EP1817365A1

EP1817365A1 - Organophosphine-stabilized intermediate layer films for laminated glazings

Info

Publication number: EP1817365A1
Application number: EP05845906A
Authority: EP
Inventors: Uwe Keller
Original assignee: Kuraray Specialities Europe GmbH
Current assignee: Kuraray Specialities Europe GmbH
Priority date: 2004-12-01
Filing date: 2005-12-01
Publication date: 2007-08-15
Also published as: WO2006058899A1; DE102004000058A1; CN101068859A; CN101068859B

Abstract

The invention relates to stabilized polymer mixtures containing polyvinyl alcohol, partially acetalized polyvinyl alcohol and/or ethylene/vinyl acetate copolymer and one or more oranophosphines while using recycling material.

Description

Confession

Organophosphine-stabilized interlayer films for composite glazing

The invention relates to polymer mixtures stabilized by organophosphines, which can be used as an interlayer film in laminated safety slices.

Laminated safety washers consisting of two glass panes and an adhesive film connecting the glass panes are used in particular as windshields in motor vehicles, it being possible for a pane of glass to be replaced by a plastic pane. The material used for the panes in addition to silicate glass or float glass amorphous polyamide, transparent PMMA, polycarbonate or polyester, for the interlayer film preferably partially acetalized polyvinyl alcohols, especially polyvinyl butyral (PVB) are used. Also in the construction sector, z. B. as windows or as intermediate walls, such silicate glass / silicate glass or silicate glass / plastic composites are used, depending on the use, for. As composite armored glasses, and multiple composites, ie composites that consist of more than two supporting layers are used.

State of the art

Similar to the extrusion of other plastics, in the production of interlayer films for composite glazing, the extrusion mass must be stabilized against thermal or oxidative degradation. The stabilization is particularly necessary when using recycled material, as this material is repeatedly exposed to a number of times the temperature and shear loads of the extrusion process by a continuous recycling of eg the Kantenbeschnitts. This is reflected in one measurable degradation of the average molecular weight of the polymer and an increase in the yellowing of the film product.

To stabilize interlayer films of PVB resins, these or the extrusion composition are frequently subjected to phenolic antioxidants, such as e.g. BHT or Hostanox 010 added.

Alternatively or in addition to the phenolic antioxidants, e.g. from WO 03/33583 Al the use of phosphites or phosphonites known as a stabilizer, which are particularly well suited for the suppression of yellowing of the film. US Pat. No. 3,950,305 A1 describes the use of esters of phosphorous acid (phosphites) mixed with phenolic antioxidants as a stabilizer for PVB with the aim of increasing the thermal stability of the PVB. This is assessed on the basis of the yellowing under oxygen access and elevated temperature and the torque curve in the case of kneading tests.

From another technical field, the stabilization of polyolefins or polyacetals such as polyoxymethylene, mono-, di- or triphosphines are known as stabilizers (WO 02/06390, US 5,588,079, US 3,637,908 and WO 02/102886). Furthermore, US 5,852,138 and US 5,627,256 disclose phosphines for the stabilization of polycarbonates.

However, these polymers have lower water contents and contain no alcohol-capable hydroxyl groups or are extruded under lower thermal loads than the materials commonly used as interlayer films.

The use of the known phosphite or phosphonite-based stabilizers in interlayer films is made difficult, that they extremely increase the adhesion tendency of the film to the glass. In practice, it is hardly possible to lower the adhesion, which is increased by these compounds, with customary non-sticking agents to such an extent that a laminated glass with good penetration resistance results. This effect presumably results from the action of hydrolysis or alcoholysis products of the phosphites / phosphonites, such as phosphate ions, due to the presence of water and polyvinyl alcohol constituents of the PVB in the extrusion mass or the passage of the film through water baths from different conditioning tanks downstream of the extrusion outlet may occur. Even as hydrolysis-stable phosphite stabilizers such as Hostanox PAR 24 under these conditions cause an adhesion increase of the stabilized film on glass surfaces.

task

It is an object of the present invention to provide stabilizers for interlayer films containing recycled material for composite glazings which ensure good color stability even under extrusion conditions and have as little influence as possible on the adhesion of the polymeric material to glass.

It has surprisingly been found that phosphines are outstandingly suitable as stabilizers of polymer blends used as interlayer films for composite glazing. In addition to an effective reduction of the polymer degradation results in films with a greatly reduced yellow value and without significant increase in adhesion of the film to glass.

