CA1163395A - Aqueuous dispersions for the production of coating compositions - Google Patents
Aqueuous dispersions for the production of coating compositionsInfo
- Publication number
- CA1163395A CA1163395A CA000358515A CA358515A CA1163395A CA 1163395 A CA1163395 A CA 1163395A CA 000358515 A CA000358515 A CA 000358515A CA 358515 A CA358515 A CA 358515A CA 1163395 A CA1163395 A CA 1163395A
- Authority
- CA
- Canada
- Prior art keywords
- weight
- polymer
- vinyl
- aqueous dispersions
- styrene
- 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
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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
- D21H19/36—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
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D109/00—Coating compositions based on homopolymers or copolymers of conjugated diene hydrocarbons
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D157/00—Coating compositions based on unspecified polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds
Abstract
ABSTRACT OF THE DISCLOSURE
Aqueous dispersions which are suitable for the production of improved coating compositions for flat substrates, particularly for coated print carriers, conprising a) as binder polymers A from one or more of the monomers styrene, butadiene, isoprene, acrylonitrile, Cl-C12-alkyl esters of acrylic and methacrylic acid, ethylene, vinyl acetate and vinyl chloride, and b) as co-binder water-soluble polymers B which 1) contain at least 40 mol % of polymerized units of an unsaturated carboxylic acid amide, vinyl pyrrolidone, ethylene oxide, vinyl alcohol or allyl alcohol, 2) are present in a quantity of from 0.5 to 50 % by weight, based on polymer A, and 3) are partially or completely bonded to polymer A, the quantity of bonded polymer B being at least 0.5% by weight of polymer A.
Aqueous dispersions which are suitable for the production of improved coating compositions for flat substrates, particularly for coated print carriers, conprising a) as binder polymers A from one or more of the monomers styrene, butadiene, isoprene, acrylonitrile, Cl-C12-alkyl esters of acrylic and methacrylic acid, ethylene, vinyl acetate and vinyl chloride, and b) as co-binder water-soluble polymers B which 1) contain at least 40 mol % of polymerized units of an unsaturated carboxylic acid amide, vinyl pyrrolidone, ethylene oxide, vinyl alcohol or allyl alcohol, 2) are present in a quantity of from 0.5 to 50 % by weight, based on polymer A, and 3) are partially or completely bonded to polymer A, the quantity of bonded polymer B being at least 0.5% by weight of polymer A.
Description
1 1 ~ 3 ~
AQUEOUS DISPERSIONS FOR THE PRODUCTION OF COATING
COMPOSITIONS
This invention rela-tes to aqueous dispersions which contain a) polymers in dispersed -~orm (Polymer A) and b) water soluble polymers (polymer B) in such quantities that at least 0.5 ~ by wei~ht, based on Polymer A, of said Polymer B is bonded to Polymer A. These aqueous dispersions are suitable for the production of improved coating compositions for flat substrates, particularly for.coated print webs.
In the production of coated prillt webs, particularly coated papers which are suitable for printing, natural binders, such as casein and/or starch, are being increasingly replaced partly or completely by synthetic binders based on copoly-mers of acrylic acid esters, styrene, butadiene and unsaturated carboYylic acids, which are in the form of aqueous dispersion. Binders based on natural products have the disadvantages that they are no-t always produced in the same quality, they often have a disturbing colouring, are sensitive to micro-organism attacks, have tohe solubilised by means of complicated processes and prodwce highly viscous solutions with a small solids content. Binders based on synthetic high polymers no longer exhibit these defects and have additional ad-vantages.
Due to the constantly increasing demands on the quality of the printed paper, even better characterlstics of the binders are required. In this respect, improvemen-ts are achieved by adding so-called co-binders, e.g. mixed polymers o~ vin~l acetate and acrylic amide 30 (German Offenlegungsschrift No. 2,450,039; G. Hirsch, Das Papier 32 (l0 A), 1978 66-72). However, as a result of this, individual characteristics are improved but there is no simultaneous qualitative improvement for the majority of the required characteris-tics.
Le A _9 79 ~ 1~339~
Paper coating composi-tions containing pigments are known from German 0ffenlegungsschrift No. 2,703,418, which, apart from containing a syn-thetic latex, which is usually used as a binder, based on polyacrylates, poly-methacrylates, styrene-b-utadiene-polymers or polymers of vinyl acetate in the form of aq-ueous dispersions9 also contain a high molecular weight, water-soluble polymer as a co-binder. The preparation of the water-soluble polymer by polymerisation in a water-in-oil emulsion is essential for these paper coa-ting compositions. Thereby, the viscosity behaviour, the water retention ability and the surface bonding strength are improved.
Howe-ver, it still remains a problem to achieve a high film strength with a simultaneous effective binding power, a low tendency towards migration in the pigment matrix, a particularly effective fibre covering, a good opacity and, particularly where lightweight coated papers are concerned (of a lowerweight), a smaller ink-absorption into the paper. Only recently has the demand for papers having a low weight clearly increased (decrease in the raw material and dispatch expenses), so that ior this area o~ light-weight coated rotogravure papers, tne smoothness o~ the coating, the fibre covering, the opacity and the ink receptivity become extremely important in industrial and economical terms~
It has now been found that improved paper coating compositions containing pigments which meet the demands mentioned above may be prepared using dispersions which, in addition to containing a synthetic polymer suitable as the binder, also contain a relatively low-molecular-weight water-soluble polymer as a co-binder, which is chemically and/or physically bonded partially or Le A 19 976 ~ 1~3~
completely to the synthetic polymer. Thereby, the particles of the synthetic polymer in the dispersion are partially or completely surrounded by a shell of the water-soluble polymer.
The invention provides aqueous dispersions with a solids content of between 35 and 65% by weight of:
a) polymers A, used as a binder, and optionally containing hydrophi]ic groups, which are formed from one or more of the monomers styrene, butadiene, isoprene, acrylonitrile, Cl-Cl2-alkyl esters of acrylic and methacrylic acid, ethylene, vinyl acetate and vinyl chloride, and b) water soluble polymers B, used as a co-binder, characterized in that the water-soluble polymers B
l) contain at least 40 mol % of polymerized units of an unsaturated carboxylic acid amide, vinyl pyrrolidone, ethylene oxide, vinyl alcohol or allyl alcohol,
AQUEOUS DISPERSIONS FOR THE PRODUCTION OF COATING
COMPOSITIONS
This invention rela-tes to aqueous dispersions which contain a) polymers in dispersed -~orm (Polymer A) and b) water soluble polymers (polymer B) in such quantities that at least 0.5 ~ by wei~ht, based on Polymer A, of said Polymer B is bonded to Polymer A. These aqueous dispersions are suitable for the production of improved coating compositions for flat substrates, particularly for.coated print webs.
In the production of coated prillt webs, particularly coated papers which are suitable for printing, natural binders, such as casein and/or starch, are being increasingly replaced partly or completely by synthetic binders based on copoly-mers of acrylic acid esters, styrene, butadiene and unsaturated carboYylic acids, which are in the form of aqueous dispersion. Binders based on natural products have the disadvantages that they are no-t always produced in the same quality, they often have a disturbing colouring, are sensitive to micro-organism attacks, have tohe solubilised by means of complicated processes and prodwce highly viscous solutions with a small solids content. Binders based on synthetic high polymers no longer exhibit these defects and have additional ad-vantages.
Due to the constantly increasing demands on the quality of the printed paper, even better characterlstics of the binders are required. In this respect, improvemen-ts are achieved by adding so-called co-binders, e.g. mixed polymers o~ vin~l acetate and acrylic amide 30 (German Offenlegungsschrift No. 2,450,039; G. Hirsch, Das Papier 32 (l0 A), 1978 66-72). However, as a result of this, individual characteristics are improved but there is no simultaneous qualitative improvement for the majority of the required characteris-tics.
Le A _9 79 ~ 1~339~
Paper coating composi-tions containing pigments are known from German 0ffenlegungsschrift No. 2,703,418, which, apart from containing a syn-thetic latex, which is usually used as a binder, based on polyacrylates, poly-methacrylates, styrene-b-utadiene-polymers or polymers of vinyl acetate in the form of aq-ueous dispersions9 also contain a high molecular weight, water-soluble polymer as a co-binder. The preparation of the water-soluble polymer by polymerisation in a water-in-oil emulsion is essential for these paper coa-ting compositions. Thereby, the viscosity behaviour, the water retention ability and the surface bonding strength are improved.
Howe-ver, it still remains a problem to achieve a high film strength with a simultaneous effective binding power, a low tendency towards migration in the pigment matrix, a particularly effective fibre covering, a good opacity and, particularly where lightweight coated papers are concerned (of a lowerweight), a smaller ink-absorption into the paper. Only recently has the demand for papers having a low weight clearly increased (decrease in the raw material and dispatch expenses), so that ior this area o~ light-weight coated rotogravure papers, tne smoothness o~ the coating, the fibre covering, the opacity and the ink receptivity become extremely important in industrial and economical terms~
It has now been found that improved paper coating compositions containing pigments which meet the demands mentioned above may be prepared using dispersions which, in addition to containing a synthetic polymer suitable as the binder, also contain a relatively low-molecular-weight water-soluble polymer as a co-binder, which is chemically and/or physically bonded partially or Le A 19 976 ~ 1~3~
completely to the synthetic polymer. Thereby, the particles of the synthetic polymer in the dispersion are partially or completely surrounded by a shell of the water-soluble polymer.
The invention provides aqueous dispersions with a solids content of between 35 and 65% by weight of:
a) polymers A, used as a binder, and optionally containing hydrophi]ic groups, which are formed from one or more of the monomers styrene, butadiene, isoprene, acrylonitrile, Cl-Cl2-alkyl esters of acrylic and methacrylic acid, ethylene, vinyl acetate and vinyl chloride, and b) water soluble polymers B, used as a co-binder, characterized in that the water-soluble polymers B
l) contain at least 40 mol % of polymerized units of an unsaturated carboxylic acid amide, vinyl pyrrolidone, ethylene oxide, vinyl alcohol or allyl alcohol,
2) are present in a quantity of from 0.5 to 50% by weight, based on polymer A, and
3) are partially or completely bonded to polymer A, the quantity of bonded polymer B being at least 0.5% by weight of polymer A.
