JPS5839178B2 - Method for adjusting the adhesion of a partially acetalized polyvinyl alcohol sheet containing a plasticizer to inorganic glass - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Joining two or more glass plates and glass plates;
Composite plates made of adhesive sheets, for example made of partially acetalized polyvinyl alcohol, are known.

It is also known to use plasticized polyvinyl butyral (P, VB) as an adhesive sheet in the production of glass/plastic composite plates.

Suitable plastic plates are in particular those made of amorphous polyamide (see German Patent No. 1,596,781).

In order to produce a composite safety board, in which a particularly compact composite board is desired for safety reasons, a moisture content of 0.2
~ 0.9 wt., free OH groups (calculated as vinyl alcohol) about 10 to about 25 wt., advantageously about 16 to about 23
Plasticized, partially butyralized polyvinyl alcohol having a weight ratio and plasticizer content of from about 18 to about 65 parts by weight, preferably from 33 to 44 parts by weight, based on 100 parts by weight of PVB.

Sheets have proven particularly advantageous.

Joining two glass panes and glass panes, preferably PVB
Composite safety panels made of an adhesive sheet made of are used in particular as windshields for motor vehicles; in some cases, a glass plate can advantageously be replaced by a plastic plate made of amorphous polyamide.

Such silicate glass/silicate glass or silicate glass/plastic composite panels are also used in building components, for example as window panes or partition walls; depending on the application, e.g. composite exterior glass is also used. It is also used as a multi-composite board, ie a composite board consisting of two or more supporting layers.

Partially acetalized polyvinyl alcohol is
It is produced by saponifying polyvinyl acetate and subsequently acetalizing it with aldehydes such as formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, etc.

The alcohols usually contain about 0.5 to 1.2 weight φ, calculated as vinyl acetate groups, with about 0.5 to 5 weight φ of acetyl groups.

Other polyvinyl esters of fatty acids having up to 9 carbon atoms can also be saponified and subsequently acetalized.

Partially acetalized polyvinyl alcohol resins, hereinafter referred to as PVA-resins, together with plasticizers, optionally stabilizers and optionally other additives, are prepared in a device known for sheet production, For example, it is processed into a sheet using an extruder.

In order to adjust the desired humidity content for the composite safety glass, the sheet is optionally placed in an air-conditioned room (Kl im
Post-process with a kammer ).

In practice, in most cases, composite safety plates are first prepared by forming the individual supporting layers as well as the adhesive film at elevated temperatures into a precomposite plate, with the laminate preferably being evacuated.

The preliminary composite board is then formed into a finished composite board under the influence of temperature and pressure, for example in an autoclave, for example at about 10-15 kp/d and at a temperature of about 130-150 DEG C.

The thickness of each layer of the composite safety plate can be changed as desired depending on the intended use.

The following layer thicknesses have been proven to be advantageous for automobile windshields: PVB = between 1 and 3;
Approximately 0.630 to 0.80, preferably 0.76 door E glass 2
~4, preferably 3rIL~ Plasticizers include esters of polybasic alcohols, such as dibutyl sepersade, di(β-butoxyethyl)adipate, dioctyl phthalate, triethylene glycol-bis-diethyl acetate. , triethylene glycol-di(2-ethylbutyrate), and the like are suitable.

In the case of composite safety panels, used as automobile windshields, the adhesion to the glass sheet should be optimal.

That is, when glass is broken by an impact action, at a very high degree of adhesion, the breakage occurs at the center of the impact without breaking much of the glass.

With very poor adhesion, impact tools, such as hammers or falling balls, are actually supported elastically from the sheet, but the crushing action is very severe.

In the case of a rear-end collision with glass breaking due to a head impact, the sheet should on the one hand gradually dissipate the kinetic energy by stretching, but on the other hand the broken glass should be stretched to avoid dangerous cuts and injuries. It should also adhere well to the sheet.

For this reason, the adhesion force should be adjusted to be optimal.

In contrast, when used as architectural glass, such as window glass, a high degree of adhesion to the sheet of glass is desired.

This is because, in this case, cuts and injuries are primarily to be ignored.

The problem of controlled adhesion of a glass plate to a partially acetalized PVA sheet is important in the windshield area.

Plasticized, partially butyralized PVA sheets are generally
It is known to have a very high degree of adhesion to glass, which is undesirable for windshield applications.

Pummel value (P
ummelwerte) 2 to 4 are valuable O From the literature, a series of publications are known on the problem of manufacturing windshields for motor vehicles, and in which a reduction in adhesion is achieved by the addition of salts of organic acids. is proposed.

However, the known method has the disadvantage that a series of salts causes discoloration of the sheet.

Furthermore, with additives of this type there is a risk of peeling of the sheet from the glass surface.

This is because salts are sensitive to moisture and thereby have an adverse effect on the moisture content of the adhesive sheet.

