DE3909876A1 - MOLDING FOR THE PRODUCTION OF FILMS FOR COMPOSITE SAFETY WINDOWS - Google Patents

Abstract

A moulding material for the manufacture of films for laminated glass panes is based on plasticized, partially acetalized polyvinyl alcohol, in particular polyvinyl butyral (PVB), with silane compounds as adhesion-regulating additives. The invention also concerns the use of this moulding material to manufacture extruded films used as the intermediate layer in laminated glass panes. It is proposed that the silicon compound is an organosilane of formula (I), where R<1> and R<2> independently are a possibly branched alkyl group with 1 to 4 carbon atoms or a group of formula (II); each R<3> is a possibly branched alkyl group with 1 to 4 carbon atoms or hydrogen, and the R<3> groups can be the same or different; each R<4> is a possibly branched alkylene group with 2 to 4 carbon atoms, and the R<4> groups can be the same or different; R<5> is a possibly branched alkylene group with 1 to 6 carbon atoms; and each m can be any number from 0 to 16.

Description

Technical field

The invention relates to a molding composition for the production of films or the like. For composite safety washers based on plasticized, partially acetalized polyvinyl alcohol, in particular partially butyralized polyvinyl alcohol (polyvinyl butyral, PVB) with silane compounds as adhesion-regulating additives and their use as an intermediate layer (adhesive film) in composite safety panes.

For the production of composite safety washers especially proven plasticized (plasticized) PVB films, which have a moisture content of 0.2 to 0.8% by weight. The Polyvinyl butyral resin is by a proportion of 10 to 28 wt .-%, preferably 15 to 23 wt .-%, labeled vinyl alcohol units. The plasticizer content of the plasticized polyvinyl butyral resin is 20 to 60 parts by weight, preferably 33 to 44 parts by weight, based on 100 parts by weight of polyvinyl butyral resin.

Laminated safety glasses are wide in the automotive and construction sectors spread. The requirements placed on the laminated glass panes are very diverse. For quality and security the laminated glass panes are ultimately the chemical-physical ones Properties of the plasticized molded polyvinyl butyral crucial, the intermediate layer two or more Connects glass panes. Has this intermediate layer the task of providing the composite pane with good shock resistance lend and the glass splinters created in the event of an impact to bind through good liability.

In addition to these mechanical properties, the intermediate layer has also high transparency, light, moisture and aging resistance To ensure (liability resistance).  

The used as an intermediate layer for laminated safety glass plasticized polyvinyl butyral films generally have for the vehicle construction has too high a glass adhesion. So that the windshield is preserved in its entirety in the event of impacts and at the same time the shock can be absorbed by energy absorption liability can be optimized.

State of the art

It is known that the glass adhesion of the films by addition various alkali or alkaline earth compounds, for example in the form of hydroxides, salts, complexes (DE-B-15 96 902, DE-B-15 96 894, US-A-32 49 488, US-A- 32 49 489, US-A-32 62 835, US-A-32 62 836).

The disadvantages of these alkaline compounds are in a chemical change in the plasticizing polyvinyl butyral resin, which results in discoloration due to damage of the polyvinyl butyral / plasticizer system and in turbidity of the resulting laminated safety glass due to unsatisfactory Expresses moisture resistance. Discoloration and clouding impair the transparency of the laminated safety glass. They also change due to the alkalinity as more Follow molecular sizes such as molar mass and distribution of the Polymers as well as the aging resistance. If the edge is dampened the film's adhesion is reduced and it occurs Detach the film from the glass.

It was therefore already the use of silanes as the Liability influencing agents in plasticized polyvinyl butyral films considered (JP-A-81296/69, DE-C3- 24 10 153, DE-A1-26 50 120). All previously proposed However, silanes have poor reproducibility of the adhesive properties on. The hydrolyzed silanes during the large-scale production of condensation and networking products - with the naked eye as nodules recognizable in the film - close a requirement Quality of laminated safety glasses and a reproducible  Adhesion adjustment of the film to the glass, so that its application has so far failed in practice.

