CS235954B2 - Softeners containing foil from partially acetalized polyvinyl alcohols - Google Patents

Abstract

1. Plasticiser-containing foils formed from partially acetalised polyvinyl alcohols, characterised in that they contain as plasticiser mixtures of a) esters of organic, cyclic acids with alcohols of 4 to 10 carbon atoms and b) esters of glycols and aliphatic monobasic acids with 4 to 10 carbon atoms, in the ratio of 85:15 to 15:85% by weight.

Description

The invention relates to a film of partially ecetelieovaných polyvinylalcohols containing zrnmZovedla that look I ^to about lepLcí foil in free ^beta ečnootních NRA ^ en ^ h ^{KL ec} h. Obzv ^ S ^ the present invention relates to novel polyvinylbutyrelovými films and by using these sheets, for the production of laminated safety glass.

Laminated safety glasses generally consist of two sheets of silicate glass ^and of ^j «^ ^{NATURAL l} ep ^I C ^{and the sheet} e ,, e ^{kt ack Both KL} en No ^{D of} EAK ^y together. The plate of ^the bubble-silicon can optionally be replaced by a plate of plastic hmoo ^y. Such laminated safety plates are mainly used as windshields for vehicles, especially cars; may, however, also used in the construction sector, whereby the method according Vida vyuuítí can be mated more than two panes of glass or plastic or adhesive ^{OMM p-tert-lli.} 'Such a ^{s t} oe ceori desk ^y may desire as t ^and Ke j ^p and cerium ° glass.

J ^ Rili tackiness ^as in TFCM laminated glasses bezpečnootních ouží ^ ^ev AI ^{EXAMPLE some} částetaě ^acetal izov ^an e Pol oinylal ^{y i} s ^h s ^l SOE ^tert He Processed zrnmZoovidly. For ^{there above a} r t b ^{u n} e ^nu partially acetalized poly ^{y y} oinylalishsl manufactured zrnmdelněním polyvinylacetate and subsequent scetalizecí alifatckkých using aldehydes such as formaldehyde, acetaldehyde, butyraldehyde, and other aldehydes with 3-10 carbon atoms. Ztýddenění generally let proceed completely, so that polyvinyl alcohols comprising mostly still from 0.5 to 5% by weight, and ^ i ^^ tulle groups, calculated as ^y oin lecetátsoé group.

Also acetalization is generally let proceed completely, and partially acetal-ZOT ^ A ^ e ^ pol Nu ^Vin / lвlishoS used to produce films usually contains still josloé hydroxyl groups; with partially butyralizovaného pol ^{y y} lelkshslj oin the content of hydroxyl groups per vinyl-L-alcohol amount to 10 to 27% hmoStlosi] them. In the context of the present invention, all these resins fall under the term partially ecelectrically polysoylalishols.

In the manufacture of laminated safety glasses, these partially acetalized polyvinyl alcohols are used as films having a certain surfactant content. The type and quantity of the softening agent used affects the properties of the laminated safety glass produced. In practice, it has therefore been found that particularly non-shattered laminated safety glasses can be obtained by using a partially butyralized polysilicon-coated film which contains 15 to 40% by weight, preferably 25 to 31% by weight, of a granulating agent and whose the content of free hydroxyl groups is 10 to 25%, preferably 16 to 23% w / w, based on the partially butyralized polsoinyl-alkali metal-free drying agent. The moisture content of such a partially butyralized polsoiosilane resin is in the range of 0.2 to 0.9 wt.

In practice, a tri-ethylene glycol ester of 2-ethylbutyric acid is used as a granulating agent for such partially sealed polysiline aluminum foil. The use of dibutyl sebacate, dihexyl adipate and dioctyl phthalate has also been described.

Despite the fact that many other granulating agents for partially acetalized polyvinylbutyrals are still known, so far a very small fraction of these compositions have found widespread use in the practice of laminated safety glass laminates in partially butyralized polysvinyl alcohols. The basis for this is the fact that the partially styled polyoloyl is a commpex which can be made with a wide variety of variations in the content of tyral, hydroxyl and residual ester groups, the breadth of these variations being determined by different possible molecular masses and the kind of hydroxyl group distribution on the polymer chain . ir

Is excluded from this large number of acceptable or partly acceptable změkčwací ^ ^ uužtí ^means in my ^ rs ^^ h to ^b e ^a t pečnostní ^{VRS vena glass} Ebola ^{n must} be very accurately to meet each other working conditions mmzi polymer and for ^the změZovacím . ^ ⁱ ^ <^ c ^ ⁱ ^ <^ ^i. ^ ^N DiootySft methacrylate EMA ^For example the hledlsZ this ^{AD n ic} s prakt pouHtí for ^Me interlayer partially butyralizovaného polsvinylelkshslj.