In addition to this, the reagents only have a reducing effect on adhesion.

It is also known that certain organosilicon compounds can be used to influence the adhesion of plastic resins to inorganic substrates.

Compounds of this type are silanes.

Silanes include substitution products of hydrogen silicide.

Written by Noll 1.
"Dell Silicone" (Chemieund Techn.
According to ik der Silkone, 2nd edition, p. 10 (1968), silane has only silicon functionality.
, one organofunctional only“and one silicon-and organofunctional”
It is classified into the following groups.

In the case of silicon-functional silanes, functional groups, such as halogen or alkoxy groups, are bonded directly to the Si atoms.

Groups of this type can be easily hydrolyzed.

The organic functional groups are bonded to silicon via one or more C atoms and the iron groups are reactive, for example via amino- or epoxy groups or via double bonds.

The terminology used by Knoll will also be used below.

It is also known from US Pat. No. 3,341,399 to bond glass plates to each other using silane-treated PVB sheets.

Silicon-functional as well as silicon- and organic-functional silanes have been proposed, namely aminoalkyltriethoxysilanes, alkyltriethoxysilanes, aryltriethoxysilanes and vinyltriethoxysilanes.

The silane is added to the PVB in an amount of 1 to 10 weight φ.

The underlying problem of the invention was to increase the shear strength as well as the steam stability of composite plates.

Partially acetalized PVA containing plasticizer
No effort is made in the US patent specifications to adjust the adhesion of the sheet to the inorganic glass to the Pummel value desired for the respective application.

Nothing could be inferred from the specification of the US patent to solve the problem underlying the invention.

The present invention is based on an inorganic glass of a partially acetalized polyvinyl alcohol resin sheet having 10-25% by weight of free OH groups (calculated as vinyl alcohol) containing 18-65% by weight of plasticizer. Regarding the method of adjusting the adhesion to the Pummel value desired for the particular application, this is done by applying a pre-heat treatment to the partially acetalized polyvinyl alcohol resin before or during its processing into sheets by methods known per se. 0,005~0.
7 weight φ of (a) a silicon-functional silane or a mixture of various silicon-functional silanes that reduce adhesion; or (b
) adding a silicon/organofunctional silane or a mixture of silicon/organofunctional silanes to increase adhesion; or (C) a mixture of at least one silicon-functional silane and at least one silicon/organofunctional silane. It is characterized by

The present invention also provides for the production of a modified partially acetalized polyvinyl alcohol sheet of this type,
Regarding composite safety plates.

According to the invention, silicon-functional silanes are preferably used with the general formula: Number of atoms: 1~
18 alkyl group, R' is halogen, preferably (this is C7, or the same or different, optionally interrupted by a heteroatom, e.g. -0- or -8-,
represents a saturated alkoxy group having 1 to 8 carbon atoms, and n is O to 3].

Examples include: propyltriethoxysilane, propyltrimethoxysilane, inpropyldimethoxyethoxysilane, n-butyl or isobutyltriethoxy or trimethoxysilane, etc.

Silicon/organofunctional silanes that increase adhesion are preferably those according to the invention (more preferably those of the general formula:
"= optionally a heteroatom, e.g. -0- or -S
--containing C1-18-alkyl group), R'
represents an alkyl group having 1 to 18 carbon atoms, and A is 2 having 1 to 10 carbon atoms, which may optionally be branched.
and Z represents a functional group, such as -C
H,,, CH2 or -C double- or NR// R///
(In that case, R" is also H or 2 carbon atoms in the alkyl group.
represents an aminoalkyl group having ~8 atoms, and R'' also represents H or R'', and n is 1 to 3 and p is also 1 or O in the case of Z=-CH=CH2; Use something like

Silicon/organofunctional silanes of this type are therefore difunctional.

Besides the at least one hydrolyzable group which reacts with the glass surface in the composite plate, there is additionally at least one reactive group capable of reacting with the partially acetalized PVA sheet. Should.

Examples include: vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyl-tris(β-methoxyethoxy)silane, r-methacryloxypropyltrimethoxysilane, γ-glycidyloxyprobyl. trimethoxysilane,
γ-Aminopropyltriethoxysilane, etc.

The silicon-functional silane used according to the invention is preferably isobutyltrimethoxysilane, and the silicon/organo-functional silane is preferably gamma-glycidyloxypropyltrimethoxysilane.

In the process of the invention, the starting point is a partially acetalized polyvinyl alcohol resin which still contains OH groups.

Preference is given to using vinyl alcohol groups containing 10 to 25 weight φ, preferably 17 to 23 weight φ.

Partially butyralized polyvinyl alcohols are preferably used.

In the case of composite safety panels used in building components, for example as window panes or fusing walls, the adhesion of the inorganic glass to the sheet is of decisive importance.

