DE2042438A1 - Dispersions for paper coating slips - Google Patents

Description

LONZA AG, Gampel / Wallis (Management: Basel)

Dispersions for paper coating slips

The invention relates to the production of terpolymer dispersions from vinyl ester; Vinyl chloride and ethylene.

These dispersions are preferably used for the production of paper coating slips. Under paper In the present case, fiber products (fiber surface products), in particular paper, are paper-like materials and cardboard box, understand.

. It is known / for finishing high-quality paper, for example art print and chromo paper, or cardboard, for example for packaging purposes, to treat the surface with a coating slip. If necessary, additional smoothing is then carried out by brushing or calendering (satin finishing) to achieve gloss effects. This treatment fills in pores and / or covers fibers, so that a uniform, fine-pored, flat surface is created, which enables image-sharp reproduction when printing. Their behavior towards the printing ink during the printing process and during drying is dependent on their composition and production type and can be set within wide limits .

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The coating slips mainly consist of the. two main components pigments and binders while Processing aids, e.g. to regulate the flow properties, the water retention, to improve the Calenderability, for foam dampening, among other things, a quantitative one make up a small proportion. The pigments used are mainly kaolin and kaolin Chalk types, possibly together with staining oxides or other pigments, in the form of finely divided Suspensions used.

The proportion of the "dry binder is generally between 10 and 25 percent by weight of the dry pigments. It depends in each individual case on the effectiveness of the binder on the one hand and on the requirements to be met during further processing (use) of the coated material on the other hand Binding agents can consist of modified natural products such as protein bodies or starch derivatives. In recent times, however, natural products have mostly been partially or completely replaced by synthetic binding agents. Practical requirements for the properties of the coating slips are extremely varied. On the one hand, they must be in a liquid state can be adapted to the changing conditions of numerous application methods, while various support materials in terms of their technical characteristics. on the other hand, the composition of the FSR has

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term coating layer depending on the requirements of further processing of the end product can be varied.

Although the pigments form the main part and therefore have an important influence on the properties of the dry coating layer, the binders and the above-mentioned auxiliaries are the part which is responsible for the variation in the processing properties of the liquid coating slips and for the anchoring of the pigments on the carrier material after completion of the Λ

Coating process and for the adjustability of the physical Properties of the cement substance between the pigment particles is decisive.

For a synthetic binder, which may be used together with natural binders and other auxiliaries, the following requirements result from this, with special consideration of the versatile applicability, whereby the synthetic binder in the form of an aqueous dispersion % is taken into account:

Apart from the basic properties of dispersion binders, such as the ability to form films on their own . with the development of sufficient adhesive and cohesive forces, must have good compatibility with other, especially water-soluble binders, such as those used in the manufacture

Development of coating slips can be used. In the liquid state, this compatibility is shown in the fact that no segregation phenomena, such as

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Phase separation or flocculation arise. In the solid state, After the formation of a mixed film with the other binders, this compatibility shows up in the physical ones Properties of the same (homogeneity, good ductility, high tensile strength) and in its ability to withstand the pigments as well as the carrier material develop good binding ability. Another key requirement for the versatility of a dispersion binder is due to the fact that the application devices, depending on their construction, exert different mechanical loads on the coating slips. The mechanical stability of the dispersion component, favorable flow properties and the highest possible The dry matter content of the coating slip must be balanced in each individual case against the degree of water retention, that for the surface structure of the given carrier material, taking into account the and drying device specified physical conditions gives the best coating properties. These diverse requirements explain the fact that for coating slips · dispersions of various kinds are in use are.

Dispersions of copolymers of acrylic acid esters and / or vinyl esters have already been used as binders used for paper coating slips. Such dispersions are, however, either with larger pigment, casein and starch not tolerated or they form highly viscous, difficult to process spreading slips, or spreading

masses that are initially of low viscosity, but then thicken. Such paper coating slips are therefore only conditionally useful.

There are also Streichina ssen known whose binders consist of copolymers and small amounts a polymerizable acid amide included in the form of polymerized units. These coating slips also gradually thicken and have poor pleating properties. Furthermore, they are not very stable against shear stress.

Binders made from dispersions based on vinyl chloride-vinyl acetate, which must be "heavily softened," tend to become sticky, causing processing the coating slips produced with such binders is impaired.

