GB2054407A

GB2054407A - Decorative covering material

Info

Publication number: GB2054407A
Application number: GB7926420A
Authority: GB
Original assignee: GAF Corp
Current assignee: GAF Corp
Priority date: 1979-07-30
Filing date: 1979-07-30
Publication date: 1981-02-18

Abstract

A decorative sheet-type covering material has a substrate comprising a porous mat saturated and completely coated on both sides with foamed, curved PVC plastisol or organosol or with foamed, flexible urethane. It is made by coating one side of a porous mat with foamable PVC plastisol or organosol and then heating and foaming the plastisol or organosol or by coating one side of the porous mat with reactive urethane mixture which is then allowed to foam. The mat may consist of glass fibres.

Description

SPECIFICATION Decorative covering material Background of the invention Decorative, flexible, sheet-type covering materials such as wall or floor coverings are conventionally manufactured with non-woven organic or glass fiber mats or woven cloth as a substrate. Where glass fiber mats are used, it is desirable to insure that both faces of the glass mat are covered with a protective coating to protect those handling the covering material from the skin irritation associated with handling glass fiber material. Availability of a suitable surface for printing is also desirable. Satisfactory substrates using glass mats are especially desirable as a replacement for the more commonly used asbestos felt substrates in view of the currently recognized hazards to health involved in the use of asbestos.

While glass mats coated with protective material are known, the use of such mats coated on both sides or faces with protective material has in the past involved lamination of coatings, the use of release paper or saturation as in a dip and squeeze process. In other applications, glass mats have been coated on one side with cured polyvinyl chloride (PVC) plastisol or organosol as illustrated for instance in U.S. Patent 3,490,985 to Marzocchi et al.

Summary ofthe invention It is an object of the invention to provide improved, decorative flexible sheet-type covering material which has a substrate comprising a porous mat saturated and completely coated on both faces with foamed, heat cured PVC plastisol or organosol or with foamed, heat cured flexible urethane.A further object of the invention is to provide a method for making covering material of the invention comprising coating one side only of a porous mat with foamable PVC plastisol ororganosol or with heat curable, foamable urethane mixture, causing said plastisol or organosol, or urethane mixture to completely penetrate said mat, foaming said plastisol or organosol, or urethane mixture so as to saturate said mat and completely coat said mat on both sides with the thus foamed plastisol or organosol or urethane mixture and then heat curing the thus foamed plastisol or organosol or urethane mixture to provide sheet-type covering material of the invention.

Detailed description As mentioned above, the decorative, flexible, sheet-type covering material of the invention has a substrate comprising a porous mat saturated and completely coated on both faces with foamed, heat cured PVC plastisol or organosol or urethane. While the invention is applicable to porous mats made from any flexible material, the preferred material is glass fibers in woven or nonwoven form with nonwoven glass fiber mats being especially preferred. Mats for use in the invention should have openings of a suitable size so that the PVC plastisol or organosol or urethane reaction mixture used can penetrate the mat as described below to insure saturation of the mat and thorough coating of the mat on both sides with the foamed PVC plastisol or organosol or urethane.Complete coverage of both sides of the mat is essential to protect those handling the finished covering material from exposure to the glass fibers making up the the mat. When using the preferred plastisols ororganosols or urethane mixtures described below, nonwoven glass fiber mats suitable for use in the invention generally have openings averaging between about 1 and about 20 mils in the smallest linear dimension with at least about 50% of such openings having smallest linear dimensions between about 2 and about 10 mils. Preferred mats include those having a thickness between about 10 and about 40 mils and a density between about 1 and about 4 Ibs. per 100 square foot.Such mats may be manufactured by conventional techniques used for manufacturing nonwoven glass mats with the glass fibers used preferably having an average diameter between about 5 and about 20 microns, more preferably between about 7 and 15 microns, and fiber lengths between about 0.2 and about 1.5 inch. Binders conventionally used for coating glass fibers may be used and where used are normally present in amounts between about 1 and about 50 wt% of the mat. Suitable binders for coating glass fibers of the mats used in the invention include, for instance, urea-formaldehyde, latexes, thermosetting resins such as polyester resins, epoxy resins and the like and may include, among other conventional binders, those mentioned in U.S. Patent 3,554,851 to Modigliani. The binder may, of course, be applied to the glass fibers in a conventional manner.

