DE2025742A1 - Coating slip for paper - Google Patents

Description

concerning: "coating slip for paper "

A new coating slip is described which essentially from a suspension of a ^ o ^ yele ^ gglytbinder and a Pigments in the ratio of \ (up to 8 parts of binder 100 parts pigment. A preferred polyelectrolyte is the sodium salt of the copolymer of acrylic acid and ethylene. The coating slip leads to improved optical properties and to a more economical pigment application.

The invention relates to new coating slips for paper. It relates more precisely to the use of a polymer polyelectrolyte (hereinafter referred to simply as "polyelectrolyte"), which forms polymer bridges between ionic sites of different pigment particles rather than, as in usual Coating slips, serves as a solid matrix for the pigment.

The paper manufacturers supply coating papers for many purposes.

009850/1849

Coating papers are used a lot for magazines, for example, because they are economical, can be printed and have good optical properties. So can relatively cheap board with a pigment that with a suitable binder is mixed, coated, Wp- " the result is a paper that has a high hiding power and a high whiteness content.

The pigments typically used for this are clays. Other substances that can also be used are including chalk, colored pigments, synthetic silicates, etc. The pigment is mixed with the binder that makes up one layer

or matrix that forms the pigment particles with one another

and adheres to the paper substrate.

A common coating slip for printing papers produced in large quantities contains at least 20 parts of enzymatically digested or otherwise treated starch per 100 parts of clay in a dispersion which contains approximately 60 % solids. In general, this type of litter must be produced in a simple and uncomplicated manner. Dispersing aids have to be added in order to obtain complete dispersion of the clay in water. If granular starch, the cheapest corn starch that can be used, is to be used, 7J it must be mixed in water and boiled in the presence of a precisely determined amount of a suitable enzyme until its granular structure has been destroyed and the molecular size has been reduced to give the fast a satisfactory pourability and to give the resulting coating slip suitable retention characteristics. Then the dispersions of clay and starch need to be mixed.

It goes without saying that the known manufacturing processes for coating compounds are still considerably more complicated.

009850/1 ">

■ ^; ■■: ■> ■■ ' ORIGINAL INSPECTED

■ - ■ "■ ■ -..- ■ ■: - 3 -

Further additions and additional process steps, all of which serve to create cheaper or better coating slips for certain types and weights of paper, and special ones Manufacture printing process.

It is known that the papers improve their optical properties obtained by the pigments. The fundamental property of the pigments, from which their hiding power (or fecal properties) results, is the refractive index between the pigment particles and the surrounding medium. It is known that connective Medium reduce the hiding power and the whiteness of the pigments, since the refractive index between the pigment particles and the adjacent binder matrix is less than that Refractive index at the pigment / air interface.

Therefore, manufacturers generally use it when painting

use the lowest possible amount of binder in paper.

Experience has repeatedly shown that the minimum amount

corresponds roughly to the amount that the spaces between fills the neighboring pigment particles sufficiently to a more or less coherent layer or matrix to form, which holds the pigment particles in place. Lower amounts of binders had previously not been found to be effective. i

New coating slips have now been invented which essentially consist of a polyelectrolyte-figure complex as a coating agent for the paper. Surprisingly, it arises in the pigment-binder systems according to the invention at an unusually low ratio of binder to Pigment a layer whose physical properties the common pigment-binder systems and which has significantly improved optical properties.

Because of the great reduction in the need for binding agents, the coating slips according to the invention are very economical

009850/1849

1A-38 029

However, the economic benefits go beyond those in addition, which result from the saving of binders, since the pigment is better used and less expensive pigments can be used. These advantages can be made use of by applying the substance applied to the paper base Significantly reduces the amount of pigment compared to the previously used minimum or by using cheap pigments, those in the usual binder systems do not correspond have good properties or by both being the case. Another important advantage is that calendering is facilitated. -

It is believed that the unusually good results can be achieved in that a complex with a three-dimensional lattice by ionic bonds between the polyelectrolyte and preferred locations on the pigment. It is assumed that every pigment particle has ionic salts * like bonds with a variety of polyelectrolyte polymer chains forms, which in turn are bound to a large number of other pigment particles, creating a three-dimensional The structure of the pigment particles is created by the polyelectrolyte bridges are firmly connected between the neighboring particles. Although a single polyelectrolyte chain can be sufficient to bind the pigment particles, it is reasonable to assume that a number of polymer molecules. can bridge the nearby areas.

