DE1696194B2 - Process for the production of organopolysiloxane-coated release paper - Google Patents

Description

1,896,194

siloxane mixture, adding known crosslinking siloxane content to storage. One moves

medium immediately before the application of the coating then usually continues in such a way that this master

preparation and subsequent heating of the diluted solution for application and the crosslinking

layered paper is characterized in that middle mix adds. It then lasts at 20 ° C

the organopolysiloxane mixture from (A) 50 to 80 Ge 5 several hours until the so for application to the

parts by weight of a, eo-bis- (triorganosiloxy) -polydior- paper finished solution noticeably thickens. With

ganosiloxans of the formula of this solution one covers the paper in a thin layer

R _a Si (CH ₃ ) ₃ - "- O - [·. (- SiR ₄ (CH ₃ ), - * - O -) _m ^Sch ! ^cht > for example by means of roller or squeegee

(Qwrvi \ η \ ι <i; rru \ d coating device, and caused by heating the

I bi (I_H _{3) 2} - υ -) _ "-J- bi (CH _{3) 3} - _a R" _{io paper so coated pref} ei _S e to 120 ° C, the

where R denotes an alkenyl radical, η is so highly crosslinking that it is already full after one minute

is chosen is that the viscosity ends at 20 ° C at least.

10 ^e cP is, a = 0, 1, 2 or 3, b = 1 or 2 and m The speed and for the so-called wan-

r. . · Π,. -, ν η. , .... resistance to significant completeness of the

= O a value from 2 to _w , in the remaining _{i5 Vern (} £ _{ung is to look surprisingly} ; it was

i f d

_g ^

Cases has a value from 0 to ^ -, (B) 20 to 50 Ge? ^ad ? ^ Current level of experience at least

100 ' ^v ' for the supporting polymerization reaction

parts by weight Λ, ω-dihydroxypolydimethylsiloxane from the unsaturated substituents of the polysiloxane (A) at least 1000 cP viscosity at 20 ° C and (C) 1 to not expected. Just as little was to be foreseen 10%, based on the sum of the weights of the poly-20 that the paper besiloxanes carried out according to the invention (A) and (B),, co-bis (trimethylsiloxy) poly-layer for a considerable improvement in the methylhydrogensiloxane of a maximum of 1000 cP plus the generally opposing viscosity at 20 ° C, as a crosslinking agent, it has properties of low peel force, i. e. Mixture of (D) 1 to 10%, based on the sum of low adhesion between release paper and adhesive, the weights of the polysiloxanes (A), (B) and (C), a 25 and extensive maintenance of adhesive strength, d. H. largest organic Peroxyds and (E) 0.5 to 10%, based on possible adhesion between the adhesive and the like (D), a crosslinking accelerator from which after peeling off the release paper in fixed rows the heavy metal carboxylates, dialkyltin carbides brought into contact with the surface of another counteroxylate, Amines and quaternary ammonium compounds.

fertilizing is used and the crosslinking of the paper 30 that each in the following, that claimed

coating by means of brief heating to 100 to process non-restrictive execution examples

120 ° C is carried out. play is paper used as a coating underlay

Preferably used as component (A) is glassine with a square meter weight of

one whose alkenyl radicals R vinyl or allyl radicals approximately 40 g.

whose viscosity is 10 ⁷ to 10 ⁸ cP at 20 ° C. 35 The measured values referred to as "peel force"

and in which the number a = 1 or 2, the number b - 1 and were determined as follows: A one-sided with

j λ 4. · * "'· j WT * r. u · -ic in ι a kleorigen coating, 24mm wide

the quotient - one of the values from 0 to 15 · 10- « _Zellglas _ _Ban | _{was VOI} f _{hand so on} ' _{the coated} te

Has; as component (B) such a pressed side of the release paper that it is smooth and without

10'cP viscosity at 20 ° C; as component (C) an inclusion of air bubbles between adhesive and

those of 15 cP at 20 ° C. The weight ratio of release paper was applied. Then the tape was underneath

(A): (B): (C) of these three mixture components is the interposition of a spring balance perpendicular to the

preferably in the range of 62: 35: 3 to 67: 30: 3 paper area at a speed of 10 cm

to choose. deducted per minute and the force required for this

As examples of component (D) of the invention 45 read on the spring balance.

