CS261138B1 - Mixture for polyvinylbutyral foils production intended for cased security glasses - Google Patents

Abstract

The present invention relates to a composition for producing polyvinyl butyral film for laminated safety glass used in construction or in transport. Most used is glass-foil-glass configuration where the foil from the composition of the invention affects depending the composition of the optical properties of laminated glass. The effect is manifested by a reduction in level transmissive radiation in the UV, VIS and IR regions of the spectrum, without negative distortion of the color of objects or sources color radiation. A blend for making such (The film consists of 55 to 85 parts by weight polyvinyl butyral, 15 to 45 wt parts of plasticizer, addition of active ingredient 0.005 to 5 parts by weight of carbon black and optionally other ingredients such as UV absorbers, lantioxidants, pigments and adhesion regulators foil to glass. Used carbon black is acidic, neutral or basic pH, medium particle size 10 to 500 µm and specific surface 5 to 450 m 2 / g.

Description

The invention relates to a composition for the production of polyvinyl butyral films intended for laminated safety glasses used in construction or transport. Most commonly used is a glass-foil-glass configuration wherein the film of the composition of the invention affects the optical properties of laminated glass depending on the composition. The effect itself is manifested by the reduction of the level of transmitting radiation in the UV, VIS and IR regions of the spectrum, while there is no negative distortion of the color of objects or sources of color radiation. A composition for making such a film (consisting of 55 to 85 parts by weight of polyvinyl butyral, 15 to 45 parts by weight of plasticizer, addition of active ingredient 0.005 to 5 parts by weight of carbon black and optionally other additives such as UV absorbers, lantioxidants, pigments and glass. Used a carbon black having an acidic, neutral or alkaline pH value, mean particle size 10 to 500, "has a specific surface area from 5 to 450 m ^z / g.

The present invention relates to a composition for the production of polyvinyl butyral films intended for laminated safety glasses. These films are combined with glass layers to form a laminate with safety properties. By themselves, polyvinyl butyral films do not have a technical meaning.

The production of these films is mostly carried out by extrusion on single-screw or twin-screw extruders with melt filtration, which is further formed by a wide-slot extrusion head onto the resulting sheet. The extruder is fed with a mixture consisting of mixing the polyvinyl butyral polymer powder with a plasticizer.

depending on the desired final properties of the film, a suitable ratio of the amount of polymer to the plasticizer is selected, or various additives to modify the polyvinyl butyral film are added.

It is almost a rule that the polymer manufacturer since the necessary amount of the heat stabilizer to prevent degradation during the melt extrusion at temperatures up to 220 ^Q C, and later when the final products exposed to sunlight or other sources of heat. Virtually all film manufacturers also add UV stabilizers, so-called UV absorbers, to the blend. Since the polyvinyl butyral films are bonded to the resulting laminate with glass layers, it is possible to add substances that increase or decrease the adhesion of the film to the glass, which is very important to optimize to achieve the security character of the laminated glass. Another possibility, of course, is to adjust the color of the film by adding a certain amount of pigments.

Finished films are used exclusively for the production of laminated safety glass for building applications or for glazing of vehicles. In both basic applications, the main utility feature is the safety nature of the laminate, significantly reducing the possibility of personal injury in the event of breakage or impact to * laminated safety glass *.

The laminated safety glass is usually produced in two stages. In the first stage, the so-called pre-pressing is carried out, in which air is to be removed from the interface between the loosely stacked glass and polyvinyl butyral films. The most common configuration is glass — foil — glass, but it can also be multilayered, or other plastic, most often transparent, layers can be incorporated into the laminate. The pre-compression can be accomplished by expelling air between the layers by passing between two rubberized rollers or by vacuuming the air using a sealing rubber perimeter profile.

The second stage of production of laminated safety glass is pressing in pressure vessels - autoclaves. When pressed, the product gets the resulting appearance and properties.

Since the laminate consists of different layers, each of these layers, by its optical properties, affects the resulting optical properties of the laminate. Thus, the most common combination is glass and polyvinylbutyral foil. For example, if we cut a laminate of two glass thickness 3 m with a connection with a 0.8 mm thick polyvinyl butyral foil, we can measure the absorption of UV radiation up to the wavelengths of 310 to 315 nm. When a suitable type of UV absorber is added to the film formulation, a laminate of the same composition can absorb UV radiation up to 360 * to 395 nm. Improving the absorption properties of UV radiation is of great importance, for example in the protection of works of art, but also of a wide variety of materials and biological solutions, where exposure to ultraviolet radiation may cause undesirable changes.

