US3671479A

US3671479A - Barrier coatings

Info

Publication number: US3671479A
Application number: US119371A
Authority: US
Inventors: August F Ottinger; Paul R Graham
Original assignee: Monsanto Co
Current assignee: Monsanto Co
Priority date: 1968-04-03
Filing date: 1971-02-26
Publication date: 1972-06-20
Anticipated expiration: 1989-06-20

Abstract

Composition comprising a polyblend of ethylene/vinyl chloride/acrylamide interpolymer and polyvinylidene-chloride useful as a flexible barrier coating for fibrous substrates.

Description

United States Patent Ottinger et al. [4 1 June 20, 1972 [s41 BARRIER COATINGS [56] References Cited [72] inventors: August F. Ottinger, St. Louis; Paul R. N D T E P Graham, Ballwin, both of Mo. U [TE S AT 5 ATENTS 3,428,582 2/1969 Des Deex ..260/8 [73] 3,567,491 311971 Graham et al. ..1 17/76 [22] Filed: Feb. 26, 1971 Primary Evaminer-William H. Short [21 1 Appl' I Assistant Examiner-E. Nielsen Reh'gd U.$ A li u p.1 Attorney-John E. Maurer et al. [63] Continuation-impart of Ser. No. 718,367. April 3,

1968, Pat. No. 3,567,502. [57] ABSTRACT Composition comprising a polyblend of ethylene/vinyl [52] US. Cl. ..260/29.6 RW, 1 WI] 15 UA, ll7/l6l UT, chloride/acrylamide interpolymer and polyvinylidene- 260/897 C chloride useful as a flexible barrier coating for fibrous sub- [51] Int.Cl ..C08I 29/22,C08f 37/18 sgr mg [58] FieldolSemh ..260/29.6RW,897C

9 Claims, No Drawings 1 BARRIER COATINGS This application is a continuation in part of copending application Ser. No. 718,367 filed Apr. 3, l968-now US. Pat. No. 3,567,502, which was issuedMarch 2, 1971.

This invention relates to a composition comprising a polyblend of ethylene/vinyl chloride/acrylamide interpolymer and polyvinylidenechloride usefulas a flexible barrier coating for fibrous substrates.

The term E/VCl/A interpolymer" as used herein means ethylene/vinyl chloride/acrylamide terpolymers and high polymers thereof.

Fibrous substrates, such as paper, are widely used in packaging operations. Paper, however, has very poor resistance to penetration by water'vapor, gases, oil, solvents and greases. To improve resistance to penetration by such sub-' stances, paper has been coated with a variety of materials. The most common paper coating is wax. While wax coated paper has good resistance to penetration while in a smooth or uncreased condition, it has poor resistance after it is'creased. Apparently the brittleness of the wax is so greatthat creasing causes it to fracture and break thereby providing many areas through which 'water vapor can pass with little or no resistance. Additionally, wax coated paper does not serve to form a hard and scuff resistant surface.

The coating of paper with asphalt has also been tried and although good resistance to water vapor is obtained, the coated paper has poor resistance after being creased. Additionally, asphalt is a black, toxic material which limits its application as a paper coating; particularly in the food packaging industry. Furthermore, asphalt coatings are subject to changes in flow properties with a variance in temperature.

To improve water vapor, oil, solvent and grease resistance, paper has been treated with polyvinylidene chloride. The characteristic brittleness of polyvinylidene chloride causes failures of such coatings with creasing. Attempts to improve this limited flexibility by the use of plasticizers and comonomers with the polyvinylidene chloride results in decreased resistance to penetration of water vapor. The poor impact resistance of the polyvinylidene chloride also results the rupture ofthe film during high speed scoring and creasing.

' In view of the state of the art, it has become highly desirable to' discover materials which form flexible barrier coatings on fibrous substrates having improved resistance to penetration by oil, grease, solvent and water vapor.

It is accordingly an object of this invention to provide a polyblend which will provide improved fibrous substrate coating compositions.

It is a further object of this invention to provide a polyblend having improved resistance to penetration by oil, grease, solvent and water vapor when used as a coating for fibrous substrates.

Other objects and advantages of the invention will be apparent to those skilled in the art from the following detailed description and claims.

