DE2914223A1 - CLEAR TRANSPARENT PLASTIC COMPOSITION WASHER, THEIR USE AS GLAZING MATERIAL AND THE VEHICLE THEREFORE - Google Patents

Description

29U223

Clear, transparent plastic composite pane, its use as glazing material and vehicle equipped with it

The invention relates to clear, transparent plastic composite panes and their use as glazing material, in particular for vehicles. Plastic disks or composite disks are already used as glazing material. The higher scratch sensitivity compared to mineral glass becomes a disadvantage felt. Scratch-resistant coatings based on silicone compounds or by vapor deposition with silicon oxides are generated, grant a temporary protection, but even then the service life of the disc is still through the limited scratch resistance or limited by the adhesive strength of the scratch-resistant layer, especially when exposed to weathering.

It is common practice to use plastic washers against damage the sensitive surface during transport and processing through a cover made of paper or plastic films to protect. These protective coatings are fitted with the plastic disc no later than before the use of the Object removed. According to GB-PS 582 253, acrylic glass panes are used provided with a cover made of polyvinyl alcohol, which is applied in the form of an aqueous solution and dried. The cover is clear, transparent and colorless, but not water-resistant and not one of the ones for undisturbed viewing sufficient optical quality. Hence the

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Coverings are always removed again after the pane has been installed. From Japanese PS 76 14 554 protective films made of plasticizer-containing PVC are known which have an adhesive resin layer on one side and on the other hand have a silicone rubber layer with increased abrasion resistance. Such a slide, too is only suitable for a temporary protection of the surface of a plastic pane and is always used before use deducted.

From CH-PS 456 127 it is known to have plastic disks with a Mineral glass film, which by means of a soft-elastic adhesive resin layer may be applied to overlay. Although it achieves a scratch resistance equivalent to that of mineral glass, is the breaking strength of the mineral glass film is too low. The looks through is gradually impaired in use by cracks and cracks in the affixed film. Because the film does not peel off the entire disc must be replaced.

The coating of a mineral glass pane with a plastic film is known from US Pat. No. 3,681,179. The film is provided with a metal coating that reflects solar radiation. It is also known to apply clear, tough films as splinter protection in the event of the mineral glass pane breaking.
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None of these measures provide curist disks that. can be left at the place of use indefinitely without damaging them Surface must be removed and replaced. The invention is based on the object of providing a clear, transparent plastic pane for glazing purposes, in particular for glazing

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Vehicles to provide that are not affected because of the influence of surface damaging influences Review needs to be replaced. While the previously known protective measures were only used to prevent damage of plastic panes for the duration of an increased risk to their surface, namely during transport and during installation, to protect with a coating to be peeled off before use or to protect the surface of use against damage To make influences as resistant as possible, the invention takes a novel approach. The surface of use, its gradual Damage is inevitable, is designed to be replaceable so that it can be exchanged for a new surface, as soon as the view is impaired by scratches and other surface damage.

The clearly transparent plastic composite pane according to the invention has the structure described in the claims. The as interchangeable Surface-serving plastic film can be attached to only one side of the plastic disc, if surface-damaging Influences can only act on one side, as is the case with picture frames or instrument glazing. Preferably Both sides of the plastic base plate are covered with a plastic film. The replacement of the scratched film against A new film is usually associated with a significantly lower cost of materials and work than replacing the whole Disc.

As a base pane, each can be used as a glazing material on its own suitable plastic washer can be used. It can be flat or curved cylindrically. To a visually flawless To ensure transparency, the base plate must be parallel

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Surfaces, i.e. have a uniform thickness. The size of the base disk can range from a few square centimeters to several square meters are enough. The thickness depends on the strength requirements and is generally between - * 1 and 8 mm. The base disk can in turn be a composite disk be made of several plastic panes or made of plastic and mineral glass panes, with at least one outer layer made of plastic.

'® The preferred material for the plastic pane is acrylic glass. These include homopolymers of methyl methacrylate, copolymers of a predominant proportion of this ester in addition to minor amounts of other monomers which can be copolymerized therewith, and copolymers of methyl methacrylate

'Understood with a predominant amount of acrylonitrile. the A ^ .yl glass panes can be polymerized between panes of glass and then have a polymer molecular weight of one million or more. The base disk can also be produced by extrusion of thermoplastic acrylic glass and subsequent calendering; in in this case, polymers with a molecular weight between 100,000 and 300,000 are used.

The base plate can also be made from other hard plastics

with a glass transition temperature above 300 K, in particular above 350 K. Examples of these plastics are polystyrene, Polyvinyl chloride and especially polycarbonate.