As already mentioned, you can use a much smaller amount of binder can be used to produce coatings with satisfactory physical properties, e.g. "an IGT pick of about 150 ft./min. with a No. 3 tack ink or more " In general, the ratio of binder to pigment in the coating slips according to the invention is fcis to about 8 Parts by weight of binder to 100 parts of pigment. Usually at least 2 parts of binder per 100 parts of pigment used. It is believed that this unusual result

, 0 09850/1849 ■ · - 5 -

1A-38 029

nis is obtained by the formation of strong ionic bonds between the binder and the pigment.

An important consequence of this low binder to pigment ratio is that the interstices between the neighboring pigment particles are no longer more or less filled with binder. Hence they are The optical properties of the resulting coating are improved by the fact that air / pigment interfaces are in the spaces arise that have a higher refractive index.

In addition, due to the porosity of the applied Coated paper can be easily calendered at low roll pressures. The one in the present invention preferred range of up to 8 parts of binder 100 parts pigment ensures that the amount of binder is not so great that it has an adverse effect on the optical properties of the resulting coated paper exercises. Within this wide range there is an optimal ratio of binder to pigment, which includes a line gives the best mechanical properties.

The density of the polymer bridges between the pigment particles I. depends on many complicated stoichiometric relationships from and is only little enlightened. These relationships include the number and location of the ionic sites on the surface of pigment particles and the type of those associated with the pigments Ions as well as those that result from the ion exchange with the aqueous medium associated with the pigment » Changing stoichiometric relationships is the equilibrium between the solubility of the polyelectrolyte as it is with reacts to the ions on the surface of the pigments and those in the solution, the size of the pigment particles and the Number and distribution of their io.nischea centers, the temperature and the concentration of the watery system, which the stream * »

. "G " m ■

009B5Ü / iüAQ

1A-38 029

~ ^{Contains 6} agents.

Regardless of the complexity of the line system and its stoichiometry, it is clear that if the layer dries, a maximum particle-particle bond occurs at a point and that the coating layer obtained in this way is optimal possesses physical properties. If a larger proportion of polyelectrolyte is used, the bond between the particles are lowered because a corresponding part of the bridges between the particles is then carried out by two polymer molecules each of which is bound to different pigment particles. This leads to a "softer" structure. in the Extreme case in which all points of the pigment particles with individual Polyelectrolyte molecules are occupied that are not attached another pigment particle is bound, the structure becomes not through laonomolecular bridges between the pigment particles rather, polymer-polymer bonds form when the dispersant is removed.

If less polyelectrolyte is used than is necessary to achieve maximum particle-particle bonding, the result is a softer or weaker structure, in this case with too little polymer to create an unusual one to result in a coherent structure, so the properties change if either too little or too much polyelectrolyte is used.

The polymer bonds between the pigment particles can vmrden also modified by you, ausetat a proportion of an organic mono electrolytes such Uatriumolaate, occurs dösaen anion with the polyelectrolyte in dia cationic £> barking in konkurrens »· Careful application of this principle leads below a regulated Softening the

0 0 9 8 5 D / 1 8 % 9

1A-38 029

The polyelectrolytes used for the present invention are derived from thermoplastic polymer materials having a molecular weight greater than JO,000 and having either cationic or anionic ionizable functions at intervals along the polymer chain. The frequency of occurrence of the ionizable sites is sufficient that the salts of the polyelectrolyte with suitable monovalent anions or cations (depending on whether the polyelectrolyte is cationic or anionic) are dispersible in water. A preferred polymer for the present invention is the copolymer of ethylene and acrylic acid, resulting in a polymeric material with a hydrocarbon chain on which there are randomly distributed carboxylic acid groups. The ratio of acrylic acid to ethylene is typically less than approximately 1: 1 but sufficient that there are enough acrylic acid groups to render the polymer dispersible in an aqueous alkaline solution The degree of polymerization is sufficient to produce a solid polymer which normally has a molecular weight in excess of about 30,000 regardless of its presence the carboxylate groups of the polymer exhibits many properties that are typical for polyethylene a typical polymer of this type has a ratio of acrylic acid to ethylene between g about 1:. 5 to 1:40, and a melting point of about up to 99 ⁰ C (150 to 210 ⁰ F) Very similar substances include other polymers made from ethylene or Pro pylene with acrylic acid, methacrylic acid or maleic acid.