Object of the invention

The object of the present invention is to provide a molding compound Manufacture of foils or the like for composite safety washers based on plasticized, partially acetalized polyvinyl alcohol with silane compounds as adhesion regulators To provide additives that have the disadvantages mentioned does not have.

Presentation of the invention

The invention solves this problem in that as a silane compound an organosilane of the general formula

is used, whereby
R¹ and R² each independently of one another are an optionally branched alkyl group having 1 to 4 carbon atoms or a group of the formula

are;
R³ is in each case an optionally branched alkyl group having 1 to 4 carbon atoms or hydrogen, where the groups R³ can be identical or different;
R⁴ is in each case an optionally branched alkylene group having 2 to 4 carbon atoms, where the groups R⁴ can be the same or different;
R⁵ is an optionally branched alkylene group with 1 to 6 carbon atoms and
m is independently one of the numbers from 0 to 16.

Connect the organosilanes proposed according to the invention surprisingly the advantages of alkali or alkaline earth compounds - reproducible liability regulation - with those of the known Silicon compounds - high transparencies, avoiding one Edge clouding and discoloration - without their specific  Have disadvantages. This is all the more surprising since more than twenty years with great effort in vain for the corresponding Substances is sought.

An organosilane of the formula (I) is preferably used in which
R⁴ is a straight chain alkylene group having 2 to 4 carbon atoms, the groups R⁴ being the same;
R³ is a straight chain alkyl group having 1 to 4 carbon atoms;
R⁵ is a straight chain alkylene group with 2 to 6 carbon atoms.

The groups preferably correspond R1 and R2 each have the formula

and are with each other equal.

R⁴ is furthermore preferably an alkylene group with 2 carbon atoms (ethylene group) and R³ is in each case a methyl group. M is preferably 3 in each case.

Organosilanes suitable according to the invention are, for example 3- (methyltriethylene glycol) -propylsilane-tris-methyltriethylene- glycol ester the structure

CH₃- (OC₂H₄) ₃-O- (CH₂) ₃-Si - [(OC₂H₄) ₃-O-CH₃] ₃;

3- (methyltriethylene glycol) -2-methylpropylsilane-tris-methyltriethyle-nglycol ester the structure

3- (ethyltriethylene glycol) -propylsilane-tris-ethyltriethylene glycol ester the structure

CH₃-CH₂- (OC₂H₄) ₃-O- (CH₂) ₃-Si - [(OC₂H₄) ₃-O-CH₂-CH₃] ₃;

3- (ethylenetriethylene glycol) -2-methylpropylsilane-tris-ethyltriethylene glycol ester the structure  

3- (butyltriethylene glycol) -propylsilane-tris-butyltriethylene glycol ester the structure

CH₃- (CH₂) ₃- (OC₂H₄) ₃-O- (CH₂) ₃-Si - [(OC₂H₄) ₃-O- (CH₂) ₃-CH₃] ₃;

2- (methyltriethylene glycol) -ethylsilane-tris-methyltriethylene glycol ester the structure

CH₃- (OC₂H₄) ₃-O- (CH₂) ₂-Si - [(OC₂H₄) ₃-O-CH₃] ₃;

4- (methyltriethylene glycol) -butylsilane-tris-methyltriethylene glycol ester the structure

CH₃- (OC₂H₄) ₃-O- (CH₂) ₄-Si [(OC₂H₄) ₃-O-CH₃] ₃;

3- (Methyltetraethylenglykoxi) -propylsilan-tris-methyltetraethylengly-kolester the structure

CH₃- (OC₂H₄) ₄-O- (CH₂) ₃-Si - [(OC₂H₄) ₄-O-CH₃] ₃;

3- (methylene pentaethylene glycol) propylsilane tris methyl pentaethylene glycol ester the structure

CH₃- (OC₂H₄) ₅-O- (CH₂) ₃-Si - [(OC₂H₄) ₅-O-CH₃] ₃;

Si-methyl (methylene triethylene glycol) methyl bis-methyltriethylene glycol cholesterol

CH₃ (OC₂H₄) ₃OCH₂Si (CH₃) [(OC₂H₄) ₃OCH₃] ₂;

Si-Si-dimethyl- (methyltriethylene glycol) -methyl-methyltriethylene glycol ester

CH₃ (OC₂H₄) ₃OCH₂Si (CH₃) ₂ (OC₂H₄) ₃OCH₃.

