FI77602B - FLERSKIKTSAEKERHETSGLAS. - Google Patents

Abstract

1. A laminated pane comprising only a glass sheet and a layer of transparent plastics material, characterised in that the layer of transparent plastics material has properties of absorption of energy and interior protection defined by a scratch resistance greater than 20 g measured with the Erichsen type 413 apparatus and an abrasion resistance according to European Standard R43 such that the haze difference is less than 4% and at a thickness of about 0.5 mm a flow stress sigma y at -20 degrees C not exceeding 3 daN/mm**2 , a rupture stress sigma R at +20 degrees C of at least 2 daN/mm**2 , a lengthening at rupture epsilon R at +20 degrees C from 250% to 500%, and a tear resistance Ra at +20 degrees C of at least 9 daN/mm**2 , and in that the layer of plastics material is formed essentially of a polyurethane obtained by continuous reactive casting on a flat horizontal support of a reaction mixture of an isocyanate component and a polyol component, the isocyanate component comprising at least one aliphatic or cycloaliphatic di-isocyanate or a di-isocyanate prepolymer, this component having a viscosity measured at +40 degrees C less than about 5 Pas, the isocyanate component containing urea functions, the content of urea being up to 10% of the total weight of isocyanate component, the urea content preferably being from 5 to 7%, and the polyol component comprising at least one long difunctional polyol of molecular weight from 500 to 4000 and at least one short polyol as a chain lengthening agent, the ratio of isocyanate group equivalents to hydroxyl group equivalents is about 1, and the proportions between the different polyols are selected so that the number of hydroxyl group equivalents due to the short diol represents from 20 to 70% of the total hydroxyl groups.

Description

1 77602

Layer Safety Glass

The invention relates to a new laminated glass comprising a single layer of glass and a single layer of plastic material.

Laminated glass, called safety glass, generally consists of two layers of glass and one intermediate layer of energy-absorbing properties, usually of polyvinyl butyral. One disadvantage of this type of laminated glass when used as a vehicle windshield is that when the head of a person in the vehicle hits it, the edges of the broken inner glass layer can cause cuts or other wounds. Therefore, for example, FR patents 2,187,719 and 2,251,608 suggest that a layer of plastic material consisting essentially of a thermosetting polyurethane having anti-slit properties is applied to this inner glass layer. In addition, such a layer of plastic material is self-scarring, i.e. it is a material in which surface scratches and local depressions disappear rapidly, the rate of disappearance depending on the nature of the scratch and the temperature of the plastic material.

For example, FR patent 2,398,606 also proposes a laminated glass comprising a single layer of glass, a thermoplastic layer having energy-absorbing properties and a coating layer made mainly of a thermosetting polyurethane which is self-scaring and scratch-resistant. In this type of glass, each layer has its own function, whereby the thermoplastic layer acts mainly as an energy-absorbing layer, but it does not sufficiently withstand abrasion or foreign substances, and the top layer acts as a protection of the energy-absorbing layer and does not have good energy-absorbing properties.

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For example, U.S. Pat. Nos. 3,509,015 and 3,808,077 have already proposed laminated glasses comprising a single layer of glass and a single layer of plastic material having energy absorbing properties. However, this type of glass never appears to have been completely satisfactory, apparently due to the insufficient abrasion and scratch resistance of the plastic layer used as the outer layer.

It is generally acknowledged that a laminated glass structure with a single layer of plastic material having both energy-absorbing properties and good resistance to scratches and external substances is obviously not good. According to the expert, it is somewhat contradictory that the same layer could act as both an energy-absorbing and a scratch-resistant layer. In order for a layer to have good energy-absorbing properties, it is generally believed that it must be substantially thermoplastic. On the other hand, in order for a layer to be very scratch-resistant, it is also generally believed that it must be substantially thermosetting and have a mesh structure. Such mechanical properties associated with thermoplasticity or thermosetting are described, for example, in FR Patent 2,398,606 and EU Patent 0,054,491.

A single layer of plastic material has now been invented which, in the layered glass structure in which it is attached to the glass layer, acts as an energy absorbing layer and a protective layer against glass fragmentation and which is also highly resistant to abrasion and scratching and various external substances.