Other polymers useful in the present invention are, inter alia, copolymers of hydrocarbons with organic acids, along the carboxylic acid or sulfonic acid groups of the main chain have sufficient frequency that resins are formed which are dispersible in aqueous alkaline solutions are. Other polymers are those that are spaced

009 8 50/1849 - ■

1A-38 029 - 8 -

have polycationic sites, ζ «Β. those made from tetravalent Ammonium compounds that have a polymerizable contain ethylenic group, together with ethylenically unsaturated Gomonomer are formed «Such compounds should have a sufficient number of cationic sites that They are soluble in strong aqueous acids. It is assumed that these substances are analogous to those described above polyanionic compounds react by forming ionic bonds between cationic sites along the polymer chain and anionic sites on the pigment particles.

The preparation of 25% aqueous solutions of salts of the typical polyethylene polycarboxylates is very simple. Sodium salt is preferred for many purposes because it is non-volatile and cheap. In the coating slips according to the invention, the sodium salt and other polycarboxylates result in binder pigment systems of unusually low viscosities compared with the conventional binder pigment systems with a comparable solids content. The advantage of this low viscosity is obvious, since it enables more concentrated dispersions to be used and facilitates the application of the coating slips.

For other applications ^ ζ _β Β _β if it is desired to remove the -alkali ions, the ammonium is preferred »

Beads of the polymer are added while vigorously guarding to an aqueous alkali solution in a covered vessel, which is kept at 99 to 100 ⁰ G and stirred until all the polymer is dissolved. A faster 18s @ n can be achieved if maa Tb> © i HöhoK »©» Temperatures in e.ia @ »Pressure vessel and_working under heavy pressure © t ₉ u® the melted drops & © b Polyners sm gert © il © a Maä the finely distributed quick © ia & ®r AlkaliliSrag au Wsttileao Such a Gemieeli must @ © lb © tT © r © täsdli © & b © v © r aaa das

M ξ) C

009850 / 18AS

1A-38 029

Pressure vessel opens to be cooled ^{below 10O 0 O.}

In a similar way, other alkali salts, especially potassium salts, be used. It is believed that strongly basic quaternary ammonium compounds also have soluble salts form with the polyanionic polymer.

In order to obtain the best possible results, the amount of alkali used should be just sufficient to neutralize the polyanionic polymer. This is easily achieved by using the ' alkali hydroxides. If the amount of alkali * is insufficient to neutralize the polymer, ie the carboxylic acid groups are not completely ionized, the polymer tends to be difficult to disperse and to form colloidal systems. In addition, the ionizable groups of the polymer that are not fully ionized by reaction with a salt-forming ion are unable to complex with the ionic sites of the pigment. On the other hand, if the amount of alkali added exceeds the stoichiometric amount, the excess is usually not useful and can lead to an undesirable increase in the viscosity of the resulting dispersion. After a suitable dispersion of the polyelectrolyte I has been prepared, the coating slip according to the invention is obtained by mixing the pigment with the dispersion. Typically, it has been found that dispersions of the pigment can be readily prepared with conventional high-performance mixing equipment. A dispersing aid for dispersing the pigment is usually not necessary. But you can use it if necessary. The spreads typically contain 60 to 80 % pesticides.

Cj 0- 3 8 t η / I 8 4 S

«Ίο -

example 1

In a 113.56 1 (30-gallon), glass-lined vessel were added to 52 ₉ 6 kg (116 pounds) Water 18.71 kg (41.25 pounds) of a Athylenacrylsäurecopolymers containing a carboxyl group to about 20 ethylene units , and 3.5 kg (7.7 pounds) of a 50% solution of sodium hydroxide were added. The reaction was stirred and heated indirectly with steam (in a steam jacketed vessel) from 1.2 kg / cm ² (17 psi) to 113 ° C (235 ° F) and held at that temperature for half an hour. The batch was then cooled and placed in a storage vessel. The 25% solution prepared in this way was used as the starting solution for the coating slips described below.