Among the many requirements imposed on interlayers for laminated safety glasses, among others, high toughness of the film, high resistance to film separation and good marginal stability, characterized by its ability to bind water, can be counted. The tensile stress at 100% elongation is also used.

Although a number of phthalic acid esters have already been described in the literature as being useful with partially butyralized polyvinyl alcohols, there are no references to the applicability in partially butyraliolated psyl vinyl alcohols to safety laminated glass layers. The description of obedience, for example, in the publication Mooern Plastice Encyclopedia 1975 to 1976 on pages 698 and 699 is so little specified that it is impossible to determine any direct moonnot utilization. The examples do not always follow the same assumptions. From the reported data, it will be appreciated by those skilled in the art that the esters to be used include esters of C 5 -C 10 -alksyl to ish-C 1-6 -alkylene, while esters with shorter alcohol chains, iso-C 8-18 -ols and lao-Cg. -alcohols are characterized as ommzen usable.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide adhesive films for laminated safety glasses based on partially etetalized polymers containing a softening agent using phthalic acid esters alone or in admixture with glycol esters which, in comparison with With the known adhesive films for laminated safety glasses, due to the lower water absorption, they exhibited good marginal stability or resistance to layer separation and which would have excellent toughness while maintaining other common mechanical properties.

Accordingly, the present invention relates to partially acetylated polyvinyl alcohols which contain a plasticizing composition which, as a lubricant, is either:

(a) esters of organic cyclic acids and alcohols with 4 to 10 carbon atoms; or

(b) mixtures of glycol esters which are derived from polybasic aliphatic acids of up to 10 carbon atoms and esters referred to in paragraph (a).

Films made of such softened resins exhibit advantageous mechanical properties and lower water uptake than films made using glycol esters alone.

DE-OS No. 28 20 780 describes the use of phthalic acid esters whose suitability for partially acetalized polyvinyl alcohols is so low due to their long alcohol chain that they are not themselves usable. Their utilization is only possible when they get mixed! with good gelling oxygen esters. phosphorus.

Of the organic cyclic acid esters of the present invention, phthalic acid esters of aliphatic and / or aromatic alcohols having from 4 to 10 carbon atoms are preferred. Mixed esters of alcohol-containing mixtures as well as mixtures of esters are also suitable, wherein the aliphatic alcohols may be a chain or a branched chain, such as, for example: di-esters of di- and di-di _- phthalate, di-hexyl _- phthalate, di-epyl _- phthalate, 111cylphthalate, diethylglycylphthalate, eutylglycyl phthalate, ethylhexyl phthalate, ethylphenol phthalate, olylbenzylphthalate, outsylcycloyl phthalate, oexyl dimethyl phthalate, oexyl dimethyl phthalate, and the like. Phthalic acid esters with glycolic acid esters may also be used.

Suitable glycol esters are, for example, polyethyl silicic acid esters of ethyl butyric acid, caproic acid, enantic acid, ceprylic acid, ethylhexaic acid, pelargonic acid or capric acid. Preference is given to diethyl ether, triethylene glycol or tetraethylene glycol. Examples of such esters which can be used according to the invention are triethylene glycol-2-ethyl-butyrate, triethyl 16,14,14-diheptane, diethyl glycol diphosphate or tetraetilenglicol ester of velerioic acid, ethylbutyric acid or ethylhexanoic acid.

235954 4

However, it is also possible according to the present invention to use esters of glycerin or glycolic acid with the abovementioned acids.

^Partially acetate-tyvin readjusted ^ ^ altohoty use ^p-shrinkable ccording ^p ředloíe ⁿ eh ^{on Modeling of microns} ohou contain from 5 up to 30 wt%, in the hydroxyl SKU ^p, calculated as vinyl alcohol. The content of the hydroxyl groups is preferably 16 to 23% by weight.