The above and other objects of this invention are carried out by a method which comprises admixing E/VCl/A interpolymer with' polyvinylidene chloride in order to form an E/VCl/A interpolymer-polyvinylidene chloride polyblend.

The polyblend compositions of this invention comprise from about 0.05 to about 20 parts by weight of E/VCl/A interpolymer for each one part by weight of polyvinylidene chloride and preferably from about 0.l to about 0.4 parts by weight of E/VCl/A interpolymer amide for each one part by weight of polyvinylidene chloride.

The compositions of this invention can be prepared by admixing the E/VCl/A interpolymer and the polyvinylidene chloride by any means known in the art as for example by stirring, kneading or grinding. Suitable mixing equipment includes dough mixers, banberry mixers, rollers and the like. Admixture can be carried out by dissolving each polymer in a common solvent followed by solvent removal to obtain a homogeneous polyblend. Suitable solvents include dimethylformamide, dimethylacetamide, pyridine and the like. Admixture can also be carried out by adding the polyvinylidene chloride in dispersed form to an aqueous emulsion or dispersion of the E/VCl/A interpolymer. In many applications the E/VCl/A interpolymer-polyvinylidene chloride polyblends in aqueous emulsion or dispersion will be used in latex form without further treatment. In the form of an aqueous dispersion or emulsion the E/VCl/A interpolymer polyvinylidene chloride polyblend can comprise from about 1 percent to about 99 percent by weight of the dispersion or emulsion and preferably from about 2 percent to 75 percent by weight when used as coating compositions.

The polyvinylidene chloride useful in this invention may be of any suitable molecular weight (weight average molecular weight as measured by gel permeation chromatography), but generally the molecular weight is not less than about 25,000 and may be as high as 500,000 or more. Preferably the weight average molecular weight is from about 100,000 to about 200,000.

The E/VCl/A interpolymers which are useful in the preparation of the E/VCl/A interpolymer-polyvinylidene chloride compositions of this invention generally contain from about 2 to about 70 weight percent ethylene, from about 30 to about 88 weight percent vinyl chloride, and from about 0.1 to about 10 weight percent of an additional polar monomer component. The polar monomer component can be entirely acrylamide or a portion of the acrylamide can be replaced by one or more polar monomers selected from the group consisting of acrylonitrile, N-(lower alkyl) acrylamide and N-(lower alkyl) methacrylamide containing from one to three carbon atoms in the lower alkyl groups, N-methylol acrylamide, N[2- (2-methyl-4-oxopentyl)] acrylamide, acrylic acid, methacrylic acid, and alkali metal and ammonium salts of acrylic and methacry-acrylic acids, maleic acid, fumaric acid, half and complete alkali metal and ammonium salts of maleic and fumaric acid, aconitic acid, itaconic acid, citra conic acid, and alkali metal and ammonium salts thereof, acrylyl and methacrylyl esters of hydroxyalkanoic acids having from two to about six carbon atoms in the alkanoic acid moieties, acrylylamides and methacrylylamides of aminoalkanoic acids having from two to about six carbons in the aminoalkanoic acid, hydroxyethyl and hydroxypropyl esters of acrylic, methacrylic, maleic, and fumaric acids, vinyl esters of alkanoic acids having from one to six carbon atoms such as vinyl acetate, vinyl propionate, and lower alkyl (one to six carbon atoms) sulfonic acid, vinyl esters of phenylsulfonic acids, and alkylphenylsulfonic acids and acrylyl and methacrylyl esters of hydroxyalkylsulfonic acids having from one to six carbon atoms in said alkyl moieties, and hydroxyalkylsulfonamides having from one to six carbon atoms in said hydroxyalkyl moieties. The polar monomer component generally contains at least 10 weight percent acrylamide and preferably at least 50 percent acrylamide.

Thus the interpolymers are at least terpolymers containing ethylene, vinyl chloride and acrylamide and may be a quaternary or higher polymers containing one or more of the above exemplified additional polar monomers in small quantities,

Generally such additional polar monomers will not be present in the interpolymer inquantities greater than about 3 percent by weight.

It is preferred that the interpolymer contain from about 15 percent to about 70 percent ethylene, 30 percent to about percent vinyl chloride, and from about 1 percent to about 5 percent acrylamide. A specific example of choice is a terpolymer containing from about 19 to about 23 percent ethylene, about 74 to about 78 percent vinyl chloride, and from about 2 to about 4 percent acrylamide.

