bond in the norbornane ring system.
It has long been recognized that some photographic ,-~
developers contain aromatic alcohols such as those having the formula ~ (CH2)xOH where x is a positive integer from 1 to 3, for example ~-phenylethyl alcohol, y-phenyl-n- ¦-propyl alcohol, and benzyl alcohol (see United States Patent No. 2,304,925). Another is a,a'-xylenediol. Such aromatic alcohols are solvents for many edge sealing compositions even though present in the photographic formulation to the 30 extent of only about 1 to 4 percent. With time~ the aromatic alcohol dissolves prior art compositions, thus allowing contact o~ the upper and lower poly(vinyl chloride) innermost layers of the pod, and these layers fuse together and form a strong bond that will not break at the desired pressure.
Sometimes it is necessary to apply a small quantity of liquid material in a thin layer over a fairly large surface within a piece of apparatus, such as a camera, without gaining access to the interior of the apparatus. For example, a photosensitive film may be processed or a photograph may be toned by applying on the surface thereof within a camera a layer of a liquid processing reagent, such as a developer for a silver-halide emulsion, or a solution of a toning agent. The present invention makes it possible to apply such a thin layer by incorporating within the apparatus a disposable fluid container in the form of a pod or pouch having at least one wall (and preferably two walls) which is -formed of a flexible compressible material, and having sealed edge areas which are relatively weak at one part and relatively stronger at another part for selective opening of the weak seal area while the stronger edge seals are unbroken -when the wall is compressed. With this construction, the flexible container wall or walls can be compressed by an internal mechanical device, whereupon the liquid contained within the container is expelled unlformly through the opened weak seal in the desired direction onto the surface 1 -to be coated.
It is particularly important that such containers be so constructed as to resist deterioration in storage as the result of chemical action by the contained liquids.
Deterioration of the container not only may cause leakage from the container, but also may cause contamination of the contained fluid. Also, action of an aromatic alcohol on the weak edge seal area may cause it to become too strong as a result of dissolving the seal composition and permitting the ~ .

~--.~ -underlying resin areas to fuse together. When this happens, a camera user may rind that he cannot successfully develop an exposed film within the camera.
The task underlying the present invention is to overcome the aforementioned drawbacks and to provide a container for fluid photographic processing material which will function properly in the presence of aromatic alcohol in the photographic processing material.
This task is accomplished by providing the initially-10 mentioned container, wherein: -said polymeric sealing composition is one of the - -following methacrylic acid derivatives:
a) a crosslinked homopolymer or copolymer of 2-acetoacetoxyethyl methacrylate having the formula I:

CH O O O
. 3 ~
CH2=C - C-O-CH2-CH2-0-C-CH2-C-CH3 (I) the copolymer being composed of the compound of formula I and a 2-norbornyl ester of methacrylic acid having the general formula III:

R"
(CH2)n- - ,C, - ,C CH2 R' O CH3 (III) 1 -wherein R' is selected from the group consisting of a hydrogen atom, a straight-chain or branched alkyl group ¦ -of from 1 to 4 carbons, and a phenyl group; R" is selected from the group consisting of a hydrogen atom and an alkyl group of from 1 to 2 carbons; and n is 0 to 3;

said homopolymer or copolymer prior to being crosslinked having an inherent viscosity in benzene or chloroform measured at a concentration of 0.25 g/deciliter of solution at 25C ranging from about 0.2 to 1, or b) a crosslinked homopolymer of a norbornene derivative of methacrylic acid ester having the general formula .

~ (CH2)n-0-C-c = CH2 R" (II) wherein R' is selected from the group consis~ing of a hydrogen atom, a straight-chain or branched alkyl group ¦
of from 1 to 4 carbons, and a phenyl group, R" is selected from the group consisting of a hydrogen atom ¦
and an alkyl group of from 1 to 2 carbons, and n is 0 to 3, :, 108~090 said homopolymer prior to being crosslinked having an inherent viscosity in benzene measured at a concentration of 0.25 g/deciliter of solution at 25C ranging from -about 0.1 to 1.
Further advantageous embodiments are described in the subclaims and the specification. The values of the inherent viscosity of the polymers derived from the compound of formula I are practically identical when measured in benzene or chloroform.
The ratio of compound of formula I to compound of formula III can vary from 100:0 to 10:90, preferably from 60:40 to 20:80, more preferably from 50:50 to 25:75 by weight. Also preferred is a ratio of approximately 50:50, by weight.
All starting monomers are either known or readily obtainable. The compounds of formula I, and III for example are described in U.S. Patents 3,459,790 and 3,243,416- --respectively.
According to the invention the weak seal of a pod is formed by coating one or both mating edges of a pod with a layer of the present sealing composition.
The term "alkyl group with 1 to 2 carbons" is meant to include methyl and ethyl.
The term "straight-chain or branched alkyl group with 1 to 4 carbons" is meant to include methyl, ethyl, n-propyl,-i-propyl, n-butyl, i-butyl, sec.-butyl and tert.-butyl.
The term "n" in the general FormulP III of claim 3 is 0 to 3, but preferably 0 to 1.
A) homopolymers and copolymers of the monomer of formula I: ~ -The homopolymer and copolymers of the monomer of formula I ~-can be prepared by conventional addition polymerization ~-reactions.