The polymers ~, which form the disperse phase of the aqueous dispersions embrace in the present context all synthetic polymers which are suitable as bi~ders. They consist of homopolymers of butadiene, styrene, Cl 12-alkyl esters of (meth) acrylic acid, vinyl acetate, ethylene and vinyl chloride, and/or mixed polymers which are formed from 70 to 100% by weight of polymerized units of styrene/butadiene, acrylonitrilelbutadiene, methyl methacrylate/butadiene, styrene/isoprene, styrene/Cl 12 alkyl esters of acrylic acid, vinyl acetate/
ethylene, ethylene/vinyl-1 ~33gS
chloride or vinyl acetate/vinyl chloride, ancl from O to 15% by weight of a hydrophilic monomer such as unsaturated carboxylic acids and the amides thereof, e.g. fumaric acid, itaconic acid, maleic acid and (meth) acrylic acid 5 and (meth)acrylamide and/or monomers con-taining sulphonic acid-, amino- and hydroxyl groups and from 0 -to 15% by weight of one or more other monomers.
Polymers A preferably consist of styrene/butacliene-mixed polymers containing from 30 to 75% by weight o-~
10 styrene, from 17 to 6~o/o by weight of butadiene and from1 to 8% by weight of one or more unsaturated carboxylic acids.
In another preferred form, Polymers A of the present invention consist of mixed polymers containing from 3O to 15 75% by weight of styrene, from 17 to 690/o by weight of a Cl 12a~kyl ester of acrylic acid and from 1 to 80,b by weight of unsaturated carboxylic acids.
In a particularly preferred form, the polymers A of the present invention consist of mixed polymers con-taining 20 from 3O to 75% by weight of styrene, from 17 to 690/o by weight of butyl acrylate and from 1 to 8% by weight of unsaturated carboxylic acids.
In another preferred form, the polymers A of the present invention consist of from 3O to 75% by weight of 25 styrene, from 17 to 690/o by weight of butadiene and from 1 to ~% by weigh-t of unsaturated acid amides.
The water~soluble polymers B of the present invention consist of homopolymers of unsa-turated acid amides, vinyl pyrrolidone, ethylene oxide 3 vinyl alcohol, allyl alcohol 30 and/or mixed polymers, in which at least 40 mol o,h of polymerised units of the previously mentioned polymers are contained~ whereby the molecular weights of ~he water-soluble polymers are between lOOO and l,OOO,OOO.
Le A 19 796 3 ~ ~
The -term "unsaturated acid amides" designates amides of unsaturated monocarboxylic acids, e.g. of (meth)acrylic acid and cro-tonic acid, N-substitllted amides such as N-methylol-(me-th)acrylamide and/or mono- or diamides of dicarboxylic acids, e.g. of itaconic, fumaric and maleic acid. The water-soluble polymers B of the present invention preferably contain ~t least 70 mol /0 of units of vinyl alcohol, ethylene oxide, unsaturated acid amides, vinyl pyrrolidone and/or allyl alcohol polymerised therein, 10 whereby the molecular weights of the water-soluble polymers are between 5000 and 200,000.
As comonomers for the water-soluble polymers B of the present invention for the mentioned, water-soluble monomers vinyl alcohol, (meth)acrylic amide, vinyl pyrrolidone and 15 allyl alcohol, all known monomers which are co-polymerisable with these monomers are included.
The following are men-tioned by way of e~ample:
mono-olefinically unsaturated, aliphatic monomers, mono-olefinically unsat~r~ted aromatic monomers, conjugated 20 diene monomers, esters and/or semi-esters of alcohols, including amino alcohols, with unsaturated mono- and dicarbox~lic acids, semi-esters of dialcohols with unsatllra-ted mono- and/or dicarbo~ylic acids, esters or semi-esters of unsaturated mono- and dialcohols with 25 saturated mono- and dicarboxylic acids, unsaturated alcohols, unsaturated mono and dicarbo~Yylic acids and unsaturated aldehydes and ketones.
The monomers mentioned above, may be used as comonomers in water-soluble polymer B, both individually 30 as well as combined together.
Suitable mono-olefinically unsaturated aliphatic monomers are e.g. ethylene, propylene, butylene and Le A 19 796 1 16~3~S
is~butylene and such monomers in which one or more hydro~en atoms ~re replaced by halo~en- and cyano groups, as is the case with cacLylonitrile, methacrylonitrile, vinyl chloride and vinylidene chloride.
The following are suitable as mono-ole~inically 5 unsatura-ted, aromatic monomers: styrene, substitutecl styrenes (e.g. styrene with halogen, alkoxy, cyano or alkyl substituents) and vinyl naphthalene.
A few specific examples of subs-tituted styrenes are the followi~g:c~ -methylstyrene, Ar-methylstyrene, 10 Ar-ethylstyrene,~ -Ar-dimethylstyrene, Ar-o~ -dimethyl-styrene, Ar-tert.-butylstyrene, methoxystyrene, cyano-s-tyrene, monochlorostyrene and dichlorostyrene.
Acyclic conjugated dienes are e.g. butadiene, substituted butadienes and other acyclic compounds which 15 have at least two C-C-double bonds in conjugation Specific examples of such monomers are isoprene, chloro-prene, 2,3-dichlorobutadiene, 2,3~dimethylbutadiene and pentadiene l,3.
Esters of unsaturated carboxylic acids with satura-20 ted alcohols are e.g. esters o-f methyl, ethyl, butyl and higher alcohols with (meth)acrylic acid, crotonic acid and vinylacetic acid. The alcohols mentioned may also be esterified to semi-esters or di-esters with unsaturated dicarboxylic acids such as, ~or example fumaric, maleic 25 and itaconic acid.
Examples of semi-esters formed i`rom, dialcohols and unsaturated acids are ~-hyclroxye-thyl acrylate and ~-hydroxyethyl methacrylate.
An ester of amino alcohols and unsaturated acids 30 having a catlonic nature is e.g. N,N-dimethyl aminoethyl (meth)acrylate.
Le A 19 796 1 ~3395 From the series of the esters and semi-esters of unsaturated alcohols containing saturated mono- and dicarboxylic acids, the following are mentioned: allyl ace-tate, vinyl acetate, vinyl laurate, vinyl benzoate, vinyl palmitate and dia:Llyl phthalate.
Allyl alcohol i9 mentioned from the series of unsa-turated alcohols and methyl vinyl ketone ancl acrolein are mentioned from the series of unsaturated aldehydes and ketones. Finally, unsaturated acids and the salts thereof e.g. (meth)acrylic acid, crotonic acid and vinyl-acetic acid ~nd also dicarboxylic aci~s such as fumaric, maleic and itaconic acid are suitable as comonomers.
Comonomers for ethylene oxide in the water-soluble polymers B of the present invention include epoxides, e.g. propylene oxide, and those compounds which may be linked with (poly)-ethylene oxide through an OH group, e.g. satura-ted and unsaturated alcohols. The possibility then exists with the unsaturated alcohols o~ carrying out a radical polymerisation at the vinylic double bond using suitable monomers. This principle may also be applied if a polyethylene oxide con-taining OH-groups is reacted with unsaturated carboxylic acids and a radical polymerisation is then carried out at the vinylic double bond using suitable comonomers.
Finally, copolymers containing built in units of ethylene oxide for water-soluble polymers B of the present invention may also be obtained by reacting polyethylene oxides containing OH-groups with isocyanates or polymeric isocyanates.
The water-soluble polymers B of the present invention most preferably consist of homopolymers of (meth)acryl-amide~Vinyl pyrrolidone, vinyl alcohol, whose OH-groups Le A 19 796 3 3 (~ ~
may be partly acetalised, and ethylene oxicle and/ol mixed polymers of (meth)acrylamicle-styrene, vinyl pyrrolidone-vinyl acetate, vinyl alcohol vinyl ace-tate, (meth)acryl~
amide/v~nyl acetate and ethylene oxide-propylene oxide~
5 in which the molecular weights are between 5000 and 500,000.
The aqueous dispersions according to the invention preferably contain the water-soluble polymers B in a quantity of from 0.5 to 30% by weigh-t, based on polymer 10 A~ at least 0.5 ~ by weight, based on pol~ A, of said poly~er B being bonded to polymer A.
The aqueous dispersionsaccording to the invention particularly preferably contain the water-soluble polymers B in a quantity of from 0.5 to 15% by weight, 15 based on polymer A, at least o.50/O by weight, based on polymer A, of said polymer B being ~onded to polymer A.
The aqueous dispersions according to the invention are produced simply by preparing an aqueous solution of the water-soluble polymer B and mixing it with a polymer 20 dispersion which contains polymer A as the dispersed phase. The quantlties are thereb~y measured so that from 0.5 to 50% by weight of polymer B, based on polymer A, are present in the aqueous dispersion.
A mixture of this type is particularly suitable as 25 a binding agent for the production of coating composi-tions for print webs. In addition to containing the binding agent, these coating compositions also contain pigments and optionally conventional thickening agents (e.g. po]yacrylate). Mineral products are mainly inclu-30 ded as pigments, but partially or even comple-tely organic pigments may be used. Con~entional pigments are, for example, clay varieties, titanium dioxide, calcium carbo~ate, calcium sulphate, barium sulphate, blanc fi~, Le A 19 796 ~ ~3~95 satin white, a]uminium hydro~ide and zinc pigments, such as ~inc o~ide and zinc sulphide.
The quantity of water-soluble polymer B clepends on the affinity between the water-soluble polymer B and polymer A and on the particle size of the latex particles, which are formed from polymer A, and must be measured so that the non-bonded wa-ter-soluble polymer B does not exceed 2% by weight of the pigment. 'rhe quantity of water-soluble polymer B should preferably be measured so that the non-bonded polymer B does not exceed 1% by weigh-t of the pigment.
In contrast to the previously known systems in which a co-binder is added to a latex, it is essential for the improvemen-t of the characteristics of coating compositions for print webs -by the aqueous dispersions of the present invention that, before mi~ing the binder and pigment, the water-soluble polymer B is added to the latex containing the disperse phase of polymer A and the water-soluble polymer B is chemically or physically 20 bonded par-tially or completely to polymer A. Surprisingly, there is no improvement if the water-soluble polymer B is not bonded to polymer A or is fiYstly added to the mi~ture of binder and pigment or moreover firstly to the pigment suspension.