It is only necessary to dilute the starting solution to the desired polyelectrolyte content and then to do this by simply Mix to add the pigment «,

A coating slip with a solids content of 70 % and containing 3 * 0.% binder based on the weight of the pigment was prepared by adding 48 g of the starting solution from Example 1 (12 g dry weight of polyelectrolyte) with 141 g of water in dilute a beaker and stirred with a turbine-type stirrer, to the dry pulverföraigen pigment was 400 g of ground calcium carbonate (Gamaco brand) portionwise added and further stirred for 15 minutes, "The coating composition was then added ia © inen ^w 0sterizer ^Bt mixer ,, stirred for 3 minutes," and then sieved through an O _S 148 (100 mesh) sieve made of corrosion-free steel »The pH of the coating slip produced was 10.8.

ο ο a η 5 ο

■ -..-- 11 ■ - ■

Field viscosity was measured at 28.3 ° C (83 ° F) at various speeds, which is the speed gradually increased and then decreased again to the first low speed to show if the coating agent Was thixotropic or not, The following values were found:.

Rpm cPs 10 190 20th 185 50 174 100. 185 10 190 Example 3

A coating slip containing 60% solids including 4 % binder, based on the weight of the pigment, was prepared exactly as described in Example 2 with the exception that 64.0 g of the 25% starting solution of the polyelectrolyte (or 16 g . Solid), diluted with 225 g of distilled water and added 400 g of calcium carbonate pigment. The pH of the resulting coating slip was 11.0 and the BrookfieMViskositäijdie at 35.0 ⁰ C |

(95 ° F) was:

MpM cPs
■ MMM 10 24 20th 26th 50 36 100 53 10 25th

In a similar manner, coatings containing approximately 60 % solids were prepared using various clays, calcium carbonate, titanium dioxide, talc and various pigment mixtures as pigments. The resin content

009-850 / 1849

of these coating slips varied between 3> 5 and 16.67%, based on the weight of the pigment. Coating slips with a solids content higher than 60% (30%, 40%, 50%, 70%) with calcium carbonate as pigment and 3.0 to 4.0% resin were also produced and investigated. The composition of these coating slips and the results obtained in the tests on these coating slips and the papers coated therewith are shown in the table below. The table also contains two comparative tests: Test No. 22 relates to a coating slip with 60% solids, which contains HT clay as pigment and 20% starch (Stayco M) as binder and in which the clay and starch were cooked together . Trial 28 is for a paint with 60% total solids calcium carbonate and 20% starch (Stayco M) cooked together. Resin was not contained in any of the comparison substances. All samples were calendered on a 3-roll mill with through slots at 66 ⁰ C (150 F) and a pressure of 136 kg (300 pounds).

The following tests were carried out for each coating slip:

Brightness G.E., iPAPPI T452, both for

*. calendered as well as for not

w . calendered paper

Opacity Bausch & Lomb, TAPPI T425,

for both calendered and non-calendered paper

Gloss Bausch & Lomb, TAPPI T480,

for both calendered and for non-calendered paper

Smoothness BEKK, TAPPI T479

Wet Friction Resistance The results obtained

if you run a wet finger over it 10 χ 2.5 cm are classified as follows: A = excellent, G = good, M = moderate, and S = bad;

Brookfield viscosity TAPPI T648, indicates the viscosity

- 13 0098 50/1849

~ 13 ~

Brookfield viscosity at 10,20,50,200- and

V again at 10 rpm at the specified temperature

The .pH-Y / er't aller-coating mass *! was decided·

14 -

0/1849

Attempt no.

% Solids in
of the üreichniasae

Pigmenb

1 2 3 4

60.4 60.7 60.9 61.1 61.4 HT tone ——————

Partly polyelectrolyte 100 parts pigment

kg (Ibij) coating slip / Biee paper

(63.5 κ 96.5 cm-500)

Brightness, GE
(TAPPl T 452)

not b

calendered

calendered

Opacity, B&L not calendered (TAPPI T 425)

calendered;

Gloss, B&L
(TAPPI T 480)

not calendered fc calendered 4.8 7.15

2.72 2.63 (6.0) (5.8)

80.7
79.1

88 ^ 2

79.8 78.5

88.3 87.2

16
50

9.53 • 2.59.