1~)8ZO9O

Advantageously the copolymer comprises a 2-norbornylmethyl ester of methacrylic acid. -A preferred embodiment is concerned with the use of crosslinked homo- and copolymers containing units of 2-acetoacetoxyethyl methacrylate, the homopolymer being some-times called Polymer H hereinafter, in the preparation of weak pod seals~ The monomer has the formula:

CH
CH2 = C - C - O - CH2CH23 - C - CH2 - C - CH3-O O O
(I) The methylene group (marked by the asterisk) flanked by two carbonyl groups is an "active methylene" group. When the homopolymer, poly(2-acetoacetoxyethyl methacrylate) is heated, it tends to become insoluble, possibly as the result of the formation of crosslinks via the enol form, or possibly via hydrogen bond formation involving this form.
This compound reacts with aldehydes, e.g. aliphatic mono- and dialdehydes of 1 to 10 carbon atoms, e~g. formal-dehyde, acetaldehyde, propionaldehyde, n- and i-butyraldehyde, n- and i-valeraldehyde ? n- and i-caproaldehyde~ n- and i-heptaldehyde? mucochloric acid~ etc " glyoxal~ malondialde-hyde, succindialdehyde, glutaraldehyde, adipic aldehyde, pimelic aldehyde, suberic dialdehyde etc.~ especially formal-dehyde, glyoxal and glutaraldehyde.~
Monoaldehydes are, therefore, difunctional toward Polymer H, and dialdehydes, such as glyoxal, are tetra-functional, Polymer H also reacts with amines. Thus diamines, -for example aliphatic or aromatic diamines, for example diamines of the general formula 108zoso H ,,,H
/ N - (CH2)n - N

wherein Rl and R2 are independently H, alkyl, e.g. alkyl with 1 to 10, especially 1 to 4 carbon atoms, cycloalkyl, wherein the ring carbons are optionally replaced by hetero atoms, like 0, N, S, aryl, e.g. phenyl or alkyl-substituted phenyl, and wherein n is an integer from 0 to 10, will therefore act as crosslinking agents.

Ethylene diamine can advantageously be used as a hardener.
In general, crosslinking can be accomplished with any I -gelatin hardener such as bis(vinyl-sulfonylmethyl) (or ¦-ethyl-, propyl- or butyl-) ether, bis(vinylsulfonyl)alkanes, and ! - -aldehydes. The following known compounds are well-suited for this purpose: bis(vinylsulfonyl)methane, 1,2-bis(vinyl-sulfonyl)ethane, 1,3-bis(vinylsulfonyl)propane, 1,4-bis(vinyl-sulfonyl)butane, 1,5-bis(vinylsulfonyl)pentane, 2,2-bis(vinyl-sulfonyl)propane, N,N'-bis(2-vinylsulfonylethyl)piperazine), 1,2-bis(vinylsulfonylmethoxy)ethane, 1,2-bis(2-vinylsulfonyl-20 ethoxy)ethane, 1,4-bis(2-vinylsulfonylethoxy)butane, bis[2-(2-vinylsulfonylethoxy)ethyl]sulfone, N,N'-bis[2-(2-vinyl-sulfonylethoxy)ethyl]urea, 1,14-bis(vinylsulfony.1)-3,6,9j12-tetraoxatetradecane, N,N'-bis(2-vinylsulfonylethyl)-n-propylamine. Advantagéously, the hardener should be used in an amount between 1 and 2 mols per mol of crosslinkable ~
monomer, but an amount down to as low as 0.25 mol per mol can also be used. ¦-~
Examples of the use of Polymer H in forming crosslinked ¦~
benzyl alcohol insoluble compositions for pod edge seals

3~ follow. The following polymers were tested:
(1) The homopolymer (Polymer H) of 2-acetoacetoxyethyl methacrylate (2) A copolymer of 2-acetoacetoxyethyl methacrylate - - . - ~ . - . :

1C~8ZO~O

and 2-norbornylmethyl methacrylate containing 50% by weight of each compound (sometimes called Copolymer C hereinafter);
(3) A copolymer of 2-acetoacetoxyethyl methacrylate and 2-norbornylmethyl methacrylate containing 25% by weight -of the former (sometimes called Copolymer D hereinafter).
2-norbornylmethyl methacrylate has the structure:

CH2 - O - C - C = CH2 (IIIa) and is representative of 2-norbornyl methacrylate esters having the following general structural formula III (as in United States Patent 3,243,416), that can be copolymerized with 2-acetoacetoxyethyl methacrylate:

~CH2)n-0 - ,C, - C, CH2 R~ CH3 . , (III) wherein R' is selected from the group consisting of a hydrogen atom~ a straight-chain or branched alkyl group of from l to

4 carbons, and a phenyl group; R" is selected from the group consisting of a hydrogen atom and an alkyl group of from l to 2 carbons, and n is a whole number from O to 3, preferably O to l.

Other suitable 2-norbornyl methacrylate esters are:

2-norbornyl methacrylate 3-methyl-2-norbornylmethyl methacrylate 2,3-dimethyl-2-norbornylmethyl methacrylate ' 3-phenyl-2-norbornylmethyl methacrylate 2-(,3-methyl-2-norbornyl)ethyl methacrylate 2-(2,3-dimethyl-2-norbornyl~ethyl methacrylate 2-(3_phenyl-2-norbornyl~ethyl methacrylate 2-(2-norbornyl)ethyl methacrylate 3-(,3-methyl-2-norbornyl~propyl methacrylate 3-(2~3-dimethyl-2-norbornyl)propyl methacrylate ,, .

3-(,3.phenyl-2-norbornyl)propyl methacrylate 3-(,2-norbornyl)propyl methacrylate 3-ethyl-2-norbornylmethyl methacrylate 2,3-diethyl-2-norbornylmethyl methacrylate 3-butyl-2-ethyl-2-norbornylmethyl methacrylate The polymers and copolymers of the invention made from the monomer of formula I havinga suitable degree of polymerization ~-. . . - : :.
: ~ ., . . . : -. .