Decorative, flexible, sheet-type covering material contemplated by the invention includes conventional wall and floor coverings and especially materials such as sheet vinyl, linoleum and the like. Such sheet vinyl flooring frequently has one or more foamed or unfoamed vinyl layers of the PVC type generally used in vinyl flooring over the substrate. The vinyl layer may comprise any of the PVC resin materials normally used in connection with the manufacture of sheet vinyl flooring and may specifically include but is not limited to those described in U.S. Patent 3,458,337. The vinyl layer in such flooring materials is typically on the order of between about 5 and about 25 mils thick and may be opaque, translucent or transparent as desired. Other layers of sealer, pigmented layers, plastisols, wear layers, etc. known in the art may, of course, be used.

Where transparent or translucent vinyl layers are used, it is frequently desirable to apply a printed design to the coated substrate formed in accordance with the invention. Since the foamed coating on the substrate may not always be sufficiently smooth for direct printing on some designs, a conventional sealing or priming coat of latex or of plastisol or organosol as described for instance in U.S. Patent 3,519,460 may be used.

Conventional latex containing an acrylic polymer such as the prime coat described in the above-mentioned U.S. Patent 3,458,337 is, for instance, suitable for this purpose.

PVC plastisol or organosol used in forming the foamed coating of the product of the invention may be any of the conventional PVC materials known in the art for use as foamed layers on flooring materials and includes for instance those described in the abovementioned patent 3,458,337. A variety of PVC plastisols and organosols suitable for use in the invention are also described in U.S. Patent 3,293,094. The foaming or blowing agent incorporated in the foamable plastisol or organosol may be a conventional blowing agent or catalyst-activated blowing agent such as are well known in the art for producing foamed plastisols or organosols. Suitable blowing agents include, for instance, azodicarbonamide (ABFA) and other conventional blowing agents such as those enumerated in the above-mentioned U.S. Patent 3,293,094.

Heat curable, flexible, foamable urethane mixtures suitable for use in the invention include a wide variety of urethane materials. By the term "heat curable, foamable flexible urethane mixture" is meant a mixture which, when foamed and cured in the form of an unreinforced 1/4 inch urethane foam sheet, can be bent 180 F. around a one inch mandrel without permanent set. In general suitable urethanes include the reaction product of an organic compound having at least two active hydrogen atoms, such as, a hydroxy-terminated polyester, polyesteramine, amide or polyether, and an organic polyisocyanate.

In general, any organic compound containing at least two active hydrogen atoms may be employed herein for reaction with the polyisocyanate to produce a flexible polyurethane foam. Examples of suitable types of organic compounds containing at least two active hydrogen groups are castor oil, hydroxy-containing polyesters, polyalkylene polyether polyols, hydroxy-terminated polyurethane polymers, polyhydric polythioethers, alkylene oxide adducts of acids of phosphorus, aliphatic polyols, as well as mixtures thereof.

Any suitable hydroxyl-containing polyester or polyester amide may be used such as are obtained, for example, from polycarboxylic acids and polyhydric alcohols. Likewise, any suitable polyalkylene polyether polyol may be used, such as the polymerization product of an alkylene oxide or of a mixture of alkylene oxides with a polyhydric alcohol. Typical polyether polyols include polyoxyethylene glycols, poly-1,2- oxybutylene and polyoxyethylene glycols polytetramethylene glycols, block copolymers, e.g., combinations of polyoxypropylene and polyoxyethylene glycols, poly-1,2-oxybutylene and polyoxyethylene glycols and poly-1,4-oxybutylene and polyoxyethylene glycols, and random copolymer glycols prepared from blends or sequential addition of two or more alkylene oxides.

Any suitable polyhydric polythioether may also be used, such as, for example, the condensation product of thiodiglycol or the reaction product of a dihydric alcohol.