The interpolymers used in accordance with this invention can be modified, but non-modified interpolymers are preferred. The interpolymers are particularly amenable to hydrolytic modification by the use of small quantities of a strongly alkaline material such as an alkali metal hydroxide, or a quaternary ammonium hydroxide such as tetramethyl ammonium hydroxide, or by a strong acid such as the mineral acids, e.g., hydrochloric, sulfuric, phosphoric, nitric. The base or acid used preferably has an ionization constant higher than at 25 C.

The hydrolytic modification is carried out by treating an aqueous dispersion or polymer latex of the ethylene, vinyl chloride, and acrylamide with aqueous base or acid in an amount chemically equivalent to from about 0.1 percent to about 100 percent of the amide equivalent in the interpolymer.

Specific examples of additional polar monomers which can be used, as described above, to replace part of the acrylamide in the polar monomer component of the interpolymer useful in this invention include acrylonitrile, N-methacrylamide, N- ethylacrylamide, N-propylacrylamide, N-metholylacrylamide, methacrylamide, acrylic, methacrylic, maleic, fumaric, itaconic, aconitic, and citraconic acids and alkali metal and ammonium salts of such acids, preferably the sodium potassium or ammonium salts, alkyl esters of such acids, e. g., methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, butyl methacrylate, ethyl methacrylate, mono ethyl maleate, dipropyl fumarate, acrylyl 3-hydroxypr0pionate, methacrylyl hexamide Z-hydroxyethyl and 2-hydroxypropyl esters of acrylic, methacrylic, maleic, fumaric, itaconic, aconitic and citraconic acids, vinyl formate, vinyl acetate, vinyl hexanoate, vinyl and alkyl esters of propanesulfonic acid, vinyl phenylsulfonate, acrylyl and methacrylyl esters of 2-hydroxypropyl sulfonic acid, and N-acrylyl and N-methacrylyl 2 hydroxypropanamides.

Illustrative of interpolymers which are useful in this invention are ethylene/vinyl chloride/acrylamide, ethylene/vinyl chloride/acrylamide/hydroxyethylacrylate, ethylene/vinyl chloride/acrylamide/N-isopropylacrylamide, ethylene/vinly chloride/acrylamide/diammonium itaconate, ethylene/vinyl chloride/acrylamide monobutyl acid maleate, ethylene/vinyl chloride/acrylamide/N-methacrylyl propionamide, ethylene/vinyl chloride/acrylamide/sodium acrylate and ethylene/vinyl chloride/acrylamide/sodium methacrylate.

The ElVCl/A interpolymers generally have a molecular weight (weight average molecular weight) from about 20,000 to about 150,000 as measured by intrinsic viscosity or gel permeation chromotography.

The E/VCl/A interpolymers useful in this invention are readily prepared by various means well known to the art. The interpolymers can be prepared by first mixing ethylene and vinyl chloride in an aqueous medium in the presence of any suitable anionic or nonionic emulsifier and any initiator capable of generating free radicals'in the chemical mixture at the chosen reaction temperature and pressure. The acrylamide, preferably in aqueous solution either alone or mixed with the appropriate amounts of other polar monomers, is added to the polymerizing ethylene and vinyl chloride mixture gradually throughout the reaction. The addition of the acrylamide is preferably begun after about 40 to 50 percent of the desired conversion of the ethylene and vinyl chloride has been reached. A shell-core latex in which the polar monomer is concentrated in the outer layers is produced.

The ethylene/vinyl chloride interpolymers used in this invention are preferably prepared by a process which comprises mixing ethylene and vinyl chloride monomers in the presence of an alkaline buffered reduction-oxidation (redox) initiatorcatalyst system, water, and from about 1 percent to about 8 percent by weight based upon the monomer feed, or from about 4 percent to about 7 percent based upon the polymer product of an anionic or nonionic emulsifying agent having a hydrophilic-lipophilic balance (HLB) value of from about 10 to about 40, and reacting the mixture at a temperature and pressure and for a time sufficient to cause polymerization between the ethylene and vinyl chloride, and then to introduce acrylamide, either alone, or mixed with other monomers in minor amounts in an appropriate diluent such as water into the pressurized polymerizing reaction mixture of the ethylene and vinyl chloride. This process is described in detail in U. 8. Pat. No 3,428,582 and the subject matter thereof is expressly incorporated herein by reference.