~(~82090 are those having an inherent viscosity in benzene or chloroform measured at a concentration of 0.25 g/declliter of solution at 25C ranging from about 0.2 to 1, preferably about 0.3 to o.8, most preferably about 0.4 to 0.7.
B) homopolymers of methacrylate esters of norbornene compounds according to the general formula II:
The rings in compounds having the above general formula II with crosslinkable ethylenically unsaturated groups are made by Diels-Alder reactions of cyclopentadiene with variously substituted alcohols. This limits substitution sites to those corresponding to the alcohols used.
A preferred embodiment of the invention employs poly(5-norbornen-2-ylmethyl methacrylate), for simplicity called Polymer N hereinafter:

., ' ~ CH2 - 0 - C C - CH ~
L~ ~
(IIa) wherein the structure within the brackets represents that of recurring units in the polymer structure.
The polymers of the invention of the general formula II
having a suitable degree of polymerization are those having an inherent viscosity in benzene measured at a concentration of 0.25 g/deciliter of solution at 25C ranging from about 0.1 to 1, preferably 0.2 to o.8, most preferably about 0.3 to 0.8.
Among specific compounds that may be used are:

Poly(5-norbornene-2-yl methacrylate) Poly(3-methyl-5-norbornene-2-ylmethyl methacrylate) Poly(2,3-dimethyl-5-norbornene-2-ylmethyl methacrylate) 1~8Z090 Poly(3-phenyl-5-norbornene-2-ylmethyl methacrylate) Poly[2-(3-methyl-5-norbornene-2-yl)ethyl methacrylate]
Poly[2-(2,3-dimethyl-5-norbornene-2-yl)ethyl methacrylate]
Poly[2-(3-phenyl-5-norbornene-2-yl)ethyl methacrylate]
Poly[2-(5-norbornene-2-yl)ethyl methacrylate]
Poly[3-(3-methyl-5-norbornene-2-yl)propyl methacrylate]
Poly[3-(2,3-dimethyl-5-norbornene-2-yl)propyl methacrylate]
Poly[3-(3-phenyl-5-norbornene-2-yl)propyl methacrylate]
Poly[3-(5-norbornene-2-yl)propyl methacrylate]
Poly(3-ethyl-5-norbornene-2-ylmethyl methacrylate) Poly(2,3-diethyl-5-norbornene-2-ylmethyl methacrylate) Poly(3-butyl-2-ethyl-5-norbornene-2-ylmethyl methacrylate).
The material can for example be deposited from solution in an organic solvent containing 1 to 10% by weight of solids, for example poly(5-norbornene-2-ylmethyl methacrylate). -The invention is further illustrated by the drawing wherein:
Fig. 1 is a side elevational view, partly broken away and shown in section, of a photographic developer pod in 20_ accordance with the invention;
Fig. 2 is a perspective view of a blank which can be folded to form the pod of Fig. l; and Fig. 3 is a plan view of the pod of Fig. 1.
Figs 1 and 3 show a rectangular container C comprising an upper wall 11 and a lower wall 12, both of flexible material, which are sealed together along marginal areas 13, 14, 15 extending around three sides of the container. The -fourth side 16 is closed as a fold of the laminated sheet from which the container is formed, but this side also could comprise two edges sealed together when forming the container from separate sheets. The internal areas of the container walls are not sealed together, but are spaced apart to form ~ -a storage space for liquid in the form of bubble-like protu-~erances 17, 18 on each side of the container.
. .

.

~08Z090 Now, referring to Fig. 1, the two flexible walls 11 and 12 are of laminated construction and include several layers which are adhesively joined to one another. Specifically, layer 21 of strong kraft paper is adhered to layer 23 of metal foil, such as lead or aluminum which is impervious to the passage of liquid and to the passage of air from the outside into the liquid. Such paper-foil laminates are generally purchased in sheet form as they are readily available on the market.
The innermost layer 25 is a polymeric resinous material such as poly(vinyl chloride) or a copolymer of vinyl chloride -with 2-15 percent by weight of vinyl acetate which is l-resistant to the action of the contained liquid. Layer 25 can be applied to the foil by extrusion, or solvent coating, or ¦-by an adhesive composition. A final layer 22 is the novel sealing composition of the present invention which is coated as a narrow strip along one long edge of the pod where a relatively weak bursting seal is wanted.
The two halves 11 and 12 of the container are joined together along marginal portions 13, 14, 15 by heat and pressure sealing. Where the layers of resin 25 are in contact with one another along edges 13 and 15 a strong seal results such as 2 to 3 lbs/in. Where the strip 22 along edge 14 contacts layer 25, a relatively weaker bursting seal results such as 0.3 to 0.7 lb/in. When the photographic processing liquid is to be expelled through the weak seal on edge 14 by passing a pair of rolls over the container, the nip of the rolls can be positioned at the back edge 16 and moved toward the front edge 14 to break seal 22 and expel the liquid. Success is 30 achieved when the seals at edges 13 and 15 are sufficiently stronger than weak seal 22 to resist bursting.