The multiplicity of the plasticizer or the emission of the plasticizer can be 10 to 40% by weight, based on the total weight of the film. They depend, inter alia, on the degree of acetalization of the polyvioyl alcohol and on the acetalization of the aldehyde used, as well as on the types of individual plasticizers used. Generally also chosen so that the Shore A hardness of productions ^b Ene film according předloton ^ o ^y la discovery ^would at 23 ° C of ¹ 00, and 50.

The ratio between organic cyclic acid esters and glycol esters may vary between 99: ¹ and 1:99. Follows gearbo ^I N ^{E =} mr ^ ccording ítví and ranging even Bilit ^yl ester in C ^ tangent acetalized polyvinyl lalkoho ^. Furthermore selected depends on the properties of the individual agents and for formation of partially acetalZtivaného _{polyvinylalčtholž>} as well as requirements for mass produced film. The preferred ratio is in the range of 85:15 to 15:85 (in% by weight).

In addition to the above-described improvements in mechanical properties and water-binding properties, thereby guaranteeing better edge stability of the laminated safety glass, the adhesive ^film for laminated safety glass with gelstoleste has the advantage of the aforementioned environments. Of the glycol esters and esters of organic cyclic acid, it is possible to add more than 1 glycol ester than the glycol ester itself without losing the good mechanical strength of the film. This allows the extrusion of the film of the present invention at lower temperatures to substantially reduce thermal degradation of the mass.

Předloíeného making the film of the invention may be carried by any, according to known zp.ůsob ^y. After sieving of the sieve components, the obtained film mass is further processed to form a film. The mass obtained is capable of extruding or curing, not spraying or pressing. The wastes can advantageously be reprocessed, for example, by extrusion into films.

The film weights can further be adjusted using suitable excipients known per se, such as stabilizers, dyes, pigments, additives, tackifiers and blocking agents.

The laminated safety glass for which the film of the present invention is processed consists of at least one layer of the film. They may be made of unhardened, tempered, planar, arcuate, smoky, extruded, tinted, etched or structural silica glass, which optionally contains wires, as well as colorless, color-transparent, color-covering or printed foil according to the present invention, which optionally comprises an embedded wire wire mesh, fabric or other objects. The thickness of the silica glass or film produced according to the present invention is selectable depending on the purpose of the coating, as well as the number of laminated safety glass layers.

Z t ^o h ^to payments ^- ývilídí ο ο ^ ^ Ι pouH.tí layered S ^ l ^ sahnuících Jato adhesive film according to the invention before ^ íeného stliebníctií example in the door or door ·. for windows and window devices, for parapets of balconies or plasters, for partition walls for partitioning of rooms, separation of balconies or basic parts of fencing, for roofs or roofs of terraces, light roofs or. greenhouses, for cell or computer equipment, showcases, cash registers or prisons or areas with a risk of explosion or implosion, vision as safety glass to protect against: burglary, bullet, fire, sound, cold, temperature, heat , optionally after. using an alarm or heating wire. .

In the transport sector, the windows of motor vehicles, rail vehicles, ships and airplanes are suitable for windshields, rear windows or sidebars, or glazing of dividing doors. walls and the like.

In addition, the films of the present invention can be used extensively in conjunction with transparent, highly elastic plastics.

In addition to polycarbonate, plastic sheets which can be used are polymethylreactrlate, polyethylene terephthalate, hardened polyvinyl chloride, polyamide, cellulose esters, styrene polymers and crystals and the like.

Example 1 (comparative)

To a conventional partial butyralized polyvinyl alcohol propyl group having a hydroxyl group content of 20.7% by weight, calculated as vinyl, is admixed as a mixture with the composition on a rolling mill. various variables are known to include di-2-di-2-trifluorobutyrate. Multiple 0.76 mm thick films with a finely matte finish are produced under pressure on a roll stand, which are tested at 23 ° C and 60% relative humidity to see if the admixed plasticizer sweats. Tensile strength, elongation at break, tensile stress of 100% and cold impact were also determined. Cold shock measurement is performed by the VDCh 22-02 method on specimens with S 3 in accordance with DIN 53 504 by following the lowest ttoltУk at which no more than one of the six curved specimens breaks by striking a 200g test weight , o ^and dak ^: cutting from a height of 200 mm.

The following values were found during the measurement:

Amount of softener (% wt.) 28 30 32 sweating No No No tensile strength (MPa) 26.9 24.7 22.1 tensile stress at 100% elongation (MPa) 3.2 2.6 ', 5 .. impact cold value (° C) -55 -5> -55

Λ

Although the emollient exhibits good compatibility with the polybutyl alcohol film partially butl-nitrate polymer when it is offered ^{in an} entanglement of 30%, then the tensile strength and &lt; 32% tensile are also warm, so that the emollient does not reside in g. ≥30% suitable for achieving good film values.