In the event of inadvertent breakage, the glass should adhere firmly to the sheet, thereby avoiding severe cutting injuries.

Composite boards in which high Pummel values are desired can therefore advantageously be made with the highest possible Pummel adhesion by adding silicon/organofunctional silanes or mixtures thereof to the corresponding partially acetalized PVA resin. adjusted to the value,
Partially acetalized polyvinyl alcohol sheet (hereinafter referred to as partially acetalized PVC sheet)
Manufactured using.

The method according to the invention has the advantage that the adhesion of the partially acetalized PVA sheet to the mineral glass can be adjusted to an optimal Pummel value adapted to the respective intended use.

Thus, for example, preliminary tests (thus, glass/partially acetalized PVA-sheet/glass composites are suitable as composite safety panels in building components due to their high Pummel values, but not as automotive windshields). Partially acetalized PVA confirmed to produce boards
The resin charge can be made 'windshield quality' by adding adhesion-reducing silicon-functional silanes in amounts confirmed in preliminary tests.

In the opposite case, a partially acetalized PVA resin of "1 windshield quality" can be changed into one having "1 construction component quality" by adding silicon/organofunctional silane in an amount confirmed in preliminary tests. Can be done.

Therefore, there is no concern at all about the quality of the partially acetalized PVA resin to be processed.

Dual storage, which was often common in the past, is not desired.

The sheet waste from the composite board industry is usually recycled by the sheet manufacturer and processed into new sheets in an extruder together with fresh material after a post-processing step.

However, the quality of the new sheets is thereby influenced in a non-adjustable manner.

In most cases, the waste is not traditionally supplied strictly sorted according to windshield or architectural glass sheet quality.

An undefinable waste mixture therefore results in sheets with undefinable adhesion to glass.

However, according to the invention it is also possible to process waste materials which have not been classified according to the preferred combination of silane types used according to the invention into sheets with a defined adhesive strength.

That is, experiments using various partially acetalized PVA sheet materials of unknown and different quality with respect to the Pummel value showed that the sheet materials were free from silicon/organo-functional silanes that increase adhesion and silicon-functional silanes that decrease adhesion. It has been found that the desired objective can be achieved if a mixture of:

The amount of silane to be added or the type of silane to be added depends on the intended use of the composite plate and the partially acetalized PV to be modified.
A: Depends on the characteristics of the resin.

The loading capacity depends on the Pummel value of the unmodified partially acetalized PVA sheet.

The adhesion of glass plates to partially acetalized polyhinyl alcohol sheets containing plasticizers is determined by the so-called "Pummel test".

Composite glass plate approximately 150x300mm in size (Gala 3
Partially acetalized PvA sheet/glass) approx. 2-8
Cool at -188C±0.5C for hours.

The iron plate is then placed on a metal block inclined at approximately 45° and hammered with a flat-headed hammer until the glass is crushed.

The test plane is approximately 1100 x 1500i dog.

The adhesion state is evaluated on a scale of 0 to 10.

The amount represents:

Free sheet surface (related) Pummel value 100 0 95 1 90 2 85 3 60 4 40 5 20 6 10 7 8 9 0 10 Visual evaluation is based on the Pummel value at each stage in addition to the Pummel value at the stage described. This can be made easier by adding a diagram.

It has been found that this non-quantitative one-Pummel test is completely sufficient for implementation and that the visual evaluation (by means of which the desired adhesion force adjustment can be carried out with sufficient precision).

If the Pummel value of the resin to be modified cannot be predetermined by addition of sheet waste, it is advantageous to add the minimum amount of silicon/organofunctional silane that yields the highest Pummel value: at the same time. Add the amount of silicon-functional silane required according to the calibration diagram for adjustment of the desired Pummel value.

However, it is also possible to produce a composite plate sample body and check the Pummel value before processing the new charge of partially acetalized PVA resin into sheets.

Starting from this defined Pummel value, a silane suitable for the desired purpose can then be added in an amount previously confirmed experimentally in a series of experiments.

In practice, the amount of silane will vary between approximately 0.005 and 0.7 parts by weight per 100 parts by weight of sheet material.

The silane to be added according to the invention can be added before the partially acetalized polyvinyl alcohol resin is processed into a sheet.

For example, partially acetalized PVA resin particles, which are kept mobile and still do not contain plasticizer, are sprayed with silane or a silane solution or dispersion.

Partially acetalized P is preferably used as a solvent or dispersant.
Use those that are inert or behave sufficiently inert towards VA resins.

As a solvent it is possible to use, for example, water or a water/alcohol mixture.

If the solvent or dispersant is removed in a subsequent drying step, a free-flowing PVA resin is present which is subsequently processed by the sheet manufacturer in a manner known per se after addition of the desired amount of plasticizer. It is advantageously processed into sheets by extrusion.