1~8ZO9O

Instead of coating only one strip 22 along the weak seal edge, both mating edge areas may be similarly coated so that the final seal along that edge is by one strip to the other.
Side 16 need not be sealed at all for operability, although it should be sealed for storage purposes. When back edge 16 is formed by sealing two laminates together, success ~ -can be achieved when the seal at edge 16 is stronger, weaker, or the same strength as seal 22. Such a seal on the back ,-edge can be accomplished with the same coating composition 10 as on edge 14 for ease of manufacture. When seals 16 and 22 are by the same alcohol-resistant composition and are of equal strength, the container or pod can be positioned wlth either edge forward for ease in assembly of film packs or rolls.
Referring again to Fig. 1, even though back edge 16 of the container is closed inherently, it is desirable ¦-to pinch and heat seal the adjoining areas together so as to 1-form a streamline design to make it easy to pass a pair of compressing rollers or similar compressing devices across the container.
Instead of sealing the entire length of edge 14 under conditions to form a weak seal, it sometimes is desirable to provide alternating areas of weak and strong sealing to assure uniform distribution of the liquid contents. For example, two areas coated with weak sealing material may be -provided, spaced apart by a central or intermediate area of strong sealing material (such as the vinyl polymer or copolymer !-layer) whereby the liquid is ejected in two separate streams which merge subsequently.
The principle of the invention depends primarily upon the use of novel sealing compositions which, when locally coated on a part of marginal sealing areas, react to the -15- - ;

-: . . - -1~)8ZO9O

application Or heat and pressure to form seals of lesser strength than the seals between uncoated marginal areas.
According to the invention it was unexpectedly found that the present polymeric materials, when crosslinked, form excellent relatively weak seals for the bursting edge seals of pods containing photographic developer, which makes such pods especially useful for in-camera film development.
Furthermore, the relatively weak seals are insoluble in the presence of an aromatic alcohol and can therefore be employed to advantage as sealants for pods holding photographic developers containing such aromatic alcohols. The polymers of the invention combine such insolubility with the ability to form burst seals of the desired low strength (0.3-0.7 lb/in) over a wide temperature range. Another advantage is ;
their good resistance to changes in strength as they age in storage.
The examples which follow serve to further illustrate the advantageous results achieved by the present teaching.
Examples 1 to 18 relate to homopolymers and copolymers deriving from the monomeric material of formula I. Examples 19 to 36 relate to homopolymers deriving from the methacrylate esters of norbornene compounds of the general formula II.

Example 1 - Preparation of poly(2-acetoacetoxyethyl methylacrylate) - Polymer H
Poly(2-acetoacetoxyethyl methacrylate) was prepared by refluxing in a 65C bath 100 grams of the monomer, 400 ml of acetone and 1 gram of 2,2'-azobis(2-methylpropionitrile) for 6 hours. The resulting polymer solution was used in the following examples.

.

~82090 Example 2 - Preparation of the copolymer poly(2-acetoacetoxy-ethyl methacrylate-co-2-norbornylmethyl methacrylate) in 50:50 weight ratio - Polymer C
The copolymer poly(2-acetoacetoxyethyl methacrylate-co-2-norbornylmethyl methacrylate) in a 50:50 weight ratio was prepared by refluxing in a 65C bath 10 grams of 2-norbornylmethyl methacrylate, 10 grams of 2-acetoacetoxyethyl methacrylate, 80 ml of acetone, and 0.80 gram of 2,2'-azobis (2-methylpropioni-trile) for 24 hours. The resulting copolymer solution was 10 used in the following examples. I

Example 3 - Preparation of the copolymer poly(2-acetoacetoxy- '' !
ethyl methacrylate-co-2-norbornylmethyl methacrylate) I -in 25:75 weight ratio - Polymer D
The copolymer in a 25:75 weight ratio was prepared by refluxing in a 70C bath 75 grams of 2-norbornylmethyl methacrylate, 25 grams of 2-acetoacetoxyethyl methacrylate, 400 ml of acetone, and 1 gram of 2,2'-azobis (2-methyl- ~
propionitrile) for 94 hours. A portion of the solution was blended with methanol and the resulting white solid was l 20 dried in a vacuum at 35C for 3 hours. It had an inherent '--'viscosity {~} = 0.29 (chloroform) and tg = 100.5C. The remaining portion of the solution was used in the following examples. 1-Examples' 4'to 12 ~- The general procedure was to dissolve the polymer or copolymer derived from the compound of formula I in methylene --chloride (5 ml per gram) and cast a film on a glass slide, which was then appropriately treated. Stoichiometric amounts of solutions of the crosslinking additives were added to the methylene chloride solutions immediately before casting the films. The glyoxal was used as a 40% by weight solution in water, the glutaraldehyde, as a 50% by weight water solut~on.

.. ~ .

. . . ,,- ' . ,: ' - . ~ . : ,~ ' ' 1C~82090 One-half of the slide bearing the film was then immersed in 100% benzyl alcohol for one hour, then dried in a vacuum at 100C for one hour, and the two halves of the slide compared to ascertain the action of the benzyl alcohol. Benzyl alcohol was used as a conveniently available representative of aromatic alcohols.
The results are given in Table I.

TABLE I

. Treatment Action in 100% .
Ex. Material Treatment Time Benzyl Alcohol 4 Polymer H Add formalde- 2 hours Insoluble; very hyde at room swollen temperature (1) " Same at 60 to2 hours Insolublej very 65C swollen 6 " Same at room 3 days Insoluble;
temperature swollen 7 " Add formalde- 1 hour Insoluble;
hyde at 70C slightly swollen (2) 8 " Add glyoxal at1 1/4 Insoluble, room tempera- hours slightly swollen ture (3) 9 " . Aad glutaralde-1 hour Insoluble;
hyde at room slightly swollen temperature (4) " Add ethylene- 1 hour Insolubie diamine at swollen room tempera-ture (5) 11 Copolymer C Add glyoxal at1 hour Insoluble;
room tempera- swollen ture (6) 12 Copolymer D Add glyoxal at1 hour Insoluble;
room tempera- moderately ture (7) swollen - -. : - -l()~ZOgO
-(1) 20% solids; gelled in 2 minutes (2) 4% solids; no gel in 3 days (3) 4% solids; no gel in 3 days.
A 20g solids solution plus glyoxal gelled in 2 minutes (4) 4~ solids; no gel in 3 days.
A 20% solids solution plus glyoxal gelled in 3/4 of an hour.