Example 2

In the same manner as described in Example 1, different amounts of phthalic acid esters are mixed with a partially butyralized polyvinyl alcohol resin with a hydroxyl group content of 20.7% by weight, calculated as vinyl alcohol, and a film is produced from this mass. The results of the quality tests of the produced film are given in Table 1 below:

T a b u 1 k a 1

Alcohol component of phthalic acid ester Quantity (% wt.) Sweat Tensile strength (MPa) Impact Cold Value - (° C) Tensile stress at 100% elongation (MPa) n-C 1-4 -alcol 28 No 25, T -45 3.6 30 No 22.8 -50 2.8 32.5 No . 19.4 -55. 1.9 35 No 15.3 -55 1.5 n-O-alcohol O 28 No 27.3 -50 5.7 30 No 25.9 -50 4.2 32.5 No 21, 8 -55 3.6 35 No 18.2 -55 2.3 n-Cy-alcohol 28 No 29.3 -50 7.4 30 No 28.1 -55 5.3 32.5 No 25.5 -55 4.0 35 No 22.2 -55 2.6 n-C8-alcohol 28 No 29.4 -55 7.8 30 No 27.3 -55 5.8 32.5 Yes 25.0 -55 4.8 35 Yes 21, 2 -55 3.5 80% C ₆ 28 No 30.6 -45 9.2 10% Cg 30 No 28.2 -50 5.9 ¹⁰ % ^Cl 0 32.5 No 23.9 -55 3.4 35 No 22.1 -55 3.3 40% C? 28 No 27.8 -50 9.8 40% Cg 30 No 26.4 -55 4.8 20% Cg 32.5 No 24.2 -55 2.9 35 Yes 21, 7 -55 3.2

»» Example3 '

A commercially available partially butyralized polyvinyl alcohol resin having a free hydroxyl group content of 20.7% by weight, calculated as vinyl alcohol, is mixed with various sizes of triethylene glycol di-2-ethylbutyran on a rolling mill. (3 GH) and a mixed ester (C 6/10) of phthalic acid e a mixture of alcohols having 6, 8 and 10 carbon atoms in an 80:10:10 ratio by weight. Foils of 0.76 mm thickness, the properties of which are shown in Table 2, are pressed on a roll stand. The properties are determined in the same manner as in Example 1. None of the prepared foils are sprayed.

Tt ^ ull ^ ki2 ·

Softener content (% wt.)

GH C 6/10 total

Tensile strength (MPa)

Tensile stress at 100% elongation (MPa)

Impact cold value (° c)

14 14 28 26.6 3.7 -50 8 20 May 28 28.5 3.9 -50 15 Dec 15 Dec 30 27.6 2.8 -50 1 5,5 15.5 31 24.9 2.7 -50

Samples of each film were processed into laminated bezpečnootní · glass so that klimatizovaly at 32% relative vlhkooti air is then sandwiched between two sheets of ^ emičHáho ^KL aa connection with zajisVúlo zatápím to a temperature between ¹³⁰ and ¹ 5 ^{0 C} at a pressure of 1.2 MPa. The laminated safety glass obtained was tested for adhesion between silica glass and partially butyraliolated polyvinyl alcohol film according to the plummel method, which is described, for example, in DE-PS 24 10 153. All laminated safety glasses produced exhibit a plummel value of 10.

Example 4

Analogously to Example 3, films are produced from partially butyreliolated polyvinyl alcohol having a hydroxyl group content of 20.7% by weight, with a variable content of triethyl glycol diheptanthate (3 G7) and heptyl phthalic acid ester (C 7), and their properties are determined. The results are shown in Table 3. In all cases, plasticizers are acceptable for the resin.