The layer according to the invention is prepared by a continuous process by reaction casting on a horizontally detachable substrate from which it is removable, a reaction mixture of an isocyanate moiety and a moiety containing active hydrogen atoms, in particular a polyol moiety, an isocyanate moiety comprising at least one aliphatic or cycloaliphatic or a diisocyanate prepolymer of 3,77602 mers, the viscosity of which part being less than about 5,000 centimeters as measured at + 40 ° C, the polyol moiety comprising at least one bifunctional long chain polyol having a molecular weight of 500-4000 and at least one short chain diol the chain extension agent.

By reaction molding is meant that the liquid mixture of the ingredients, which are monomers or prepolymers, is cast as a layer or film, after which this mixture is polymerized by heat. This reaction casting, which gives the layer its good mechanical and optical properties, is described more fully in the description below.

The proportions of the polyurethane components are chosen so as to obtain a preferably balanced stoichiometric system, i.e. such that the ratio of NCO group equivalents in the diisocyanate moiety to OH group equivalents in the polyol moiety, i.e. long or long polyols and short diols, is about 1. NCO / OH- when the ratio is less than 1, the more it decreases, the faster the desired mechanical properties deteriorate for the intended use. When all the components of the polyurethane are bifunctional, the lower limit of the NCO / OH ratio for obtaining good mechanical properties is about 0.9. When at least one of the components is triple function, this lower limit may drop to as low as about 0.8. When the NCO / OH ratio is greater than 1, the higher it becomes, the more certain mechanical properties of the reaction casting layer are strengthened, for example the layer becomes stiffer, but considering the higher cost of the isocyanate moiety compared to the polyol moiety, the NCO / OH ratio is substantially 1. is a good compromise between the features and price obtained ss i.

The relative amounts of long polyol and short diol may vary depending on the desired properties, as mentioned below, however, the number of short diol OH group equivalents is 4,7602, generally 20-70% of all equivalent groups of the polyol moiety in the OH group ratio of about 1. Increasing the relative proportion of the short diol causes the layer to harden and its modulus to generally increase.

Suitable diisocyanates for use in the context of the invention are selected in particular from the following aliphatic-tolerable bifunctional isocyanates: hexamethylene diisocyanate (HMDI), 2,2,4-trimethyl-1,6-hexanediisocyanate (TMDI), bis-4-isocyano ), bis-3-methyl-4-isocyanate cyclohexylmethane, 2,2-bis- (4-isocyanate cyclohexyl) propane, 3-isocyanatomethyl 3,5,5-trimethylcyclohexyl isocyanate (IPDI), m- xylylene diisocyanate (XDI), m- and p-tetramethylxylene diisocyanate (m- and p-TMXD1), trans-cyclohexane-1,4-diisocyanate (CDHI), 1,3- (diisocyanate methyl) -cyclohexane (hydrogenated XDI).

Especially due to the cost price, IPDI is preferably used.

According to one feature of the invention, an isocyanate moiety containing urea groups is used. These urea groups improve some of the mechanical properties of the layer. Urea may be present in up to about 10% of the total weight of the isocyanate moiety containing urea groups. Preferably, the proportion of urea is 5-7% of the total weight of said part. For the above reason, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate containing urea groups (IPDI and derivatives) is preferably used.

Suitable long polyols are selected from polyether diols or polyester diols having a molecular weight of 500-4000; polyester diols include divalent acids such as adipic acid, succinic acid, palmitic acid, azelaic acid, sebacic acid, o-phthalic acid and a diol such as ethylene glycol, 1,3-propanediol, 1-4-butanediol, 1,6-hexane

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5,7602 diol esterification products, polyether diols of the general formula H £ 0 (CH2) n im OH, where n = 2-6 and m such that the molecular weight is between 500 and 4000, or the general formula ch3 H £ * OCH - CH2im OH, in which in formula m is such that the molecular weight is similarly in the range of 500-4000, polyether diols. Polycaprolactonediols can also be used.

Preferably, a polytetramethylene glycol (n = 4) having a molecular weight of about 1000 is used.

Suitable chain extenders include short chain diols such as: ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-, 1,3- and 1,4-butanediol, 2,2-dimethyl-1,3-propanediol (neopentyl glycol ), 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol, cyclohexanedimethanol, bis-phenol A, 2-methyl-2,4-pentane -diol, 3-methyl-2,4-pentanediol, 2-ethyl-1,3-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, 2-butyne-1 , 4-diol, 1,4-butenediol and decynediol substituted and / or etherified, hydroquinone bis-hydroxyethyl ether, bis-phenol A etherified with two or four propylene oxide, dimethylolpropionic acid groups. In general, the short-chain the diol, the harder the layer.