The organic polyisocyanates which are advantageously employed in the present invention can be represented by the formula: R(NCO)z wherein R is a polyvalent organic radical selected from the group of aliphatic, aromatic, arylalkyl and alkylaryl organic radicals as well as mixtures thereof; and z is an integer corresponding to the valence number of R and is at least 2. Representative of the organic polyisocyanates contemplated herein includes, for example, the aromatic diisocyanates, such as 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, mixture of 2,4-and 2,6-toluene diisocyanate, crude toluene diisocyanate, methylene diphenyl diisocyanate, crude methylene diphenyl diisocyanate and the like.Other organic polyisocyanates include polymethylene polyphenylisocyanate, hydrogenated methylene diaphenylisocyanate, m-phenyene diisocyanate, naph thylene-1 ,5-diisocya nate, 1 -methoxyphenyl-2,4-diisocyanate, diphenyl metha ne-4,4'-diisocyanate, 4,4'biphenylene diisocyanate, 3,3'-dimethoxy-3,4'-biphenyl d;;socyanate, 3,3'-dimethyl-diphenylmethane-4,4'diisocyanate. These polyisocyanates are prepared by conventional methods known in the art such as the phosgenation of the corresponding organic amine. In the practice of the present invention, it is preferred to use as the isocyanate either crude toluene diisocyanate, an 80:20 weight mixture of 2,4-and 2,6-toluene diisocyanate, polymethylene polyphenyl polyisocyanate, crude methylene di(phenylisocyanate) or mixtures thereof.

In accordance with the present invention, a polyisocyanate is preferably employed at an isocyanate index of from about 105 to 115. As used herein, the term isocyanate index means the actual amount of isocyanate used divided by the theoretically required stoichiometric amount of isocyanate multiplied by one hundred.

See Bender, Handbook of Foamed Plastics, Lake Publishing Corp. Libertyville, 111 (1965). Conventional catalysts, such as tertiary amines and the like, may be incorporated into the foam formulation in order to provide the products envisioned hereby. This same fact is true with regard to conventional diamine cross-linking agents.

In addition to the previously defined ingredients useful in the preparation of the foam, other ingredients, such as surfactants, fillers, pigments and the like can also be included. Surfactants which can be used are the conventional surfactants such as the polysiloxanes or the alkylene oxide adducts of organic compounds containing reactive hydrogen atoms and are generally employed in an amount ranging from about 0.1 part to 5 parts by weight thereof per hundred parts of polyol. Conventional urethane blowing agents, such as water, halohydrocarbons, hydrocarbons, and the like can also be employed herein in their conventional mode.

Urethane foam mixtures used in making foams suitable for the invention should have cream times (time from formation of the mixture to beginning of foaming) sufficientto allow penetration of at least about one-half the thickness of the mat before foaming begins. Where mixtures are formed at wating temperature and immediately coated onto the mat, cream times of at least about three seconds preferred. Creaming will of course occur when the urethane is heated to curing temperature if creaming has not previously occurred.

While a wide variety of conventional PVC plastisols or organosols or urethane reaction mixtures are suitable for use in the product and process of the invention, selection of a particular plastisol or organosol or mixture thereof or a particular urethane mixture suitable for a given application preferably takes into account such factors as the nature of the porous mat to be saturated and coated, the particle size of PVC resin, the viscosity and degree of solvation of the plastisol, viscosity of urethane mixture, etc. Generally the most important factors are the nature of the mat, especially the distribution and size of the openings in the mat, the amount and size of resin particles in the plastisol or organosol, reaction time (cream and gel time) of the urethane mixture, viscosity of the urethane mixture before reaction begins, and the viscosity of the plastisol or organosol.For ease of application to the mat and to insure complete saturation and coating of both sides of the mat by the foamed plastisol or organosol or urethane mixture be of a suitable viscosity so that it can be coated on one surface only of the porous mat and allowed to penetrate the mat either at the coating temperature or by increase in temperature after the coating step. If material of too great a viscosity is used, complete penetration, saturation and coating of both sides of the mat will not take place and the finished substrate may well be of the type desired in the above-mentioned patent 3,490,985 rather than the type which is the subject of the present invention. If material of too low a viscosity is used, it will tend to pass through the porous mat too readily prior to foaming and proper saturation and coating may not be obtained.

While suitable viscosities for plastisols, organosols and urethane mixtures used in the present invention may vary widely depending upon the type of mat and coating and foaming conditions used, preferred viscosities when using preferred glass fiber mats of the type described above are between about 500 and about 10,000 centiposies (cp) at coating temperatures as measured on a Brookfield RVF viscometer with a number 3 spindle at 20 RPM. While coating is frequently carried out at room temperature, this is by no means essential and coating temperatures between about 50 and about 1 50"F are frequently suitable.In a preferred embodiment of the invention, coating is carried out at between about 50 and about 120oF using a plastisol or organosol or urethane mixture which penetrates the mat to a depth of between about one half and about three fourths the thickness of the mat at coating temperature. The coating is then heated to a temperature between about 200 and about 4000F to cause the plastisol or organosol or urethane mixture to completely penetrate the mat. Heating to cause penetration of the mat may be a separate manufacturing step or may be part of the heating process used to foam and cure the plastisol or organosol or urethane mixture.