80 _s 0 78.3

88.0 86.8

15 47

Smoothness, BEKK (TAPPI T 479) calendered - Sees.

IGT color holder (TAPPI T 499) 50 kg - spring A.

Working speed (J- ¹ oet / min.) M / mm

Color viscosity - Tack Ink No.

K&N ink resistance (TAPPE RC 19) from 1, very receptive to 10, very resistance « able to

Wet-high-burner strength lOaal

2.5 cm (Ten I "Strokes) with well on a finger

Disparate, good, moderate, battle

Brookfield viscosity of the slurry mass (TAPPI T 648) 119 91 * 4
390) (300}

122 (400)

11.91 16.67 (5 * 6) (6 | 2)

80.0 78.3

88.0 86.5

13 45

188 350 317

125. £ 10)

78.2 76.7

86.5

32

341

101 (332)

cPa at 10 RPM C Fs at 20th U / Mln c company bai 50 RPM CB3 at 100 RPM c Rj at 1Q U / Hin

O ₁

at eias & r temp, from _n G

( ⁰

1208 1608 2100 2600 4240 740 970 1250 1560 2650 426 518 670 866 1480 298 340 430 562 1016 1132 1432 1900 2370 3760 33.3 32.8 " 34 ₅ 4 34.4 ■ 36.1 (92) (91) (94) (94) (97)

pH of the Streichaassen 10.0 10.1 Λ0Α

,8th

Note: All tests were carried out on roller mills with 3iachea. Passage calendered at 66 ⁰ C (15O ⁰ F) and -136kg (300 lbs),

15th

0 9 0 5 0/1843

Attempt no.

% Solids in
the coating

pigment

9 10

60.4 60.7 60.9 61.1 61.4 RAYOX LD-C *

Parts of polyelectrolyte to 100 parts of pigment

kg (lbs) coating slip / BieB paper

(65.5 x 96.5 cm-500)

Brightness, GE
(TAPPI T 452)

not

calendered

calendered

Opacity
(TAPPI T 425)

Gloss, B&L
(TAPPI T 480)

B&L doesn't

calendered. calendered

not

calendered

calendered 4.8 7.15 9.53 11.91 16.67

2.86
(6.3)

89.5
87.9

93.2
92.0

3.04
(6.7)

88.6
87.2

92.3
91.4

20th
62

2.90 2.95
(6.4) (6.5)

88.3 87.8

87.2 86.9

92.0 91.6

91.0 90.6

20th
57

Smoothness, BEKK (TAPPI T 479) calendered - Sees.

IGT color holder (TAPPI T 499) 50 kg - spring A.

Working speed (feet / min.) M / min Ink viscosity - Tack Ink No.

K&N printing ink resistance (TAPPI RC 19) of 1, very receptive up to 10, very tough

Wet abrasion resistance ^- 10aal 2.5 cm (Ten 1 "Stroke") with a wet finger

Excellent, Good, Moderate, Bad

Brookfield viscosity of the Coating Slips (TAPPI T 648)

43.4 (14th?)

cPs at 10 O / min. cPs at 20th o / min. cps at 50 O / min. cPs at 100 O / min. cPs at 10 O / min.

at a l'emp. by C

( ⁰ F)

pH of the streak

a titanium dioxide pigment 48.5
4th

11.1
(365)

17th
50

241 265 259

96.7
. (317)

2.95 (6.5)

87.0 86.2

90.9 90.3

14 42

274

96.1 (315) 8

100 188 256 248 700 87 132 190 184 555 83 94 138 142 418 91 102 136 145 344 100 180 228 200 570 35.9 35.0 35.0 34.4 34.4 (93) (95) (95) (94) (94) 10.2 10.2 10.4 10.2 10.3

- 16 -

0098 50/1849

Experiment No. 11 12 13 14 15

% Solids in 6O 4 60 9 60 Q 61 1 61 4

of the coating material ^bü ' ^{4 bü </ bUfV Μ} ' ^{Π bT} '

Pigment CaCO ₅ - $>

Divide polyelectrolyte

100 parts pigment 4.8 7.15 9.53 11.91 16.6?

kg (lbs) coating weight /.

Riee paper 2.27 2.49 2.2 ₇ 2.63 ^ 2 H.

