DE2015154C3 - Process for the production of a non-stick coating of cellulosic! Fiber material - Google Patents

Description

u · 20 ⁰ C dissolved, optionally in the form g

(B) 28 to 350 parts by weight of a ω-bis-emulsion of such a solution present mixture (hydroxy-dimethylsiloxy) -polydimethylsiloxane * ⁵ ™ ⁿ "^ permanent silanol group-containing po y, a viscosity between 10 ° and 10 'cP for dimethylsiloxanes and«, cB .s-itnmethvlsiloxyVpoly-20 ⁰ C nd methylhydrogensiloxanen, adding a heavy

(C) 2 to 13.7 parts by weight parts of an _A, a, bis- (trimethyl- ™ taUcarboxylat containing Vernetzungsbeschleunithylsiloxy) - polymethylhydrogensiloxane a gers immediately prior to application of the mixture

f ^ iff ¥ ^{tensl (X) cPund 30} SSÄÄ ^ is

f r ^ ifhf n ¥ S

(D) SSSÄSSS Sum of the weight to crosslinking of the applied siloxane mixture, weight of the polysiloxanes (A), (B) and (C), one ^{which is} characterized by the fact that a mixture of heavy metal carboxylates or dialkyltin (A) 100 parts by weight of one «- (Hydroxydimethylsilcarboxylates or a mixture of such ³⁵ oxy) - ω - (trimethylsiloxy) - polydimethylsilcans carboxylates with a viscosity between 10 ² and 10 'cP at 20 ° C,

(B) 28 to 350 parts by weight of an <x, a> bis (hydroxy-

is used and the crosslinking of the mixture of dimethylsiloxy) polydimethylsiloxane a Vis-

by brief heating to 100 to 120 ⁰ C viscosity between 10 * and 10'cP at 20 ° C and

is effected. 40 ^ _{2 to 67 parts by} weight of a «, co-bis (trimethyl-

siloxy) -polymethylhydrogensiloxane a viscosity at 20 ⁰ C of at most 100 cP, preferably about 15 cP and as a crosslinking accelerator (D) 0.5 to 15%, preferably 10%, based on the

_. _ _, .. ". ,,., _T. ⁴⁵ Sum of the weights of the polysiloxanes (A), (B)

The invention relates to agents for impregnating _{and (c)> a} heavy metal carboxylate or

or coating of cellulosic! Fiber material, dialkyltin carboxylate or a mixture

like paper and cardboard, with the aim of _{preventing such} carboxylates from adhering

to reduce sticky substances applied.

For this purpose it is customary for a long time, is used solu- 5 ° and the cross-linking of the mixture solutions of organopolysiloxanes or aqueous emulsifier by brief heating to 100 to 12O ⁰ C causes versions of such solutions applied, whereby paper.

is soaked, brushed or sprayed. For the choice examples of well-known crosslinking accelerators (D)

The siloxanes to be used for this purpose are zinc octoate, dibutyltin dilaurate, and dibutyltin adhesion-reducing agents Effect another number of 55 diacetate, dioctyltin maleate. The polysiloxanes (A), other requirements must be observed, especially if (B) and (C) can be obtained using known processes, the paper for temporarily covering the adhesive side the polydimethylsiloxanes (A) and (B) for example of self-adhesive foils and tapes. as in the German Auslegeschrift 11 34 S81 bein in this case, the adhesive strength of the foils should write.

even with prolonged contact with the cover 60 If the viscosity of the polydimethylsiloxane (A, B) paper does not decrease significantly; Furthermore, if the chosen value is greater than 10 ⁶ cP, it is advisable to apply the siloxane layer so firmly to the paper base of the mixture according to the invention in solution that it cannot be rubbed off, nor is it then taken for every 100 g of the component (A) when the paper is bent and creased it tears off or, preferably, 105 to 118 g of component (B) and crumbles. The highest possible gloss of the 65 5.5 to 5.9 g of component (C) and mixes this siloxane layer is also desirable. three polysiloxanes in a solvent such as toluene,

Known means for solving this problem are xylene, petroleum ether, perchlorethylene, or in one Mixtures of an α, ω-dihydroxypolydimethylsiloxane mixture of such solvents, the amount of which

is usually dimensioned so that you get a trunk and the more so, the longer the coated paper

Solution with 30 to 40 percent by weight of poly- stored.

siloxanes (A), (B) and (C) in total for stockpiling The in the following working examples

receives. For use, this solution and comparison tests are diluted as a coating base

with further amounts of solvent, e.g. B. cellulosic fiber material used with the 5 is a sati-

three times the weight, you add a solution of ned, unbleached base paper with a square

from 40 to 60 percent by weight of the crosslinking meter weight of 60 g. The abrasion resistance wedge of the

Schleunigers (D) in one of the aforementioned solution-wetting polysiloxane coating was used in the usual

medium added. Way by rubbing your finger on the finished

The viscosity of the polydimethylsiloxanes (A, B) j.o release paper is checked.