Where heating to cause penetration of the mat is used as a separate manufacturing step, the foam coated mat is preferably heated to a temperature less than about 200 F. Curing temperatures between about 200 and about 400"F are preferred to allow cure times between about 0.5 and about 3 minutes.

For use with the preferred type of glass fiber mat described above, PVC resins are usually a combination of suspension and dispersion resins, although completely satisfactory results are obtained with 100% dispersion resin. Dispersion resins in general are more expensive than suspension resins but tend to have smaller particle sizes, e.g. between about 0.5 and about 5 microns, and higher intrinsic viscosities than suspension resins. Dispersion resins are commonly made by emulsion polymerization and are well known to those skilled in the art. Suspension resins are made by suspension polymerization and have relatively lower intrinsic viscosity and relatively larger particle size than dispersion resins. Particle sizes for typical PVC suspension resins frequently range between about 5 and about 50 microns.In practicing preferred embodiments of the invention, PVC plastisols or organosols in which dispersion resin comprises between about 35 and about 100 weight percent of the total PVC resin content are preferred with dispersion resin contents between about 45 and about 75 weight percent being especially preferred when the preferred glass fiber mats described above are used and the organosol or plastisol is coated on one side of the mat but does not penetrate completely through the mat until further heating takes place.

Application of PVC plastisol or organosol or urethane mixture to porous mats in accordance with the invention may be by any suitable means such as knife coating or roll coating. Using the preferred glass fiber mats and plastisols, or urethane mixtures described above, foam coatings between about 10 and about 20 mils thick are generally satisfactory to provide complete saturation and coverage of both faces of the mat when the plastisol, organosol or urethane mixture is foamed.

The following examples illustrate preferred embodiments of the invention but are not intended to limit the scope of the invention.

Example I To demonstrate the utility of the invention, a metered coating approximately 1 2 mi 12 milsthickoffoamable PVC plastisol was drawn onto a nonwoven fiberglass mat using a conventional knife coater. The mat was made up of glass fibers having an average diameter of about 9 microns and an average length of about 0.75 inch.

The fibers were coated with a urea-formaldehyde binder with the binder making up about 15 weight percent of the mat. The mat has a total density of 1.4 Ibs. per 100 square feet with openings in the mat having smallest linear dimensions averaging about 5 mils. The mat was 15 mils thick. The plastisol was coated onto the mat at a temperature of 75"F. The foamable plastisol coated onto the mat had the followng composition:: Ingredient Parts by weight PVC Homopolymer Dispersion resin 50 PVC Homopolymer Suspension Resin 50 Plasticizer 60 Pigment 7.5 Blowing Agent (ABFA) 2.5 Stabilizer-Catalyst 2.5 After coating of the mat as described above, the coated mat was then heated to a temperature of 370"F whereby the plastisol, which had an original viscosity at coating temperature of 800 cp and had previously penetrated about one-half the thickness of the mat, was allowed to completely penetrate the mat. Upon foaming of the plastisol, it was found that the finished substrate product was completely saturated and coated on both sides with the foamed PVC plastisol.

Example II Utility of the invention was further demonstrated by coating approximately a 12 mil thick layer of foamable plastisol onto one face only of a nonwoven fiberglass mat approximately 18 mils thick and weighing approximately 2.3 Ibs. per 100 square feet using a conventional three roll reverse roll coater. The plastisol used was the same as that described in Example I except that PVC was used in amounts of 65 parts by weight dispersion resin and 35 parts by weight suspension resin. The glass mat was similar to that used in Example I except that the binder was a latex binder making up about 40 weight percent of the mat. Except as mentioned immediately above, Example II was conducted in the same manner as Example I.As in example I, the plastisol penetrated about one-half the thickness of the mat until subsequent heating and curing when the plastisol completely penetrated the mat and the foamed plastisol expanded to completely saturate the mat and cover both faces thereof.

