US3681116A - Flexible cast-coated paper - Google Patents
Flexible cast-coated paper Download PDFInfo
- Publication number
- US3681116A US3681116A US33092A US3681116DA US3681116A US 3681116 A US3681116 A US 3681116A US 33092 A US33092 A US 33092A US 3681116D A US3681116D A US 3681116DA US 3681116 A US3681116 A US 3681116A
- Authority
- US
- United States
- Prior art keywords
- paper
- coating
- cast
- coated
- papers
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H19/00—Coated paper; Coating material
- D21H19/72—Coated paper characterised by the paper substrate
- D21H19/76—Coated paper characterised by the paper substrate the substrate having specific absorbent properties
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H19/00—Coated paper; Coating material
- D21H19/36—Coatings with pigments
- D21H19/44—Coatings with pigments characterised by the other ingredients, e.g. the binder or dispersing agent
- D21H19/50—Proteins
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H19/00—Coated paper; Coating material
- D21H19/36—Coatings with pigments
- D21H19/44—Coatings with pigments characterised by the other ingredients, e.g. the binder or dispersing agent
- D21H19/56—Macromolecular organic compounds or oligomers thereof obtained by reactions only involving carbon-to-carbon unsaturated bonds
- D21H19/58—Polymers or oligomers of diolefins, aromatic vinyl monomers or unsaturated acids or derivatives thereof
Definitions
- This invention relates to cast-coated papers and, more particularly, to cast-coated papers that have improved properties of flex, ply, stretch, and a more natural limp, rag-like hand.
- Cast-coated papers are quite desirable for some uses due to their high coating weights, their high bulk and greater ink absorption as compared with papers made by conventional processes involving supercalendering, which tends to compress and density the coating, and, most importantly, the coated papers are desirable for their ultra high finish and gloss.
- these papers are relatively stifl, which stifiness may be objectionable in some applications.
- the coating will usually fracture and expose the paper substrate. Since many applications for high gloss cast-coated papers are for decorative purposes, such as wrapping papers and the like, the comparative inflexibility of the coating and its tendency to crack away from the paper when folded is particularly undesirable.
- cast-coated papers can be manufactured which, when compared to those known to the prior art, have a much higher degree of flex, ply and stretch, while at the same time they preserve all of the desired properties of the cast-coated paper, such as high gloss.
- Another object of this invention is to provide a castcoated paper in which the coating will not crack or fracture when the paper is repeatedly flexed or creased at a sharp angle.
- Another object of this invention is to prepare a cast- ;oalted paper that has a comparatively limp and rag-like Briefly, these and other objects of this invention are attained by selecting as the paper substrate a saturated paper having a porosity within a narrowly selected range.
- the coating By the use of such saturated papers, the coating, quite surprisingly, displays a much lesser tendency to crack and is considerably more flexible than the coatings applied to ordinary paper substrates that are not saturated.
- Saturated papers such as are of utility for use as a substrate in this invention are well known in the industry. Generally, they may be defined as papers that have been impregnated with various synthetic and natural thermoplastic resins or rubbers in order to improve the physical and/or optical properties of the paper.
- saturated refers to the fact that the paper contains some resinous component and not to the fact that the papers are saturated with some material.
- the quantity of resins that may be added to the paper can vary over a considerable range. For most applications, the amount of resins added to the paper are somewhat less than would be required to close all of the pores of the paper and cause the resin to exist in a continuous phase. If resins are added to this extent, the absorptive properties of the paper will be lost and they will not readily receive inks.
- the water of the coating composition is removed from the wet coating variously by being absorbed into the paper substrate and by evaporation through the back surface (the side away from the drum) of the paper.
- the time that the coated surface of the paper is in contact with the heated drum is of considerable importance.
- the time must be of sufficient duration to enable removal of substantially all of the water in order to form a hard surface coating, and, on the other hand, the time must not be too great, for, if it is, the coating surface may lose its gloss and begin to yellow.
- the rate at which water can be removed from the coating material is, to some extent, a function of the porosity of the paper. With many papers, the porosity can vary over a considerable extent, but, however, in the case of saturated papers, a porosity must be selected within a comparatively narrow range if successful cast coating is to be achieved.
- the reason for the greater criticality of the porosity of the saturated papers in cast coating operations lies in the fact that the resinous content of the paper changes the capillary structure of the paper. As the resins will tend to coat individual fibers of the paper, internal absorption of the water component of the aqueous coating is materially decreased. Also, the total number of open pores in the paper is reduced as some are filled by the resins. It is believed that in most instances, saturated papers have a considerably less total number of pores, although the pores that do remain are comparatively open and pass relatively straight through the paper as opposed to a relatively more tortuous path of the pores in papers not containing resin.