The binding of the water-soluble polymer B to polymer A of a latex can be tested by separating by centrifugation a sample of the late~ into a first phase, which consists predominantly of polymer (A + B), seperating a second phase, the serum, and detec-ting a portion of the water-30 soluble polymer B which possibly remains in the serum.
The water-soluble polymer B may be detected by chemical or spectroscopic methods. These methods are described, e.g. for polyvinyl alcohols and copolymers of vinyl Le A 19 796 ~ ~3~g~
a]cohol and vinyl acetate, in J. appl. Polym. Sci. 9 (1965), 239~ and for polyethylene o~ide and polyacrylamide in Br. Polym. J. 7 (1975), 135.
By using the aqueous dispersions of the present invention, the most important and the majority of the required paper coating characteristics may be simultan-eously optimised in a manner which leads, -to improved results compared to those obtained with the hitherto known co-binder processes. The aqueous dispersions o-f the invention are preferably used for the production of paper coating compositions, although other areas of use are also conceivable and possible, e.g. the production of coating compositions for other substrates such as paper-board, ~ard~oard, te~tiles and leat~er.
1~ The process of the invention enables both the simultaneous optimisation of many characteristics as well as the intended, excellent optimisation of specific coating characteristics, such as compressibility, micro-porosity, ink-receptivity, smoot~ness and binding power.
By using the aqueous dispersions, i.e. the modified latices according to the present invention, in the production of printed papers having a low weight, it is surprisingly found that the latex does not penetrate the 25 paper, that the fibre covering is improved and a homogen-eous regular coating matrix is produced. Thereby, the opacity, the brightness and the smoothness are improved a~d a regular and rapid ink-absorption is obtained with a constant or improved binding power. The further 30 advantage of the binder of this in~en~iQn~ is the fact that irreversible thickenings are avoided which may arise in the hitherto conventional use of e.g. polyvinyl alcohol in coating compositicns.
Le A 19 796 I ~)33g~
The latices modi~ied according to the invention, in contrast to the prior art, cause more voluminous and regularly ~icroporous coatings. In offset prin-ting, this stipulates a rapid regular colour acceptance which affords particular advantages in multi-colour printing wet in wet.
For rotogravure printing, the latices modi~ied according to this inv~ltion cause a high compressibility and smooth-ness of the coated paper with a decreased calender step. Due to the described coating structure, a high rapid ink 10 acceptance and a hi~h print clarity are obtained~
As is the case with offset-papers, stiffer papers are also required in roto~ravure printmg. ~Iitherto, the produc-tion of stiffer papers was not possible because, when using latices with hard films, there was a clear deterior-15 ation in the printing characteristics: irregular porosity,decreased compressibility, a pbor print (missing do-ts).
Due to the particular coating structure while retaining the characteristi~s required for rotogravure printing, latices modified according to the invention having a hard 20 film allow stiff papers to be printed on for the first time in the roto~ravure ~rinting ~rocess.
Due to the regular embedding o~ the modi~ied binder in the coating matrix, -the binder portion in the co~ating composition~ may be reduced as a result of its high bind-25 ing power9 whieh in the final analysis leads to a furtherimprovement in the printing characteristics.
The following E~amples illustra-te the invention.
Percentages and parts are all based on weight unless stated otherwise.
Le A 19 796 -~ 1~3~
E~YAMPLE 1 different paper_coa~ing lat ces.
(a) Modification of the latices The latices described below of various polymer compositions for the produc-tion of paper coating composi-tions are set, using water, to a solids content of 45,% in each case. A 10% aqueous solution of a partially saponi-fied 10 polyvinyl acetate is gradually added to these latices, with stirring, for the modification step. The added quantity is 5% (on a solid to solid basis). ~he partially saponi-fied polyvinyl acetate has a degree of hydrolysis of 88 mol /0, and a molecular weight of 25,000.
The following latex types are modified according to the invention, as described above:
Carboxylated styrene-butadiene latex having a conventional film hardness and a high pigment binding 20 power (commercially conventional paper coating latex) (600/o styrene, 360/o butadiene and 4% (meth)acrylic acid).
In modified Form = Latex A
_ Carboxylated styrene-butadiene lat~ hav~ng g~eater_film 25 hardness but a decreased pigment binding power.
In modified Form = Latex B_ Acrylate Latex __ Styrene-acrylic acid butyl ester latex having a slightly greater film hardness but a lower pigment binding power than SBR-latex type l (commercially conventional paper coating latex).
Le A 19_796 i ~33g~
In order to equilibrate the modified latices were stored for 24 hours before being further processed.
As a comparison, -the two SBR-latices (type l and type 2) and the acrylic latex were testecl concomitantly in non-modi~ied -form.
The binder characteristics are stated in Table l.
Table l ~
Latex Solids content pH value Viscosity ~ ~ a.s)_ A 38.6 7.4 244 B 38.6 7.4 llO
1~ C 38.6 8.7 93 Comparison non-modified SBR-Type l 45 7.2 68 SBR-Type 2 45 6.8 72 20 Acrylate 45 8.5 62 Note:
Viscosity: Brookfield LVT. Spindle 3 or 4, 60 rpm 20C
(b) Production of the paper coatin~ comp~osition and performance of the coatin~_exp rime_t lO0 parts of nhina clay are stirred into an aqueous solution of 0.2 parts of sodium polyacrylate, 0.2 parts ~ sodium polyphosphate and l part o~ aqueous ammonia using a high-speed stirrer and are dispersed into a Le A 19 796 33~
homogeneous suspension. 10% ( solid on solid, based on clay) of the latices described under (a) are respec-tively added as the binding agen-t. The pH is adjusted to 8.5 using aqueous ammonia. The respective composition can be seen -from Table 2~
Table 2 Composition of the paper coatin~ compositions (Parts are respectively parts by weight) Ex~eriment l 2 3 4 5 6 _, . . . , , . , , _ 10 Water ~ -- 74.0 Sodium polyacrylate ~ ~ 0.2 Sodium polyphospate ~ 0.2 -------------China Clay Dinkie A ------- lOO -------------Modified Latex (38.60/o) A 27.2 B 27.2 C _ _ 27.2 - - -Comparison non-20 modified latex) SBR-Latex, Type l - - - 27.2*
SBR-Latex, Type 2 - - - 27.2*
Acrylate Latex - ~ 27.2*
pH value ------- 8 . 5 -------------25 Solids content (/O) ------- 55 -------------*) 22.2 parts of 45/0 Latex ~ 5.0 parts of water.
The characteristics of the coating compositions are given in Table 3.
Le A 19 796 j33~S
Table ~.
Characteristics o:L the paper coatin~_compositions _periment _ _ _ 1 _ _ 2_ ~ 4 _ 5_ 6 Solids conten-t (,~) 54 9 55.1 54 8 54.8 54.9 54.9 5 pH value 8.4 8.5 8 4 8.68.68.5 Viscosity (mPa.s) Brookfield immediately 594 670 390 175182195 Brookfield after 24 hours 724 960 435 780720680 Rheomat 10 a-t D = 3.5x101345 320 410 140145190 at D = 1x103 45 38 54 2731 33 Setting Point (,/o) 73.4 73-1 74.1 76.8 77.3 77.1 Water retention sligh- more sligh-(comparison with tly impr- tly 15 non-mod.~fied impro- oved impro-late~) ved ved Note-_ _ See Example 1, part d for description of testing method.
After stabilizing and deaerating, the coating comp-20 ositions thus produced are coated OlltO a bleached base paper, containiny wood~pulp, consisting of 55 % of mechanical wood pulp and 45% of bleached sulphite pulp (conifers), having an ash content of 9. 9% and a weight of 50 g/m2 on both sides, with a coating weight of ~rom 8 to 10 25 g/m2~ per side (dry), using experimental ~lade coater, at a speed of 200 m/min.
Even after a lengthy operating time, the coating compositions containing the modified late~ do not form a coagulum or a covering on the Dlade or on cylinders.
Le A 19 796 ~ ~633g5 Also, no penetration by the coating composition throuyh the paper onto the blade-cylinder could be detectea. The coated papers are ~en finished with a supercalender (2 transits) and, arter bein~ cli~.~tised at ~ and 650/o relative air humidity, are 5 tested. ~he resu]ts of the test are assembled in Table 4, Table L~
~L}~
Coating appl~cation -~ - 10 -~
(g/m per side) ~hickness (mm) 0.074 0.079 0.078 0.070 0.070 o.o69 Wate~ absorp-tion (g/m ) according to Cobb (60 sec) 21.5 22 23 20.0 21 20.5 Smoothness accordin~ to Bekk 510 660 640 350 310 320 (sec./ml) Roughness according to Bendtsen (ml/Min) 25 21 22 39 36 35 Stiffness according to Schlenker, 40 40 62 42 42 61 47 IGT-dry pick /cm/Sec.) 94 76 62 116 80 88 K. and N. ~k recepti-vity test (~ 20.5 30 29 18 24 24 Rotogravure printmg-Test according to P.n~au 1 1 2 3 3 3 Micro contour test 2 1 2 4 4 4 Gloss (%) 28 32 26 22 24 23 Opacity (%) 93.9 93. 92.6 91.6 91.4 91.1 Whiteness (%~ 82.3 82.4 82.2 81.4 81.4 81.6 Fibre covering (o,b) 79.4 77.6 78.0 69.2 69.1 ~9.7 Note:
See E~ample 1, part d for description of testing methodO
Le A 19 796 ~ ~,33~
(c) Evaluation In contrast to -the papers (Experiments 4 to 6) coated with conventional latices, the coated papers of Experiments 1 to 3, the coating compositions of which contained the latices modified according to the invention, show clearly improved prin-tability characteristics, smoothness, opacity and particularly a high fibre covering.
The gloss was also increased. The setting point of these coating compositions was lowered so that a premature coating-immobilisation is possible before the actual drying, and the migration of the ~inder can be suppressed.
It is surprising that even a coating which contains a comparatively hard binder (Experiment 2), has a very effective printability for roto~ravure printing. In this manner, a paper having a low weight but a high stiffness is obtained which is suitable for rotogravure printing.