Preferably, 1,4-butanediol is used, which is a good compromise for providing a layer that is neither too hard nor too flexible for use as such an energy absorbent.

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One characteristic of the layer according to the invention is that it is made by casting by reaction casting on a horizontal plane. Such a reaction molding, already described in FR-A-2,442,128 for producing a thermosetting polyurethane layer from a mixture of ternary parts, surprisingly according to the invention gives a layer which is not completely thermoplastic when the ratio of NCO / OH groups is substantially 1 when the starting components are bifunctional.

The reaction casting requires a rapid polymerization reaction in order for the layer to form in a time suitable for industrial production. This requires a high temperature, about 100-140 ° C, at which temperature secondary branching reactions take place, generating, for example, allo-fanate and / or biuret moieties between the urethane chains, such as:

-R-NH-CO-O-R '- O -OCN - R - NCO

-R-NH-CO-O-R '-O- - R A ^ N - CcT \ 0 - R' -Οι f.

, CO 'allophanate ‘l / VNH, \ R / Ä’

C/O

OF

-R-N-CO-R '- O - or

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7 77602 - R "- NH - CO - NH - R" -

OCN - R - NCO

- R "- NH - CO - NH - R" - _ 4 _ - R "f- N - CO - NH f R" - '/ / <CO ^ \ * ^. NH 2 biuret

\ -V R

ίώ

C/O

- R "- \ j - CO - NH - R" -

When, under such operating conditions, which are the same when using bifunctional components, the NCO / OH ratio is approximately equal to or greater than 1 as mentioned above, the substance obtained is not completely thermoplastic; namely, it does not melt or dissolve in most polyurethane solvents such as tetrahydrofuran, dimethylformamide. This is not a disadvantage, as the layer has already formed; on the contrary, the advantage is that the layer has better mechanical properties, in particular in terms of creep resistance <Γ%, elongation at break, tensile expansion Ra, scratch resistance as measured by the ERICKSEN test, as described below, , where only linear polycondensation occurs.

When the NCO / OH ratio is less than 1 and about 0.8-0.9, crosslinking of the type described above occurs only to a negligible extent.

In one embodiment of the polyurethane layer according to the invention, the polyol moiety may contain a small amount of at least one polyol having more than two reactive groups, and in particular aliphatic triol monomers such as glycerol, trimethylolpropane, triols with polyether chains, in general 90-1000, polyether / polyester secatriols having more than 2 reactive groups, for example 2-3 groups. The addition of a polyol having more than two reactive groups provides additional bridging bonds between the polyurethane chains and may thus further improve the strength of the layer.

The relative amounts of long chain polyol, short chain diol and possible polyol containing more than two reactive groups may vary depending on the desired properties. In general, the proportions are selected such that per hydroxyl equivalent, the long chain polyol contains about 0.30 to 0.45 equivalents, the short chain diol about 0.2 to 0.7 equivalents, and the polyol containing more than 2 reactive groups about 0 to 0.35 equivalents. Under these conditions, the layer shall have the following mechanical properties, measured in accordance with AFNOR NFT 46.002, 51.034 and 54.108: - creep resistance at −20 ° C less than or equal to 3 daN / mm2, - breaking stress 0 ° r + 40 ° C: greater than or equal to 2 daN / mm2, - elongation at break £ r + 20 ° C 250-500%, - tensile expansion resistance Ra + 20 ° C greater than or equal to 9 daN / mm mm, - scratch resistance more than 20 g measured by the test described below, - abrasion resistance with a turbidity deviation of less than 4% measured by the test described below.

According to one feature of the invention, part of the polyol component may be replaced by a substance containing various active hydrogen atoms, such as an amine.

According to another embodiment of the plastic layer according to the invention, the isocyanate moiety may contain limited

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9 77602, for example less than 15% NCO equivalent, at least one triisocyanate such as an isocyanate biuret or a triisocyanurate.

In order to fulfill all the tasks required of it, the polyurethane layer according to the invention must generally be more than 0.4 mm and preferably more than 0.5 mm thick.

The layer according to the invention may contain various additives, the purpose of which is generally to facilitate its preparation by reaction casting. It may contain a catalyst such as a tin catalyst, for example tin dibutyl dilaurate, tributyltin oxide, tin octoate, an organo-mercury catalyst, for example a phenyl ester of mercury, an amine catalyst, for example diazabicyclo (2,2) - (5,4,0) -l-decene-7 days. The layer may contain a stabilizer such as bis- (2,2,6,6-tetramethyl-4-piperidyl) sebacate, an antioxidant phenol.