In order not to have to change the plastic film too often,

^According to the invention, films are used whose scratch resistance is not less than that of the base plate. A method for numerical determination of the scratch resistance, which can be used both on the base pane and on the film, is

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stands in the scattered light measurement after exposure to a certain Wear and tear; the method is specified in detail in ASTM D 1044. With increasing destruction of the claimed Surface scratches cause an increasing proportion of the incident light to be scattered on the surface. Of the Part of the scattered light, related to the incident light, Expressed as a percentage, it is therefore a useful measure of the scratch resistance, the scratch resistance being all the higher

is, the lower the percentage is. /

In general, the proportion of scattered light on the surface of the base plate and on the film should not be greater than about 30 % after a wear load of 100 turns of the friction wheels used according to ASTM D 1044, each loaded with 5 Newtons

¹ ^ (Taber Abraser). It is preferred to use foils whose scratch resistance clearly exceeds that of the base pane and results in a value of at most about 5% in the specified test method. Films with a special scratch-resistant coating and a scattered light value are particularly preferred

about 1 %.

A high level of scratch resistance can be achieved on plastic films by numerous known methods. Silicate layers are according to GB-PS 1 365 630, FR-PS 1099 087 or DE-OS 15 21 294 through

² ^ vapor deposition with silicon oxides, according to DE-AS 1 204 048 with the additional use of aluminum oxide, according to DE-OS 20 00 with simultaneous glow discharge. According to US Pat. No. 2,771, silicate layers are produced by the hydrolysis of silicon tetrachloride. Scratch-resistant coatings based on silicon

* According to US Pat. No. 3,451,838, bonds are obtained from polysiloxanes, according to US-PS 2,408,540 made of ethyl orthosilicate, according to US-PS 3,650

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from methyl-trialkyloxysilane, according to DE-PS 2 446 279 from a combination of colloidal silicon dioxide and a partial silanol condensate, according to US Pat. No. 3,720,699 also on biaxially oriented polymethyl methacrylate. Highly cross-linked organic polymers also increase the scratch resistance, e.g. layers of amino resins according to US Pat. No. 2,481,809 and 3,420,733, DE-OS 2 317 874, in combination with urethane resins according to DE-OS 26 11 783, or coatings made of polyunsaturated Monomers, such as allyl methacrylate CDE-AS 1 181 407, DE-PS 1 014 741, US-PS 2,423,583) Ethylene glycol dimethacrylate (US-PS 2,413,973, DE-PS 1 014 741), ethylene-bis-allyl carbonate CFR-PS 1 460 725) or tri- and tetraacrylates or methacrylates of polyols with UV curing CDE-OS 24 55 715). The thickness of the scratch-resistant Coatings is, for example, between 1 and 20 µm. Films with suitable coatings can even when used on Motor vehicles have a service life of one or more years before they are so damaged that they need to be replaced.

The glued-on film should allow the view through the plastic composite pane influence as little as possible. For this reason, calendered, optically undisturbed films are preferably used. Around To reliably prevent damage to the plastic pane, the plastic film should have a thickness that is the usual depth of Significantly exceeds scratches. Films from 20 to 150 µm, in particular A thickness of 30 to 80 μm is particularly suitable.

The material of the film is chosen so that no life is limited by the always existing scratch sensitivity disturbing weathering, yellowing or other aging occurs. ^ O Films that are soluble in water or that swell strongly in water, such as polyvinyl alcohol or cellulose films, are particularly unsuitable for outdoor use. If a usage period of one year or

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is intended to be exposed to the elements for a longer period of time, such as vehicle glazing, are highly weather-resistant materials particularly suitable, preferably polymethyl methacrylate. Biaxially oriented films are generally preferred. The slide or At least one layer thereof can contain known UV absorbers, light stabilizers and, if desired, a dye for tinting contain. Colorless films are preferred.

Under certain circumstances it is sufficient if a weather-resistant one is only to a limited extent Foil, for example made of polycarbonate, with a thin layer of polymethyl methacrylate or another high weatherproof plastic is coated. With such composite films, properties that are otherwise not in a film material come together, making it usable at the same time, e.g. the high toughness of a base film made of polyester or polycarbonate and the weather resistance of the top layer.

The one used to connect the film to the plastic disc Pressure-sensitive adhesive should adhere more firmly to the film than to the plastic pane. Otherwise it has to be pulled off Any adhesive remaining on the film must be carefully removed before applying a replacement film. Are well suited Adhesive resin layers that adhere to the plastic surface with a pull-off force of 10 to 200 N / cm. The desired good adhesion between the film and the pressure-sensitive adhesive is generally achieved when the pressure-sensitive adhesive layer is applied to the film in a manner known per se is applied. It is advantageous to use pressure-sensitive adhesives that do not contain any components that age under the effects of light and weather do not contain any plasticizers that penetrate the plastic disc.

Permanently elastic pressure-sensitive adhesives based on them are particularly advantageous of acrylic ester polymers which are known per se. You can go out

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aqueous dispersions or solutions in organic solvents in a layer thickness of e.g. 2 to 50 µm on the Foil can be applied. Known type of pressure-sensitive adhesives with glass transition temperatures below 250 K are suitable. The pressure-sensitive adhesive layer Like the film itself, it must be optically perfect, completely clear and homogeneous so as not to impair the view through and preferably colorless and must not become brittle, yellow or visibly age during the service life.