(5) 4% solids

(6) 4% solids

(7) 4% solids The testing of the above listed polymers was carried out under the most drastic conditions by exposing them to 100~ benzyl alcohol for the duration of the experiments. It is noteworthy that even under these extreme conditions, the desired insolubility in an aromatic alcohol remained essentially intact. It is fair to conclude that the desired insolubility of these polymers will even be better preserved under the conditions encountered with photographic developer solutions which are approximately only 4% of the aromatic alcohol.
Reaction with formaldehyde causes crosslinking and the product is insoluble but swells in 100% benzyl alcohol.
Glyoxal and glutaraldehyde give tightly crosslinked products that are insoluble and swell very little in 100% benzyl alcohol. At the low concentration of benzyl alcohol in a photographic developer, these crosslinked composltions formed by heating, or those containing the hardeners and --crosslinking agents formaldehyde, glyoxal, ethylene diamine, and glutaraldehyde are resistant against being dissolved.
The reaction rate of crosslinking with the aldehydes is dependent on the polymer concentration in the solution; a 4%
30 solids solution was not gelled by adding, e.g., glyoxal. An acceptable range is 1 to 10% solids to avoid gelation before application to form a seal.
Examples of the fabrication of pods using H, C and D formulations follow. In each example, the solution con- -taining hompolymer or copolymer, and crosslinking agent when --19-- `

.: - - , . , . ~ . .. . :.

used, was coated along one edge 22 of a blank, treated (if desired), and then the blank was folded and the seal effected by heat and pressure. Coating was at a level of 160 mg/ft2 using a 4% by weight solids solution.
Burst strength of a seal was determined by cutting out a strip l/2-inch wide perpendicularly across the weak seal (of an actual pod, or a simulated pod), placing the adjacent strip sections in sçparate jaws of an Instron tensile tester, pulling the Jaws apart, noting the force in pounds required 10 to peel the two halves of the seal apart, and doubling the value to establish the burst strength in lbs/inch.
Example 13 Polymer H was coated from a solution in acetone. After incubation at 120F (49C) for 3 days, the burst strength-temperature profile was: sealed at 275F (135C), 0.27 lbs/in; 300F (149C), 0.26 lbs/in; 325F (163C), 0.32 lbs/in; 350F (177C)~ 0.23 lbs/in. These seals were subjected I -to the action of a solution containing 4% benzyl alcohol and found to be insoluble.
In this and the following examples the burst strength-temperature profile serves to demonstrate the wide operational ranges of the corsslinking methods leading to superior results.
Example 14 A 4% solids solution of Copolymer C in acetone was treated with glyoxal at the rate of 0.09 gram glyoxal per 8 -~
grams of copolymer. The burst strength-temperature profile was: sealed at 225F (109C), 0.39 lbs/in; 250F (121C), ~ -0.74 lbs/in; 275F (135C), 0.72 lbs/in; 300F (149C), o.60 lbs/in. The product of the treatment was insoluble in 100%
30 benzyl alcohol.

Example 15 A 4% solids solution of Copolymer D in acetone, untreated, was used. Burst strengths varied but little from 0.53 lbs/in when sealed at 250F (121C) to o.38 lbs/in at 375F (191C).

. . .

1~82090 The material was not affected by incubation at 145F (63C) for 3 days. When sealed at 300F (149C), the unincubated material had a burst strength of o.46 lbs/in. When it was sealed and then incubated, the strength was 0.30 lbs/in; and when it was incubated and then sealed the burst strength was 0.45 lbs/in.
Example 16 The solution of Example 15 was treated and crosslinked -with glyoxal at the rate of 0.19 gram glyoxal per 8 grams 10 polymer. A film of this product was insoluble in 100% -- - -benzyl alcohol. The temperature-burst strength profile was broad and well within the desired range as shown in Table II.

Table II

Sealing Temperature, F (C) Burst Strength, lbs/inch 225 (107) o.38 250 (121) 0.55 275 (135) 0.49 300 (149) 0.40 20325 (163) o.38 350 (177) 0.44 Incubation for 3 days at 145F (63C) had no effect on the seal strength.
Example 17 The solution of Example 15 was treated and crosslinked with glutaraldehyde at the rate of 0.13 gram glutaraldehyde per 8 grams polymer. The product was insoluble in 100%
benzyl alcohol. The burst strength profile was shifted to lower temperatures by this substitution of glutaraldehyde for glyoxal: sealed at 225F (107C), 0.29 lbs/in; 250F
(121C), 0.51 lbs/in; 275F (135C), 0.50 lbs/in.