according to the crosslinking agent combination to be used To determine the »maintenance of adhesive strength« of the

be benzoyl peroxide, dichlorobenzoyl peroxide, tertiary adhesive tape, the procedure was as above

Butyl peroxide and preferably dicumyl peroxide described in detail; then that was glued on

called. Examples of the tape to be used as component (E) between glass plates for 24 hours

The metal compounds used are lead, cobalt, 50 with a load of 10 g / cm ² against the release paper

Zinc, manganese, zirconium, cerium and tin salts are pressed higher, with the temperature in a series of experiments

Fatty acids, dioctyltin maleate, dibutyltin diacetate at 20 ° C, in another at 70 ° C.

and preferably dibutyl tin dilaurate. Afterwards the adhesive tape was removed from the release paper

proportions are variable within wide limits; preferably drawn on a chrome-plated and polished metal plate

they are to be dimensioned in such a way that the total mixture is glued each 55 and from this with the interposition of a

100 g of the polysiloxanes (A), (B) and (C) 5 to 6 g spring balance at an angle of 135 ° again with

Peroxide (D) and 8 to 10 g of crosslinking accelerator removed at a rate of 10 cm per minute.

(E) contains. These two components (D) and (E) on the scales were meanwhile that of the belt

can be read off together in the remaining bond strength for easier handling. The associated original

an inert solvent, e.g. B. xylene, dissolved 60 initial adhesive strength, in the following

will. Cases measured at 240 to 235 g was made in the manner

Likewise, it is not essential for the method that an identical piece of tape first on a

Hch, but advantageous for its convenient implementation, glued clean glass plate, peeled off again and then

the mixture of polysiloxanes (A), (B) and (C) in the test described on the metal plate

an inert solvent such as toluene, xylene, 65 was drawn. The quotient from the after action

White spirit, trichlorethylene or perchlorethylene of the release paper and the remaining adhesive strength

first to be solved in such an amount that one gives an original bond strength of the tape the amount

Stock solution with 30 to 40 percent by weight poly- the maintenance of adhesive strength.

In the following, "Tl." Means parts by weight; all viscosity values are measured at 20 ° C.

example 1

To prepare a stock solution, mix 122 Tl. «, W-bis (vinyldimethylsiloxy) -porydimethylsiloxane of 3 · 10 ⁷ cP viscosity, 60 parts. Α, ω-Dihydroxypolydimethylsiloxane of 8 · 10 ^e cP viscosity, 6 Tl.«, Ω - Bis (trimethylsiloxy) - polymethylhydrogensiloxane with a viscosity of 15 cP and 312 parts of xylene. The viscosity of this stock solution is 5 · 10 ⁴ cP.

10 parts of it is diluted with 40 parts of toluene and 1 part of a mixture of 20 parts of dicumyl peroxide is added. 33 parts of dibutyltin dilaurate and 57 parts of xylene. The solution obtained in this way is applied with a glass squeegee in a layer about 10 microns thick on the paper and then heat it to 120 ° C for 1 minute. Leaning force = 1 g;

Maintenance of adhesive strength at 20 ° C

at 70 C ^c

242 g

167 g

242 g

= 71%;

= 69%.

Example 2

The vinyl compound used in Example 1 is replaced by 122 parts of an oc, co-bis (vinyldimethylsiloxy) vinyl methy] polysiloxane the formula

CH ₃

CH ₃ -Si-O

CH = CH ₂

CH ₃ O \ - - Si - / n— m CH ₃

CH ₃

[
- Si - CH ₃

CH - CH ₂

with - = 0.0015 and 4 ■ ΙΟ ⁷ cP viscosity and proceeds η

furthermore, as described there. Stock solution viscosity = 57,000 cP; Peel force = 1 g;

^25th

Example 4

Maintenance of adhesive strength at 20 ° C

181g 245g

at ^{70 0} C IUIi = 67%. 245 g

Example 3

The vinyl compound used in Example 1 is replaced by 122TI. a, co-bis (methyldiallyIsiloxy) -polydimethylsiloxane of 3.7 · 10 ⁷ cP viscosity and proceeds as described there. Stock solution viscosity = 6400 ocP; Peel force = 1 g;

Maintenance of adhesive strength at 20 ⁰ C ^ i. = 86%;

The 312 parts of xylene used in Example 3 to prepare the stock solution are replaced by 525 parts of 30 trichlorethylene and the rest of the procedure is as there ⁼ 74 / i; described.