There are also known coating slips which use dispersions of copolymers of ethylene and vinyl acetate as binders. Such dispersions not show all in paper coating compositions usual natural binders, M adequate compatibility. The processability of such paper coating slips produced with these binders is not sufficient in all cases.

The object of the present invention is to provide a plastic dispersion for use in paper coating slips that covers a wide range of applicability, i.e. that is well tolerated to additives and their viscosity and

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Structural viscosity is designed so that the coating

ability of the coating paste. high stress is retained and which allows 'to produce coating slips with a high proportion of dry matter ... ·'

¹ * ι *

According to the invention this is achieved in that • one mixtures of 60-80 parts Vinylester, 10-30 ', parts of vinyl chloride under a Aethylenpartialdruck • of at least 10 and a maximum of 70 atm, a final product' ..with an ethylene content of ¹ 5-25 Divide: in the presence of a four-part emulsifier mixture, consisting of ' . _it a) 0.3-3%, based on vinyl chloride, and vinyl ester, of a "· 'oxaethylated polyoxypropylene with an average

; borrowed molecular weight up to 3000, and an ethylene oxide content

• ■ "- ■. · λ up to a maximum of 20%; ■ ·.

· ■ ' JslP »5-4 # based on vinyl chloride and vinyl ester, one

• *

.oxaethylated polyoxypropylene with an average ' borrowed molecular weight of at most 5000 and "one Ethylene oxide content of 60-80%;

'6) 0.2 to 0.55 ^ i based on vinyl chloride and vinyl ester, an alkali salt of a substituted alkyl, aryl or alkylarylsulfonate or an alkali salt of a sulfuric acid half-ester of an alcohol with 8-18 carbon atoms and / or d) 0.2-2%, based on vinyl chloride and vinyl ester, of one O-adduct of about 5-10 moles of ethylene oxide with an alkali salt of a monosulfonated phenol or a polyoxyethylated one Alkylphenolsulfonates, as well as $ 0.2-0.5, based on vinyl chloride

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tmd vinyl ester, in present

/ a water-soluble monomer, - "" customary pH buffering agents and water-soluble polymerization initiators polymerized in emulsion at 60-85 ° C., the anionic emulsifiers c and / or d, the water-soluble monomers, buffering agents and initiators being initially introduced in the aqueous phase and the nonionic emulsifying agents a and b together with the Vinylester and vinyl chloride are metered in and so a dispersion is obtained in which the film formation is Stemper a door held at 5 -20 C, and the elongation at break of ER * films at least 300 and a maximum of 1000%.

. The emulsifiers mentioned under a) and b) are nonionic. The amounts to be used are preferably at 0.5-1.5% for those named under a) and 0.5-3% for those named under b).

The emulsifiers mentioned under c) and d) are anionic in nature.

In some cases it is advantageous to add ^ j

borrowed 1 to 3% of a condensation product from ethylene with alkylphenols or fatty alcohols with 12-18 carbon atoms, whose AethylenoxydgehaIt is between 40-70%, the emulsifier mixture to add. These products are nonionic emulsifiers and are like those mentioned under a) and b) Emulsifiers together with the vinyl ester / Vinyl chloride added during the polymerization.

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According to the invention as alkali salts of substituted Alkyl, aryl or alkylarylsulfonates those used which contain about 8-18 carbon atoms in the molecule, whereby sodium sulfosuccinic acid diethyl ester, sodium diphenyl disulfonst or sodium dodecylbenzylsulfonate, particularly preferably Averden. A preferred alkali salt is one Sulfuric acid half-ester is sodium laurel sulfate.

As an O-adduct of ethylene oxide in the invention Emulsifier mixture a sulfated O-adduct of 5-10 mol Ethylene oxide of a nonyl or octyl phenol in the form of Alkali salt preferred.

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The vinyl esters are esters of organic ones

Acids with 1-18 carbon atoms, the chains of which are branched or unbranched, are used. Vinyl acetate is preferred and vinyl propionate are used. Vinyl esters of branched acids are, for example, vinyl ethyl butyrate and vinyl ethyl hexanate are used.