1~8'ZOgO

Example 18 A 4% solution in acetone of Polymer H was treated with ethylenediamine, the crosslinked product was insoluble in 100% benzyl alcohol. The burst seal strength after coating from a 4% solids solution in acetone was 0.13 lbs/in when sealed at 400F (204C).
While the foregoing examples relate to copolymers containing 50% or 25% by weight of 2-acetoacetoxyethyl methacrylate, the balance being 2-norbornylmethyl methacrylate, comparatively advantageous results can be secured when the former comprises 10% to 50% and the latter 90% to 50% by weight of the copolymer.
The following examples relate to crosslinked poly(5-norbornene-2-ylmethyl methacrylate) useful in the manufacture of pod seals.
Example 19 - Preparation of poly(5-norbornene-2-ylmethyl methacrylate) - Polymer N
5-norbornene-2-ylmethyl methacrylate monomer was prepared in a flask fitted with a vertical condenser with water at 75C
20 circulating through the jacket, attached at the top to a downwards cold water-cooled condenser. There were refluxed for 2 hours 372 grams (3.0 moles) of 5-norbornene-2-methanol, 450 grams (4.5 moles) of methyl methacrylate, 526 grams of N,N-dimethylformamide, 28.8 grams of hydroquinone, and 8.1 grams (0.15 mole) of sodium methoxide. A total of 252 ml of distillate was collected (theoretical methanol equals 121 ml).
The flask contents were cooled, diluted with ether, and washed with water, ex~.ess dilute hydrochloric acid, water, 5% aqueous sodium hydroxide until the washes were colorless, and again 30 with water. The ether solution was dried with anhydrous sodium sulfate, 11.5 grams of p-(p--tolylsulfonyl-amido) diphenylamine were added, and the ether was removed in a rotary evaporator !~
at 60C and about 15 mm pressure. To the residual oil o.58 gram 108'~09~

of hydroquinone was added and the product was distilled through a Vigreux column to give 431 grams of product having a boiling point of 770 C/1.4 mm, n20 = 1.4848. The monomer was then passed through a column of activated sodium aluminum -silicate.
To prepare the polymer, there were refluxed in a 75C
bath for 4 hours 50 g of 5-norbornene-2-ylmethyl methacrylate (free of inhibitors), 100 ml acetone, 100 ml benzene, and 0.5 gram 2,2'-azobis(2-methylpropionitrile) (AIBN). The reaction mixture was blended with methanol and the solid polymer which had formed was filtered, washed with methanol, and dried in a vacuum at 35~C. The yield was 36.3 g (72.6%), {~} = 0.32 (benzene). The desirable range for ~ is about 0.2 to 1). This polymer was readily soluble in 100% benzyl alcohol. The polymer had an absorption band in the ultraviolet at 208 nm.
The fact that the double bond in the ring of Polymer N
is very reactive has been utilized in four ways in this ~ -invention to convert Polymer N to crosslinked compositions which are insoluble in aromatic alcohols. There have been used: (1) energy in the form of heat or light; (2) peroxides or other radical sources as crosslinking initiators; (3) mono-mercaptans containing functional groups capable of forming hydrogen bonds as crosslinking agents; and t4) bismercaptans as crosslinking agents. ~-The mechanism of crossIinking by heat or light is not certain, but it is hypothesized that radical sources -give free radicals which add to the double bond of the ring givlng new free radicals which undergo interchain combinations.
Mercaptans add extremely rapidly to the norbornene double bond via a radical chain reaction. If, e.g., mercaptoacetic acid is used, a -SCH2C02H substituent is introduced and ~08Z~90 crosslinking via interchain hydrogen bonding occurs. Bis-mercaptans give, via interchain additions, covalently crosslinked products.
Examples 20 to 27 Laboratory examples Or ~or~ing crosslinked materials and testing their resistance to solution in aromatic alcohols follow. The general procedure was to dissolve treated or untreated Polymer N in methylene chloride (5 ml per gram) and cast a rilm on a glass slide. For the mercaptan addition, 10 a stoichiometric amount of mercaptan was added to the methylene chloride solution immediately before casting a film. The other treatments were done after casting the film.
One half of the slide bearing the film was immersed in 100% benzyl alcohol for one hour, then dried in a vacuum at 100C for one hour, and the two halves of the slide compared to ascertain the action of the benzyl alcohol. Benzyl alcohol was used as a conveniently available representative of -aromatic alcohols. The results appear in Table III below for Examples 20 to 27: -Table III

Example Treatment of Polymer N Action in 100% Benzyl Alcohol Heat at 190C ror 60 sec. Insoluble; swells 21 H1gh pressure Hg lamp, Insoluble; swells 30 sec. (a) 22 Xenon flash, 9.9 kv.g Insoluble; swells 50 usec.

23 Heat 60 sec. at 190C with Insoluble; swells 25 mole % dl-t-butyl peroxlde 24 Heat 60 sec. at 190C wlth Insoluble; swells 25 mole % AIBN

Heat 60 sec. at 190C with Insoluble; not swollen 25 mole % benzoyl peroxide 26 React with mercaptoacetic Insoluble; swells acid (HSCH2C02H) (b) -7 React with 1,3-dimercapto-2- Insoluble; not swollen propanol (HSCH2CHOHCH2SH) (c) 1(~8;~090 100% poly(5-norbornene-2-ylmethyl methacrylate) (a) A 30 min. exposure to "black light" W caused no reaction.
(b) The same result was obtained with mercaptopropionic acid (HSCH2CH2C02H), 2-mercaptoethanol (HSCH2CH20H), and 3-mercapto-2-hydroxy propanol (HSCH2CHOHCH20H).
(c) 1,2-dimercaptoethane (HSCH CH2SH), 1,5-dimercapto-3-oxa-pentane (HSCH2CH2eCH2CH2SH~,and 1,5-dimercapto-3-thiapentane (HSCH2CH2SCH2CH2SH) reacted similarly.

All the above compositions are suitable because of their insolubility in the aromatic alcohol. The fact that there was swelling in some examples is not significant because the tests were run in 100% benzyl alcohol rather ~ -than the much lower concentration to be expected in photo-graphic processing solutions. I
Examples of the application of the above reactions to the fabrication of pods follow. The sealant was machine coated along one long edge of the blank as shown at 22 in Fig. 2 at a level of 160 mg/ft2 using a 4% by weight solids solution in methylene chloride treated and then formed into a pod.
It is an important and unexpected finding that the reaction of Polymer N with mercaptans is concentration dependent with respect to Polymer N. When, for example, a stoichiometric amount of HSCH2CHOHCH2SH was added to Polymer N
dissolved in CH2C12 (1 gram per 5 ml CH2C12 or 16.7% solids by weight), gelation occurred in 30 min. When the same bismercaptan was added to a 4% by weight solids solution no gelation was observed after several days. For best results without detrimental gelation it is preferred that the solution contain no more than 10% solids, desirably 1-10% by weight.