The subject of the present invention is therefore

Interlayer films for laminated glazing, containing a

Mixture of a polymer of the group consisting of polyvinyl alcohol, partially acetalated polyvinyl alcohol and / or ethylene / vinyl acetate Copolymer, one or more organophosphines of the general formulas I, II, III and IV

in which

^R 1, ^R 2, ^R 3, ^R 5, Re, Re, ^R 9Λ ^R IOΛRn ^{= in} each case independently aliphatic, cycloaliphatic, aliphatic-aromatic or aromatic radicals having 1 to 20

Carbon atoms, R ₄ = divalent aliphatic, cycloaliphatic, aliphatic-aromatic or aromatic radicals having 1 to 20 carbon atoms, R ₇ = trivalent aliphatic, cycloaliphatic, aliphatic-aromatic or aromatic radicals having 1 to 20 carbon atoms and Ri 2 = tetravalent aliphatic, cycloaliphatic, aliphatic aromatic or aromatic radicals having 1 to 20 carbon atoms

and optionally one or more plasticizers, wherein the film comprises 0 to 90% by weight of the mixture as virgin material and 100 to 10% by weight of a recycled material containing the same polymer as the virgin material. The films of the invention may consist entirely of recycled material. Optionally, the amount of recycled material may be 90, 80, 70, 60, 50, 40, 30 or 20% by weight.

Preferred stabilizers of the mixtures according to the invention are those having aromatic substituents (phenyl, naphthyl radicals) of the phosphorus atoms, in particular the phosphines V and VI disclosed in WO 02/06390. Ri and R2 have the meanings mentioned.

Particularly preferred phosphines in the context of the present invention are benzyldiphenylphosphine, bis-1,2-diphenylphosphinobenzene, 1,3-bis (diphenylphosphino) -2,2-dimethylpropane or 1,1,1-tris (diphenylphosphinomethyl) propane.

The films of the invention preferably contain 0.001 to 1 wt.%, Preferably 0.005 to 0.5 wt.% In particular 0.01 to 0.3 wt.% Of said organophosphines, each based on the polymer. Based on the total formulation, the proportion of organophosphines is 0.065 to 0.65% by weight, preferably 0.0325 to 0.325, in particular 0.065 to 0.195% by weight. The addition of these organophosphines is particularly useful when processing recycled materials. This is understood to mean, for example, an extruded material which has substantially the same composition with respect to the polymer and / or the plasticizer as an unprocessed mixture (with or without the addition of organophosphines). The recycled material is preferably made, like the virgin material, by extrusion of the polymer and optionally one or more plasticizers. Recycled materials fall in particular when cutting ("trimming") an interlayer film in the production of composite glazings as so-called. "Trimmings" on.

Ideally, the recycled material will have the same composition as the raw material except for the addition of organophosphines. The addition of the organophosphines therefore makes it possible to further process already extruded materials which contain no special stabilizers for a recycling process.

In a particular variant, films according to the invention contain a recycling material which has the same composition as the virgin material.

In a further variant, the recycled material contains no organophosphines, so that they can be added if necessary with the fresh material in the production of the film.

The interlayer films according to the invention preferably contain one or more plasticizers. Suitable plasticizers are all known in the art plasticizers, in particular esters of polybasic acids, esters of polyhydric alcohols or Oligoetherglykolen. Suitable examples are adipic acid esters, sebacic acid esters or phthalic acid esters, in particular di-n- hexyl adipate, dibutyl sebacate, dioctyl phthalate, esters of di-, tri-tetraglycols with linear or branched aliphatic carboxylic acids and mixtures of these esters. As a standard plasticizer, esters of aliphatic diols with long-chain aliphatic carboxylic acids, especially esters of triethylene glycol with aliphatic carboxylic acids containing 6 to 10 carbon atoms, such as 2-ethylbutyric acid or n-heptanoic acid, are frequently used. Particular preference is given to one or more plasticizers from the group consisting of di-n-hexyl adipate (DHA), dibutyl sebacate (DBS), dioctyl phthalate (DOP), esters of di-, tri- or tetraglycols with linear or branched aliphatic carboxylic acids, in particular triethylene glycol bis- 2-ethyl butyrate (3GH), triethylene glycol bis-n-heptanoate (3G7), triethylene glycol bis-2-ethylhexanoate (3G8), tetraethylene glycol bis-n-heptanoate (4G7), tetraethylene glycol bis-2-ethylhexanoate (4G8) ,

The plastic material plasticized with the plasticizers mentioned preferably contains from 25 to 45 parts by weight and more preferably from 30 to 40 parts by weight of plasticizer, based on 100 parts by weight of polymer.