The following examples will illustrate this invention. Parts and percent are by weight unless otherwise indicated. In the polymer preparation examples, all of the polymerization are carried out in a 3,820 ml. pressure vessel at 30 C. at a rotary stirrer speed of 600 rpm.

EXAMPLE 1 This example illustrates the preparation of a 21/76/3 ethylene/vinyl chloride/acrylamide trpolymer latex, and the post-stabilization of such latex with an emulsifier.

Reaction Vessel Initial Charge:

.0 g K S O (KPS) l5.0 g NaHCO 0.8 g Fe(NO;,) 911,0 1.5 g Tetrasodium ethylenediaminetetraacetate (Na EDTA) 1.2 g Sodium lauryl sulfate (SLS) H 0 to make 1700 ml 450 g Vinyl chloride (VCl) 150 g Ethylene (E) and the pressure was kept constant by the addition of pure vinyl chloride as required. After three hours had elapsed, a 50 percent solution of acrylamide in water solution was added at 40 ml/hr. The reaction stopped after 5.5 hours and the feed streams were turned off. A total of 1330 g of VCl,'95 ml of the 50 percent acrylamide, 27 ml of the l M SFS/LS M NH ,OH solution, and 92 ml of the 25 percent SLS solution had been added. The resulting polymer latex was vented out the bottom of the autoclave. A total of about 3,500 g of the ethylene/vinyl chloride/acrylamide polymer latex was obtained containing 47 percent total solids, and 1.5 percent sodium lauryl sulfate (based on the weight of the polymer). It had a pH of 7.7. The composition of the terpolymer was about 21/76/3 ethylene/vinyl chloride/acrylamide. After addition of 1.5 percent of sodium dodecyl benzene sulfonate or 3 percent tridecyloxy(CH CH O), H, the latex was ready for use directly as a barrier coating.

EXAMPLE 2 This example illustrates the preparation of the basemodified ethylene/vinyl chloride/acrylamide terpolymer.

Using the same reaction Vessel and ingredients as are described in Example l, except that only 10.0 g of KPS, and only 0.5 g of SLS was used in the initial ingredient charge. The SFS/Nl-LOH solution was added at the rate of 4 ml/hr and the SL8 solution was added at 8 ml/hr. The polymerization reaction stopped after 5.75 hours with a total of about 1,340 g of vinyl chloride, ml of acrylamide solution, 23 ml of SFS/Nl-LOH solution, and 43 ml of 25 percent SLS being added. The resultant terpolymer latex was post-stabilized by mixing therewith an additional 17 ml of 25 percent sodium lauryl sulfate (SLS). The stabilized latex was then vented from the bottom of the reaction vessel. There was obtained 3,460 g of material containing 49 percent total solids, 1 percent of the SL8 and essentially the same tel-polymer as described in Example The particle size of this polymer latex was somewhat larger than that of Example 1.

This stabilized ethylene/vinyl chloride/acrylamide terpolymer latex was warmed at 50 C. for 4 to 16 hours after adding 0.42.0 g of sodium hydroxide (added thereto as a l0 percent NaOH in water solution) per kilogram of latex.

' EXAMPLE 3 A four monomer component polymer latex was prepared as follows:

A pressure reaction vessel was initially charged with 9.0 g KPS 12.0 g NaHCO 1.5 g Na EDTA 0.5 g SLS H O to make 1,700 ml 470 g VCl This mixture was sealed and warmed to 1,550 psig. Polymerization was started by pumping into the vessel contents a l M SLS/1.5 M Nl-LOH solution at the rate of 4 ml/hr. At the same time 10 ml/hr of a 25 percent SLS was added. Vinyl chloride sufficient to keep the pressure constant was added throughout the reaction. At the end of 3 hours of polymerization an aqueous solution containing 40 percent acryiamide and 10 percent sodium acrylate was added to the reactor atthe rate of 24 ml/hr. After 6 hours, the reaction stopped and a total of 591 g of vinyl chloride, 52 ml of 25 percent SLS, 27 ml of SFS/Nl-LOH and 72 ml of the acrylamide/acrylate solution had been added. Unreacted ethylene and vinyl chloride were vented from the top of the reactor to lower the pressure to about 250 psig, and then the latex was taken out through the bottom of the reactor. There was thus obtained about 3,060 g of latex containing 43 percent solids, and 1.1 percent sodium lauryl sulfate. The polymer composition was a 21/76/2.3/0.7 ethylene/vinyl chloride/acrylamide/sodium acrylate polymer. It was suitable for use directly as a coating composition for paper and paperboard. The procedure is repeated substituting for the sodium acrylate an equivalent amount of sodium methacrylate. An ethylene/vinyl chloridel-acrylamidelsodium methacrylate of substantially the same monomer proportions is obtained.