The silane is particularly preferred 3- (methyltriethylene glycol) -propylsilane-tris-methyltriethylene glycol ester the structure

CH₃- (OC₂H₄) ₃-O- (CH₂) ₃-Si - [(OC₂H₄) ₃-OCH₃] ₃

used.

Organosilanes of this structure are known from DE-C2-26 52 719 Additives to hydraulic fluids known. Regarding their manufacture is on this document and on DE-OS 39 08 792 (earlier registration P 39 08 792.1 from Hüls AG from March 17, 1989, Name: "Process for producing asymmetrical, terminal monounsaturated glycol ether ") and DE-OS 39 08 791 (earlier registration P 39 08 791.3 from Hüls AG dated March 17, 1989, Name: "Process for the production of organosilicon Connections ").

One or more of the organosilanes according to the invention are preferred homogeneously incorporated into the plasticizer-containing polymer.

It has surprisingly been found that the inventive Silanes even in very small amounts from 0.003 to 0.8% by weight, based on the plasticized polyvinyl butyral, the desired develop liability regulating effect.

These silicon and organofunctional silanes are preferred dissolved in the plasticizer (optionally dispersed) and with the polymer in a known manner on a calender or in a Extruder processed to preferably 0.3 to 1.5 mm thick films (EP-A1-01 85 863, GB-PS-12 71 188).

Suitable plasticizers are those known from the prior art Esters of polyvalent acids, polyhydric alcohols or oligoether glycols, such as. B. di (2-ethylhexyl) adipate, dihexyl adipate, Dibutyl sebacate, dioctyl phthalate, esters of di-, tri- and tetraethylene glycols with linear or branched aliphatic Carboxylic acids and mixtures of these plasticizers. Plasticizer mixtures with phosphoric acid esters in polyvinyl butyrals used with higher vinyl alcohol units.

As plasticizers according to the present invention, above all Esters of aliphatic diols with long chain aliphatic Carboxylic acids used, especially esters of triethylene glycol with aliphatic carboxylic acids containing 6 to 10 carbon atoms,  such as 2-ethyl butyric acid and heptanoic acid. Plasticized Polyvinyl butyral preferably contains 24 to 32% by weight Plasticizers.

In addition to incorporating the silane into the plasticized polyvinyl butyral but the silane can also in a suitable solvent, that does not affect the film properties, but the wetting of the silane on the film improves after appropriate Methods (spraying, dipping, printing) on the film surface be applied. Are suitable as solvents Aromatics, esters, chlorinated hydrocarbons and comparable non-polar Solvent.

The silane diluted in a solvent can also be dissolved apply the surface of the glass plates, which the plasticized Polyvinyl butyral in the manufacture of composite safety washers are facing.

In general, the silane concentrations are between 0.003 up to 0.8% by weight, preferred and sufficient in many cases 0.003 to 0.3% by weight, very preferably between 0.01 to 0.1 % By weight, based on the plasticized polyvinyl butyral.

The polyvinyl acetals are hydrolyzed by acetalization Made of polyvinyl esters. As aldehydes can for example formaldehyde, acetaldehyde, propionaldehyde, butyral dehyde, valeraldehyde and the like Like., Preferably butyraldehyde used will. The carboxyl group of the polyvinyl ester belongs to one aliphatic acid with 1 to 8 carbon atoms, preferably it is one Acetate group. The polyvinyl acetal contains 0 to 20% by weight, preferably 0.5 to 3.0% by weight, acetyl groups.

A partially butyralized polyvinyl alcohol (PVB) is preferred used.

In principle, any thermoplastic can be used as the polyvinyl butyral resin deformable polyvinyl butyral resin can be used. Preferably  a resin containing 15 to 23% by weight of vinyl alcohol units is used contains.