(d) I ~l} ~ D~_ The following tes-ting methods were used:
(Testing conditions, unless sta-ted otherwise 20C, 650/o relative air humidity).
pH value: electrometrically, according to DIN 53 785 Solids content: a) for latices: according to DIN 53 189 b) for coating compositions weighing difference after drying at 110C
Viscoslt~ according to DIN 53 788 a) measuring device: Brookfield viscosime-ter LVT, spindle 3 or 4, 60 rpm Testing temperature: 20C
Le A 19 79Ç
339~
~ 18 -b) MeQsuring clevice for recorc1ing rheo-gramms: Rheomat 15, measuring systems A to C, testing temperature: 20~C.
~æ~ lOOg of the coating composition are 5 ~i ~ given onto an unglazed clay dish drie~
compositions under constant cond.iticals at room temperature.
As soon as the wet lobk has disappeared from the surface of the coating composi-tion a sample is taken to determine the solids content.
m e solids content in ~ ~hus determined indi.cates the setting point, the point of immobilisation of ll L~ L~_ the wet coat an ~he paper ~ 0 cm3 of the coating campositions are coated on a paper with standar-dized conditions using a small doctor, groove depth 0.2 mm, within a few deci-seconds at a constant coating rate. As a result of the water penetrating into the paper from the coating composition, the relative air humidity rises on the lower side of the paper. This moisture increase is continuously registered using a hygroscopic moisture sensor as function of time. The higher the moisture in-crease per unit time, the poorer the water retention ability of the coating composition.
Moisture sensor: VAISALA (Fitting ~I ll) Measurements in the climatic chamber (650/o relative air humidity).
~D~ Difference between climatised samples o~ coated ancl un-coated paper (according t~ ~IN 53 lll).
Le A 19 796 I ~B3~9~
~L~a~}_ Determination according to DIN 53 105 Water Absorption accordi.ng to Cobb- Determination according to DIN 53 132, -60 seconds.
Smoothness to Bekk: Determination according to DIN 53 107, Rou,.hness -10 according to Bendtsen: Determination according to DIN 53 10 S~iffness Schlenker: Determination according to DIN 53 121, bending angle 40.
Dry pick Determination according to Tappi-Standard T 499 Su 64 using the IGTtester type AC2, and a compressive strain o~
35 kg/cm2. The IGT ~urface bonding strength tes-t colour o~ a low viscosity is used as the surace bonding strength colour.
K ~ N Test: Conventional determination of the in~
(Ink recep- absorption of coated papers according to tivity) the Tappi-routine control method RC 19, operation time: 3 minutes. The K ~ N
value is the di~ference in the whiteness between untreated paper and paper treated with the testing ink.
Le A 19 79~
I ~)3~
Measuring device: Elrepho, fil-ter R l~57 ~esting colour: K ~ N-testing ink~ the K ~ N-Laborities Inc., Melrose Park.
Micro contour Testing method to determine the c~atingreg 5 test larity, performance and holdout, similar to K T N-test, operation time however only 2 minutes, testing ink: blue testing ink 3811 from the firm Lorilleux Druckfarben GmbH, Ratingen. The de-termina-tion takes place visually using a five-stage evaluation scale, ~rom notation 1 indicating an absolutel~ homogeneous, speck-, hole- and fog-free testing surface to notation 5 indicating a heavily disturbed, irregular testing sur~ace having many defects.
Printin~ Test_ Rotogravure pr-ntLng test print on test printing machine system according to Dr.
~ner, Fa. Prufbau. The print result was tested visually and judged according to clearness of screen reproduction, regulari-ty o~ the colour absorption, completeness oi the print, transparency and the like Concerning this, three classes were estab-lishad:
1 = very good, 2 = good, 3 = poor.
Gloss: Determination of the gloss according to DIN 67 530 relative to a comparative standard at~a measuring angle of 60, measuring device: Lauge-reflectometer.
Le A 19 796 _ . _ ~ l B3~3$
Opacity: Determina-tion according to DIN 53 l46.
~ie~ Measuring using reflectance photometer Elrepho, filter ~ 457.
Fibre Coverin~: The coating colour is coated onto a black paperboard (coating weight: from 8 to lO g/m2 dry) and is carefully dried.
The whiteness (Elrepho filter R ~57) of the coated paperboard surface is then measured. The heavier the coating covers the black base~ the greater the whiteness.
Another determination of the fibre covering consists of the following method~
~ he coated paperboard su:rface is passed through using a very narrowly focused beam of the spectral photometer and 15 the diffused reflection is registered point lor point co~-nuously over a length of the paperboard of approximately lO cm. The diffused reflection fluctuations arising thereby provide a meas~re~ent~forthe regularity of the fibre covering according to a stochastic evaluation.
20 Cross section of the illumination beam O.3 x 2 mm2, rectangular screen.
EX~MPLE 2 Addition of different co=bind~c ~5c_~_e3 1 coating latex.
25 (a) ~odifica-tion of the latex As described for Example l under a), 5% (on a solid to solid basis) of the following co-binders in the form of 10% aqueous solutions were respectively added to the SBR-latex, type l:
30 - Block mixed polymer of hydrophilic polyoxethylene groups (an approximately ~O mol % part) and hydrophobic polyoxypropylene groups, total molecular weight: approxi-mately l6,OOO.
Le A 19 796 i I633~
Denoted as PE0-PP0, produces latex D
- Polyvinyl pyrrolidone having a molecular weight o~
approxima-tely 40,000 Denoted as PVP, produces latex E
5 - Polyacrylamide, having a molecular weigh-t of 30,000 -40,000 Denoted as PAA, produces latex F
- Acetalised polyvinyl alcohol (saponification number : 20), molecular weight approximately 70,000 10 Denoted as PVA acetalised, produces latex G
- as a comparison Partly saponified polyvinyl acetate as described in Example l Denoted as PVAC partially saponified, produces latex Z
15 The pH value and viscosity o-f the modified la-tices are gi~en in Ta~le 5.
Table 5.
~ ti^~ ~ the latices Latex Modified by pH-value Viscosity _ (mPa.s) D PE0-PP0 7.5 130 E PVP 7.4 52 F PAA 4.0 25 G PVA acetalised 7.3 3100 A PVAC partially 7.4 244 saponified Solids conten-t : 38 . 60/o Note: Viscosity : Brookfield LV~, spindle 3 or ~, 60 rpm 20C
Le A 19 796 ~ ~33~:~
b) Production of the paper coa~ing composition and implementation of the coatine ex~eriment ____.__ E~fec-ted llnde:r the same condi-cions as rlescribed for Example 1 under b). The compositions of -the coa-ting 5 composi-tions are described in Table 6 and the character-istics o-~ the same are described in Table 7.
During these e~periments as well, also after a lengthy operation time, no coagulum or covering appeared on the blade.
In comparison, Experiment 12 was also carried out according to Experiment 4 of Example 1, whereby the corresponding part of partially saponified polyvinyl acetate was subsequ~ntly added to the finished coating colour.
The papers coated on both sides were then finished over a .supercalender and, after being climatisecl, were tested. The coating characteristics are assembled in Table 8.
Table ~.
_ Composition of the paPer _oatin~ composi ions (Parts are respec-tively par-ts by weight) Experiment _ _ 7 _ 8 9 10 11 12 Water ~ - 74.0 ~
Sodium polyacrylate ~ --- 0 2 ------------Sodium polyphosphate ------- O.2 ------------China Clay ------- 100 ------------~odified Late~
(38.60to) D 27.2 E - 27.2 F - - 27.2 G _ _ _ 27.2 A _ _ _ _ 27.2 Le A 19 796 g ~
Table 6 Continued Experiment 7 _8 9 10 11 12 Compari-tive latex non-modified - - - - - 22.2 Polyvinyl aceta-te partially saponi~ied ( 10%) --_ _ _ _ 5 o pH-value ------ 8.5 Solids content (/0) - ---- 55 ------------Table 1 .
Experiment _ 7_ 8 9 _10 11_ 12 Solids con-tent (olO) 55.3 55.2 55.5 55.1 54.9 54.8 p~-value 8.4 8.6 8.3 8.4 8.4 8.5 Viscosity (mPa.s) Brookfield, immediately820 1150 325 1080 594 286 Brookfield, a~ter ~4 hours 960 1200 495 2800 724 980 Rheomat at D = 3.5x101 472 624 180 610 345 265 at D = 1x10337 44 27 48 45 38 Setting point (~) 72.9 73.0 74.0 74.1 73.4 76.1 Water retention more sligh- not not sligh- sligh-(comparison imp- tly imp- imp- tly tly wilh non- roved impr- roved roved impro- impro modified la-tex). oved ved ved Note-.
See Example 1, part d) for description o~ testing method,.
1,~
1 ~33~
Table 8 Coatin~ Characteristics EYDeriment 7 8 9 10 11 12 Coat~ng Applica-tion (g/m per side) ~ 10 ~
~hickness (mm) 0.76 0.74 0.730.77 0.074 0.070 Wate2r absorption (g/m ) according to Cobb (60 sec.)26.5 21.5 22 22 21.5 21 Smoothness a,ccording to Bekk (Sec./ml) 540 750 680 520 510 360 Roughness according to Bendtsen (ml/Min.)~4 19 20 25 25 33 Stiffness according to Schlenker, 40~ 39 41 40 41 40 39 IGT-Dry-pick (cm/Sec. j 88 89 120 110 ' 94 110 K&~ in~ recepti~ity ~%)22.7 24.0 19.4 18.4 20.5 18.5 Rotogravure pr~t~ng-sample print 2 2 1 2 1 3 Micro contour test 1 1 1 2 2 4 Gloss (%) 25 24 26 25 28 22 Opacity (%) 92.8 92.4 93.0 92.9 93.9 91.6 Brightness (/0) 82.4 82.3 82.3 8~.2 8~.3 81.3 Fibre coverage (/~) 76.9 77.9 77.7 78.1 79,4 69.3 Note:
See Example 1, part d) ~or description oL the testing method.
c) Evaluation As the Experiments 7 to 11 show, the modi~ication o~
the latex by co-binders according -to the presen-t invention Le ~ 19 796 ~ ~ ~33~5 . 26 -leads -to an improvement in the coating characteristics and thus to very effective characteristics in terms of printing, especially for rotogravure printing.
