WO2000063009A1

WO2000063009A1 - Multi-layered glass structure

Info

Publication number: WO2000063009A1
Application number: PCT/HU2000/000033
Authority: WO
Inventors: Miklós ZRÍNYI; János GÁCS; József FEHÉR; Genovéva FILIPCSEI; Csabáné SIMON; András SZILÁGYI
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-04-16
Filing date: 2000-04-14
Publication date: 2000-10-26
Anticipated expiration: 2001-10-16
Also published as: HUP9901222A2; AU4135300A; HU9901222D0

Abstract

The invention relates to a multi-layered glass structure for the changing of its light permeability which contains a closed space between two or more transparent pieces of glass or plastic. The characteristic feature is that the closed space contains a mixture of 0.1-100 % polymer, solvent or solvent mixture in a 0-99 % gel structure and 0-50 % dissolved material.

Description

Multi-layered glass structure

The invention relates to a multi-layered glass structure for the changing of its light permeability which contains a closed space between two or more transparent pieces of glass or plastic

Duπng the last ten years of the century significant changes have taken place in mateπals science The ever-increasing user requirements have resulted in a change of paradigm Ability to adapt to the environment has become the key word of the new way of thinking The endeavour to make mateπals passive and unchanging has been replaced by an approach that examines the dynamic coexistence of the material and its environment A new concept has appeared, which was called intelligent material The main aim is the design and production of artificial mateπals which through their active interaction with the environment they change their characteπstics favourably for the user

We call those multi-functional mateπals intelligent mateπals that directly sense one or more features of the physical or chemical state of their immediate environment, process the information deπvmg from these, then give a fast and clear answer to this by significantly changing their state

Most frequently the sensing function can be realised as a result of the balance between the mateπal in question and the environment This balance may be chemical, mechanical or thermodynamic The change in the environmental parameters necessarily bπngs about a change in the balance state And in the newly formed balance state the mateπal has different characteπstics A further important aspect is the connection between the effect bringing about the change, henceforward stimulus and the reaction happening because of this henceforward answer Non-linear stimulus-answer connections are charactenstic of intelligent mateπals in which for a small change in the environmental effect a very large change in characteπstics takes place, in other words the degree of answer is not in proportion with the size of the stimulus, but very much greater A further criterion is reversibility, that is after the effect causing the change has ceased the original state has to return A fast reaction time is an application technology requirement

The subject of the invention is the multi-layered glass so called intelligent glass This is a sandwich structure which, between two glass sheets or transparent plastic layers, contains a thin polymer system Its external appearance form is deceptively similar to sheet glass that is in commercial distπbution, in other words the polymer system does not degrade the optical characteπstics The adapting ability of the intelligent glass is provided by the polymer layer Its optical characteπstics - for example transparency - are greatly influenced by environmental effects like for example temperature change or the presence of an electric field The change in the environment may bring about changes in the intelligent glass that cause the oπginally transparent glass to become opal glass, cloudy, only allowing light through to a much smaller degree This transparent glass - opal glass transition can take place in both directions

In one of the types of intelligent glass developed by us a change in the temperature of the environment bπngs about the glass - opal glass transition With the appropπate composition it can be achieved that sun radiation causes this transition A window made from intelligent glass provides a comfortable solution for protection against strong, direct sun radiation

In another type of intelligent glass the glass - opal glass transition can be brought about by ourselves by switching on an electπc circuit With this, for example, the transparency or opacity of internal windows can be controlled with the switching on or off of a switch

Intelligent glass is suitable for making a new type of display It is possible to wπte letters of the required size in the polymer, or a drawing These may be called up and made to disappear with a thermal of electπcal effect

Intelligent glass changes its optical characteπstics due to a thermal or electπcal effect suddenly - not gradually - in a way that may be reversed The layer between the layers of glass is responsible for this change This layer may be of a cross-linked or non-cross-linked homopolymer, co-polymer, polymer solution, polymer gel or a mixture containing polymer, solvent (solvents) and other small molecule components which have lower or upper (or both) plait point temperatures, or other transformation temperatures that affect optical characteπstics (like, for example, the Kraft point or the clouding point) How the intelligent glass changes its optical characteristics depends on the layer's phase characteristics. In the case of a lower plait point an increase in the temperature brings about the glass - opal glass transition. The opposite of this takes place in the case of an upper plait point.

The value of the temperature of electric parameters bringing about the glass - opal glass transition may be changed between a wide range by changing the chemical structure of the layer and the additive materials put in the layer.

In specialist literature and general knowledge types of glass are known that change their optical characteristics due to thermal and/or electric effects. One type of such is the so- called phototropic glass. When visible light is radiated on this its light transmission ability gradually decreases, which process is reversible. In phototropic glass the linking of two significantly different phenomena results in the non-sudden change of the optical characteristics.

The operation of the other known type of glass is ensured by the structural transformation of liquid crystals.

The multi-layered glass structure that forms the subject of our invention is different from the above-mentioned types of glass both from the points of view of its chemical structure and operating method. At the same time its much cheaper material and production cost and the sudden changing of its optical characteristics creates the conditions for its wider area of application. To the best of our knowledge the application of gels to produce glass with regulatable light permeability is not known in the specialist literature.