Table 3

The content of the change in weight (% wt) Tensile strength (MPa) Tensile stress at 100% · elongation (MPa) Impact cold value (° C) 3 G7 c 7 total 14 14 28 28.3 4.6 -50 • 8 20 May 28 28.9 5.4 -50 14.5 14.5 29 26.3 3.1 -55 1> 15 Dec 30 23.6 2.7 -55 * 1 6 16 32 23.0 2.6 -55

Bezpeknootní laminated glass made of the foil described ^YKA zuuí plummelovu value přilnavooti 10th

Example 5

Analogously to Example 3 there were prepared partly butyralizovaná polyalcohols resin having a hydroxyl content of 20.7% hmotnnssních, calculated as vinyl alcohol, with trietyeenglkkoldiihepaanoáeem (3 g 7) and (C4) in different proportions hmoonostních a total content of 28% emollient hmoOtosSních _φ The results of the tests are shown in Table 4. The plasticizer mixtures used show good compatibility with the polyvinyl alcohol resin.

Table 4

Softener content (% wt) Tensile strength (MPa) Tensile stress at 100% elongation (MPa) Impact cold value (° C) 3 G 7 C 4 total 14. 14 50:50 25.6 3.1 -50 12 16 43:57 25.6 2.8 -50 10 18 36:64 25.7 2.6 -50 8 20 May 29:71 25.4 2.7 -50 6 22nd 21: 79 27.0 3.1 -50 4 24 14:86 26.2 2.8 -50

Example 6

In an analogous manner to Example 3, a partially butyralized polyvinyl alcohol resin having a hydroxyl group content of 20.7% by weight is produced. calculated as vinllalkshol with different softening agents. Overall mirnostv! The plasticizer is in each case 28% by weight. As in Example 4, triethylene glycol diheptanoate (3G7) is used as the ester of the organic cyclic acid. The mixing ratio is 1: 1. P _o applied vlastneoU means and the produced film are shown in Table 5. All used SMe ^ L změkkovadel good compatibility with used polyvioylalkohslovsu Prysk ^ is subtracted.

Table 5

Tensile strength Tensile stress Impact cooler (MPa) at 100% prot. dová hodnot.

(MPa) ( ⁰ ° C)

n-Cy, Cq, C9-phthalate 25.7 4.0 -50 n-CCg-Talc 25.9 4.8 -50 i-Cg phthalate 27.2 6.2 -45 n-Cy i-C ^ Q ~ -flate · 28.9 3.9 -50 o-C -CCC C, C. |-O-phthalate 26.0 5.1 -55 n-Cg, _C10- phthalate 27.9 4.3 -50 buuyyphalate, b 26.8 4.3 -35 bauylate, cyclohexyl acetate 26.8 3.4 -45 methylg-yl 25.9 2.3 -50 ethyl lg of the substance 28.0 2.7 -50 ^^ ty ^^^ o ^ a ^ t 27.0 3.2 -45

The laminated safety glasses made of the above films had a plummel adhesion value of 10.

Example?

A partially butyralized polyvinyl alcohol resin having a hydroxyl group content of 18.4% by weight, calculated as vinyl alcohol, is processed analogously to Example 3 to form films with a total of 30% by weight, various glycol esters and esters of organic cyclic acids in a 1: 1 weight ratio. The tensile strengths are given in Table 6. In all cases, the plasticizer mixtures for the polyvinyl alcohol resin were acceptable. The laminated sheets were made of safety laminated glass and their plummel stress value was 10.

Table 6

OH group content (as vinyl alcohol) (% by weight)

Softening agent

Tensile strength (MPa)

18,4 triethylene glycol diheptanoate, dibutyl phthalate 12,2

18.4 triethylene glycol diheptanoate hexyldecyl phthalate15.8

18,4 triethylene glycol heptanoate octyldecyl phthalate20,3

18,4 triethylene glycol caprylate 8 triethylene glycol propinate, 18,7 hexyldecyl phthalate

18,4 triethylene glycol caprylate and triethylene glycol propinate, octyldecyl phthalate19,4

Example 8

A partially butyralized polyvinyl alcohol resin having a hydroxyl group content of 20.7% by weight, or 22.3% by weight, or 26.8% by weight, calculated as vinyl alcohol, is treated, as in Example 3, together with 30% by weight of various glycol esters, and esters of organic cyclic acids in a weight ratio of 1: 1 per film. No film swelling was found in any case. The tensile strength values are recorded in Table 7. The laminated safety glasses made of these films had a pummel adhesion value of 10.