I
,' : ' Example 28 - Action of Heat -After coating the non-crosslinked Polymer N as described above, and forming a simulated pod weak seal, the weak seal had a burst strength Or only 0.24 lbs/in. at the highest seal forming temperature. However, after keeping for three days at 145F. ~63C), strength increased due to crosslinking in situ, and was 0.32 lbs/in. for a seal which had been formed at 275F (135C) and 0.47 lbs/in. for a seal formed at 325F (163C).

10 Example 29 - Action Or Heat A pod weak seal formed as in Example 28 was heated for 5 minutes at 200C. The burst strength was increased to 0.34 lbs/in. and 0.54 lbs/in. for seals formed at 300F (149C) and 375F (190C), respectively.
Example 30 - Resistance to Benzyl Alcohol .
The described sealant crosslinked Polymer N, was coated and sealed at 300F (149C). After two weeks in contact with a formulation containing 4% benzyl alcohol, the burst strength was only 0.52 lbs/in., showing that the benzyl alcohol had 20 not dissolved the seal, and thus had not permitted the poly(vinyl chloride) coatings to seal together.
Example 31 - Xenon Flash Treat_ent The burst strength of the seal of Example 28, formed I -at 325F (163C), was increased from 0.24 lbs/in to 0.40 lbs/in by xenon flashing of Polymer N.
Example 32 - Treatment with Di-t-butyl peroxide . . _ Polymer N plus 25 mole percent di-t-butyl peroxide was coated. After keeping at 145F (63C) for 3 days to promote a crosslinklng reaction the sealing latitude was 30 very good, being 0.35 lbs/in. burst strength for a seal formed --, ' ' .: ' . ' 1~)8~090 at 250F (121C) and o.63 lbs/in. for a seal formed at 325F
(163C). By sealing latitude is meant the temperature range over which satisfactory burst strengths are achieved.
Example 33 - Treatment with Benzoyl Peroxide Polymer N crosslinked with 25 mole percent benzoyl peroxide was coated, sealed, and kept three days at 145F
(63C). The sealing latitude was from 0.45 lbs/in. burst strength for a seal formed at 225F (107C) to 0.60 lbs/in.
for a seal formed at 300F (149C).
A second sample was sealed at 375F (190C) and stored in contact with a photographic formulation containing 2% benzyl alcohol. After two weeks, burst strength was , -0.33 lbs/in. and had remained constant.
Example 34 - Treatment with 2,2lazobis(2-methylpropionitrile) Polymer N crosslinked with 25 mole percent AIBN was coated, sealed, and incubated for three days at 145F (63C). ¦
Sealing latitude was from 0.40 lbs/in burst strength ~or a seal formed at 225F (107C) to 0.73 lbs/in. for a seal formed at 300F (14~C).
Example 35 - Treatment with Mercaptoacetic Acid -To a 4% solids solution of Polymer N in CH2C12 was added HSCH2C02H (0.48 gram per gram of Polymer N - a stoichiometric amount). After edge coating, the pods were sealed and incubated for three days at 145F (63C) and had the following ll sealing latitude: 0.30 lbs/in. burst strength for a seal ' -formed at 250F (121C) to 0.44 lbs/in. for a seal formed at 325F (163C). The formulation within the pod contained one percent benzyl alcohol.

.

`~
1~8ZO9O
.
Example 36 - Treatment with 1,3-dimercapto-2-propanol A 4% solids solution in CH2C12 of Polymer N was treated with 0.323 g. of HSCH2CHOHCH2SH Per gram of Polymer N
(stoichiometric amounts). After sealing and keeping at 145F
(63C) for three days the latitude was from 0.31 lbs/in burst strength rOr a seal formed at 275F (135C) to 0.50 lbs/in.
for a seal formed at 325F (163C).
In another experiment, the pods were sealed after coating at 350F (177C) and left in contac~ with formulation containing 4% benzyl alcohol for two weeks, during which the burst strength ehanged from an initial value Or 0,32 lbs/in. to 0.25 lb/in., showing that the seal had resisted solution in the benzyl alcohol. ¦ -All the simulated and actual pod seals of Examples 28 to 36 were found not to increase in their burst strengths to an undesirable extent when subjected to the action of benzyl alcohol.
In contrast to the above examples, seals formed with poly(2-norbornylmethyl methacrylate) described in Research Disclosure for November 1974, and left in contact with a formulation containing 2% benzyl alcohol, increased in burst strength from 0.30 lbs/in. to 0.90 lbs/in. in two weeks, an undesirable increase.
Seal burst strengths in the above examples were all determined in an Instron Tensile testing machine. For burst strength, a 1/2 inch wide strip was cut out perpendicularly to the weak seal. The parts of the strip on opposite sides ¦~
of the seal were placed in separate ~aws of the Instron tensile tester machine, which were then pulled apart until the seal peeled open. The force in pounds was multiplied by 2 to obtain the value in lbs/in. '~