Example lIl To demonstrate the utility of the invention, a metered coating approximately 12 mils thick of flexible, foamable urethane mixture may be drawn onto a non-woven fiberglass mat using a conventional knife coater. The mat may be made up of glass fibers having an average diameter of about 9 microns and an average length of about 0.75 inch. The fibers may be coated with urea-formaldehyde binder with the binder making up about 15 weight percent of the mat. The mat may have a total density of 1.4 Ibs. per 100 square feet with openings in the mat having smallest linear dimensions averaging about 5 mils.The mat may be 15 milsthick. The urethane may be coated onto the mat from a continuous mixing and dispersing machine at a temperature of 75"F. The urethane mixture may have the following composition: Ingredient Parts by Weight STREAM 1 Urethane prepolymer, based on poly(tetramethylene glycol) and toluene diisocyanate, having 6.35% NCO 100 Methylene chloride blowing agent 8 Silicone copolymer surfactant 2 STREAM 2 Butanediol crosslinking agent 6.5 Triethylene diamine catalyst 0.05 After coating of the mat as described above, the coated mat may then be heated to a temperature of 180"F whereby the urethane mixture, which has an original viscosity at coating temperature of about 800 cps and has previously penetrated about one-halfthe thickness of the mat, is allowed to completely penetrate the mat. The urethane may then be foamed and cured at a temperature of 300"F with a cure time of about 2 minutes. Upon foaming of the urethane, it will be found that the finished substrate is completely saturated and coated on both sides with the foamed flexible urethane.

While the invention has been described above with respect to preferred embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit or scope of the invention.

Claims

1. Decorative, flexible, sheet-type covering material having a substrate comprising a porous mat saturated and completely coated on both sides with foamed, heat cured, PVC plastisol or organosol or flexible urethane.

2. Material according to Claim I in which the mat is a nonwoven mat of glass fibers.

3. Material according to Claims 1 or 2 in which the mat comprises glass fibers having an average diameter between about 7 and about 15 microns, an average length between about 0.2 and about 1.5 inch and in which the openings in such mat average between about 1 and about 20 mils in the smallest linear dimension with at least about 50% of such openings having smallest linear dimension between about 2 and about 10 mils.

4. Method for making flexible coated substrate material comprising the steps of: (a) coating one side only of a porous mat with foamable PVC plastisol or organosol or urethane mixture; (b) causing said plastisol or organosol or urethane mixture to completely penetrate said mat; (c) then foaming said plastisol or organosol or urethane mixture so as to saturate and completely coat said mat on both faces thereof with the thus foamed plastisol or organosol or urethane mixture; and (d) then heat curing the thus foamed plastisol or organosol or urethane mixture.

5. A method according to Claim 4wherein the coating offoamable plastisol or organosol or urethane mixture applied to one side of the mat penetrates between about one-half and about three-fourths the thickness of the mat at the temperature at which such coating is applied and in which the mat is subsequently heated to a temperature sufficient to cause the plastisol or organosol or urethane mixture to completely penetrate the mat prior to foaming thereof.

6. A method according to Claim 5 wherein the mat is coated or urethane mixture at a temperature between about 50O and about 120"F and is subsequently heated to a temperature between about 200 and about 400"F to therebycause the plastisol or organosol or urethane mixture to completely penetrate the mat and to foam the plastisol or organosol or urethane mixture.

7. A method according to any of Claims 4,5 or 6 wherein the PVC plastisol or organosol or urethane mixture has a viscosity between about 500 and about 10,000 cp at the temperature at which it is coated onto the mat and wherein the porous mat is a nonwoven fiberglass mat, the openings of which average between about 1 and about 20 mils in the smallest linear dimension with at least about 50% of such openings having smallest linear dimensions between about 2 and about 10 mils.

8. A method according to any of Claims 4, 5,6 or 7 wherein the PVC plastisol or organosol contains between about 35 and about 100 weight percent based on PVC resin of dispersion resin with the remainder of such resin being suspension resin.

9. A method for making flexible coated substrate material substantially as herein described with reference to any one of the Examples.

10. Flexible coated substrate material substantially as herein described with reference to any one of the Examples.

11. A decorative sheet-type covering material having a substrate according to Claim 10 or made by the method of any one of Claims 4 to 9.