Alkali salts of alkylenically unsaturated acids, such as acrylic acid, methacrylic acid, crotonic acid, or alkali salts of monoesters of unsaturated dicarboxylic acids, such as maleic acid, can be used as water-soluble monomers. Λ

Itaconic acid, also alkali salts of vinyl or methallyl sulfonates, and acrylamide or methacrylamide are used. Preferred are alkali salts of methallyl sulfonate used.

The buffering agents, for example sodium hy-. drug carbonate, sec. Sodium phosphate, borax are useful used in amounts of 0.2-0.9%, based on vinyl chloride and vinyl ester.

The polymerization initiators used are ~

advantageously water-soluble peroxides, usually an alkali persulfate, in amounts of 0.1-1%, based on the amount of monomer used.

In some cases it is useful to use the dispersion to be conditioned afterwards. For this purpose, in a ratio of 1-10%, based on the dispersion dry substance, water-soluble colloids with very low viscosities, e.g. alkali salts of the following copolymers

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used: vinyl ester / maleic anhydride, Ölefine / maleic anhydride, Vinyl ether / maleic anhydride, styrene / maleic anhydride, polymers or copolymers of acrylic and methacrylic acid, as well as polyvinyl alcohols, polyethylene glycols, polypropylene glycols and polyvinylpyrrolidones. The molecular weight of these polymers should not significantly exceed 10,000. Preferably salts of Copolymers with maleic acid half-ester, e.g. styrene / maleic acid monoester, used.

The plastic particle size of the inventive i: Dispersion is less than 0.4 microns.

example 1

In one with a stirrer, thermometer and inflow reservoir equipped double-jacket autoclave made of stainless steel, which has a capacity of 2 liters, 600 g softened water, 3 g acrylic acid, 3 g sodium bicarbonate, 1.2 g sodium diethyl sulfosuccinate, 4.5 g potassium alkylphenyl polyethylene oxide sulfate (Penopon Co 436) and introduced 3 g of potassium persulfate. The autoclave was closed, flushed with nitrogen and then with ethylene. Then the inflow reservoir became the one Mixture of 540 g of vinyl acetate (VA), 60 g of vinyl chloride (VC), 6 g of oxyethylated polyoxypropylene with a content of £ 20 Ethylene oxide (Pluronic L 62) and 12 g of oxyethylated polyoxypropylene with a content of 80 # ethylene oxide (Pluronic P 38) contains approx. 60 g of the mixture introduced.

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Then ethylene was pressed down to a pressure of 17 atmospheres and heated to 68-70. It could an increase in pressure to 20 atmospheres can be observed. After 15 minutes and at an ethylene pressure of 20 atm the remainder of the mixture was continuously introduced from the inflow reservoir over 3 hours. After one hour Reaction was flushed with air to remove the remaining monomers, and the pH was replaced by a 5% strength sodium bicarbonate solution set to about 5.5. A fine, (0.3 micron) low viscosity dispersion is obtained a fixed salary of 50%.

Examples 2-10

As in Example 1, further modified terpolymer dispersions were prepared. In the following Table 1 (Examples 2-10) are the compositions of the aqueous phase and the copolymers of the dispersions carried, whereby Examples 3 and 7-10 as comparative examples do not correspond to the method according to the invention. Example 1 in the table corresponds to the previous example.

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Table 1

ο co co co

NJ

example
Kr. /'.ethylene
Pressure (AtD) VA VC A. Components of the aqueous oniscl
C. . e En
0 ulgat
E. iren
F. Phase. Weight-J related % "onis
ren
H before Zn
K ulga.
L. on VA / VC serlo
o * ere
H si.
0 buffer 1 20th 90 10 2 not i
S. At
to
G 0.5 vas
Cor
H 2 20th 85 15th 1 1 0.2 0.5 1 0.5 0.3 3 · ? 0 100 - 1 1.5 0.5 0.5 4th 50 70 30th 0.5 2 1 1 0.5 0.4 5 25th • 85 15th 0.5 1 1 0.3 0.5 S. 20th 70 ¹ ) 30th 0.5 .0.5 0.5 0.5 IO 7 · 25th 85 15th 2 0.5 1 1 C3
I. Β · 30th 80 20th 1 0.5 C »
O" ο · 25th 85 15th 1 2 1 0.5 0.5 10 · - 80 - 1 0.5 1 0.5 1. 0.5 · 0.5 I.