However, Experim~nt 12 shows -that a subsequent 5 addition of the co-binder to the composition does not give the required improvement.
Le A 19_ 796
The polymers ~, which form the disperse phase of the aqueous dispersions embrace in the present context all synthetic polymers which are suitable as bi~ders. They consist of homopolymers of butadiene, styrene, Cl 12-alkyl esters of (meth) acrylic acid, vinyl acetate, ethylene and vinyl chloride, and/or mixed polymers which are formed from 70 to 100% by weight of polymerized units of styrene/butadiene, acrylonitrilelbutadiene, methyl methacrylate/butadiene, styrene/isoprene, styrene/Cl 12 alkyl esters of acrylic acid, vinyl acetate/
ethylene, ethylene/vinyl-1 ~33gS
chloride or vinyl acetate/vinyl chloride, ancl from O to 15% by weight of a hydrophilic monomer such as unsaturated carboxylic acids and the amides thereof, e.g. fumaric acid, itaconic acid, maleic acid and (meth) acrylic acid 5 and (meth)acrylamide and/or monomers con-taining sulphonic acid-, amino- and hydroxyl groups and from 0 -to 15% by weight of one or more other monomers.
Polymers A preferably consist of styrene/butacliene-mixed polymers containing from 30 to 75% by weight o-~
10 styrene, from 17 to 6~o/o by weight of butadiene and from1 to 8% by weight of one or more unsaturated carboxylic acids.
In another preferred form, Polymers A of the present invention consist of mixed polymers containing from 3O to 15 75% by weight of styrene, from 17 to 690/o by weight of a Cl 12a~kyl ester of acrylic acid and from 1 to 80,b by weight of unsaturated carboxylic acids.
In a particularly preferred form, the polymers A of the present invention consist of mixed polymers con-taining 20 from 3O to 75% by weight of styrene, from 17 to 690/o by weight of butyl acrylate and from 1 to 8% by weight of unsaturated carboxylic acids.
In another preferred form, the polymers A of the present invention consist of from 3O to 75% by weight of 25 styrene, from 17 to 690/o by weight of butadiene and from 1 to ~% by weigh-t of unsaturated acid amides.
The water~soluble polymers B of the present invention consist of homopolymers of unsa-turated acid amides, vinyl pyrrolidone, ethylene oxide 3 vinyl alcohol, allyl alcohol 30 and/or mixed polymers, in which at least 40 mol o,h of polymerised units of the previously mentioned polymers are contained~ whereby the molecular weights of ~he water-soluble polymers are between lOOO and l,OOO,OOO.
Le A 19 796 3 ~ ~
The -term "unsaturated acid amides" designates amides of unsaturated monocarboxylic acids, e.g. of (meth)acrylic acid and cro-tonic acid, N-substitllted amides such as N-methylol-(me-th)acrylamide and/or mono- or diamides of dicarboxylic acids, e.g. of itaconic, fumaric and maleic acid. The water-soluble polymers B of the present invention preferably contain ~t least 70 mol /0 of units of vinyl alcohol, ethylene oxide, unsaturated acid amides, vinyl pyrrolidone and/or allyl alcohol polymerised therein, 10 whereby the molecular weights of the water-soluble polymers are between 5000 and 200,000.
As comonomers for the water-soluble polymers B of the present invention for the mentioned, water-soluble monomers vinyl alcohol, (meth)acrylic amide, vinyl pyrrolidone and 15 allyl alcohol, all known monomers which are co-polymerisable with these monomers are included.
The following are men-tioned by way of e~ample:
mono-olefinically unsaturated, aliphatic monomers, mono-olefinically unsat~r~ted aromatic monomers, conjugated 20 diene monomers, esters and/or semi-esters of alcohols, including amino alcohols, with unsaturated mono- and dicarbox~lic acids, semi-esters of dialcohols with unsatllra-ted mono- and/or dicarbo~ylic acids, esters or semi-esters of unsaturated mono- and dialcohols with 25 saturated mono- and dicarboxylic acids, unsaturated alcohols, unsaturated mono and dicarbo~Yylic acids and unsaturated aldehydes and ketones.
The monomers mentioned above, may be used as comonomers in water-soluble polymer B, both individually 30 as well as combined together.
Suitable mono-olefinically unsaturated aliphatic monomers are e.g. ethylene, propylene, butylene and Le A 19 796 1 16~3~S
is~butylene and such monomers in which one or more hydro~en atoms ~re replaced by halo~en- and cyano groups, as is the case with cacLylonitrile, methacrylonitrile, vinyl chloride and vinylidene chloride.
The following are suitable as mono-ole~inically 5 unsatura-ted, aromatic monomers: styrene, substitutecl styrenes (e.g. styrene with halogen, alkoxy, cyano or alkyl substituents) and vinyl naphthalene.
A few specific examples of subs-tituted styrenes are the followi~g:c~ -methylstyrene, Ar-methylstyrene, 10 Ar-ethylstyrene,~ -Ar-dimethylstyrene, Ar-o~ -dimethyl-styrene, Ar-tert.-butylstyrene, methoxystyrene, cyano-s-tyrene, monochlorostyrene and dichlorostyrene.
Acyclic conjugated dienes are e.g. butadiene, substituted butadienes and other acyclic compounds which 15 have at least two C-C-double bonds in conjugation Specific examples of such monomers are isoprene, chloro-prene, 2,3-dichlorobutadiene, 2,3~dimethylbutadiene and pentadiene l,3.
Esters of unsaturated carboxylic acids with satura-20 ted alcohols are e.g. esters o-f methyl, ethyl, butyl and higher alcohols with (meth)acrylic acid, crotonic acid and vinylacetic acid. The alcohols mentioned may also be esterified to semi-esters or di-esters with unsaturated dicarboxylic acids such as, ~or example fumaric, maleic 25 and itaconic acid.
Examples of semi-esters formed i`rom, dialcohols and unsaturated acids are ~-hyclroxye-thyl acrylate and ~-hydroxyethyl methacrylate.
An ester of amino alcohols and unsaturated acids 30 having a catlonic nature is e.g. N,N-dimethyl aminoethyl (meth)acrylate.
Le A 19 796 1 ~3395 From the series of the esters and semi-esters of unsaturated alcohols containing saturated mono- and dicarboxylic acids, the following are mentioned: allyl ace-tate, vinyl acetate, vinyl laurate, vinyl benzoate, vinyl palmitate and dia:Llyl phthalate.
Allyl alcohol i9 mentioned from the series of unsa-turated alcohols and methyl vinyl ketone ancl acrolein are mentioned from the series of unsaturated aldehydes and ketones. Finally, unsaturated acids and the salts thereof e.g. (meth)acrylic acid, crotonic acid and vinyl-acetic acid ~nd also dicarboxylic aci~s such as fumaric, maleic and itaconic acid are suitable as comonomers.
Comonomers for ethylene oxide in the water-soluble polymers B of the present invention include epoxides, e.g. propylene oxide, and those compounds which may be linked with (poly)-ethylene oxide through an OH group, e.g. satura-ted and unsaturated alcohols. The possibility then exists with the unsaturated alcohols o~ carrying out a radical polymerisation at the vinylic double bond using suitable monomers. This principle may also be applied if a polyethylene oxide con-taining OH-groups is reacted with unsaturated carboxylic acids and a radical polymerisation is then carried out at the vinylic double bond using suitable comonomers.
Finally, copolymers containing built in units of ethylene oxide for water-soluble polymers B of the present invention may also be obtained by reacting polyethylene oxides containing OH-groups with isocyanates or polymeric isocyanates.
The water-soluble polymers B of the present invention most preferably consist of homopolymers of (meth)acryl-amide~Vinyl pyrrolidone, vinyl alcohol, whose OH-groups Le A 19 796 3 3 (~ ~
may be partly acetalised, and ethylene oxicle and/ol mixed polymers of (meth)acrylamicle-styrene, vinyl pyrrolidone-vinyl acetate, vinyl alcohol vinyl ace-tate, (meth)acryl~
amide/v~nyl acetate and ethylene oxide-propylene oxide~
5 in which the molecular weights are between 5000 and 500,000.
The aqueous dispersions according to the invention preferably contain the water-soluble polymers B in a quantity of from 0.5 to 30% by weigh-t, based on polymer 10 A~ at least 0.5 ~ by weight, based on pol~ A, of said poly~er B being bonded to polymer A.
The aqueous dispersionsaccording to the invention particularly preferably contain the water-soluble polymers B in a quantity of from 0.5 to 15% by weight, 15 based on polymer A, at least o.50/O by weight, based on polymer A, of said polymer B being ~onded to polymer A.
The aqueous dispersions according to the invention are produced simply by preparing an aqueous solution of the water-soluble polymer B and mixing it with a polymer 20 dispersion which contains polymer A as the dispersed phase. The quantlties are thereb~y measured so that from 0.5 to 50% by weight of polymer B, based on polymer A, are present in the aqueous dispersion.
A mixture of this type is particularly suitable as 25 a binding agent for the production of coating composi-tions for print webs. In addition to containing the binding agent, these coating compositions also contain pigments and optionally conventional thickening agents (e.g. po]yacrylate). Mineral products are mainly inclu-30 ded as pigments, but partially or even comple-tely organic pigments may be used. Con~entional pigments are, for example, clay varieties, titanium dioxide, calcium carbo~ate, calcium sulphate, barium sulphate, blanc fi~, Le A 19 796 ~ ~3~95 satin white, a]uminium hydro~ide and zinc pigments, such as ~inc o~ide and zinc sulphide.
The quantity of water-soluble polymer B clepends on the affinity between the water-soluble polymer B and polymer A and on the particle size of the latex particles, which are formed from polymer A, and must be measured so that the non-bonded wa-ter-soluble polymer B does not exceed 2% by weight of the pigment. 'rhe quantity of water-soluble polymer B should preferably be measured so that the non-bonded polymer B does not exceed 1% by weigh-t of the pigment.
In contrast to the previously known systems in which a co-binder is added to a latex, it is essential for the improvemen-t of the characteristics of coating compositions for print webs -by the aqueous dispersions of the present invention that, before mi~ing the binder and pigment, the water-soluble polymer B is added to the latex containing the disperse phase of polymer A and the water-soluble polymer B is chemically or physically 20 bonded par-tially or completely to polymer A. Surprisingly, there is no improvement if the water-soluble polymer B is not bonded to polymer A or is fiYstly added to the mi~ture of binder and pigment or moreover firstly to the pigment suspension.