- the porosity of the saturated papers is given as determined on a Gurley Porosity Densitometer. In this test, a piece of paper is sealed over a standard orifice and the time in seconds is recorded that is required to pass a given volume of gas at a given pressure through the paper. Accordingly, the porosity will be referred to in units of seconds and a low number indicates a high porosity and a high number indicates a comparatively low porosity.
- the resins with which the paper may be saturated may vary considerably, but the following are listed as examples of more commonly used ones readily available on the market. All of them are sold by B. F. Goodrich Chemical Company under the trade designations listed.
- Hycar These are defined as being lateXes of butadieneacrylonitrile or polyacrylics.
- Geon- Fhis may be a vinyl chloride or homopolymers and copolymers of vinylidene chloride, vinyl chloride or acrylics.
- a typical cast coating composition will include a binder, which may be a synthetic latex or a hydrophyllic protein adhesive, such as casein or soya bean protein in an aqueous vehicle, and a mineral filler, such as a fine, coating-grade clay, calcium carbonate, blanc fixe, satin white, titanium pigments, color pigments, and the like, and various combinations thereof.
- a binder which may be a synthetic latex or a hydrophyllic protein adhesive, such as casein or soya bean protein in an aqueous vehicle
- a mineral filler such as a fine, coating-grade clay, calcium carbonate, blanc fixe, satin white, titanium pigments, color pigments, and the like, and various combinations thereof.
- Formaldehyde including the conventional formaldehyde donors, like monomethylol dimethyl hydantoin
- the present coating composition may be similar to those used in the past, and in which the preferred binder is casein and the preferred filler is clay, with colored pigments when desired.
- the composition may, in accordance with conventional practice, also contain a release agent which aids in separating the coated web from the casting drum surface, such as a fatty acid soap, like ammonium stearate, zinc stearate, and the like.
- the composition may also contain auxiliary or supplemental binders like acrylic resin, butadiene-styrene latex, and the like, and a protein viscosity-reducing agent, like dicyandiamide.
- the coating composition of the present invention will have a weakly acid pH; that is, a pH above 5 and below 7, preferably between 5.4 and 6.6.
- a weak organic acid such as formic, acetic, citric, and the like.
- the protein is normally initially solubilized by treatment with alkali, preferred practice involves markedly reducing the amount of alkali normally used in solubilizing the protein and adding sufficient weak acid subsequently to adjust the pH to within the stated range.
- Commercially aqueous formaldehyde solution is acid, containing formic acid, and may be relied upon to provide the desired pH.
- a weak acid as such may be used in place of or in conjunction with the Formalin to adjust the pH.
- formaldehyde is omitted from the coating composition
- the cast coated paper may subsequently be treated with a water proofing agent, such as a formaldehyde, to provide enhanced water-resistance, if desired.
- a water proofing agent such as a formaldehyde
- water-resistance in the coating may be provided by means other than the use of formaldehyde, as by the use of water-resistant auxiliary or supplemental binders of the type mentioned above.
- the content of solids will generally be between about 45 and about 60%, by weight, based on the total weight of the composition.
- the former will normally be present in a minor proportion, that is, less than 50%, usually in an amount between about 10 and about 30% by weight; and the pigment will normally be present in a major proportion, that is, more than 50%, usually in an amount between about 70 and about Formaldehyde (as 37% formaldehyde solu tion) may be present in an amount between about 1.5 and about 21% by weight, based on the dry weight of the protein binder.
- a saturated paper obtained from Kimberly Clark was selected for use in this experiment that was saturated with an acrylic latex.
- the paper was a modified kraft paper and the acrylic latex was applied as an impregnant after manufacture of the paper. (It should be noted that resins can also be beater added in making saturated papers.)
- the paper had a weight basis of 28 pounds per ream (a ream being 500 sheets-24 x 20") and had a porosity in the range of about 8 to 9 seconds.
- the following coating composition was prepared. (Parts are by weight.)
- the solids content of this composition is about 52%, its pH is about 5.7-6, and its viscosity, is between about 250 and about 1000 cps. Brookfield at room temperature using a No. 3 spindle at 12 rpm.
- Sheets of the saturated paper were then cast-coated using the techniques described above and in the referenced patent to the common assignee.
- the paper so cast-coated had an exceptionally high gloss, was quite flexible and had much of the hand and drape of the uncoated saturated paper.
- the fold test was performed by folding the paper away from the coating and against the grain of the paper through an arc of 180. A 2 pound weight (2" x 3" metal cylinder) was then rolled over the fold of the paper once. The paper was unfolded and held against a source of light. This permits the amount of cracking to be determined by visual examination.