ο ro

CJ OO

A = oxyethylated polyoxypropylene with 80% ethylene oxide (MoIg. Approx. 4500) B = oxyethylated polyoxypropylene with 20% ethylene oxide (MoIg. Below 3000) C = oxyethylated polyoxypropylene with 80% ethylene oxide (MoIg. Approx. 10,000) D = oxyethylated alkylphenol with 63% ethylene oxide

E = oxyethylated alkylphenol with 43% ethylene oxide
ο P- oxethylated lauryl alcohol
^ G = sodium diethyl sulfosuccinate
JJ E = sodium lauryl sulfate

^ κ = ammonium salt of sulfated alkylphenol poly (ethylene oxide) ethanol o I »= sodium salt of sulfated alkylphenol poly (ethylene oxide) ethanol ^ M = acrylic acid

N = isodium vinyl sulfonate

0 = sodium methallyl sulfonate

1) vinyl propionate

2) AethylhBxylacrylat l «o

* = not according to the invention J>

example
No. File
65 * r.lf., 2O ⁰ C Κς / approx Xi sch f Ui
St: K - 1: 1 & !? Viscosity ep
P: 3 - 100:15
St: K - 1: 1
Tr 45X
CU ..., * ICC C r condit. Refssd.
t 20th Reissd.
t 80 TiTcH "^ 40. 1 900 .'30 . 60 100 250 40 2 600 40 40 300 ICO 3 * 1100 20th 20th 80 > 500 40 4th 1000 40 ■ 30 140 30th 25th 5 500 50 -. 70 KO 20th 30th 6th 7C0 25th 30th 30th 2o ^ 50Q 7 * 600 20th 5. 30th > 500 > 500 8th* 800 20th 10 20th > 500 > 5G0 9 * 600 30th 5 20th > 500 200 10 * 500 10 > "

* · Not according to the invention

St -, strength (trek) j IC synthetic resin (dry) ' P Pigssnt (dry)>

B - binder (dry) - · Tr ■ Gesasttroc'xenstoffanteii e'er Streichcas% «

Ca) OO

From Table 1 it can be seen that dispersions 3 and 7-10, which are not according to the invention, are poorly compatible with natural binders. This is based on the value for elongation at break and tensile strength in mixed films. With values for the elongation at break of less than 25% and with tensile strength of less than

60 kg / cm, the tolerance can be described as poor. Also the viscosity properties of coating slips with dispersions not according to the invention as binders ™ are stored in such a way that they cannot be processed.

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Table 2

example
No. P: B - 100:20
St: K - 7: 3
Tr. 40? 30 · Viscosity of the coating slips ii 40 · P: B - 100:20
St.: K - 3: 7
Tr. 50? ι ep at shear gradient 155.6 sec. " P: B - 100:15
St.: K - 0:10
Tr. 60? 1 20 · P: B - 100:15
St.: K - 5: 5
Tr. 45? 25 · P: B - 100:20
St.: K - 3: 7
Tr. 55? 5 15th 50 · 100 * P: B - 100:15
St.: K - 0:10
Tr. 55? 10982 < 3- · ^ 500 ^ -500 * 20th NJ
ο, ς · »· ■ = -500 ^ 500 ^> 500 150 · 50 »· 250 · 280 ·· 350 · 100 ·· "500- 160 ·· > 500 " ■> 500 ··.
ί > 500 "

P - Pigeent (dry) B> full tie (dry)

St - starch (dry)

K · Kunsth ₃ rz (dry)

Tr · Total dry matter content of the coating

The dispersion was oit 4? Polyvinyl alcohol (H under 10,000), based on the dry matter, conditioned.

The dispersion was rated at 4.5? an ammonia salt one Copolyse from vinyl acetate and calcium anhydride (H below 10 ΟΠΟ), based on dry matter, ned.

not according to the invention.

Ca} OO

From Table 2 it can be seen that only with the dispersions according to the invention (Examples 1 and 5) Can produce coating slips that have a high dry content, whose viscosities require processing allow. In contrast, dispersions, as shown in Example 3, either in the plastic composition or, as shown in Example 7, were not polymerized with the inventive emulsifier mixture, Even with a low dry content, it can no longer be processed due to the excessively high viscosity.