If less than 10 ⁵ cP is selected, an aqueous emulsion that is referred to below as "peel force" is to be preferred for use. In this case, measured values were determined as follows: 200 to 270 g of component (B) and 2.8 to 3.6 g of 24 mm wide cellulose glass tape, preferably one-sided with a tacky coating, for every 100 g of component (A) As mentioned above in the trade under the component (C) and a solvent of the protected trade name "Tesaband 659" in such an amount as possible, was blown by hand without inclusion of the total air content of the solution of polysiloxanes 60 to on the coated side of the trean paper is 70 percent by weight. This solution emulsifies pressed. Then the tape was peeled off again in a known manner in water with the addition of a spring balance perpendicular to the paper surface of the emulsifiers used for this purpose, preferably ao, and the force required for this from a commercially available partially hydrolyzed poly was read on the spring balance.

vinyl acetate, hereinafter referred to as polyvinyl alcohol for short. The proportions are usually. Determination of the size designated in the following as "migration total so that the emulsion contains 30 to 36 weight speed" to a percentage of polysiloxanes; 25 chrome-plated metal plate has been well proven and from this a quantity ratio of 65 g of the polysiloxane, interposed by a spring balance, was withdrawn again- (A + B + C): 35 g solvent: 3 g emulsifier: 82 g withdrawn. Meanwhile, on the scales was that of the water. The resulting stock emulsion is diluted and read the remaining bond strength,
to use with water, e.g. B. to four times the influence of longer contact time was each weight, and added a 10 to 20 percent by weight of two further test pieces in the V / eise upstream of the crosslinking accelerator (D) and one of the for this purpose that the release paper and a! Piece of the Aqueous cell glass ribbon containing customary emulsifiers, initially as described above, onto an emulsion of the (D) solution described above; glued to one another and then for 4 weeks between, the preferred ratio is to 47 g of glass plates with a load of 10 g / cm ² against- (D): 53 g of solvent: 11 g of emulsifier: 172 g of water. 35 were pressed together, the temperature

For the coating of release paper, bringing the test piece on a 2O ⁰ C to ⁰ C was maintained on the other described solutions or emulsions in the conventional 6O. After that, the tape was applied in a manner, e.g. B. by means of a knife coater, in the release paper with measurement of the peel force 10 to 20 microns thick layer on the paper and detached again and the remaining adhesive force caused by heating the coated paper, 4 ° is correct, as described above. The associated preferably at 120 ⁰ C, the crosslinking, the original bond strength of the tape was completed after 1 to 3 minutes. Piece of it not in contact with polysiloxane

The adhesion-reducing coating according to the invention was obtained in an otherwise analogous manner to 600 g

tion points in comparison to similar previously known measured. The quotient from the

Means the advantage of excellent abrasion resistance to the adhesive and adhesive remaining on the release paper

be without, on the other hand, the pull-off force, d. H. the original adhesive strength of the tape is used as a measure

Adhesion between release paper and adhesive, changes resistance to migration. All viscosity information

greater or the so-called migration resistance apply at 2O ⁰ C.
and thus the retention of the adhesive strength after removing the release paper is reduced 5 ° B eis ρ ie 1 1 (solution)
will. It should be emphasized that the entirety
these advantageous properties only in the area of

quantitative ratios according to the invention is achieved. Mix to make a stock solution

If the ratio of

(C): (A + B) the amount of dihydroxylated grains 55 250 g «- (Hydroxydimethy! Siloxy) -eo- (trimethylsiloxy) -pone (B) in relation to the monohydroxylated (A) polydimethylsiloxane of 3 · 10 ⁷ cP Viscosity,

if greater than stated, the abrasion resistance of the 120 g «, w-bis (hydroxydimethylsiloxy) polydimethyl coating is insufficient; in the opposite case, siloxane with 7 · 10 ^e cP viscosity,

that is, with a ratio (B): (A) below the 10 g «, co-bis-trimethylsiluxyVpolymethylhylrogensil according to the invention Range, the crosslinking remains oxane of 15 cP viscosity and 60

incomplete, with the result that the adhesion 620 g xylene,
like someone with such release paper for a long time

covered adhesive layer decreases considerably. The 10 g of it is diluted with 30 g of xylene and added the same applies to a reduced ratio (C): (A + B). in addition Ig a solution of 50 percent by weight Di-Wähl finally the amount of (C) in the ratio 65 butyltin dilaurate in xylene. The solution thus obtained to the sum of components (A) and (B) is greater than given with the help of a squeegee in about 25 microns, this is how the adhesion between the crowning thick layer on the paper proves itself and heats it up Release paper and adhesive as unsatisfactory strong then for 3 minutes at 120 ° C.