As polymers it is possible to use partially acetalized polyvinyl alcohols such as polyvinyl butyrals, ethylene-vinyl acetates or casting resins.

Recycled material and virgin material must have the same polymer. This is understood to mean the nature of the polymer, but not chemical differences such as molecular weight, monomer distribution or the like. According to the invention recycling material and virgin material polyvinyl butyrals having different molecular weights, Restacetat-, Restvinylalkoholanteile or Acetalisierungsgrade. Not according to the invention would be, for example, the use of PVB as a virgin material and EVA as Recycled material.

The partially acetalized polymers used as preferred

Polyvinyl alcohols are prepared in a known manner by acetalization of hydrolyzed polyvinyl esters. As aldehydes, for example, formaldehyde, acetaldehyde, propionaldehyde or butyraldehyde can be used. The polyvinyl butyral preferably used as polymer material contains 10 to 25 wt.%, Preferably 17 to 23 wt.% And particularly preferably 19 to 21

% By weight of vinyl alcohol residues, and / or 0 to 20% by weight, preferably 0.5 to 2.5% by weight, of acetate residues.

The water content of the films according to the invention is preferably adjusted to 0.15 to 0.8% by weight, in particular 0.3 to 0.5% by weight.

Films according to the invention may additionally comprise further stabilizers, e.g. one or more compounds from the group of

Organophosphates or organophosphites, e.g. in WO 03/033583 A1, and / or the usual phenolic antioxidants

(e.g., Irganox 1070) and hindered amine stabilizers, respectively

(e.g., Uvinul 4050 from BASF). so-called HAS or HALS stabilizers. The additional stabilizers can each be used in the amounts mentioned for the organophosphines.

Another object of the present invention are composite glazings consisting of at least 2 glass sheets and at least one film according to the invention.

The production of such composite glazings under elevated or reduced pressure and elevated temperature, for example in autoclaves and / or vacuum laminators, is known to the person skilled in the art. In the Production of laminated glazings, it is also known to adjust the adhesion of the interlayer film to glass by adding metal salts to a lesser extent. The stabilized polymer blends according to the invention have almost the same adhesion level to glass as polymer blends without said organophosphines. In the production of interlayer films from the polymer blends according to the invention, therefore, the usual metal salts can be used as adhesion regulators in the known amounts, ie the mixture can contain one or more salts of alkali and / or alkaline earth metals with organic acids. Particularly suitable are potassium and / or magnesium acetate, heptanoate or octanoate. The metal salts are preferably used in each case in an amount of 0.001-0.1% by weight, based on the polymeric material.

To test the adhesion of films based on plasticized partially acetalized polyvinyl alcohol and to check the effect of non-stick agents, a so-called pummel test is used, which is described in the literature in certain variants. Pummel values given in the context of the present invention were determined using the pummeling test described in WO 03/033583 A1. Interlayer films according to the invention preferably have a pummel value of 2 to 8, in particular 3 to 6, compared to glass.

As a measure of the stabilization of the polymer mixture by the organophosphines, the change in yellowness of a film in a glass composite compared to a pair of glass-free glass with "white tile" applied can be given in Table 1. The yellowness contribution Δb of the intermediate layer is calculated according to Δb = b (composite) -b (Pair of glass) determined and is in films of the invention at a thickness of 0.76 mm not more than 1.0, preferably from 0.1 to 0.75. For the preparation of the films according to the invention can proceed as follows: First, the polymer is conveyed into the catchment area of an extruder, where it with the plasticizer, in the previously the UV absorber, the anti-adhesive agent and the organophosphine and optionally other additives such as anti-adhesive, other stabilizers , Dyes and UV absorbers have been distributed as homogeneously as possible, combined. Subsequently, the extrusion of the homogeneous melt through a slot die takes place to a film web.

Films of the invention or composite glazings produced therewith can be used in the construction and automotive sectors.

Ways to carry out the invention and comparative examples

The yellowness test Δb was tested with a spectral colorimeter "Labscan 5100" using the

Backward reflection (45 °, 2 ° observer, illuminant C) performed.

The test was carried out by measuring the yellowness change of a

Compound opposite a glass pair with "white tile" on.

The result gives information about the yellow value of the film according to: b (composite) - b (glass pair) = Δb.