Without restricting the protection request we illustrate the procedure for the production of intelligent glass with the following examples:

Example 1

Glass - opal glass transition brought about by temperature increase Starting mateπals polyvinyl alcohol (PVA),

Glutaraldehyde (GDA), 25 v% water solution,

HC1 37 m% water solution,

Lutidine,

To a 100 cm³ 8 m% PVA solution we add 40 cm³ 20 v% lutidine- water mixture After mixing the two solutions we add 0 4 cm³ 1 M GDA solution For the gelation we set the pH of the solution to a value of 2 with the water HC1 solution The solution is poured in a 0 5 - 1 mm gap between the pre-prepared two well sealing, flat glass sheets After the gelation has completely taken place (approx 5-8 hours) the intelligent glass may be used

Example 2

Glass - opal glass transition brought about by temperature reduction

Starting mateπals polyvinyl alcohol (PVA)

Glutaraldehyde (GDA), 25 v% water solution, Iso-butyπc acid

To a 100 cm³ 8 m% PVA solution we add 40 cm³ 15 v% lso-butyπc acid - water mixture After mixing the two solutions we add 0 4 cm³ 1 M GDA solution The solution is poured in a 0 5 - 1 mm gap between the pre-prepared two well sealing, flat glass sheets After the gelation has completely taken place (approx 1-2 hours) the intelligent glass may be used

Example 3

Glass - opal glass transition brought about by temperature reduction

Starting mateπals polyvinyl alcohol (PVA)

Glutaraldehyde (GDA), 25 v% water solution, HC1 37 m% water solution Polyethylene-polypropylene block co-polymer (PEPP) To a 100 cm³ 8 m% PVA solution we add 40 cm³ 8 m% water PEPP solution After mixing the two solutions we add 0 4 cm³ 1 M GDA solution For the gelation we set the pH of the solution to a value of 2 with the water HC1 solution The solution is poured in a 0 5 - 1 mm gap between the pre-prepared two well sealing, flat glass sheets After the gelation has completely taken place (approx 5-8 hours) the intelligent glass may be used

Example 4

Glass - opal glass transition brought about by temperature increase

Starting materials n-iso propyl-acryl-amide (NTPA),

N,N'-methylene-bιsacrylamιde (MBA),

Ammonium-persulphate (APS),

N,N,N',N' -tetramethylene-diamine (TEMED)

In a 100 cm³ water solution we dissolve 15 g NIPA and 0 133 g MBA To this we add 80 mg APS and mix 200 μl TEMED solution The solution is poured in a 0 5 - 1 mm gap between the pre-prepared two well sealing, flat glass sheets After the gelation has completely taken place (approx 5-8 hours) the intelligent glass may be used

Example 5

Glass - opal glass transition brought about by temperature decrease

Starting mateπals acryl-amide (AA),

N,N'-methylene-bisacrylamide (MBA),

Ammonium-persulphate (APS),

N,N,N',N' -tetramethylene-diamine (TEMED)

In a 100 cm³ 20 v% acetone- water mixture we dissolve 15 g AA and 0J33 g MBA To this we add 80 mg APS and mix 200 μl TEMED solution The solution is poured in a 0 5 - 1 mm gap between the pre-prepared two well sealing, flat glass sheets After the gelation has completely taken place (approx 5-8 hours) the intelligent glass may be used

Claims

1. A multi-layered glass structure for the changing of its light permeability, which contains a closed space between two or more transparent pieces of glass or plastic characterised by that the closed space contains a mixture of OJ-100% polymer, solvent or solvent mixture in a 0-99% gel structure and 0-50% dissolved material.

2. Multi-layered glass according to claim 1 characterised by that its macromolecular constituents are of the following: synthetic and natural polymers crosslinkable with physical and/or chemical links, or a mixture of these

3. Multi-layered glass according to claims 1 or 2 characterised by that the liquid phase constituent, that is the expanding agent is of the following: water, water solutions, organic solvents and mixtures of these which in themselves or through interaction with a polymer have lower, upper or lower and upper plait points, or a clouding temperature.

4. Multi-layered glass according to claims 1-3 characterised by that the component dissolved in the polymer gel is of the following: electrolyte and/or associating synthetic and natural surface-active materials, or their mixtures.

5. Multi-layered glass according to claims 1-4 characterised by that the electrolyte component dissolved in the polymer gel is of the following: strong and weak electrolytes disassociating in a water solution.

6. Multi-layered glass according to claims 1-5 characterised by that its light permeability may be changed to a great degree thermally and/or electrically in the temperature range of 50-120 °C.

7. The application of multi-layered glass according to claims 1-6 as a window, display or advertising carrier of any desired form or size.

8. Procedure for producing multi-layered glass characterised by that the space divided by the transparent materials is filled with the mixture of polymer, solvent and dissolved material according to claim 1, or with a gel of these prepared in advance, then sealed with an airtight seal.