The water content of the films should be set to 0.2 to 0.8% by weight.

In a preferred method for producing the laminated safety glass is a film according to the invention between equally thick or different glass plates brought and pressed at 60 to 100 ° C to a pre-composite. The final composite is made e.g. B. in an autoclave at 120 to 160 ° C and 8 to 16 bar within a pressing time of 10 to 30 min.

In the case of those described in the following exemplary embodiments Tests were carried out to assess the dielectric strength, the film's own color and the clouding of the edges of the laminated safety glass defined the following test methods:

The dielectric strength is based on ANSI 26.1-1983, 5.26 Test 26 checked. In a frame, one is tempered at 23 ° C Laminated glass pane of 30 × 30 cm inserted horizontally. A steel ball of 2.26 kg is from the top to the middle the laminated glass pane dropped freely. In these attempts the drop heights are varied and the drop height is determined, do not penetrate the steel ball with 8 to 10 samples will. The distance of the ball from the glass surface is called Ball drop height specified. The greater this drop height, the more the dielectric strength of the laminated safety glass is higher.

With the spectral measuring device model Labscan 5100 the yellowness index ( Δ YI, means difference from measured value of the laminated safety glass and glass without foil) according to ASTM-D-1925 (light type C, 2 ° observer) is determined. The specified Δ b value corresponds to the YI of ASTM-D-1925.

The one that influences the liability resistance and transparency Edge deterioration was determined according to ANSI 26.1-1977, para. 5.3, test 3 evaluated, whereby it is measured in what width the turbidity edge strip penetrated into the interior of the laminated safety glass is.

Ways of Carrying Out the Invention Example 1

72% by weight of polyvinyl butyral resin, which contains vinyl alcohol units of 20.5% by weight, and 28% by weight of triethylene glycol di-n-heptanoic acid ester as plasticizer, in which 0.7% by weight Tinuvin P (light stabilizer, Ciba Geigy) and 0.14 to 0.21 % By weight of 3- (methyltriethylene glycol) -propylsilane-tris-methyltriethylene glycol ester, based on the amount of plasticizer, are solved, according to EP-A1-01 85 863 to a 0.76 mm extruded thick film and, after air conditioning on a Brought an average moisture level of 0.54% by weight, with 2.2 mm thick float glass panes for laminated safety glasses processed.

Example 2

A laminated glass pane was produced as in Example 1, however, as silane, 2- (methyltriethylene glycol) -ethylsilane tris-methyltriethylene glycol ester in a proportion of 0.14 to 0.21% by weight, based on the plasticizer content, was used.

Example 3

A laminated glass pane was produced as in Example 1, however, 4- (methyltriethylene glycol) -butylsilane as the silane tris-methyltriethylene glycol ester in a proportion of 0.14 to 0.21% by weight, based on the plasticizer content, was used.

Comparative Example 4

The procedure was as in Example 1, but instead of the invention Silans 4.6 wt .-% - based on the plasticizer content  - A 10 wt .-% aqueous potassium acetate solution used has been.

Comparative Example 5

The procedure was as in Example 1, but instead of the invention Silane is an isobutyl-tri-methoxisilane accordingly DE-C-24 10 153 in amounts of 1 to 1.8 wt .-%, based on the amount of plasticizer was used.

The laminated glasses according to experiments 1 to 5 were then subjected to a ball drop test according to ANSI 26.1 - 1983 (Table 1).

Table 1

The adhesion reducing effect of the silanes, which can be found in the Ball drop expresses and the optical purity of the film (Freedom from nodules) are only with the silane according to the invention given in accordance with requirements and reproducibly. The reproducibility the dielectric strength that meets the requirements (<4m) in the silane according to the invention is on laminated glass panes demonstrated whose slides in different time periods (beginning and mid-year).

The results of the Yellowness Index tests (ASTM-D-1925) and for marginal clouding (ANSI 26.1 - 1977) are in Table 2 summarized.