Stock solution viscosity = 1.5 x 10 ⁶ cP; Peel force = 2 g;

³⁵

40

at

244: 171g 244g

= 70%.

Maintenance of adhesive strength at 20 ° C

240 g

= 75%;

at 7O ⁰ C

190 g 240 g

35

Example 5

The vinyl compound used in Example 1 is replaced by 122Tl. a, cu-bis (methyldiallylsiloxy) allylmethylpolysiloxane the formula

CH2 - CH - CH ₂

CH ₃ -Si -ΟΙ
CH ₂ = CH - CH ₂

/ CH ₃ \ / CH ₃

_ I - si - O - - Si -

CH ₁ -CH = CH, / ,, \ CH ₃ 2 - CIt = CH2 - Si - CH ₃

g - CH ^ = C1T2

with - = 0.0015 and 3.4 · 10 ⁷ cP viscosity and proceed as described there. Stock solution viscosity = 48,000 cP; Peel force = 1 g;

Klebkrafterhaltung at 2O ⁰ C - = 84%;

244 g

at 7O ⁰ C - ^ - = 67%. 244 g comparison tests

The ones described below, with siloxane mixtures Coatings carried out according to the prior art show those described at the beginning Defects, namely a decrease in the adhesive strength of the adhesive film which decreases with storage temperature or a more than a power of ten stronger adhesion of the foil, which promotes tearing Release paper on the covered film. 1. 76Tl. α, ω-dihydroxypolydimethylsiloxane from

8 · 1Ο ^β cP viscosity and 6 parts of a, oj-bis (trimethylsiloxy) -polymethylhydrogensiloxane of 15 cP viscosity were mixed with 127 parts of toluene to form a stock solution.

34 parts of this were mixed with 136 parts toluene and 1 part dibutyltin dilaurate, and the resulting solution was applied to the paper in the same way as described in Example 1 and heated.
Peel force = 2 g;

Maintenance of adhesive strength at 20 ^° C

161.5 g
240 g

= 67%;

at 7O ⁰ C

240 g

= 40%.

2. An organopolysiloxane resin solution was used which, according to the customary method, by hydrolysis of an organochlorosilane mixture of 195 parts _{CH 3 SiCl 3} , 11 _{parts C 8} H ₆ SiCl ₃ , 18 _{parts (CH 3} ) ₂ SiCl ₂ and

3 Tl. (CHs) ₃ SiCl in a mixture of 830 TI. Water, 166 parts xylene and 166 parts butanol and subsequent evaporation to 51% by weight organopolysiloxane content was prepared. 393 parts of this solution were mixed with 79 parts of a mixed hydrolysis product of 10 parts of CH _{3 SiCl 3} and 90 parts of _{(CH 3} ) _{2 SiCl 2} , 12 parts of Λ, ω-dihydroxypolydimethylsiloxane of 1000 cP and 8 parts of α, ω - Bis (trimethylsiloxy) - polymethylhydrogensiloxane dissolved in 108 parts of isopropanol. This solution was with 600Tl. Toluene diluted, then 12Tl. Dibutyltin dilaurate mixed in. Coating and heating were carried out as described in Example 1 with the solution thus completed.
Peel force = 94 g;

Maintenance of adhesive strength at 2O ⁰ C

and at 70 ⁰ C -

154 g

241g

4091530/320

Claims (5)