lnterpolymers prepared in a manner analogous to the procedure described in Example 1 are shown in Table 1.

The interpolymers prepared in Examples 4 through 6 are modified with sodium hydroxide to obtain hydrolyzedpolymer latices having the following solids content:

Latex Example N0. Polymer Example No. of Table l Solids EXAMPLES 12-] 7 Following the procedure of Example 3 and equivalent amount of the component tabulated below is substituted for the sodium acrylate to obtain a latex polymer described below composed of substantially the same proportions as the product of Example 3.

l2 Component= Hvdroxvethvl acrvlate Polymer =Ethylenelvmyl chlorrde/acrylamrde hydroxyethylacrylate l3 Component= N-isopropylacrylamide Polymer Ethylene/vinyl chloride/acrylamide/ N-isupropylacrylamide l4 ComponenF N-ethylmethacrylamide Polymer Ethylene/vinyl chloride/acrylamide/ N-ethylmethlmethacrylamide l5 Component= A diammonium salt of itaconnic acid Ethylene/vinyl chloride/acrylamide/ Polymer diammonrum itaconate Component= Monobutyl acid maleate Polymer Ethylene/vinyl chloride/acrylamide/ monobutyl acid maleate l7 Component= N-methacrylylpropionamide Ethylene/vinyl chloride/accylamide/ N-methacrylylpropionamide EXAMPLE 18 An aqueous dispersion of ethylene/vinyl chloride/ acrylamide (21/76/3) interpolymer prepared substantially in accordance with'Example l and containing about 45 weight percent polymer solids is coagulated by means of tetrahydrofuran. The interpolymer is washed with water and dried. About 100 parts of polyvinylidene chloride having a weight average molecular weight of about 100,000 is admixed with about 150 parts of the dry interpolymer by kneading to form a polyblend composition. The polyblend composition can be used as is or dissolved in a solvent or dispersed in aqueous media.

EXAMPLE 19 An aqueous dispersion of E/VCl/A interpolymer containing about 45 percent polymer solids is admixed with aqueous dispersions of polyvinylidene chloride containing about 25 percent polymer solids using moderate stirring over a period of one-fourth hour. The polyvinylidene chloride has a molecularweight of about 100,000. The E/VCl/A interpolymer contains 21 percent ethylene, 76 percent vinyl chloride and 3 percent acrylamide. The water is removed by evaporation and the polyblend compositions are observed for compatibility, i.e., exudation, blooming or tack development. Results and further details are given in Table ll below wherein the amount of E/VCl/A interpolymer in the polyblend compositions is expressed in parts by weight per l00 parts by weight of polyvinylidene chloride.

Polymer TABLE II E/VCl/A interpolymer, Amount Compatibility l Good 10 Excellent 22 Excellent 50 Excellent Good The fibrous substrates to which the polyblend compositions are applied include papers of all types, such as bond writing paper, fibrous paperboards such as cardboard, chipboard, carton stock, and the like, wrapping papers or boards, or liners for containers intended for the packaging of foods, greases, chewing gum; soap, soap powders, cosmetics, calking compounds, etc. The coated papers may also be used as wallpapers, papers for lining drawers and shelves, especially in linen closets, kitchen cabinets and the like, and the coated paper or paperboards may be used as bookcovers or book pages.

The polyblends may be applied to building construction papers and boards, such as the facing paper on plasterboard. It may be used as a release-coating on a paper to be used as a liner in a concrete molding form or adapted to be used for covering freshly-laid concrete roads.