- the saturated cast-coated paper was totally free from any visible cracks whereas at least 50% of the coating along the line of the fold was cracked away in the case of the control.
- EXAMPLE H In this example a saturated paper similar to the one used in Example I was coated. The paper had a porosity of about 5 seconds and a weight basis of 26 pounds per ream.
- the coating formulation used was as follows:
- This composition has a pH of about 6.
- the addition thereto of 5.5 parts of 37% formaldehyde lowers the pH to 5.1-5.3.
- formic acid or citric acid may be substituted for the acetic acid
- solubilized soya bean protein may be substituted for the casein
- calcium carbonate or other equivalent mineral pigment may be substituted at least in part for the clay.
- a method of making a cast-coated paper which is flexible and can withstand creasing without cracking the coating comprising coating the surface of a resin-impregnated paper substrate having a Gurley pm rosity in the range of between 4 and 30 seconds with an aqueous mineral cast-coating composition and drying the coating while in contact with a polished heated drum.
Abstract
Description
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US3309270A | 1970-04-29 | 1970-04-29 |
Publications (1)
Publication Number | Publication Date |
---|---|
US3681116A true US3681116A (en) | 1972-08-01 |
Family
ID=21868516
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US33092A Expired - Lifetime US3681116A (en) | 1970-04-29 | 1970-04-29 | Flexible cast-coated paper |
Country Status (1)
Country | Link |
---|---|
US (1) | US3681116A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2230797A1 (en) * | 1973-05-21 | 1974-12-20 | Billingsfors Bruks Ab | |
US4048380A (en) * | 1975-01-31 | 1977-09-13 | Star Paper Limited | Cast coated paper and its production and compositions for it |
US5895542A (en) * | 1994-11-23 | 1999-04-20 | Appleton Papers Incorporated | Coater and a method for coating a substrate |
-
1970
- 1970-04-29 US US33092A patent/US3681116A/en not_active Expired - Lifetime
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2230797A1 (en) * | 1973-05-21 | 1974-12-20 | Billingsfors Bruks Ab | |
US4048380A (en) * | 1975-01-31 | 1977-09-13 | Star Paper Limited | Cast coated paper and its production and compositions for it |
US5895542A (en) * | 1994-11-23 | 1999-04-20 | Appleton Papers Incorporated | Coater and a method for coating a substrate |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US4012543A (en) | Coated paper and method of making same | |
US4154899A (en) | Production of porous, smooth, coated paper using high solids water-based coating compositions in blade coating apparatus | |
US4265969A (en) | Method for manufacturing cast-coated paper | |
USRE25039E (en) | Method of producing high gloss mineral-coated | |
US4581257A (en) | Method of producing cast coated paper | |
US4620992A (en) | Method of producing cast coated paper | |
US5334449A (en) | Coated paper | |
US4335184A (en) | Recording paper | |
FI108305B (en) | Procedure for lowering the permeability of water vapor in paper, cardboard and the like | |
US2395992A (en) | Mineral-coated printing paper | |
US3681116A (en) | Flexible cast-coated paper | |
US3017295A (en) | Coated paper and paperboard and process for making same | |
US2214565A (en) | Coated paper and method of making the same | |
US4226749A (en) | Sizing composition with cationic and anionic component | |
US2819184A (en) | Production of cast surfaced coated paper | |
US3136652A (en) | Method and apparatus for coating paper | |
GB1098580A (en) | Paper coating process and product | |
JP2005068614A (en) | Coated paper for offset printing | |
US3711321A (en) | Rapid drying polyvinyl alcohol color coating process | |
JPH0849199A (en) | Base paper for wall paper | |
US2520900A (en) | Coated paper and method of making same | |
US2697669A (en) | Method of coating paper with clay compositions | |
US2776911A (en) | Process of coating paper with gellable water soluble salt of cellulose sulfate and pigment and gelling said coating | |
US3005727A (en) | Coating compositions and processes for making paper more receptive to ink | |
US2337013A (en) | Method of making coated paper |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: PAPER CORPORATION OF AMERICA 1325 MORRIS DRIVE WAY Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:ALCO STANDARD CORPORATION A CORP OF OH;REEL/FRAME:004395/0347 Effective date: 19850401 |
|
AS | Assignment |
Owner name: JAMES RIVER PAPER COMPANY, INC., TREDEGAR STREET, Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:PAPER CORPORATION OF AMERICA;REEL/FRAME:005634/0920 Effective date: 19890413 |
|
AS | Assignment |
Owner name: DECORATIVE SPECIALTIES INTERNATIONAL INC. A CORPOR Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:JAMES RIVER PAPER COMPANY, INC., A CORPORATION OF VA;REEL/FRAME:005763/0854 Effective date: 19910430 |