Table 7

OH-group content (as vinyl alcohol) (wt.%) Softening agent Tensile strength (MPa) 22.3 triethylene glycol diheptanoate dibutyl phthalate 25.8 26.8 triethylene glycol diheptanoate, dibutyl phthalate 27.9 22.3 triethylene glycol diheptanoate, hexyldecyl phthalate 24.8 22.3 triethylene glycol di-2-ethylbutyrate dibutyl phthalate 24.2 26.8 triethylene glycol di-2-ethylbutyrate dibutyl phthalate 27.1 20.7 tetraethylene glycol di-2-ethylhexanoate dibutyl phthalate 22.1

Example 9

The various films of Examples 1, 2, 3 and 5 are processed into laminated safety glasses as described in Example 3 and the water content of the joints is determined by infrared spectroscopy. The results obtained are shown in Table 8. The numerical values show the different readiness of the films to receive water.

Table 8

Total plasticizer content (% wt) Type of plasticizer Ratio in the rubbish Water content 28 3 GH . __ 0.53 28 3 G 7 - 0.54 28 C 4 - 0.49 28 C 7 - 0.42 28 C 8 ' T 0.43 28 C 6/10 - 0.42 28 C 7/9 - 0.42 28 3 G 7 + C 7 50:50 0.47 28 3 G 7 + C 7 43:57 0.46 28 3 G 7 + C 7 36:64 0.45 28 3 G 7 + C 7 29:71 0.45 28 3 GH + C 6/10 50:50 0.46 28 3 GH + C 6/10 29:71. 0.44 30 3 GH + C 6/10 50:50 0.46 31 3 GH + C 6/10 50:50 0.46 32 3 GH + C 6/10 50:50 0.47

Explanatory notes to Table 8:

GH = triethylene glycol di-2-ethylbutyrate

G 7 = triethylene glycol diheptanoate

C 7 = n-heptyl phthalate

C 8 = n-octtyphthalate

C 6 / J 0 = hexyldeyl phthalate

Example 10

A 0.76 mm thick film is formed from the following webs:

(a) 72 parts by weight of commercially available butylated polyvinyl allyl resin and 28 parts by weight of triethylene glycol di-2-ethylbutyrate (recipe a)

b) 72 wt. % of the same partially butyralized polyol-4-alcohol resin; parts of the surfactant mixture consisting of equal parts of t, riethylsilyl S-di-2-ethylbutyrate and a mixed phthalic ester and a mixture of hexanol, octanol and decenol (recipe b)

с) 69 parts by weight of the same partially butyralized polyvinyl alcohol resin and parts by weight of the plasticizer mixture described in paragraph b) (recipe c).

These three types of foil contained enough anti-adherent agent so that the pummel adhesion value was after air conditioning and processing into laminated safety glasses 2-4 as described in Example 3.

The mechanical properties of these three types of foils were determined and laminated safety glasses produced therefrom were subjected to a ball test according to DIN 52 306. The values given in the following table were obtained:

and Recipe b C tensile strength (MPa) 25.0 24.5 23.0 elongation at break (%) 27.0 27.5 28.0 tensile stress at 100% elongation (MPa) 2.6 2.5 2.5 pummel value 3 4 3 water content (% by weight) 0.52 0.46 0.48 height of fall (m) 6.50 6.50 6.50

SUBJECT OF THE INVENTION

Claims (6)

Film of partially acetalized polyvinyl alcohols containing plasticizers, preferably for laminated safety glasses, characterized in that they contain as plasticizer either: a) an ester of cyclic organic acids and alcohols having from 4 to 10 carbon atoms, or b) a mixture of esters of glycols and aliphetic monobasic acids. 4 to 10 carbon atoms with the esters referred to in a). 2. A plasticizer-containing film as claimed in claim 1, characterized in that it comprises phthalic acid esters as organic cyclic acid esters and di-, tri- or tetrathylene glycol esters as glycol esters. 3. A plasticizer-containing film according to claim 1 or 2, characterized in that, when using an ester mixture, one of the components of the plasticizer mixture is present in an amount of at least 1% by weight, preferably at least 15% by weight, based on the plasticizer mixture. 4. Plasticizer-containing films according to claims 1 to 3, characterized in that they comprise a plasticizer mixture in an amount of 10 to 40% by weight, preferably 20 to 35% by weight, based on the total weight of the film. 5. A plasticizer-containing film according to claim 1, characterized in that the partially acetalized polyvinyl alcohol contains 5-30% by weight, preferably 16-23% by weight, of hydroxyl groups, calculated as vinyl alcohol. A plasticizer-containing film according to any one of claims 1 to 5, characterized in that it has a Shore hardness A at 23 ° C of between 100 and 20, preferably between 90 and 30.