Table 2

Example 6

According to example 1, the film and laminated safety glass manufactured, but it is used as a plasticizer, triethylene glycol di-i-heptanoic acid ester instead of triethylene glycol di-n-heptanoic acid ester used.

The results are shown in Tables 3 and 4.

Table 3

Table 4

Claims (14)

1. Molding composition for the production of films or the like. For composite safety panes based on plasticized partially acetalized polyvinyl alcohol, in particular polyvinyl butyral (PVB) with silane compounds as adhesion-regulating additives, characterized in that an organosilane of the general formula is used as the silane compound is used, whereby
R¹ and R² each independently of one another are an optionally branched alkyl group having 1 to 4 carbon atoms or a group of the formula are;
R³ is in each case an optionally branched alkyl group having 1 to 4 carbon atoms or hydrogen, where the groups R³ can be identical or different;
R⁴ is in each case an optionally branched alkylene group having 2 to 4 carbon atoms, where the groups R⁴ can be the same or different;
R⁵ is an optionally branched alkylene group with 1 to 6 carbon atoms and
m is independently one of the numbers from 0 to 16. 2. Molding composition according to claim 1, characterized in that in the general formula I
R⁴ is a straight chain alkylene group having 2 to 4 carbon atoms, the groups R⁴ being the same; R³ is a straight chain alkyl group having 1 to 4 carbon atoms is; R⁵ is a straight chain alkylene group with 2 to 6 carbon atoms is.   3. Molding composition according to one of claims 1 or 2, characterized in that in the general formula I
R¹ and R² each represent a group of the formula and are equal to each other. 4. Molding composition according to one of claims 1 to 3, characterized in that in the general formula I
R⁴ is an alkylene group with 2 carbon atoms (ethylene group). 5. Molding composition according to one of claims 1 to 4, characterized in that in the general formula I
R³ is a methyl group and m is 3 each. 6. Molding composition according to one of claims 1 to 5, characterized in that one or more silanes from the group consisting of

• a) 3- (methyltriethylene glycol) -propylsilane-tris-methyltriethylene glycol ester of the structure CH₃- (OC₂H₄) ₃-O- (CH₂) ₃-Si - [(OC₂H₄) ₃-OCH₃] ₃,
• b) 2- (methyltriethylene glycol) -ethylsilane-tris-methyltriethylene glycol ester of the structure CH₃- (OC₂H₄) ₃-O- (CH₂) ₂-Si - [(OC₂H₄) ₃-O-CH₃] ₃und
• c) 4- (Methyltriethylenglykoxi) -butylsilane-tris-methyltriethylene glycol ester of the structure CH₃- (OC₂H₄) ₃-O- (CH₂) ₄-Si - [(OC₂H₄) ₃-O-CH₃] ₃ used.

7. Molding composition according to one of claims 1 to 6, characterized in that that the silane in an amount of 0.003 up to 0.8% by weight, preferably up to 0.3% by weight and in particular 0.01 to 0.1% by weight, based on the plasticized polyvinyl butyral, starts.   8. Molding composition according to one of claims 1 to 7, characterized in that the polyvinyl butyral resin has a share from 10 to 28% by weight, preferably 15 to 23% by weight, vinyl alcohol units, based on the polymer. 9. Molding composition according to one of claims 1 to 8, characterized in that the plasticized polyvinyl butyral resin has a plasticizer content of about 15 to 45 wt .-%, preferably 24 to 32 wt .-%, based on the Polymer / plasticizer mixture. 10. Use of a molding compound according to one of the claims 1 to 9 extruded film as an intermediate layer in Laminated glass panes. 11. A process for the production of composite safety panes, in which two or more panes are connected to one another by means of a plastic film based on plasticized partially acetalized polyvinyl alcohol, in particular polyvinyl butyral, and the adhesion between the panes and the plastic film is determined by an adhesion-regulating additive

• - on the disc surfaces and / or
• - applied to the film surfaces and / or
• - is worked into the film,

is influenced, characterized in that as liability regulating additive an organosilane according to one of the An sayings 1 to 6 is used.