The second region of the solar spectrum is the visible region, designated VIS, which lies within the wavelength range of 400 to 780 nm. Whether or not a UV absorber is used to produce the film, glass-film-glass laminates achieve light transmittance values of up to about 90 ° / o. This can be disadvantageous, for example, when applying a laminate for the glazing of museums or galleries, since they require a constant level of illumination, which is therefore mostly provided by artificial sources. In the case of strong sunlight, however, the described laminate transmits almost all radiation inside and disrupts the constantness of the internal illumination.

The high transmittance of infrared radiation, ie radiation with wavelengths above 780 nm in the IR region of the spectrum, adversely results in an increase in the room temperature. When laminates are used for glazing vehicles, solar radiation is not only a source of heat, but also a dazzling of the driver, which is also undesirable.

It is an attempt to overcome these disadvantages by coloring the laminate, either using colored glass or colored polyvinyl butyral film. Such a laminate suppresses the transmissive radiation value in the UV, VIS and IR regions of the spectrum and mitigates the negative effects of the intense sunlight described above.

However, this solution also has some drawback in that the waveform of the visible spectrum does not guarantee the possibility of color distortion of the perception of an object or light source of a particular color that is observed through such a laminate (or exhibits observed in a room glazed with this laminate).

This disadvantage is overcome by the polyvinyl butyral foil composition according to the invention. It is a mixture in which, apart from conventional ingredients, there is a UV absorber and a certain concentration of carbon black. A laminate made of a film of this composition does not cause color perception distortion, as a result of which the waveform transmission curve in the VIS region of the spectrum is uniform. Carbon black has the ability to uniformly damp all radiation at all visible wavelengths. It can be used with a suitable color scheme and the resulting effects to achieve the appearance and functional properties of the laminate.

According to the most characteristic properties, it is possible to use acidic, neutral and alkaline carbon black with a mean particle size of 10-500 μτη and a specific surface area measured by a BET of 5 to 450 m ² / g. Of course, the type and concentration of the carbon black and the UV absorber can influence the level of radiation transmission in all three regions of the spectrum. The waveform curve in the VIS region is then parallel to or almost parallel to the wavelength axis and there is no variation in the level of radiation transmittance - over 10%.

SUMMARY OF THE INVENTION The present invention provides a blend for the production of polyvinyl butyral films containing polyvinyl butyral with a c-content of hydroxy groups, determined as polyvinyl alcohol, 15 to 30% by weight, plasticizer and optionally other additives such as UV absorbers, antioxidants, pigments and adhesion controllers, characterized in that it additionally contains from the above-mentioned properties, with the individual components in the mixture:

% polyvinyl butyral 55 to 85 parts by weight; (h. d., plasticizer 15 to 45 d. h., carbon black 0.005 to 5. d. -h. and optionally further additives up to 5 d. h.

In the following examples, different types of carbon black with the indicated specification were used:

Soot Species , pH Mean particle size Specific surface DG-100 channel 3.4 to 4.5 17 to 45 μΐη 90 to 100 m ² / g -Nigros I retortové 7 to 8.5 18-28 95 to 135 m ² / g TG-10 thermal 7 120 to 190 ftm 12 to 16 m ² / g Example 1 cars that prevent glare from the driver

A co-extrusion technology produced a 0.8 mm thick polyvinylbutyral film with a blue-green strip. The recipe of the colored part of the foil was as follows in parts by weight:

hydropolyvinylbutyral (18.1 xyl groups) dihexyl adipate

UV absorber of the benztriazole type 0.3 green powder pigment 0.05 blue powder pigment 0.015

This film was to be used for the production of a front laminated safety glass and for the sun. Since the laminated glass with this film significantly distorts the transmitted light rays in the visible part of the spectrum, it has not been possible to detect the red warning light at the traffic lights through the laminated glass.

Therefore, it is not possible to use such a film to produce safety laminated glass in transport.