!~-- -.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A container for a fluid photographic processing material containing aromatic alcohol comprising a pair of opposed walls marginally sealed together over a substantial area to provide an internal cavity adapted to retain such material, at least one of said walls being flexible and deformable, the internal surfaces of said walls bounding said cavity comprising a polymer which resists deterioration by the action of such processing material said opposed walls being marginally sealed together over a first part of said area polymer-to-polymer, and a polymeric sealing composition interposed between said opposed walls over a second part of said area forming a seal of less strength than the seal over said first part of said area, whereby said container opens along said second part of said area upon the application of pressure to said container, characterized in that said polymeric sealing composition is one of the following methacrylic acid derivatives:
a) a crosslinked homopolymer or copolymer of 2-acetoacetoxyethyl methacrylate having the formula I:

( I ) the copolymer being composed of the compound of formula I
and a 2-norbornyl ester of methacrylic acid having the general formula III:

( III ) wherein R' is selected from the group consisting of a hydrogen atom, a straight-chain or branched alkyl group of from 1 to 4 carbons, and a phenyl group; R" is selected from the group consisting of a hydrogen atom and an alkyl group of from 1 to 2 carbons; and n is 0 to 3;
said homopolymer or copolymer prior to being crosslinked having an inherent viscosity in benzene or chloroform measured at a concentration of 0.25 g/deciliter of solution at 25°C ranging from about 0.2 to 1, or b) a crosslinked homopolymer of a norbornene derivative of methacrylic acid ester having the general formula II:

wherein R' is selected from the group consisting of a hydrogen atom, a straight-chain or branched alkyl group of from 1 to 4 carbons, and a phenyl group, R" is selected from the group consisting of a hydrogen atom and an alkyl group of from 1 to 2 carbons, and n is 0 to 3, said homopolymer prior to being crosslinked having an inherent viscosity in benzene measured at a concen-tration of 0.25 g/deciliter of solution at 25°C ranging from about 0.1 to 1.

2. A container according to claim 1, characterized in that the polymeric sealing composition is a homopolymer of 2-acetoacetoxyethyl methacrylate crosslinked by heat treatment or with ethylenediamine, or crosslinked in 1 to 10% solution of polymer with formaldehyde, glyoxal or gluta-raldehyde.

3. A container according to claim 1, characterized in that said 2-norbornyl ester is 2-norbornylmethyl methacrylate.

4. A container according to claim 3 characterized in that said methacrylic acid ester is present in an amount between 10 and 50% of said 2-norbornylmethyl ester is present in an amount between 90 and 50% of said copolymer by weight.

5. A container according to claim 4, characterized in that said methacrylic acid ester is present in an amount between 25 and 50% and said 2-norbornylmethyl ester is present in an amount between 50 and 75% of said copolymer by weight.

6. A container according to claims l, 3 and 4, characterized in that said copolymer is crosslinked with glyoxal or glutaraldehyde.

7. A container according to claim 1, characterized in that said 2-norbornyl ester is:
2-norbornyl methacrylate 3-methyl-2-norbornylmethyl methacrylate 2,3-dimethyl-2-norbornylmethyl methacrylate 3-phenyl-2-norbornylmethyl methacrylate 2-(3-methyl-2-norbornyl)ethyl methacrylate 2-(2,3-dimethyl-2-norbornyl)ethyl methacrylate 2-(3-phenyl-2-norbornyl)ethyl methacrylate 2-(2-norbornyl)ethyl methacrylate 3-(3-methyl-2-norbornyl)propyl methacrylate 3-(2,3-dimethyl-2-norbornyl)propyl methacrylate 3-(3-phenyl-2-norbornyl)propyl methacrylate 3-(2-norbornyl)propyl methacrylate 3-ethyl-2-norbornylmethyl methacrylate 2,3-diethyl-2-norbornylmethyl methacrylate, or 3-butyl-2-ethyl-2-norbornylmethyl methacrylate.

8. A container according to claim 1, characterized in that said homopolymer (b) is:
Poly(5-norbornene-2-yl methacrylate) Poly(3-methyl-5-norbornene-2-ylmethyl methacrylate) Poly(2,3-dimethyl-5-norbornene-2-ylmethyl methacrylate) Poly(3-phenyl-5-norbornene-2-ylmethyl methacrylate) Poly[2-(3-methyl-5-norbornene-2-yl)methyl methacrylate]
Poly[2-(2,3-dimethyl-5-norbornene-2-yl)ethyl methacrylate]
Poly[2-(3-phenyl-5-norbornene-2-yl)ethyl methacrylate]
Poly[2-(5-norbornene-2-yl)ethyl methacrylate]
Poly[3-(3-methyl-5-norbornene-2-yl)propyl methacrylate]
Poly[3-(2,3-dimethyl-5-norbornene-2-yl)propyl methacrylate]
Poly[3-(3-phenyl-5-norbornene-2-yl)propyl methacrylate]
Poly[3-(5-norbornene-2-yl)propyl methacrylate]
Poly(3-ethyl-5-norbornene-2-ylmethyl methacrylate) Poly(2,3-diethyl-5-norbornene-2-ylmethyl methacrylate), or Poly(3-butyl-2-ethyl-5-norbornene-2-ylmethyl methacrylate).

9. A container according to claim 1, characterized in that said norbornene compound is 5-norbornene-2-ylmethyl methacrylate.

10. A container according to claim 1, characterized in that said polymeric sealing composition is a homopolymer of 5-norbornene-2-ylmethyl methacrylate crosslinked by heat treatment, irradiation, or with di-tert-butyl peroxide, 2,2'-azobis(methylpropionitrile), benzoyl peroxide, or a mono- or bismercaptan.

11. A container according to claim 10, characterized in that said 5-norbornene-2-ylmethyl methacrylate and said mono- or bismercaptan are crosslinked in about stoichio-metrically equivalent amounts.