Clues for the structural viscosity were measured with the help of the flow time from the so-called Ford cup no. 4 with different idle times. Coating slips with a dry content of 40% with P: B = 100: 20 and St: K = 7: 3 were compared. Table 3 below shows the results obtained: Table 3

Flow time in seconds at 20 C

example 0 h Downtimes 24 hours 1 20 * 1 h 35 * 5 14th 28 * 17th 3 ** 30 * 15th not flowable 9 ** 40 * 38 * not flowable
I. not flowable

* The dispersion was conditioned as in Table 2. ** not according to the invention

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The terpolymer dispersions which can be prepared according to the invention are mainly used for the production of paper coating slips. Depending on the chosen Pigment / binder ratio, the dispersions can also be used for the production of coating slips the surface treated with it has heat-sealing properties to lend.

Other possible uses are: production of adhesives, coatings, binders for Pigments (dyes) and fillers (sand, asbestos).

Claims (9)

Claim I. Process for the production of finely divided terpolymer dispersions from vinyl ester, vinyl chloride and Ethylene, characterized in that mixtures of 6O-80 parts of vinyl ester, 15-30 parts of vinyl chloride are included an ethylene partial pressure of at least 10 and a maximum of 70 atm. to an end product with an ethylene content of P 5 to 25, in the presence of an emulsifier mixture, consisting the end a) 0.3 to 3%, based on vinyl chloride and vinyl ester, of an oxethylated polyoxypropylene with an average molecular weight of up to a maximum of 3000 and an ethylene oxide content of up to a maximum of 20%, k) 0 _f 5-4 $ based on vinyl chloride and vinyl ester, of an oxethylated polyoxypropylene with an average molecular weight of up to 5000 and an ethylene oxide content 1098 2.4 / 7020. '' from $ 60-80. c) 0.2 Ms 0.5 $ ι based on vinyl chloride and vinyl ester, an alkali salt of a substituted alkyl, aryl or alkylaryl sulfonate or an alkali salt of a sulfuric acid half ester of an alcohol with 8-18 carbon atoms and / or d) 0.2 - $ 2, based on vinyl chloride and vinyl ester, of an O-adduct of about 5-10 moles of ethylene oxide with an alkali salt of a monosulfonated phenol or a polyoxyethylated alkylphenol sulfate, and 0.2-0, 5 $, based on vinyl chloride and vinyl ester, of a copolymerizable, water-soluble monomer, polymerized in the presence of customary pH buffering agents and water-soluble polymerization initiators in emulsion at 60-85 ⁰ O, the anionic or Emulsifiers c and / d, the water-soluble monomers, the pH buffers and initiators dissolved in the aqueous phase and the nonionic emulsifiers a and b are metered in together with the vinyl ester and vinyl chloride, and a dispersion is obtained whose pilm formation temperature is + 5 ° to +20 ⁰ O and the elongation at break of the free films obtained by drying is at least 300 and at most 1000036. 109824/7020 2. The method according to claim I, characterized in that that one additional $ 1 to $ 3, based on vinyl ester and Vinyl chloride of a condensation product of ethylene with alkylphenol and / or fatty alcohols with 12-18 carbon atoms, whose ethylene oxide content is between 40-70 ^, applies. 3. The method according to claim I, characterized in that the vinyl ester esters of organic acids with 1-18 C atoms, the chains of which are unbranched, are used. Fe 4. The method according to claim I and dependent claim 3, characterized characterized in that the vinyl ester used is vinyl acetate and / or vinyl propionate. 5. The method according to claim I, characterized in that the vinyl ester esters of organic acids with 1-18 C atoms, the chains of which are branched, are used. 6. The method according to claim I and dependent claim 5, characterized in that the vinyl ester is vinyl ethyl butyrate and / or Vinylaethylhexanat used. ™ 7. The method according to claim I and subclaims 2-6 characterized in that the water-soluble monomers used are alkali salts of methallyl sulfonate. 8. Use of finely divided terpolsine dispersions according to claim 1 for the production of paper coating slips. 9. Use of dispersions according to claim 8 for the production of paper coating slips, characterized in that that one uses dispersions with 1-10 $, based on -Dispersion dry content, water-soluble colloids with a molecular weight below 10,000 are conditioned. 10982A / 2020