The binding of the water-soluble polymer B to polymer A of a latex can be tested by separating by centrifugation a sample of the late~ into a first phase, which consists predominantly of polymer (A + B), seperating a second phase, the serum, and detec-ting a portion of the water-30 soluble polymer B which possibly remains in the serum.
The water-soluble polymer B may be detected by chemical or spectroscopic methods. These methods are described, e.g. for polyvinyl alcohols and copolymers of vinyl Le A 19 796 ~ ~3~g~
a]cohol and vinyl acetate, in J. appl. Polym. Sci. 9 (1965), 239~ and for polyethylene o~ide and polyacrylamide in Br. Polym. J. 7 (1975), 135.
By using the aqueous dispersions of the present invention, the most important and the majority of the required paper coating characteristics may be simultan-eously optimised in a manner which leads, -to improved results compared to those obtained with the hitherto known co-binder processes. The aqueous dispersions o-f the invention are preferably used for the production of paper coating compositions, although other areas of use are also conceivable and possible, e.g. the production of coating compositions for other substrates such as paper-board, ~ard~oard, te~tiles and leat~er.
1~ The process of the invention enables both the simultaneous optimisation of many characteristics as well as the intended, excellent optimisation of specific coating characteristics, such as compressibility, micro-porosity, ink-receptivity, smoot~ness and binding power.
By using the aqueous dispersions, i.e. the modified latices according to the present invention, in the production of printed papers having a low weight, it is surprisingly found that the latex does not penetrate the 25 paper, that the fibre covering is improved and a homogen-eous regular coating matrix is produced. Thereby, the opacity, the brightness and the smoothness are improved a~d a regular and rapid ink-absorption is obtained with a constant or improved binding power. The further 30 advantage of the binder of this in~en~iQn~ is the fact that irreversible thickenings are avoided which may arise in the hitherto conventional use of e.g. polyvinyl alcohol in coating compositicns.
Le A 19 796 I ~)33g~
The latices modi~ied according to the invention, in contrast to the prior art, cause more voluminous and regularly ~icroporous coatings. In offset prin-ting, this stipulates a rapid regular colour acceptance which affords particular advantages in multi-colour printing wet in wet.
For rotogravure printing, the latices modi~ied according to this inv~ltion cause a high compressibility and smooth-ness of the coated paper with a decreased calender step. Due to the described coating structure, a high rapid ink 10 acceptance and a hi~h print clarity are obtained~
As is the case with offset-papers, stiffer papers are also required in roto~ravure printmg. ~Iitherto, the produc-tion of stiffer papers was not possible because, when using latices with hard films, there was a clear deterior-15 ation in the printing characteristics: irregular porosity,decreased compressibility, a pbor print (missing do-ts).
Due to the particular coating structure while retaining the characteristi~s required for rotogravure printing, latices modified according to the invention having a hard 20 film allow stiff papers to be printed on for the first time in the roto~ravure ~rinting ~rocess.
Due to the regular embedding o~ the modi~ied binder in the coating matrix, -the binder portion in the co~ating composition~ may be reduced as a result of its high bind-25 ing power9 whieh in the final analysis leads to a furtherimprovement in the printing characteristics.
The following E~amples illustra-te the invention.
Percentages and parts are all based on weight unless stated otherwise.
Le A 19 796 -~ 1~3~
E~YAMPLE 1 different paper_coa~ing lat ces.
(a) Modification of the latices The latices described below of various polymer compositions for the produc-tion of paper coating composi-tions are set, using water, to a solids content of 45,% in each case. A 10% aqueous solution of a partially saponi-fied 10 polyvinyl acetate is gradually added to these latices, with stirring, for the modification step. The added quantity is 5% (on a solid to solid basis). ~he partially saponi-fied polyvinyl acetate has a degree of hydrolysis of 88 mol /0, and a molecular weight of 25,000.
The following latex types are modified according to the invention, as described above:
Carboxylated styrene-butadiene latex having a conventional film hardness and a high pigment binding 20 power (commercially conventional paper coating latex) (600/o styrene, 360/o butadiene and 4% (meth)acrylic acid).
In modified Form = Latex A
_ Carboxylated styrene-butadiene lat~ hav~ng g~eater_film 25 hardness but a decreased pigment binding power.
In modified Form = Latex B_ Acrylate Latex __ Styrene-acrylic acid butyl ester latex having a slightly greater film hardness but a lower pigment binding power than SBR-latex type l (commercially conventional paper coating latex).
Le A 19_796 i ~33g~
In order to equilibrate the modified latices were stored for 24 hours before being further processed.
As a comparison, -the two SBR-latices (type l and type 2) and the acrylic latex were testecl concomitantly in non-modi~ied -form.
The binder characteristics are stated in Table l.
Table l ~
Latex Solids content pH value Viscosity ~ ~ a.s)_ A 38.6 7.4 244 B 38.6 7.4 llO
1~ C 38.6 8.7 93 Comparison non-modified SBR-Type l 45 7.2 68 SBR-Type 2 45 6.8 72 20 Acrylate 45 8.5 62 Note:
Viscosity: Brookfield LVT. Spindle 3 or 4, 60 rpm 20C
(b) Production of the paper coatin~ comp~osition and performance of the coatin~_exp rime_t lO0 parts of nhina clay are stirred into an aqueous solution of 0.2 parts of sodium polyacrylate, 0.2 parts ~ sodium polyphosphate and l part o~ aqueous ammonia using a high-speed stirrer and are dispersed into a Le A 19 796 33~
homogeneous suspension. 10% ( solid on solid, based on clay) of the latices described under (a) are respec-tively added as the binding agen-t. The pH is adjusted to 8.5 using aqueous ammonia. The respective composition can be seen -from Table 2~
Table 2 Composition of the paper coatin~ compositions (Parts are respectively parts by weight) Ex~eriment l 2 3 4 5 6 _, . . . , , . , , _ 10 Water ~ -- 74.0 Sodium polyacrylate ~ ~ 0.2 Sodium polyphospate ~ 0.2 -------------China Clay Dinkie A ------- lOO -------------Modified Latex (38.60/o) A 27.2 B 27.2 C _ _ 27.2 - - -Comparison non-20 modified latex) SBR-Latex, Type l - - - 27.2*
SBR-Latex, Type 2 - - - 27.2*
Acrylate Latex - ~ 27.2*
pH value ------- 8 . 5 -------------25 Solids content (/O) ------- 55 -------------*) 22.2 parts of 45/0 Latex ~ 5.0 parts of water.
The characteristics of the coating compositions are given in Table 3.
Le A 19 796 j33~S
Table ~.
Characteristics o:L the paper coatin~_compositions _periment _ _ _ 1 _ _ 2_ ~ 4 _ 5_ 6 Solids conten-t (,~) 54 9 55.1 54 8 54.8 54.9 54.9 5 pH value 8.4 8.5 8 4 8.68.68.5 Viscosity (mPa.s) Brookfield immediately 594 670 390 175182195 Brookfield after 24 hours 724 960 435 780720680 Rheomat 10 a-t D = 3.5x101345 320 410 140145190 at D = 1x103 45 38 54 2731 33 Setting Point (,/o) 73.4 73-1 74.1 76.8 77.3 77.1 Water retention sligh- more sligh-(comparison with tly impr- tly 15 non-mod.~fied impro- oved impro-late~) ved ved Note-_ _ See Example 1, part d for description of testing method.
After stabilizing and deaerating, the coating comp-20 ositions thus produced are coated OlltO a bleached base paper, containiny wood~pulp, consisting of 55 % of mechanical wood pulp and 45% of bleached sulphite pulp (conifers), having an ash content of 9. 9% and a weight of 50 g/m2 on both sides, with a coating weight of ~rom 8 to 10 25 g/m2~ per side (dry), using experimental ~lade coater, at a speed of 200 m/min.
Even after a lengthy operating time, the coating compositions containing the modified late~ do not form a coagulum or a covering on the Dlade or on cylinders.
Le A 19 796 ~ ~633g5 Also, no penetration by the coating composition throuyh the paper onto the blade-cylinder could be detectea. The coated papers are ~en finished with a supercalender (2 transits) and, arter bein~ cli~.~tised at ~ and 650/o relative air humidity, are 5 tested. ~he resu]ts of the test are assembled in Table 4, Table L~
~L}~
Coating appl~cation -~ - 10 -~
(g/m per side) ~hickness (mm) 0.074 0.079 0.078 0.070 0.070 o.o69 Wate~ absorp-tion (g/m ) according to Cobb (60 sec) 21.5 22 23 20.0 21 20.5 Smoothness accordin~ to Bekk 510 660 640 350 310 320 (sec./ml) Roughness according to Bendtsen (ml/Min) 25 21 22 39 36 35 Stiffness according to Schlenker, 40 40 62 42 42 61 47 IGT-dry pick /cm/Sec.) 94 76 62 116 80 88 K. and N. ~k recepti-vity test (~ 20.5 30 29 18 24 24 Rotogravure printmg-Test according to P.n~au 1 1 2 3 3 3 Micro contour test 2 1 2 4 4 4 Gloss (%) 28 32 26 22 24 23 Opacity (%) 93.9 93. 92.6 91.6 91.4 91.1 Whiteness (%~ 82.3 82.4 82.2 81.4 81.4 81.6 Fibre covering (o,b) 79.4 77.6 78.0 69.2 69.1 ~9.7 Note:
See E~ample 1, part d for description of testing methodO
Le A 19 796 ~ ~,33~
(c) Evaluation In contrast to -the papers (Experiments 4 to 6) coated with conventional latices, the coated papers of Experiments 1 to 3, the coating compositions of which contained the latices modified according to the invention, show clearly improved prin-tability characteristics, smoothness, opacity and particularly a high fibre covering.
The gloss was also increased. The setting point of these coating compositions was lowered so that a premature coating-immobilisation is possible before the actual drying, and the migration of the ~inder can be suppressed.
It is surprising that even a coating which contains a comparatively hard binder (Experiment 2), has a very effective printability for roto~ravure printing. In this manner, a paper having a low weight but a high stiffness is obtained which is suitable for rotogravure printing.