(63.5 x 96, § cm -500) (5.0) (5.5) (5.0) (5.8) (6.1)

conveys ⁸² ' ^{8 82} ' 3 ⁸² '° * l * ⁸⁰ ' ⁶ calendered 82.4 81.8 81.2 80.5 79.8

Opacity, B&L not

(TAPPI T 425) calendered 86.8 86.5 85.8 85.5 84.8

calendered 86.2 86.1 85.0 84.9 83.9

Shine, B&L not

(TAPPI T 480) calendered 3 3 3 3 3

calendered 10 9 8 10 11

Smoothness, BEKK (TAPPI T 479)

calendered - lake. 215 152 138 155 273

IGT color image (TAPPI T 499). 50 kg - spring A.

Ink viscosity - Tack Ink No. 8 8 8 8 8

KScN printing ink resistance

(TAPPI RO 19) out of 1, very up - 3 3 4 5 6 Acceptable up to 10, very resistant

Wet abrasion resistance 10aal '

2.5 cm (Ten 1 "strokes) ait a A AAA

wet fingers

Excellent, good, moderate, bad

Brookfield viscosity of the coating slips (TAPPI T 648)

cPs at 10 rpm.

cPS at 20 rpm. cPa at 50 rpm.

cPö at 100 rpm.

cP3 at 1Q rpm. '

with a leap, from _Λ 0

( ⁰ F)

pH of the Streichaasse

• --17 -

009850/1849

26th 35 44 50 128 26th 35 43 48 104 34 39 48 55 101 51 59 64 71 129 21st 28 40 47 112 35.0 34.4 34.4 34.4 34.4 (95) (94) (94) (94) (94) 1Oi 9 11.0 11.0 11.0 11.0

Attempt no.

% Solids in the coating

pigment

Parts of polyelectrolyte to 100 parts of pigment

kg '(lbs) coating slip / ream of paper

(63.5 x 96.5 cm-500)

17th

60.7 60.9

Peerless

18 19 2C 58.0 58.0 58, C

VPalkum

50% CaCOj

7.15 9.53 '11, 91 16.6? 4.8.

2.90 2.72
(6.4) (6.0)

Brightness, G.E, (TAPPI T 452)

not

calendered

calendered

Opacity, B&L not (TAPPI T 425) calendered

calendered 77.3
76.5

Gloss, ML
(TAPPI T 480)

not

calendered

calendered

78.7
77.8

86.6
86.6

20th
47

2.45 2.40 3.22 (5.4) (5.3) (7.1)

78.1 77.3 83.8

77.2- 76.9 83.1

86.4 85.1 88.6

85.9 85.3 88.1

16

24

4 15

Smoothness, BEKK (TAPPI T 4? 9) calendered-lake.

IGT color holder (TAPPI T 499) 50 kg - spring A.

Working speed -

(Feet / min.) M / min *

. Ink Viscosity - Tack Ink No.

289 234 256 85 203

M 6 64
380) (21C).

4 8

108 "128 (355) (420)

8 8

61 (-2Ot)

K&N ink resistance (TAPPE RC 19) of 1, very absorbable up to 10, more resistant

Wet abrasion resistance 10 x 2.5 cm (Ten 1 "strokes) ait wet finger Excellent, Good, Moderate, Bad

Brookfield viscosity of the Streichfflfiosen (TAPPI T 648)

10 rpm 20 o / min. 50 o / min. RPM

at
at

cP 8 at
cP3 at
el «at

100 / JO rpm.

at a temp of C

( ⁰ F)

pH of the Streichaassen 24100
14050
7060
4100
23700
34.4
(94)

10.0

24100

14000

6880

4030

227OO

33.9
(93)

11000
6500
3320
2040

10440

33.9
(93)

8720 5240 2768 I7I6 8200 35.0 (95)

392

338

310

304

348

22.2

(72)

10.0, 10.3 10.4 10.8

- 18th

00 98 50/184

Attempt no.

% Solids in
the coating

pigment

Parts of polyelectrolyte to 100 parts of pigment

kg (lbs) of coating slip / egg of paper

(63.5 x 96.5 cm-500)

Brightness, GE
(TAPPI T 452)

not

calendered

calendered

Opacity, B&L not calendered (TAPPI T 425)

calendered

Gloss, B&L
(TAPPI T 480)

not

calendered

calendered

Smoothness, BEKK (TAPPI T 479) calendered - Sees.