Example 2

For the production of 0.8 mm thick polyvinyl butyral film with a shielding strip, the recipe in weight parts was used for the colored part of the film:

Gray-blue stripe

Brown stripe

polyvinylbutyral 75 75 (18.4% hydroxyl groups) -dihexyladipá-t 25 25 beztriazole UV absorber 0.3 0.3 s-aze DG-100- 0,035 - carbon black Nigros I - 0.0175 yellow powder pigment - 0.001 violet powder pigment - 0,0025 blue powder pigment - 0,01-25

Foils with brown and gray-blue shading strips were used for the production of laminated safety glass for passenger cars. The distortion of the transmitted light radiation in the detectable area was minimal, so that the color of the traffic lights was not distorted.

The light transmittance level of the windscreens at the darkest point in the VIS spectrum was as follows:

Brown band light transmission (%) 10 15

Gray-blue stripe

The polyvinyl butyral film with the shielding stripes thus made can be used for the production of laminated safety glass of vehicles.

Example 3

A blend was used to produce a 0.8 mm thick gray polyvinyl butyral film, which was to have a near-zero UV transmittance of about 50 ° / o in the VIS region and below 40 ° / o in the IR region after being pressed between two glasses. Composition by weight:

polyvinylbutyral (18.3% hydroxyl groups) 75 dihexyl adipate 25 carbon black TG-10 0.02

Benzethiazole UV absorber 0.3 antioxidant substituted phenol 0.2

The film was used for the production of flat window laminated safety glasses. Laminated glass with this foil met the required properties because it had a permeability of:

UV range up to 400 nm up to 2% film A polyvinylbutyral 73 (20.4% hydroxyl groups) diethylene glycol di-2-ethylpelargonate 27 silicic acid adhesion regulator 1 benztriazole UV absorber 0.3 carbon black TG-10 0.04

VIS range 400 to 780 nm 47 + 3%

IR range 780 to 2100 nm up to 36%

The path of the transmission curve in the VIS region of the spectrum was slightly decreasing, almost parallel to the wavelength axis, so that the laminated glass did not distort the transmitted light radiation in the VIS region.

This laminated safety glass was used to glazing the gallery windows and the polyvinyl butyral film used allowed the protection of art objects from ultraviolet light and reduced the light intensity to half the level without distorting the color perception, which together with artificial lighting created almost constant lighting conditions regardless of solar daylight, daytime and weather. At the same time, the thermal radiation transmitted was reduced, which positively influenced the air-conditioning conditions.

He attaches

Possibilities of controlling the level of radiation transmittance in individual regions of the spectrum are presented by the different composition of the mixture used for the production of gray polyvinyl butyral foils of 0.4 mm thickness, in parts by weight:

foil B foil C

73

0.3

0.07

0.3

0.10

Laminated safety glasses were produced from foils A, B-and C, where different permeability values were measured:

laminate

UV range up to 400 nm up to 2%

VIS range 400 to 780 nm 32 + 1%

IR range 780 to 2100 nm up to 40%

The waveforms of the VIS spectrum were nearly parallel to the wavelength axis. Therefore, laminated glasses with polyvinyl butyral foils according to formulas A, B and C did not cause color changes in the VIS region of the spectrum.

Example 1 -a d 5

The following blend in parts by weight was used to produce green-blue polyvinyl butyralolamine B laminate C up to 2% to 2% to 19% 8 + 1% to 29% to 10% film 0.4 mm thick:

polyvinylbutyral (20.1% of hydroxyl groups) 72 diethylene glycol di-2-ethylpelargonate 27

UV absorber of the benztriazole type

0.3

S 11 3 Fj adhesion regulator silicic acid 1 blue powder pigment 0.003 carbon black TG-10 0.04

The film was laminated with flat glass to the laminated safety screens placed in front of the building windows. The film between the glasses allowed to reduce the intensity of incident light radiation by 59 ° / o, as its light transmittance in the VIS region of the spectrum is 41%. The course of the permeability curve in this area does not cause changes in the color of the observed objects. Such laminated glass looks natural and does not distort the view.

Claims (1)

SUBJECT VYNALEZU Mixture for the production of polyvinyl butyral films intended for laminated safety glasses containing polyvinyl butyral with a hydroxyl group content, determined as polyvinyl alcohol, of 15 to 30% by weight, a plasticizer and optionally other additives such as UV absorbers, antioxidants, pigments and adhesion regulators having an acid, neutral or basic pH of a mean particle size of 10 to 500 µm with a specific surface area 5 to 450 m ² / g, with the content of individual components in the mixture: wt. parts polyvinyl butyral softener soot other additives 55 to 85 15 to 45 0.005 to 50 0 to 5