Test result good abrasion resistance;

Initial peel force = 10 g,

after 4 weeks at 20 ° C. = 50 g, after 4 weeks at 60 ° C. = 50 g;

Wall resistance initially = = 81.5 "/.

600

402

after 4 weeks at 20 ⁰ C = - = 67%,

600

441

after 4 weeks at 6O ⁰ C = - =

600

co, / 0.

Example 2 (solution)

The procedure is analogous to Example 1 with the only modification that the quantitative ratio of there specified polydimethylsiloxanes changes while the sum remains the same by adding

170 g of a- (Hydroxydimethylsiloxy) -a> - (trimethylsil-

oxy) -polydimethylsiloxane and 200 g of a, ci> -Bis- (hydroxydimethylsiloxy) -polydimethylsiloxane used.

Exam result

Good abrasion resistance;

Initial peel force = 10 g,

after 4 weeks at 20 ° C = 50 g after 4 weeks at 60 ⁰ C = 40 g;

522

Wanderaig resistance initially = = 87%,

600

after 4 weeks at 2O ⁰ C = - = 70%,

600

after 4 weeks at 6O ⁰ C = - = 75%.

600 test result good abrasion resistance,

Initial pull-off force = 1 g,

after 4 weeks at 20 ° C = 20 g, after 4 weeks at 60 ° C = 80 g;

480 Resistance to migration initially = —— =

WJU

ίο 354

after 4 weeks at 20 ° C = = 59%,

600

402

after 4 weeks at 60 ^° C. = = 67%.

600

Example 4 (emulsion)

_ One proceeds analogously to Example 3 with the only change that one

147 g of the specified «- (hydroxydimethylsiloxy) - ω - (trimethylsiloxy) - polydimethylsiloxane and
g of the specified *, to-bis (hydroxydimethylsiloxy) -polydimethylsi! oxane

used instead of the amounts given in Example 3, everything else is carried out in exactly the same way.

Test result good abrasion resistance;

Initial pull-off force = Ig,

after 4 weeks at 20 ° C = 30 g, after 4 weeks at 6O ⁰ C = 50 g;

462 wall resistance initially = = 77%,

600

after 4 weeks at 20 ⁰ C = - = 60%,

600

Iftfl

after 4 weeks at 6O ⁰ C = - = 65%.

600

Example 3 (emulsion)

To make a stock emulsion, mix first

57 g (\ - (Hydroxydimethylsiloxy) -co- (trimethylsiloxy) -

polydimethylsiloxane of 1000 cP viscosity, 150 g a, o> -Bis- (hydroxydimethylsiloxy) -polydimethyl-

siloxane of 3000 cP viscosity, 2 g οί, ω- bis (trimethylsiloxy) -polymethylhydrogen-

siloxane of 15 c? Viscosity, 60 g of toluene and
55 g perchlorethylene.

The solution obtained in this way is emulsified with the addition of 100 g of an aqueous 10 percent by weight polyvinyl alcohol containing solution in so much water that the total amount of polysiloxanes in the emulsion Is 35.1 percent by weight.

12 g of this stock emulsion are diluted with 35 g of water and 2.5 g of an aqueous emulsion containing 10 percent by weight of dibutyltin dilaurate (dissolved in toluene) are added. The thus prepared mixture is brought with the aid of a doctor blade in approximately 25 microns thick layer on the paper and then this heated for 3 minutes at 12O ⁰ C.

For comparison, a number of tests with such siloxane mixtures are listed below, in which the proportion of a component is outside the limits according to the invention or completely absent.

1) An insufficient amount of the component (A) solution was prepared by adding the Example 1 described above was modified to the extent that

70 g of the specified «- (hydroxydimethylsiloxy-co-itrimethylsiloxy-polydimethylsiloxane and

300 g of the specified «, o» -Bis- (hydroxydimethylsiloxy) -polydimethylsiloxane

were applied; all other measures were retained as indicated in example 1.

The abrasion resistance of the siloxane coating was found to be insufficient because of this Rub off visible parts of the coating with a fingertip pressed onto the release paper let. Further tests were therefore not necessary.

2) A solution without component (A), in which as in example 1 and in comparison 1

370 g of hydroxylated polysiloxane were used, but here exclusively «, a> -Bis- (hydroxydimethylsiloxy) -polydimethylsiloxane and with which the procedure was otherwise as described above, also resulted in a completely unsatisfactory one Abrasion resistance of the coating.