21 60.4

25 % TAK

75% CaCO ^

4.8

2.90 (6.4)

83.4 83.0

87.9 87.6

3 10

158

IGT color holder (TAPPI T 499) 50 kg - spring A - _Q2

Working speed -

(Feet / min.) _M / _min (270)

Ink Viscosity - Tack Ink # 5

K&N printing ink resistance (TAPPI EC 19) of 1, very good. 3 Acceptable up to 10, very resistant

Wet abrasion resistance 1Q times ·· 2.5 cm (Ten 1 "Strokes) with a wet finger
Excellent, Good, Moderate, Bad

Brookfield viscosity of the coating slips (TAPPI T 648)

116 110 115 137 100

23.3 (74)

at 10 rpm.
cPs at 20 rpm.
cPs at 50 rpm.
cPs at 100 rpm.
cPs at 10 rpm.
at a teap. from

( ⁰ F) 2025742 22 *** 23 '24. 25 60.0 60.0 60.0 60.0

100 %
HT

Clay CaCO, Car-

^ bium

MM * *

79.4
78.5

87.9
87.0

186

8900
5450
3000
2050
8400
32.2
(90)

4.0 3.5 4.8

2.77 2.36 2.36 2.81 (6.1) (5.2) (5.2) (6.2)

83.4
82.1

87.5
85.0

7th
28

896

83.0 82.3

82.3 81.6

87.3 86.8

85.2 86.0

8 27

1 7

778 312

119 99.2. 97.5 94.5 (325Ü (320) (310; 5 5 .53

24
26th
36
53
25th
35.0

(95)

19th 27 22nd 32 34 . 45 53 70 19th 44 33.9 35, o (93) (96)

11.0 10.1 11.0 11.0 10 _t 9

pH of the strokes

Precipitated calcium carbonate Experiment .22 - 100 % clay as pigment - 20 starch (based on the clay weight) as starch and clay were boiled together.

Note y **

% oxidized adhesive

009850/1849 - 19 -

Attempt no.

% Pesticides in
the coating

pigment

Parts of polyelectrolyte to 100 parts of pigment

kg (lbs) coating slip / ream of paper

(63.5 x-96.5 cm-500)

Brightness, GE
(TAPPI T 452)

not

calendered

calendered

Opacity, B&L not calendered (TAPPI T 425)

calendered

Gloss, B&L
(TAPPI T 460)

not

calendered

calendered

26th 27 2025742
28 50.0
CaCO ₃ . - 40.0 60.0 CaCO,
+ 20% ^
strength
together
cooked *.O 0 1.77
(3.9) 4.0 3.36
(7.4) 82.6
82.0 1.13
(2.5) 78.6
78.0 86.5
85.0 82.0
81.4 85.4
83.9 2
14th 86.0
84.5 2
8.3 2
12th

Smoothness, BEKK (TAPPI T 479) calendered - Sees.

IGT Farbaufnahae (TAPPI T 499) 50 kg - spring A

Working speed (feet / min.) M / min

. Ink Viscosity - Tack Ink No.

K&N ink resistance (TAPPI EC 19) from 1, very receptive to 10, very resistant

Wet abrasion resistance 10aal 2.5 cm (Ten 1 "strokes) with a wet finger

Excellent, Good, Moderate, Bad

Brookfield Viscosity of Str, Calibrated (TAPPI T)

cP ₈ at 10 rpm, at 20 rpm. &beo> 50 υ / Μη. cPs at 100 rpm. CP ₈ at iö rpm. _Λ at a teap. of 667

71 ', 7
(235)

411

100.6
(330)

5.

( ⁰ F) 500

102 (335)

• S

pH of the coating mixes

10 7th 2000 15th 11 1440 23 15th 984 30th 21st 756 14th "9 1880 26.7
(80) 26.7
(80) 23.2
(74) 11.1 11.1 7.7

009850/1849 e 20 -

Attempt no.