(d) I ~l} ~ D~_ The following tes-ting methods were used:
(Testing conditions, unless sta-ted otherwise 20C, 650/o relative air humidity).
pH value: electrometrically, according to DIN 53 785 Solids content: a) for latices: according to DIN 53 189 b) for coating compositions weighing difference after drying at 110C
Viscoslt~ according to DIN 53 788 a) measuring device: Brookfield viscosime-ter LVT, spindle 3 or 4, 60 rpm Testing temperature: 20C
Le A 19 79Ç
339~
~ 18 -b) MeQsuring clevice for recorc1ing rheo-gramms: Rheomat 15, measuring systems A to C, testing temperature: 20~C.
~æ~ lOOg of the coating composition are 5 ~i ~ given onto an unglazed clay dish drie~
compositions under constant cond.iticals at room temperature.
As soon as the wet lobk has disappeared from the surface of the coating composi-tion a sample is taken to determine the solids content.
m e solids content in ~ ~hus determined indi.cates the setting point, the point of immobilisation of ll L~ L~_ the wet coat an ~he paper ~ 0 cm3 of the coating campositions are coated on a paper with standar-dized conditions using a small doctor, groove depth 0.2 mm, within a few deci-seconds at a constant coating rate. As a result of the water penetrating into the paper from the coating composition, the relative air humidity rises on the lower side of the paper. This moisture increase is continuously registered using a hygroscopic moisture sensor as function of time. The higher the moisture in-crease per unit time, the poorer the water retention ability of the coating composition.
Moisture sensor: VAISALA (Fitting ~I ll) Measurements in the climatic chamber (650/o relative air humidity).
~D~ Difference between climatised samples o~ coated ancl un-coated paper (according t~ ~IN 53 lll).
Le A 19 796 I ~B3~9~
~L~a~}_ Determination according to DIN 53 105 Water Absorption accordi.ng to Cobb- Determination according to DIN 53 132, -60 seconds.
Smoothness to Bekk: Determination according to DIN 53 107, Rou,.hness -10 according to Bendtsen: Determination according to DIN 53 10 S~iffness Schlenker: Determination according to DIN 53 121, bending angle 40.
Dry pick Determination according to Tappi-Standard T 499 Su 64 using the IGTtester type AC2, and a compressive strain o~
35 kg/cm2. The IGT ~urface bonding strength tes-t colour o~ a low viscosity is used as the surace bonding strength colour.
K ~ N Test: Conventional determination of the in~
(Ink recep- absorption of coated papers according to tivity) the Tappi-routine control method RC 19, operation time: 3 minutes. The K ~ N
value is the di~ference in the whiteness between untreated paper and paper treated with the testing ink.
Le A 19 79~
I ~)3~
Measuring device: Elrepho, fil-ter R l~57 ~esting colour: K ~ N-testing ink~ the K ~ N-Laborities Inc., Melrose Park.
Micro contour Testing method to determine the c~atingreg 5 test larity, performance and holdout, similar to K T N-test, operation time however only 2 minutes, testing ink: blue testing ink 3811 from the firm Lorilleux Druckfarben GmbH, Ratingen. The de-termina-tion takes place visually using a five-stage evaluation scale, ~rom notation 1 indicating an absolutel~ homogeneous, speck-, hole- and fog-free testing surface to notation 5 indicating a heavily disturbed, irregular testing sur~ace having many defects.
Printin~ Test_ Rotogravure pr-ntLng test print on test printing machine system according to Dr.
~ner, Fa. Prufbau. The print result was tested visually and judged according to clearness of screen reproduction, regulari-ty o~ the colour absorption, completeness oi the print, transparency and the like Concerning this, three classes were estab-lishad:
1 = very good, 2 = good, 3 = poor.
Gloss: Determination of the gloss according to DIN 67 530 relative to a comparative standard at~a measuring angle of 60, measuring device: Lauge-reflectometer.
Le A 19 796 _ . _ ~ l B3~3$
Opacity: Determina-tion according to DIN 53 l46.
~ie~ Measuring using reflectance photometer Elrepho, filter ~ 457.
Fibre Coverin~: The coating colour is coated onto a black paperboard (coating weight: from 8 to lO g/m2 dry) and is carefully dried.
The whiteness (Elrepho filter R ~57) of the coated paperboard surface is then measured. The heavier the coating covers the black base~ the greater the whiteness.
Another determination of the fibre covering consists of the following method~
~ he coated paperboard su:rface is passed through using a very narrowly focused beam of the spectral photometer and 15 the diffused reflection is registered point lor point co~-nuously over a length of the paperboard of approximately lO cm. The diffused reflection fluctuations arising thereby provide a meas~re~ent~forthe regularity of the fibre covering according to a stochastic evaluation.
20 Cross section of the illumination beam O.3 x 2 mm2, rectangular screen.
EX~MPLE 2 Addition of different co=bind~c ~5c_~_e3 1 coating latex.
25 (a) ~odifica-tion of the latex As described for Example l under a), 5% (on a solid to solid basis) of the following co-binders in the form of 10% aqueous solutions were respectively added to the SBR-latex, type l:
30 - Block mixed polymer of hydrophilic polyoxethylene groups (an approximately ~O mol % part) and hydrophobic polyoxypropylene groups, total molecular weight: approxi-mately l6,OOO.
Le A 19 796 i I633~
Denoted as PE0-PP0, produces latex D
- Polyvinyl pyrrolidone having a molecular weight o~
approxima-tely 40,000 Denoted as PVP, produces latex E
5 - Polyacrylamide, having a molecular weigh-t of 30,000 -40,000 Denoted as PAA, produces latex F
- Acetalised polyvinyl alcohol (saponification number : 20), molecular weight approximately 70,000 10 Denoted as PVA acetalised, produces latex G
- as a comparison Partly saponified polyvinyl acetate as described in Example l Denoted as PVAC partially saponified, produces latex Z
15 The pH value and viscosity o-f the modified la-tices are gi~en in Ta~le 5.
Table 5.
~ ti^~ ~ the latices Latex Modified by pH-value Viscosity _ (mPa.s) D PE0-PP0 7.5 130 E PVP 7.4 52 F PAA 4.0 25 G PVA acetalised 7.3 3100 A PVAC partially 7.4 244 saponified Solids conten-t : 38 . 60/o Note: Viscosity : Brookfield LV~, spindle 3 or ~, 60 rpm 20C
Le A 19 796 ~ ~33~:~
b) Production of the paper coa~ing composition and implementation of the coatine ex~eriment ____.__ E~fec-ted llnde:r the same condi-cions as rlescribed for Example 1 under b). The compositions of -the coa-ting 5 composi-tions are described in Table 6 and the character-istics o-~ the same are described in Table 7.
During these e~periments as well, also after a lengthy operation time, no coagulum or covering appeared on the blade.
In comparison, Experiment 12 was also carried out according to Experiment 4 of Example 1, whereby the corresponding part of partially saponified polyvinyl acetate was subsequ~ntly added to the finished coating colour.
The papers coated on both sides were then finished over a .supercalender and, after being climatisecl, were tested. The coating characteristics are assembled in Table 8.
Table ~.
_ Composition of the paPer _oatin~ composi ions (Parts are respec-tively par-ts by weight) Experiment _ _ 7 _ 8 9 10 11 12 Water ~ - 74.0 ~
Sodium polyacrylate ~ --- 0 2 ------------Sodium polyphosphate ------- O.2 ------------China Clay ------- 100 ------------~odified Late~
(38.60to) D 27.2 E - 27.2 F - - 27.2 G _ _ _ 27.2 A _ _ _ _ 27.2 Le A 19 796 g ~
Table 6 Continued Experiment 7 _8 9 10 11 12 Compari-tive latex non-modified - - - - - 22.2 Polyvinyl aceta-te partially saponi~ied ( 10%) --_ _ _ _ 5 o pH-value ------ 8.5 Solids content (/0) - ---- 55 ------------Table 1 .
Experiment _ 7_ 8 9 _10 11_ 12 Solids con-tent (olO) 55.3 55.2 55.5 55.1 54.9 54.8 p~-value 8.4 8.6 8.3 8.4 8.4 8.5 Viscosity (mPa.s) Brookfield, immediately820 1150 325 1080 594 286 Brookfield, a~ter ~4 hours 960 1200 495 2800 724 980 Rheomat at D = 3.5x101 472 624 180 610 345 265 at D = 1x10337 44 27 48 45 38 Setting point (~) 72.9 73.0 74.0 74.1 73.4 76.1 Water retention more sligh- not not sligh- sligh-(comparison imp- tly imp- imp- tly tly wilh non- roved impr- roved roved impro- impro modified la-tex). oved ved ved Note-.
See Example 1, part d) for description o~ testing method,.
1,~
1 ~33~
Table 8 Coatin~ Characteristics EYDeriment 7 8 9 10 11 12 Coat~ng Applica-tion (g/m per side) ~ 10 ~
~hickness (mm) 0.76 0.74 0.730.77 0.074 0.070 Wate2r absorption (g/m ) according to Cobb (60 sec.)26.5 21.5 22 22 21.5 21 Smoothness a,ccording to Bekk (Sec./ml) 540 750 680 520 510 360 Roughness according to Bendtsen (ml/Min.)~4 19 20 25 25 33 Stiffness according to Schlenker, 40~ 39 41 40 41 40 39 IGT-Dry-pick (cm/Sec. j 88 89 120 110 ' 94 110 K&~ in~ recepti~ity ~%)22.7 24.0 19.4 18.4 20.5 18.5 Rotogravure pr~t~ng-sample print 2 2 1 2 1 3 Micro contour test 1 1 1 2 2 4 Gloss (%) 25 24 26 25 28 22 Opacity (%) 92.8 92.4 93.0 92.9 93.9 91.6 Brightness (/0) 82.4 82.3 82.3 8~.2 8~.3 81.3 Fibre coverage (/~) 76.9 77.9 77.7 78.1 79,4 69.3 Note:
See Example 1, part d) ~or description oL the testing method.
c) Evaluation As the Experiments 7 to 11 show, the modi~ication o~
the latex by co-binders according -to the presen-t invention Le ~ 19 796 ~ ~ ~33~5 . 26 -leads -to an improvement in the coating characteristics and thus to very effective characteristics in terms of printing, especially for rotogravure printing.