3) An emulsion without component (A), analogous to Example 3, but with the change that the there used 207 g of hydroxylated polysiloxane here exclusively from a, w-bis (hydroxydimethylsiloxy) - Polydimethylsiloxane passed, while all other measures were the same, again resulted in insufficient abrasion resistance.

4) A solution with an increased proportion beyond the range according to the invention of component (A) was prepared by modifying Example 1 insofar as

310 g of the indicated α- (hydroxydimethylsiloxy) -eo- (trimethylsiloxy) -polydimethylsiloxane and

60 g of the specified «, co-bis (hydroxydimethylsiloxy) polydimethylsiloxane

were applied; all other measures were retained as indicated in example 1.

After heating, the resulting siloxane coating on the paper was found to be incomplete networked; it showed a film of oil on its surface, so that further tests are superfluous was.

5) A solution without component (B), in which 370 g of hydroxylated polysiloxane were used as in Example 1, but here exclusively a - (hydroxydimethylsiloxy) - co- (trimethylsiloxy) polydimethylsiloxane and with which the procedure was otherwise as described in Example 1 resulted in an incompletely crosslinked siloxane coating on the paper and consequently inadequate migration resistance.

6) An emulsion without component (B) in which, as in Example 3, 207 g were again hydroxylated Polysiloxane were used, but here exclusively a- (hydroxydimethylsiloxy) -eo- (trimethylsiloxy) -polydimethylsiloxane and which was otherwise dealt with in this way; as described in example 3, although an abrasion-resistant coating but of insufficient resistance to migration.

Exam result

Initial peel force = 10 g,

far after 4 weeks at 20 ° C = 40 g after 4 weeks at 60 ⁰ C of more than 300 g;

402

Initial migration resistance = = 67%,

600

after 4 weeks at 20 ° C = - = 58%,

600

after 4 weeks at 60 ^° C. considerably

below 10%.

7) Finally, an emulsion with a particularly large proportion of component (C) was prepared by mixing
105 g (x- (hydroxydimethylsiloxy) -w- (trimethylsil-

oxy) -polydimethylsiloxane (1000 cP), 345 g «, co-bis (hydroxydimethylsiloxy) -polydime- »° thylsiloxane (3000 cP),

30 g «, cu-bis (trimethylsiloxy) -polymethylhydro-

gensiloxane (15 cP),
140 g of toluene and
llOg perchlorethylene

^a 5 and emulsification of the solution thus obtained with the addition of 200 g of the same polyvinyl alcohol emulsion, as indicated in Example 3, with so much water that the polysiloxane content of the emulsion was a total of 35 percent by weight.

The resulting stock emulsion was then used as described in Example 3. the While the siloxane coating on the paper showed good abrasion resistance and migration resistance, it was but completely unsuitable because of the strong adhesion to the tape.

Exam result

Initial peel force = 45 g,

after 4 weeks at 20 ° C = 200 g, after 4 weeks at 60 ° C = 330 g;

504

Initial migration resistance = = 84%,

oUU

504

after 4 weeks at 20 ° C = = 84%,

600

420

after 4 weeks at 6O ⁰ C = = 70%.

600

609609/172

Claims (1)

with a methyl hydrogen polysiloxane or organo- Claim: polysiloxane resin or both of the latter polysil oxanes at the same time and a crosslinking accelerator, Process for the production of a non-stick, for example a zinc, tin or dialkyl salt Impregnation or coating of cellulose- 5 a carboxylic acid. containing fiber material using one obtained in one with such coating agents Release paper dissolved in an inert solvent is noticeable in relation to the foregoing in the form of an aqueous emulsion, however, one of the requirements is not satisfactory such a solution present mixture of end-it that the detachment of the paper of one with it Permanent Polydim- io-covered adhesive film containing silanol groups requires too great a force thylsiloxanes and oc, a> -Bis- (trimethylsiloxy) -poly- it that the adhesive strength of the film after removing the separating methylhydrogensiloxanes, Adding a crosslinking that contains heavy metal carboxylate significantly compared to the original value is weakened because some of the organopolysiloxanes are added accelerator passed from the paper to the adhesive layer immediately before application. of the mixture on the fiber material and after- 15 The task of producing a release paper that subsequent heating of the impregnated with it or none of the deficiencies mentioned above, coated fiber material up to the crosslinking was now with a new organopolysiloxane Gedes applied siloxane mixture, thereby mixed to an extent not previously achieved. Counter characterizes that a mixture of the invention is accordingly a method for , a, £ & ££ X £ SS