% Solids in '
the coating

pigment

Parts polyelectrolyte to 100 parts pigment

kg (lbs) coating weight /

Eies paper

(63.5 x 96.5 cm-500)

Brightness, GE
(TAPPI T 452)

Opacity,
(TAPPI T 425)

Gloss, B&L
(TAPPI T 480)

not

calendered

calendered

B&L doesn't

calendered calendered

not

calendered

calendered

Smoothness, BEKK (TAPPI T 479) calendered - Sees.

IGT color holder (TAPPI T 499) 50 kg - spring A.

Working speed (feet / min.) _M / _min

70.0 2.5% Eayox

RG - 97.5% CaCO ₇ .

3.0

3.08 (6.8)

83.8 83.3

88.9-87.2

2 17

500 77, ö

(255)

Ink Viscosity - Tack Ink # 3

K&N printing ink resistance (TAPPI EC 19) from 1, very receptive to? ^ 10, very capable resis-

Wet abrasion resistance 10 times

Ten 1 "strokes with a wet finger

Excellent, Good, Moderate, Bad

Brookfield viscosity of the coating slips (TAPPI T 648)

cPs at 10 rpm.
cP s at 20 rpm.
cPs at 50 rpm.

cPs at 100 rpm.
. cPs at 10 rpm
at a temp of

pH of the Streichaasse

( ⁰ F)

'2JÖ 29.4

'(85) 30

70.0 CaCO-

3 65

£ 025742

3.0 3.0 3.58 (7.9)

83.8 83.1

88.9 87.8

11 330 81, £

(284) 4-

3-

-.G

190 185 174

1.32 (2.9)

82.4 81.7

86.3 54.6

2 8

410 97.5

(320) ■ 3

.2

• 38 "58

32

10.8 10.8

0 0 9 8 5 0/1 8 4.9

Similar results are expected when using potassium hydroxide instead of sodium hydroxide is used, ammonium hydroxide can also be used as an alkaline dispersion medium o In this case, however, it is normally because of the Dissociation equilibrium between the ammonium ion, ammonium hydroxide and ammonia, a substantial excess of alkali needed. -

Obviously, a particular benefit of the present invention is that unusually light strokes can be made. Typically, the preferred coating slips of the invention are used in an amount of about 1.36 to 2.2? 3-5 pounds (kg) per ream (500 sheets 63 »5 x 96.5 cm) applied. Another important advantage is that the coating slips of the invention set unusually quickly, especially when they contain 60% or more solids. This makes subsequent handling and drying much easier.

Claims

- 22 -

009850/1849.

Claims (1)

Patent claim Ji c he M. ) Coating slip for paper composed of a binder and a pigment characterized in that the binder is a polyelectrolytic thermoplastic resin with a molecular weight of more than 30,000, which has enough ionizable groups along the polymer chain to allow salts to be dispersible with monovalent ions form, wherein the ionizable groups have a charge which is opposite to that of ionic sites on the pigment, and that the ratio of polyelectrolyte to pigment is no greater than .approximately 8 parts of polyelectrolyte to 100 parts of pigment and is large enough _# that together with The pigment creates a physically coherent coating slip that contains so much water that it is liquid. 2. coating slip:, according to claim 1, characterized in that the polyelectrolyte is a copolymer of an ethylene monomer such as ethylene or propylene and a carboxyl! See monomer such as acrylic acid, methacrylic acid and - or maleic acid is ₉ where the ratio of carboxylic monomer to ethylene monomer is less than about 1 j 1, but large enough that the polyelectrolyte is dispersible in aqueous solutions. 3. coating slip, according to claim 1 or 2 characterized g e k e η η indicates that the polyelectrolyte has a weight ratio of carboxylic monomer to ethylenic Monomer between about 1s5 and 1s40 and a melting - 23 - 009850/1849 point from about 66 to 99 ⁰ O (150 to 210 ° P). after
4 · Coating slip-V claims 1 to 3 characterized in that the polyelectrolyte is dispersed in an aqueous sodium or potassium hydroxide solution before it is combined with the pigment. is" 5. Coating: ·, according to claim ΐ to 3, characterized in that the polyelectrolyte before it with the Pigment is combined in an aqueous ammonium hydroxide solution is dispersed. A coating slip according to claim 4, characterized in that the amount of sodium hydroxide used corresponds essentially to the stoichiometric amount necessary to neutralize the carboxylic acid groups in the polyelectrolyte j. · 009850/1849. - ORIGINAL INSPECTED