The layer may also contain a coating agent such as a silicone resin, a fluoroacylated ester, an acrylic resin.

The following explains examples of the manufacture of laminated glass and the manufacture of a layer of plastic material used in their manufacture.

Example 1

To prepare the plastic layer, a polyol moiety is prepared in advance by mixing a polytetramethylene glycol having a molecular weight of 1000 (e.g., marketed by QUAKER OATS under the name Polymeg 1000) with 1,4-butanediol, the relative proportions of the two components being such that the polytetramethylglycol contains 0.3 while 1,4-butanediol contains them 0.63.

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To the polyol moiety is added a stabilizer of 0.5% by weight of the total weight of the polyol moiety and the isocyanate moiety, a coating agent of 0.05% by weight calculated in the same manner and a catalyst, namely dibutyltin dilaurate calculated in the same manner as above.

The isocyanate moiety used is 3-isocyanate ethyl ethyl 3,5,5-trimethylcyclohexyl isocyanate (IPDI) with urea groups obtained by hydrolysis to IPDI and NCO moieties at about 31.5% by weight.

These parts are used in such amounts that the NCO / OH ratio is 1. After the parts have been degassed in vacuo, the mixture heated to about 40 ° C is cast by a casting die, such as that described in FR Patent 2,347,170, on a movable glass substrate coated with a erotusaineel-la. A layer about 0.755 mm thick is formed, which is subjected to a polymerization treatment, i.e. it is heated for about 25 minutes at 120 ° C.

After polymerization, the layer is pulled off the glass substrate and forms a film that can be stored or used immediately to make the laminated glass.

To make the glass, the plastic film prepared above is attached to a 2.6 mm thick layer of annealed glass. The glass may be tempered or tempered. This joining can be performed in two steps, in the first step the pre-joining is performed by guiding the glass parts between two calender rolls, for example using the apparatus described in EU patent 0 015 209, and in the second step the layered product is placed in an autoclave. at a temperature of about 135 ° C. The autoclave cycle can possibly be replaced by pressure-free furnace heating.

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The resulting glass is optically excellent and completely transparent.

The adhesion between the glass layer and the plastic layer is measured by the release test described below.

Cut a 5 cm wide strip from the top layer. Remove the end of the strip and draw it perpendicular to the surface of the glass at a drawing speed of 5 cm per minute. The procedure is performed at a temperature of + 20 ° C. Note the average traction required to release the tape. In this way, an attraction of 10 daN / 5 cm is obtained.

The glass prepared according to the example is further subjected to impact tests at different temperatures.

The first impact test is carried out at + 20 ° C on a steel ball weighing 2,260 kg (large ball test), which is allowed to fall into the center of a 30.5 cm long test piece of stretch glass, tensioned into a rigid frame. Determine the approximate height at which 90% of the samples tested at the selected temperature can withstand the fall of the sphere without passing through it.

The value obtained with the laminated glass according to the example is 12 meters.

The second impact test is carried out on a steel ball weighing 0,227 kg and having a diameter of 38 mm. One experiment is performed at -20 ° C. The second test is performed at a temperature of + 40 ° C. The values obtained are 12 and 11 meters, respectively.

Taking into account the European standard R 43 in force, the results must be at least 4 meters for a large ball, at least 8.5 meters for a small ball at -20 ° C and at least 9 meters for a small ball at + 40 ° C.

Scratch resistance is measured by a scratch test known as the "MAR strength test" performed with an ERICHSEN 413-1277602. The load on the diamond blade is measured, which, when attached to the glass substrate, produces a permanent scratch on the plastic layer. The load must be greater than or equal to 20 g for the plastic layer to self-scar.

The scratch resistance measured according to this experiment is 32 g on the glass of the example.

Abrasion resistance according to European standard R43 is measured. For this purpose, the glass test piece is rubbed with a scouring pad. After 100 scrubbing cycles, the turbidity deviation between the rubbed part and the non-rubbed part is measured with a spectrophotometer. The turbidity deviation (Δ turbidity) must be less than 4% for the layer to be abrasion resistant.

With the layer according to the example, the turbidity deviation is 0.94%.

The glass according to the example has all the characteristics which make it suitable for use as a windscreen for a vehicle.