^ The preferably used adhesives are polymers or copolymers which are composed predominantly of alkyl esters of acrylic acid, mainly those having 4 to 12 carbon atoms in the alkyl radical. As a rule, these esters form at least 80% by weight of the polymer. The lower alkyl esters of acrylic acid with 1 to 4 carbon atoms in the alkyl radical and the alkyl esters of methacrylic acid, styrene, vinyl chloride, vinylidene chloride or vinyl acetate can be involved in the formation of the copolymers in smaller amounts. Preferably, in minor amounts, generally not more than 20% by weight, comonomers with polar groups are involved in the structure of the copolymers; these include acrylic or methacrylic acid, itaconic acid, maleic anhydride, hydroxyalkyl esters and aminoalkyl esters of acrylic or methacrylic acid, amides of these acids, in particular N-alkyl-substituted acrylic or methacrylamides, such as N-octylacrylamide

or N-tert-butyl acrylamide or methacrylamide. Small quantities, preferably not more than 1% by weight of crosslinking monomers with two or more polymerizable double bonds are of Advantage. Mixtures of different polymers are often used as tackifier resins, for example mixtures of those described

^J Acrylic ester polymers and copolymers with polyvinyl alkyl ethers or oxyethylated polyvinyl alcohol. Typical pressure-sensitive adhesive resins are described, for example, in US Pat. Nos. 3,558,574 and 3,617,362.

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Before it is applied to the pane, the pressure-sensitive adhesive layer of the film can be covered in a known manner by a protective layer of paper or plastic film, which is removed before attachment. IM to facilitate the precisely fitting application of the film, it is advisable to use a protective cover made of several parts, so that the film on the still covered Parts can be held precisely> while the already exposed Adhesive layer is applied to the plastic disc. ■ A strip consisting of three parallel strips is particularly useful Protective cover, with the middle strip overlapping the two outer strips and peeled off before the film is applied will. The film can then be attached to the remaining side strips be held precisely and glued to the exposed median strip first.

In an adhesive system known from US Pat. No. 3,681,179 Permanently elastic adhesive layer through a water-soluble dry Protected overcoat. The plastic pane to be glued is moistened, the film is applied and the water layer in between, in which the protective coating dissolves, from the middle pushed outwards. In this way, the protective film can be applied particularly easily without bubbles or wrinkles.

A film particularly suitable for the purposes of the invention can consist of the following layers:

1. Scratch-resistant silicone plastic layer of about 10 µm;

2. Weather-resistant layer made of polymethyl methacrylate, 0.2 to 30 m;

3. Polycarbonate base film, 30 to 80 µm;

4. Pressure sensitive adhesive based on polyethylhexyl acrylate 2 to 30 µm;

5. water-soluble protective layer made of a vinyl ether-maleic acid copolymer.

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The clear, transparent plastic panes according to the invention are used according to the invention as glazing material. In contrast to the well-known manufacture of glazing made of plastic discs with a temporarily applied 'protective film, which after the insertion of the disc before the actual Use as glazing material is removed again, according to the invention, the film-coated plastic composite pane ver? as the actual glazing material? turns. The window glazing and furniture glazing are important Applications for the plastic composite panes of the invention. A preferred object of the invention is the equipment of Vehicles, in particular motor vehicles, with glazing made from the plastic composite panes according to the invention. Not only In the case of airplanes, but increasingly also in the case of motor vehicles, weight saving is gaining in importance. The Verv, The use of plastic panes in motor vehicles has hitherto been fairly limited because of their inevitable sensitivity to scratching. The invention allows the use of plastic discs in vehicles without regular replacement of the installed window being necessary. The windows according to the invention on vehicles where they are in proportion are exposed to a small amount of surface-damaging influences. This applies primarily to those roughly in the direction of travel lying discs.

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Claims (9)

29H223 Clear, transparent plastic composite pane, its use as a glazing material and vehicle equipped with it Claims
ι I.JClear transparent plastic composite pane, consisting of A) one at least 1 mm thick, clearly transparent Base plate made of plastic with parallel surfaces, B) at least one clear, transparent plastic film with a scratch resistance not less than that the base disk is C) at least one clear, transparent, arranged between the base plate and the plastic film Adhesive resin layer that is inextricably attached to the film and can be removed from the base plate. 2. Plastic composite pane according to claim 1, characterized draws that the plastic film CB) on its outer Side has a scratch-resistant coating. 3. Plastic composite disc according to claims 1 and 2, characterized characterized in that the plastic film is colorless. 4. Plastic composite pane according to Claims 1 to 3, characterized in that the plastic film is calendered and optically . is undisturbed. S. Plastic composite pane according to "Claims 1 to 4, characterized in that characterized in that the adhesive resin layer is free of low molecular weight plasticizers and consists essentially of acrylic esters is constructed. 030044/0036 ORIGINAL INSPECTED 6. Use of a plastic composite pane according to claims 1 to 5 as a glazing material. 7. Use of a plastic composite disk according to the claims 1 to 5, as glazing material for vehicles, in particular motor vehicles. 8. Vehicle, in particular motor vehicle, equipped with plastic composite panes according to Claims 1 to 5. 9. Vehicle according to claim 8, characterized in that the plastic composite disks are approximately parallel to the direction of travel are appropriate. 030044/0036