For Comparative Examples 1 and 2 and Example 3 according to the invention was prepared at a mass flow rate of 160 kg / h of film of a thickness of 0.76 in the conventional manner known in the art according to EP 0 185 863 with high levels of recycled material. For this purpose, the latter was homogenized and melted together with a mixture of commercially available PVB (Mowital® LP B 68/1 SF from KSE) with the plasticizer DHA in a single-screw extruder at a throughput of 160 kg / h and extruded through a slot die. The recycled material was shredded before being fed into the extruder with cooling and consisted of residues of the product TROSIFOL MV-FR 0.43 and contained besides the said PVB resin, the plasticizer DHA in an amount of 24.5 wt .-% and as an anti-adhesive potassium acetate in an amount of 0.035 wt .-%. With this throughput and the increased proportion of recycled material, the extrusion system used produces films with a markedly increased non-marketable yellowness Δb of more than 2.0. The mixture had no stabilizer.

In Comparative Example 2, the film of 70% recycled content and 30% Frischgutanteil consisting of 75.5 wt .-% PVB and 24.5 wt .-% of the plasticizer DHA, as an anti-stick agent 0.04 wt.% Potassium acetate as an aqueous solution and of the UV absorber Tinuvin P. extruded. As much Alkanox TNPP was added over the plasticizer content of the fresh material that a content of 0.15% based on the finished film, i. E. 0.50% based on the Frischgutmischung or 2.04% based on the plasticizer. Comparative Example 2 shows due to the stabilizer used very high adhesion to glass (high Pummelwerte).

In Inventive Example 3, the film was prepared as in Comparative Example 2, except that the phosphine bis (diphenylphosphino) -2,2-dimethylpropane was used in place of the phosphine Alkanox TNPP.

The experimental data of the examples given in Table 1 show that the films according to the invention have, in addition to a low yellowness Δb, good adhesion to glass according to the Pummelt test. Films without stabilizer have too high a yellow value Δb. Although films stabilized with phosphites also have good Δb values, they are unacceptably strong Glass .

Table 1. All data in% by weight are based on the fresh product content.

Claims

claims

1. Interlayer film for composite glazing comprising a mixture of a polymer of the group polyvinyl alcohol, partially acetalized polyvinyl alcohol and / or ethylene / vinyl acetate copolymer, one or more organophosphines of the general formulas I, II, III and IV

in which each independently aliphatic, cycloaliphatic, aliphatic-aromatic or aromatic radicals having 1 to 20 carbon atoms, R ₄ = divalent aliphatic, cycloaliphatic, aliphatic-aromatic or aromatic radicals having 1 to 20 carbon atoms,

R ₇ = trivalent aliphatic, cycloaliphatic, aliphatic-aromatic or aromatic radicals having 1 to 20 carbon atoms and

R 12 = tetravalent aliphatic, cycloaliphatic, aliphatic-aromatic or aromatic radicals having 1 to 20 carbon atoms and optionally one or more plasticizers, characterized in that the film comprises 0 to 90% by weight of the mixture as virgin material and 100 to 10% by weight of a recycling material which contains the same polymer as the virgin material.

2. Interlayer film for laminated glazing according to claim 1, characterized in that the mixture contains one or more plasticizers from the group of esters of polybasic acids, esters of polyhydric alcohols or Oligoetherglykolen.

3. Interlayer film for laminated glazing according to claim 1 or 2, characterized in that the mixture contains one or more salts of alkali and / or alkaline earth metals of organic acids.

4. interlayer film for composite glazing according to one of claims 1 to 3, characterized in that the

Mixture contains one or more organophosphates, organophosphites, phenolic antioxidants and / or hindered amines as additional stabilizers.

5. interlayer film for composite glazing according to one of claims 1 to 4, characterized in that the

Recycled material is produced by extrusion of the polymer and optionally one or more plasticizers.

6. interlayer film for composite glazing according to one of claims 1 to 5, characterized in that the

Recycled material is produced from blanks of interlayer films for composite glazing.

7. Interlayer film for laminated glazing according to one of claims 1 to 6, characterized in that the film has a Pummelwert of glass from 2 to 8.

8. interlayer film for laminated glazing according to one of claims 1 to 7, characterized in that the

Recycled material contains no organophosphines.

9. Interlayer film for laminated glazing according to one of claims 1 to 8, characterized in that the film has a yellowness Δb of at most 1 at a thickness of 0.76 mm.

10. Laminated glazing, consisting of at least two glass sheets and at least one film according to one of claims 1 to 9.