Example 2

The procedure is the same as in Example 1 except that the polyol moiety is formed from a mixture of polytetramethylene glycol having a molecular weight of 1000, 1,4-butanediol and polycaprolactonitrile (e.g., marketed by UNION CARBIDE under the name Niax 301) in which they are used in such proportions that a total of 0.35, 0.45 and 0.20 hydroxyl equivalents per hydroxyl equivalent are used.

A 0.70 mm thick layer is made. The mechanical and optical properties of the obtained glass are completely satisfactory. The values measured in the various tests are as follows: - adhesion 11 daN / 5 cm, 8 m large sphere, 11 and 11 m small sphere at -20 ° C and + 40 ° C respectively, - abrasion resistance 35 g and abrasion deviation in abrasion ti 77602 1.2%.

The glass made according to the example is thus suitable for use as a windshield.

Example 3

The procedure is the same as in Example 2, except that the proportions of the different polyols are such that a total of 0.35, 0.55 and 0.10 hydroxyl equivalents per long polyol, short diol and triol are used per hydroxyl equivalent.

A layer 0.66 mm thick is formed. The values measured in the various tests are as follows: - adhesion 11 daN / 5 cm, 10 m for a large sphere, 13.5 and 13.5 m for a small sphere at -20 ° C and + 40 ° C respectively, scratch resistance 25 g and turbidity deviation rubbing 1.2%.

The glass made according to the example is thus suitable for use as a windshield.

Example 4

The procedure is the same as in Example 1 except that the polymerization of the layer is carried out only at 60 ° C and lasts for 20 hours.

In the impact tests, a small sphere at -20 ° C gives a value of 6.5 meters, which is insufficient.

A comparison of this example with Example 1 shows the effect of the polymerization temperature used during the reaction casting. Here this temperature is too low.

Claims (8)

14 7 7 602 Laminated glass comprising one layer of glass and one layer of transparent plastic material, characterized in that the transparent plastic layer has energy-absorbing and internal protection properties determined by scratch resistance of more than 20 g as measured by the Erichsen 413 device and is in accordance with European standard R43 Abrasion resistance, turbidity deviation of less than 4% and, with a thickness o of about 0,5 mm, a creep limit resistance at σ -20 C of less than 2 o or equal to 3 daN / mm, breaking stress at σ +20 C Laminated glass according to Claim 1, characterized in that the isocyanate moiety comprises 3-isocyanatomethyl 3,5,5-trimethylcyclohexyl isocyanate. is 77602 2 R greater than or equal to 2 daN / mm, the elongation at break ε o R at +20 C is between 250 and 500%, the tensile expansion resistance at R + 20 C is greater than or equal to 9 daN / mm, and a that the plastic layer is formed essentially of a polyurethane obtained by reaction casting by continuously casting on a horizontal substrate a reaction mixture of an isocyanate moiety and a polyol moiety, the isocyanate moiety comprising at least one aliphatic or cycloaliphatic diisocyanate, an isocyanate At 40 ° C is less than about 5 Pa.s and the isocyanate moiety contains urea groups, the urea moiety may be up to 10% of the total weight of the isocyanate moiety, preferably between 5 and 7%, and the polyol moiety comprises at least one bifunctional long chain polyol having a molecular weight of between 500 -4,000, and at least one short chain diol as a chain extender, isosya with about 1 to about 1, and the relative amounts of the various polyols are selected such that the number of hydroxyl group equivalents contained in the short-chain diol is 20 to 70% of the total number of hydroxyl groups. Laminated glass according to Claim 1 or 2, characterized in that the isocyanate moiety is formed essentially from 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate containing urea groups and in that the polyol moiety is formed essentially from polytetramethylene glycol and 1,4-bu -taanidiolista. Laminated glass according to one of Claims 1 to 3, characterized in that the polyol having a functionality of more than two is a polycaprolactonitrile. Laminated glass according to one of Claims 1 to 4, characterized in that, for one hydroxyl equivalent, the total long-chain polyol represents 0.30 to 0.45 equivalents, the short-chain diol 0.2 to 0.7 equivalents and the polyol having more than two functionalities. 0-0.35 equivalents. Laminated glass according to one of Claims 1 to 5, characterized in that the polyurethane layer, which has energy-absorbing properties and internal protective properties, contains additives such as a catalyst, a coating agent and a stabilizer. Laminated glass according to one of Claims 1 to 6, characterized in that the transparent plastic layer is produced by reaction molding using a polymerization temperature of more than 80 ° C. Laminated glass according to one of Claims 1 to 7, characterized in that the isocyanate moiety additionally contains at least one triisocyanate. 16 77602