However, Experim~nt 12 shows -that a subsequent 5 addition of the co-binder to the composition does not give the required improvement.
Le A 19_ 796
Claims (10)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Aqueous dispersions having a solids content of from 35 to 65% by weight of a) polymers A, used as a binder, and optionally containing hydrophilic groups, which are formed Erom one or more of the monomers, styrene, butadiene, isoprene, acrylonitrile, Cl-C12-alkyl esters of acrylic and methacrylic acid, ethylene, vinyl acetate and vinyl chloride, and b) water-soluble polymers B, used as a co-binder, wherein the water-soluble polymers B
1) contain at least 40 mol % of polymerized units of an unsaturated carboxylic acid amide, vinyl pyrrolidone, ethylene oxide, vinyl alcohol or allyl alcohol, 2) are present in a quantity of from 0.5 to 50% by weight, based on polymer A, and 3) are partially or completely bonded to polymer A, the quantity of bonded polymer B being at least 0.5% by weight of polymer A.
1) contain at least 40 mol % of polymerized units of an unsaturated carboxylic acid amide, vinyl pyrrolidone, ethylene oxide, vinyl alcohol or allyl alcohol, 2) are present in a quantity of from 0.5 to 50% by weight, based on polymer A, and 3) are partially or completely bonded to polymer A, the quantity of bonded polymer B being at least 0.5% by weight of polymer A.
2. Aqueous dispersions according to claim 1, wherein polymer A contains incorporated therein from 70 to 100% by weight of polymerized units of styrene/
butadiene, butadiene/acrylonitrile, ethylene/vinyl chloride, styrene-(meth) acrylic acid ester, vinyl acetate/ethylene or vinyl acetate/vinyl chloride, from O to 15% by weight of other monomers and from O to 15% by weight of un-saturated carboxylic acids, the amides thereof and/or hydrophilic monomers con-taining sulphonic acid, amino or hydroxyl groups.
butadiene, butadiene/acrylonitrile, ethylene/vinyl chloride, styrene-(meth) acrylic acid ester, vinyl acetate/ethylene or vinyl acetate/vinyl chloride, from O to 15% by weight of other monomers and from O to 15% by weight of un-saturated carboxylic acids, the amides thereof and/or hydrophilic monomers con-taining sulphonic acid, amino or hydroxyl groups.
3. Aqueous dispersions according to claim 1, wherein the water-soluble polymer B consists of polyvinyl alcohol, poly(meth)acrylamide, polyethylene oxide, poly-vinyl pyrrolidone, polyallyl alcohol and/or copolymers of vinyl alcohol/vinyl aceta-te, (metil)acrylamide/vinyl acetate, vinyl pyrrolidone/vinyl acetate, vinyl alcohol/
(meth)acrylamide, (meth) acrylamide/styrene or ethylene oxide/propylene having molecular weights of from 1000 to 1,000,000.
(meth)acrylamide, (meth) acrylamide/styrene or ethylene oxide/propylene having molecular weights of from 1000 to 1,000,000.
4. Aqueous dispersions according to Claim 3, wnerein the water-soluble polymer B has a molecular weight of from 5000 to 200,000.
5. Aqueous dispersions according to Claim 2, wherein polymer A is a mixed polymer consi.sting of from 30 to 75% by weight of styrene, from 17 to 69% by weight of butadiene and from 1 to 8% by weight of one or more unsaturated carboxylic acids.
6. Aqueous dispersions according to Claim 2, wnerein polymer A is a mixed polymer consisting of from 30 to 75% by weight of styrene, from 17 to 69% by weight of a Cl-12-alkyl ester of (meth)acrylic acid and from 1 to 8% by weight of one or more unsaturated carbox-ylic acids.
7. Aqueous dispersions according to Claim 2, wherein polymer A is a mixed polymer consisting of from 30 to 75% by weight of styrene, from 17 to 69% by weight of butadiene and from 1 to 8% by weight of an unsaturated acid amide.
8. Aqueous dispersions according to Claim 3, wherein the water soluble polymers B are homopolymers of (meth)acrylamide, vinyl pyrrolidone, vinyl alcohol, ethylene oxide and/or mixed polymers of (meth)acrylamide/
styrene, vinyl pyrrolidone/vinyl acetate, vinyl alcohol/
vinyl acetate, (meth)acrylamide/vinyl acetate or propylene oxide/ethylene oxide.
Le A 19 796
styrene, vinyl pyrrolidone/vinyl acetate, vinyl alcohol/
vinyl acetate, (meth)acrylamide/vinyl acetate or propylene oxide/ethylene oxide.
Le A 19 796
9. A process for the production of a coating composition for print carriers wherein the aqueous dispersions according to claim 1, 2 or 3 are used as a binding agent.
10. A process for the production of a coating composition for print carriers wherein the aqueous dispersions according to claim 1, 2 or 3 are used as a binding agent, and wherein the aqueous dispersion added to the pigment composition contains less than 2% by weight, based on the pigment of non-bonded polymer B.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP2933765.3 | 1979-08-21 | ||
| DE19792933765 DE2933765A1 (en) | 1979-08-21 | 1979-08-21 | AQUEOUS DISPERSIONS FOR THE PRODUCTION OF COATING MEASURES |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1163395A true CA1163395A (en) | 1984-03-06 |
Family
ID=6078912
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000358515A Expired CA1163395A (en) | 1979-08-21 | 1980-08-19 | Aqueuous dispersions for the production of coating compositions |
Country Status (9)
| Country | Link |
|---|---|
| EP (1) | EP0024602B1 (en) |
| JP (1) | JPS5630456A (en) |
| AT (1) | ATE4998T1 (en) |
| BR (1) | BR8005275A (en) |
| CA (1) | CA1163395A (en) |
| DE (2) | DE2933765A1 (en) |
| ES (1) | ES8106747A1 (en) |
| FI (1) | FI802609A (en) |
| NO (1) | NO802401L (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4879336A (en) * | 1986-07-08 | 1989-11-07 | Wacker-Chemie Gmbh | Novel coating slips |
| US6736936B1 (en) | 1999-07-27 | 2004-05-18 | Ciba Specialty Chemicals Water Treatments Ltd. | Coating color |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3105779A1 (en) * | 1981-02-17 | 1982-09-02 | Bayer Ag, 5090 Leverkusen | AQUATIC DISPERSIONS, THEIR PRODUCTION AND USE |
| DE4209384C1 (en) * | 1992-03-23 | 1993-04-22 | Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung Ev, 8000 Muenchen, De | |
| CA2301928A1 (en) * | 1999-04-30 | 2000-10-30 | Gerald Owen Schulz | Latex for aggregate treatment |
| US7732525B2 (en) | 2004-05-20 | 2010-06-08 | Ciba Specialty Chemicals Water Treatments Limited | Polymers for paper and paperboard coatings |
| WO2008061177A2 (en) * | 2006-11-15 | 2008-05-22 | Dow Global Technologies Inc. | Paper coating composition |
| FR2916768B1 (en) | 2007-05-31 | 2009-07-24 | Arjowiggins Licensing Soc Par | CRISIS RESISTANT SECURITY SHEET, METHOD FOR MANUFACTURING SAME, AND SAFETY DOCUMENT COMPRISING SAME |
| US8106120B2 (en) * | 2007-12-21 | 2012-01-31 | The Euclid Chemical Company | Easily removable concrete curing compound |
| JP5403829B2 (en) * | 2010-06-15 | 2014-01-29 | ダウ グローバル テクノロジーズ エルエルシー | Redispersible polymer powder composition made from styrene butadiene based latex for dry blend formulations |
| FR2998588B1 (en) | 2012-11-29 | 2015-01-30 | Arjowiggins Security | FACTOR RESISTANT SAFETY SHEET, PROCESS FOR PRODUCING THE SAME, AND SAFETY DOCUMENT COMPRISING THE SAME. |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE619688A (en) * | 1961-07-03 | 1900-01-01 | ||
| BE820589A (en) * | 1973-10-29 | 1975-04-01 | COATING COMPOSITIONS FOR FULLY SYNTHETIC BINDER PAPER | |
| DE2442704B2 (en) * | 1974-09-06 | 1976-07-08 | COATING COLORS FOR THE SURFACE FINISHING OF PAPER | |
| GB1500513A (en) * | 1975-01-31 | 1978-02-08 | Harlow Chem Co Ltd | Coating compositions |
-
1979
- 1979-08-21 DE DE19792933765 patent/DE2933765A1/en not_active Withdrawn
-
1980
- 1980-08-08 AT AT80104683T patent/ATE4998T1/en active
- 1980-08-08 DE DE8080104683T patent/DE3065285D1/en not_active Expired
- 1980-08-08 EP EP80104683A patent/EP0024602B1/en not_active Expired
- 1980-08-11 NO NO802401A patent/NO802401L/en unknown
- 1980-08-19 FI FI802609A patent/FI802609A/en not_active Application Discontinuation
- 1980-08-19 JP JP11308980A patent/JPS5630456A/en active Pending
- 1980-08-19 CA CA000358515A patent/CA1163395A/en not_active Expired
- 1980-08-20 ES ES494380A patent/ES8106747A1/en not_active Expired
- 1980-08-20 BR BR8005275A patent/BR8005275A/en unknown
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4879336A (en) * | 1986-07-08 | 1989-11-07 | Wacker-Chemie Gmbh | Novel coating slips |
| US6736936B1 (en) | 1999-07-27 | 2004-05-18 | Ciba Specialty Chemicals Water Treatments Ltd. | Coating color |
Also Published As
| Publication number | Publication date |
|---|---|
| EP0024602B1 (en) | 1983-10-12 |
| ES494380A0 (en) | 1981-09-01 |
| BR8005275A (en) | 1981-03-04 |
| EP0024602A1 (en) | 1981-03-11 |
| ATE4998T1 (en) | 1983-10-15 |
| NO802401L (en) | 1981-02-23 |
| DE3065285D1 (en) | 1983-11-17 |
| FI802609A (en) | 1981-02-22 |
| JPS5630456A (en) | 1981-03-27 |
| DE2933765A1 (en) | 1981-03-12 |
| ES8106747A1 (en) | 1981-09-01 |
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