The fibrous substrate, such as paper, which may be coated with latex polyblends of polyvinylidene chloride polymer latex and ethylene/vinyl chloride/acrylamide interpolymer latex to produce a product of enhanced barrier characteristics may contain from about 0.5 to pounds of latex blend on one side per ream. (A ream is 3,000 sq. ft. and equals 500 sheets, 24 inches by 36 inches.) Generally, however, about 1 to 20 pounds of latex blend per ream is adequate while 1 to 4 pounds is all that is needed for many purposes.

The processes for applying a latex polyblend coating to fibrous substrates are well known in the art. Such techniques include spraying, roller coating, air-knife coating, trailing blade coating, curtain coater and use of a Mayer rod (machine).

The following examples illustrate the advantageous and unexpected properties which areachieved by the used the polyblends of the present invention as fibrous substrate coating materials, but it is not intended that this invention be limited by or to the examples.

The latex polyblend are applied to the felt side of the substrate by means of a wire wound rod. Coating rod numbers 6, 18 and 28-are utilized in applying the film. A No. 6 rod has a smaller wire diameter and more winds for a given rod length which deposits a light continuous wet film whereas the N0. 28 rod has a larger wire diameter and fewer winds per inch which deposits at much heavier film.

A series of paper sheets were coated with latex blends as shown in Table 111 containing varying proportions of polyvinylidene chloride polymer and E/VCl/A interpolymers. in these examples all parts are parts by weight. The coatings are then tested for various physical properties. The test procedures are hereinafter described and the results are listed in Tables 1V and V.

The test methods used to determine the physical properties of the fibrous substrates coated with the latex polyblends of this invention are listed below along with explanatory notes where necessary. Samples were conditioned according to TAPPI T402m-49 before testing. The paper base stock used in the testing hereinafter described is indicated where applicable for individual examples.

Oil ResistanceCreased Box Test A 6 X 6 inch coated one side specimen blank is folded diagonally from comer to corner, each fold is subjected to a 5 lb. pressure. The blank is further folded one'inch from each edge and then made up into a 4 X 4 inch box having 1 inch side walls with the coated surface inside. All creases, except those made by the side wall folds converge as an apex in the center of the box bottom. 50 cc NO. 10 SAE oil is poured into the box and the time required to penetrate the creased areas is noted.

Moisture-Vapor Transmission Rate A.S.T.M.' 3-988 (tropical atmosphere)-Reported as Grams H O/100 sq. inches/24 hrs. at 100 F. and 90 percent relative humidity.

TABLE IIL-IROPERTIES 0F POLYVINYLIDENE CHLO- RIDE POLYMER, ETHYLENE VINYL CHLORIDE ACRYLAMIDE INTERPOLYMER LATEX POLYBLENDS Component Latex Exan1plo Percent Viscosity. total cps. at

Composition PVDO u 1 2 S solids 25 C. p11

The Polyblends of Table 111 were used in preparing a series of coated papers of 30 lb blue white glassine stock by applying two coats of each composition to one side of each sheet with a No. 6 rod. The water vapor transmission rates of the coated papers are set forth in Table IV.

TABLE IV Moisture Vapor Transmission Rates for Coatings of Latex The oil resistance properties obtained with a series of paper stock of 50 1b bleached kraft, double coated with a No. 6 rod on one side of each sheet with the compositions of Table 111 are shown in Table V.

POLYVINYLIDENE CHLORIDE POLYMER AND ETI'IYLENE/VINYL CHLO RIDE/ACRYLAMIDE IN'IE RPOLYMERS Number of penetrations Coating wt., Time, U nct'cascd Cast film Composition 1b./1,000 11:. seconds Greased areas characteristic 4. 74 660 13 32. 5 4. 42 330 14 14 Flexible. 4. 03 390 10. 5 22. 5 Do. 4. 23 270 9 32. 5 D0. 4. 18 135 8 45 Do. 4. 90 112. 6 7 37. 5 Do. 4. 78 210 18 D0. 4. 55 185 15 100 D0. 5. 11 10 100 Do. 4. 83 117 8 75 Do. 4. 45 92 i) 50 Do. 3. 87 480 13 20 D0. 3. 79 540 9. 5 20 D0. 4. 05 1, 095 4. 5 6 D0. 4. 28 1, 695 0 3 D0. 4. 7) 6, 540 0 5 D0.