However, preference is given to combining the silane as well as the plasticizer with the partially acetalized polyvinyl alcohol resin in the melt, for example during processing into the sheet in an extruder.

In the case of the process, it is advantageous for the silane to first be dissolved or dispersed in the plasticizer to be added, before the silane/plasticizer mixture is added to the partially acetalized PVA resin to be extruded.

It is advantageous to choose a plasticizer that dissolves the silane.

The plasticizers first mentioned in the prior art are suitable for the process according to the invention, with preference given to triethylene glycol-di(2-ethylbutyrate).

The amount of plasticizer to be added corresponds to the amount customary in the production of partially acetalized PVA sheets.

The partially acetalized PVA sheets modified according to the invention are preferably used as adhesive sheets.

The use is carried out in a manner customary in the composite safety plate industry.

Advantageously, (a) a plasticizer content of from about 18 to about 65 parts by weight per 100 parts by weight of PVB, preferably from 33 to 44 parts by weight, (b) a water content of from 0.2 to 0.9 parts by weight, and (c) )OH
Calculated as base weight vinyl alcohol, 10-25
Heavy weight, heavy type has 16 to 23 weight φ, silane 0
．． A partially acetalized polyvinyl alcohol sheet modified with a weight range of 0.005 to 0.7 is used as the adhesive sheet.

A composite safety plate using a partially acetalized PVA sheet modified according to the present invention comprises two or more glass plates and a partially acetalized PVA sheet modified with a silane according to the present invention, a plasticizer disposed between each two glass plates. Contains PVA sheet.

In some cases, the glass layer in glass/glass composite panels is made of, for example, amorphous polyamide (for example West German Patent No. 15).
96781) can be substituted.

In this case, it is advantageous to arrange two adhesive sheets between the two layers (this being the glass layer), the adjoining adhesive sheet having been modified with silane according to the invention and made of plastic. The adhesive sheet in contact with the layer is not modified.

In the case of composite plates consisting of two or more supporting layers, for example glass/plastic/glass composite plates, this can be rolled up in the same way.

In glass/plastic/plastic/glass composite plates, only unmodified partially acetalized PVA sheets are preferably used as adhesive sheets between the plastic/plastic layers.

Breaking strength (Durchschlagfe) described in Examples
Stigkeit) is DIN (German Industrial Standard) 5
2306 (February 1, 1973) is 08AS.

Z26.1, Test Numm
er) 26 (1966) using a falling ball**.

The changes in the Pummel value resulting from the addition of silane as shown in the table below are:
It was carried out using a composite safety board manufactured as follows; the addition of silane to PVB resin (OH group content, 18.5 parts by weight calculated as vinyl alcohol) was carried out in an extruder with PVB/sheet/ During manufacturing (this was done).

The PVB resin of Table 1 used came from a different charge than the resin of Table 2.

In the example, a composite plate having a 0.76 mm thick PVB sheet arranged between two glass plates with a thickness of 3 mm was tested.

Manufacture of composite board is at humidity 130-135℃, compressive force 10-1
It was carried out at 5 kp/die and compression time of 10 to 30 minutes.

As a plasticizer, triethylene glycol-di(2-
ethyl butyrate) per 100 parts by weight of PVB resin.
Parts by weight were used.

Table 2 As shown in the following example: It will be done.

Adhesion was significantly increased and Examples 9 and 10 relate to the use of sheet waste with fresh, partially butyralized polyvinyl alcohol resin.

The Pummel value is not defined by the increase in composition of the sheet material: Example 9 Silane 1 = 0.1 weight ratio + Silane 2 = 0.45 weight ratio Pummel - 5 Example 10 Silane 1 = 0.1 weight ratio + Silane 2 = 0 ．．
6 weight polypummel=2 In the above-mentioned medium silane γ-glycidyloxypropyltrimethoxy-silanesilane 2-inbutyl-trimethoxy-silane The amounts listed in the table relate to 100 parts by weight of the sheet material.

Claims (1)

[Claims] 1 Partially acetalized polyvinyl 7/L containing plasticizer
/ To adjust the adhesion of the coal sheet to the inorganic glass to the desired Pummel value for each purpose of use, add 18 to 65 parts by weight of plasticizer, and free OH group content of 10 to 10.
25 weight φ of partially acetalized polyvinyl alcohol resin, before or during processing into a sheet by a method known per se, a predetermined amount of 0.005 to 0.7 weight φ.
(a) a silicon-functional silane or a mixture of different silicon-functional silanes that reduce adhesion, or (b) a silicon/organo-functional silane or a mixture of silicon/organo-functional silanes that increase adhesion, or (c) at least Adjustment of the adhesion of plasticizer-containing, partially acetalized polyvinyl alcohol sheets to inorganic glass, characterized by the addition of a mixture of one silicon-functional silane and at least one silicon/organo-functional silane Method.