1 2 are used and the crosslinking is carried out at approximately patent claims: 120 ° C. 1. Method of making release paper by applying a sticky adhesive 5 Substance-reducing coating on a paper surface using an inert
Solvent dissolved, possibly also in Form of the solution emulsified in water of the The invention relates to the production of separating crosslinkable organopolysiloxane mixture, io paper, d. H. of paper whose surface is through Adding known crosslinking agents directly to the impregnation or coating is changed in such a way that before the application of the coating and after that sticky substances applied to it are not or only not following heating of the coated paper, stick insignificantly. characterized in that it has been known for a long time that one can use this layering an organopolysiloxane mixture of 15 purpose paper with organopolysiloxanes, usually (A) 50 to 80 parts by weight of an a, co-bis (tri- in solution or in the form of an aqueous emulsion organosiloxy) polydiorganosiloxane of the formula of such a solution, soak, brush or spray can. For the choice of the one to be used here R _o Si (CH ₃ ) ₃ -o - O - [- (- SiR & (CH ₃ ) ₂ -6 - O- ) _m Siloxane is apart from the adhesion-reducing effect (- Si (CH ₃ ) ₂ - O - ) nm -] - Si (CH ₃ ) ₃ -oRa to a number of further requirements to be observed, especially if the paper is for temporary where R is an alkylene radical, η as high as covering the adhesive side of self-adhesive films it is chosen that the viscosity should serve at least at 20 ° C and ribbons. In this case it is allowed 10 ⁶ cP, a = 0, 1, 2 or 3, b = 1 or 2 Adhesiveness of the films even under long-term and> »in the case a = 0 a value from 2 to ^, ^{not essential in 25 contact} with the masking paper 100 should be reduced, the paper should be as possible in the other cases has a value from 0 to ^ - ,! ^{calibrated VOI} \ ^d " adhesive layer: peel off the foils ⁶ 100 ', and the siloxane layer should be firmly on top of it (B) 20 to 50 parts by weight «, cu-dihydroxypoly paper backing adhere. At the same time, however, this should dimethylsiloxane with a viscosity of at least 1000 cP at 20 ° C and (C) Ibis 10%, based on the sum of bending or creasing of the paper does not tear or tear Weights of the polysiloxanes (A) and (B), crumble. «, W-bis (trimethylsiloxy) -polymethylhydrogensilo- It is often also desirable that the adhesion xan with a maximum viscosity of 1000 cP at 20 ° C, adversity limited to one side of the release paper A mixture of (D) 1 to 35 remains as a crosslinking agent, so that the other still works well with others 10%, based on the sum of the weights of the material can be glued or printed. Polysiloxanes (A), (B) and (C), an organic one. So far, several have been used to solve this problem Peroxides and (E) 0.5 to 10%, related to (D), proposals have been made which agree a crosslinking accelerator from the series that can be crosslinked by brief heating Heavy metal carboxylates, dialkyltin carboxylates, 40 organopolysiloxane mixtures that essentially Amines and quaternary ammonium compounds are composed of Λ, ω-dihydroxy are used and the crosslinking of the paper or α, ω-dialkoxypolydimethylsiloxane, a methyl coating by brief heating on 100 hydrogenpolysiloxane or organopolysiloxane resin or is carried out at 120 ° C. two last-mentioned polysiloxanes at the same time and one 2. The method according to claim 1, characterized in 45 crosslinking accelerator, for example a zinc, draws that polysiloxanes with vinyl or allyl, cobalt, tin or dialkyltin salt of a carbon radical as alkenyl radicals R are used. acid. 3. The method according to claim 1, characterized in that obtained with such coating agents indicates that the organic peroxide dicumyl release papers are with respect to the above on peroxide is used. 50 requirements but not satisfactory, 4. The method according to claim 1, characterized in that it is too great a force to detach from draws that as a crosslinking accelerator (E) require an adhesive film covered with it, be it Dibutyltin dilaurate is used. that the adhesive strength of the film after removing the separating 5. The method according to claim 1, characterized in that the marked paper is significant compared to the original value draws that an organopoly 55 is reduced as a coating. siloxane mixture from (A) 62 to 67 parts by weight A paper coating process was now carried out of an a, cu-bis (triorganosiloxy) -polydiorganosilo- found which has the desired property xans of the formula given there, where R = Vi- namely little effort when pulling off the nyl or allyl, a = 1 or 2, b = 1, in = 0 to release paper, largely maintaining the adhesive strength 0.0015 η and η is chosen so high that the Vis- 60 a covered adhesive layer, good anchoring The viscosity at 20 ° C is 10 ⁷ to 10 ⁸ cP, (B) 35 bis and the flexibility of the paper coating, not previously 30 parts by weight «, co-dihydroxypolydimethylsi- can be achieved. This procedure for loxane of about 10 'cP viscosity at 20 ° C and production of release paper by applying a (C) about 3 parts by weight of a, co-bis (trimethyl- anti-tack coating siloxy) -polymethylhydrogensiloxane of about 55 on a paper surface using a 15 cP viscosity at 20 ° C, optionally in an inert solvent as a crosslinking agent (D) and (E) 5 to 6 parts by weight of dicumyl peroxide dissolved, optionally also in the form of such a solution in and 8 to 10 parts by weight of dibutyltin dilaurate water emulsified, crosslinkable organopolymers