The results set forth in Tables IV and V show that compositions B through P impart to the paper the desirable combination of oil and water vapor resistance and good flexibility. Such combination of properties is not attainable when polyvinylidene chloride polymer is used as the sole coating material.

The replacement of latices l, 2 and 8 of the compositions B through P with Examples 3 through 7 and 9 through 17 results in coated papers having properties similar to those presented in Tables lV'and V. Paperboard such as cardboard, carton stock and chipboard exhibit similar excellent properties as shown in Tables IV and V when coated with the latex polyblends of this invention.

The paper to be coated can be of a wide variety of types including kraft, bond, parchment, etc. The type, weight and other physical properties of the'paper to which the coating is applied do not significantly offer the improvement in oil resistance and moisture vapor transmission rate brought about by the method of the invention.

The coated papers provided by the present invention have utility for many purposes which will be obvious to those skilled in the art. In particular, the coated papers may be used to wrap food products where it is desired to prevent the transmission of moisture from the atmosphere to the packaged product. The coated papers are easily heat sealed and hold liquids well. As a result, such coated papers can be used in the manufacture of paper drinking cups and the like.

The E/VCl/A interpolymer-polyvinylidene chloride polyblend compositions of this invention are also useful as protective coatings for substrates such as wood, metal and glass; as laminating adhesives for safety glass, paper products and the like; as wrapping films and sheeting and as shaped articles such as protective bumper extensions and caps. When used as protective coatings for substrates such as wood, metal and glass the polyblend compositions can be applied in the form of an organic solvent solution or in the form of aqueous dispersions optionally containing pigments and dyes.

The embodiments of this invention in which a particular property or privilege is claimed are defined as follows:

i. Ethylene-vinyl chloride-acrylamide interpolymerpolyvinylidene chloride polyblend composition comprising (I) an ethylene-vinyl chloride-acrylamide interpolymer selected from the group consisting of (A) an ethylene-vinyl chlorideacrylamide interpolymer containing from about 2 to about 70 weight percent ethylene, from about 30 to about 88 weight percent vinyl chloride, and from 0.1 to about weight percent of an additional polar component selected from the group consisting of 1. acrylamide, and

2. acrylamide in combination with at least one additional polar monomer selected from the group consisting of acrylonitrile, N-(alkyl) acrylamide having from one to three carbon atoms in said alkyl groups, N-methylol acrylamide, N[2-( 2-methyl-4-oxopentyl)] acrylamide, methacrylamide, N-(alkyl) methacrylamide having from can onto three carbon atoms in said alkyl groups, acrylic acid, methacrylic acid and alkali metal and ammonium salts of acrylic and methacrylic acid, maleic and fumaric acids, itaconic and citraconic acids, half alkyl esters of maleic, fumaric, itaconic, and citraconic acids having from one to six carbon atoms in said alkyl groups, acrylyland methacrylyl esters of hydroxyalkanoic acids having from two to six carbon atoms in said alkanoic acids, acrylylamide and methacrylylamides of aminoalkanoic acids having from two to six carbon atoms in said aminoalkano- I ic acid, hydroxyethyl and hydroxypropyl esters of acrylic, methacrylic, maleic and fumaric acids, vinyl esters of alkanoic acids having from one to six carbon atoms, vinyl esters of alkylsulfonic acids having from one to six carbon atoms in the alkyl group, vinyl esters of phenylsulfonic acids, acrylyl and methacrylyl esters of hydroxyalkylsulfonic acid having from one to six carbon atoms in said alkyl moieties, and acrylyl and methacrylyl ester of hydroxyalkylsuflonamides, having from 1 to 6 carbon atoms in said hydroxyalkyl moieties; and (B) interpolymers of the type described in (A) treated with an acid or a base having an ionization constant higher than about l0 in amounts equivalent to up to about 100 percent of the amide content of said interpolymer, and (II) polyvinylidene chloride wherein (l) is present in an amount from about 0.05 parts to about 20 parts for each one part by weight of (II). 2. Composition of claim 1 wherein the interpolymer contains from about 15 to about 70 weight percent ethylene, from about 30 to about weight percent vinyl chloride and from about I to about 5 weight percent acrylamide.

3. Composition of claim 1 wherein the interpolymer is represented by (B).

4. Composition of claim 1 wherein the ethylene-vinyl chloride-acrylamide interpolymer is present in an amount from about 0.1 parts to about 0.4 parts by weight for each one part by weight of (ll).

5. Composition of claim 1 wherein the interpolymer contains from about 15 to about 70 weight percent ethylene, from about 30 toabout 85 weight percent vinyl chloride and from about I to about 5 weight percent acrylamide and is present in an amount from about 0.! parts to about 0.4 parts by weight for each one part by weight of ll).

6. Composition of claim 1 wherein the interpolymer contains about 76 percent vinyl chloride, about 21 percent ethylene and about 3 percent acrylamide.

7. Composition of claim 1 wherein the additional polar component comprises acrylamide and N-methylol acrylamide.

8. Composition comprising a dispersion of the polyblend composition of claim 1 in an aqueous medium.

9. Composition of claim 8 wherein the polyblend composition the interpolymer contains from about 15 to about 70 weight percent ethylene, from about 30 to about 85 weight percent vinyl chloride and from about 1 to about 5 weight percent acrylamide.

Claims

2. Composition of claim 1 wherein the interpolymer contains from about 15 to about 70 weight percent ethylene, from about 30 to about 85 weight percent vinyl chloride and from about 1 to about 5 weight percent acrylamide.
2. acrylamide in combination with at least one additional polar monomer selected from the group consisting of acrylonitrile, N-(alkyl) acrylamide having from one to three carbon atoms in said alkyl groups, N-methylol acrylamide, N(2-(2-methyl-4-oxopentyl)) acrylamide, methacrylamide, N-(alkyl) methacrylamide having from one to three carbon atoms in said alkyl groups, acrylic acid, methacrylic acid and alkali metal and ammonium salts of acrylic and methacrylic acid, maleic and fumaric acids, itaconic and citraconic acids, half alkyl esters of maleic, fumaric, itaconic, and citraconic acids having from one to six carbon atoms in said alkyl groups, acrylyl and methacrylyl esters of hydroxyalkanoic acids having from two to six carbon atoms in said alkanoic acids, acrylylamide and methacrylylamides of aminoalkanoic acids having from two to six carbon atoms in said aminoalkanoic acid, hydroxyethyl and hydroxypropyl esters of acrylic, methacrylic, maleic and fumaric acids, vinyl esters of alkanoic acids having from one to six carbon atoms, vinyl esters of alkylsulfonic acids having from one to six carbon atoms in the alkyl group, vinyl esters of phenylsulfonic acids, acrylyl and methacrylyl esters of hydroxyalkylsulfonic acid having from one to six carbon atoms in said alkyl moieties, and acrylyl and methacrylyl ester of hydroxyalkylsuflonamides, having from 1 to 6 carbon atoms in said hydroxyalkyl moieties; and (B) interpolymers of the type described in (A) treated with an acid or a base having an ionization constant higher than about 10 4 in amounts equivalent to up to about 100 percent of the amide content of said interpolymer, and (II) polyvinylidene chloride wherein (I) is present in an amount from about 0.05 parts to about 20 parts for each one part by weight of (II).
3. Composition of claim 1 wherein the interpolymer is represented by (B).
4. Composition of claim 1 wherein the ethylene-vinyl chloride-acrylamide interpolymer is present in an amount from about 0.1 parts to about 0.4 parts by weight for each one part by weight of (II).
5. Composition of claim 1 wherein the interpolymer contains from about 15 to about 70 weight percent ethylene, from about 30 to about 85 weight percent vinyl chloride and from about 1 to about 5 weight percent acrylamide and is present in an amount from about 0.1 parts to about 0.4 parts by weight for each one part by weight of (II).
6. Composition of claim 1 wherein the interpolymer contains about 76 percent vinyl chloride, about 21 percent ethylene and abOut 3 percent acrylamide.
7. Composition of claim 1 wherein the additional polar component comprises acrylamide and N-methylol acrylamide.
8. Composition comprising a dispersion of the polyblend composition of claim 1 in an aqueous medium.
9. Composition of claim 8 wherein the polyblend composition the interpolymer contains from about 15 to about 70 weight percent ethylene, from about 30 to about 85 weight percent vinyl chloride and from about 1 to about 5 weight percent acrylamide.