JPS6361179B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a laminated safety glass consisting of a synthetic resin layer and a hard substrate layer having a multilayer structure with exposed surfaces, and a method for manufacturing the same, and particularly to a laminated safety glass with excellent surface characteristics and its manufacturing method. This relates to a manufacturing method.

A laminated sheet of an inorganic glass (hereinafter simply referred to as glass) sheet and a synthetic resin sheet is well known as laminated safety glass. For example, a laminated sheet having a three-layer structure of glass, polyvinyl butyral, and glass is widely used as safety glass for automobiles. The synthetic resin layer laminated between such glass sheets is called an interlayer film, and various synthetic resins such as polyvinyl butyral, polyurethane, and others have been used or proposed. on the other hand,
In laminated safety glass made of glass and synthetic resin, laminated sheets with exposed synthetic resin layers, such as glass-synthetic resin or glass-synthetic resin-glass-synthetic resin, are laminated sheets in which one side is glass and the other side is synthetic resin. The sheets are attracting attention for use in automobile safety glass, etc. This laminated safety glass is considered to be even safer than traditional double-sided glass laminated safety glass. For example, if this laminated safety glass is used as a car windshield with the synthetic resin side facing the inside of the car, there will be fewer lacerations and cuts when a driver etc. collides with the windshield, and even if the glass breaks. It is thought that this will reduce the chance of glass shards flying into the interior of the car. Such laminated safety glass, in which one side is glass and the other side is synthetic resin, is hereinafter referred to as "bilayer glass."

Bilayer glass is described, for example, in JP-A-48-41423, JP-A-48-25714, JP-A-49-34910, and JP-A-53-27671. As can be seen from these known examples, the exposed synthetic resin layer (hereinafter referred to as bilayer layer) is usually composed of polyurethane. Polyurethanes are also well known as interlayers in laminated glass. Polyurethanes include so-called thermoplastic polyurethanes and thermosetting polyurethanes; the former is a linear polymer, usually obtained by reacting a high molecular weight diol, a chain extender, and a diisocyanate compound, and the latter is a crosslinked polymer. For example, it can be obtained by reacting a high molecular weight diol, a crosslinking agent, and a diisocyanate compound.
The bilayer layer needs to be strongly bonded to the glass. However, when thermosetting polyurethane is used as a bilayer layer, there is a problem that it does not adhere firmly to glass. On the other hand, thermoplastic polyurethane adheres strongly to glass, but as long as it is used as a bilayer layer, the other side will be exposed, so the nature of its surface becomes a problem. That is, thermoplastic polyurethane has insufficient weather resistance and is easily attacked by solvents. These problems are explained in detail in the above-mentioned Japanese Patent Application Laid-Open No. 53-27671, particularly on pages 6 to 7.

In order to solve the above problems, the invention described in JP-A-53-27671 consists of a bilayer layer consisting of two polyurethane layers, the surface of which is made of thermosetting polyurethane, and the adhesive surface with glass made of thermoplastic. We are trying to solve this problem by using polyurethane. Since both polyurethanes adhere strongly, this invention solves the problems of adhesion and surface properties of the bilayer layer to the glass. However, it is not considered that all problems have been completely solved by this invention. That is, the laminated safety glass of the present invention is characterized by utilizing the self-repairing properties and tear-resistant properties of the thermosetting polyurethane, and the thermoplastic polyurethane is used as an adhesive for bonding the thermosetting resin and the glass. used as an agent. Therefore,
The bilayer layer in this laminated safety glass consists of a thick thermoset polyurethane and a thin thermoplastic polyurethane. However, as a bilayer layer for laminated safety glass, thermoplastic polyurethane is far superior to thermosetting polyurethane except for surface properties. For example, thermoplastic polyurethane is superior in terms of impact strength, penetration resistance, energy absorption properties, tear resistance, moldability (ease of forming sheets or films), and the above-mentioned adhesive properties. Regarding self-repairing properties, it is possible to achieve performance equivalent to that of thermosetting polyurethane by selecting the composition of thermoplastic polyurethane. Therefore, the bilayer layer is most preferably a thermoplastic polyurethane in its main portion (i.e., its thickest portion).

On the other hand, thermosetting polyurethane is not a very suitable material when considering the manufacturing method of laminated safety glass. There are restrictions on the molding of thermosetting polyurethane, and casting uncured thermosetting polyurethane is almost the only way to make sheets or films. Moreover, once it has been hardened, it cannot be plastically worked. Therefore, for example, in order to form a bilayer layer as in the above-mentioned known example, it is necessary to use a method in which a preformed sheet containing thermosetting polyurethane molded by a casting method is laminated with glass. If only a plastic material such as thermoplastic polyurethane is used, a sheet or film can be formed by various easy methods. Of course, a casting method is also possible, and there is a large degree of freedom in the manufacturing method of laminated safety glass. In addition, there are various advantages by not using thermosetting polyurethane, such as the ability to smooth the surface of the bilayer layer by compressing the surface with a smooth mold material using a lamination method such as thermocompression bonding.

As a result of various research studies in consideration of these problems, the inventor of the present invention made the main part of the bilayer layer a polyurethane-based thermoplastic resin, and in order to solve the problem of its surface characteristics, the outermost layer of the bilayer layer By making a certain surface layer a thin crosslinked synthetic resin layer and making the crosslinked synthetic resin a crosslinked synthetic resin crosslinked with light or moisture, we have discovered a laminated safety glass that has excellent performance and is easy to manufacture. Ivy. By using this material, the surface properties are improved, and it can be handled in the same way as thermoplastic resin before it is exposed to light or moisture, making it extremely easy to manufacture safety glass. . The present invention relates to this laminated safety glass and its manufacturing method, and the laminated safety glass of the present invention will be explained below, and then the manufacturing method will be explained.

The laminated safety glass of the present invention is a transparent or translucent laminated safety glass having two surface layers and at least one inner layer between them.
One surface layer is a hard substrate layer made of inorganic glass or organic glass, the other surface layer is a thin layer of polyurethane-based crosslinked synthetic resin crosslinked by light or moisture, and the main part of the inner layer is polyurethane. The present invention is a transparent or translucent laminated safety glass characterized in that the thermoplastic resin layer is in contact with the thin layer of the crosslinked synthetic resin. Schematic cross-sectional views of the laminated safety glass of the present invention are shown in FIGS. 1 to 3. FIG. 1 is a sectional view showing one example of the laminated safety glass of the present invention. In the laminated safety glass consisting of a synthetic resin layer 1 and a hard base layer 2 made of inorganic glass, the synthetic resin layer 1 is a surface layer made of a crosslinked synthetic resin. It has a two-layer structure of 3 and an inner layer 4 made of thermoplastic resin. FIG. 2 is a sectional view showing another example of the laminated safety glass of the present invention, in which the synthetic resin layer 1 consists of a surface layer 3 and two inner layers 4 and 5, and the main portion 4 of the inner layer is made of thermoplastic material. The inner layer 5, which is made of resin and is in contact with the hard substrate 1, is made of a synthetic resin that has high adhesiveness to the hard substrate. FIG. 3 is a sectional view showing another example of the laminated safety glass of the present invention, in which the hard base layer 1 is composed of two inorganic glasses 6 and 7 and an interlayer film 8 such as butyral resin present between them.
It consists of a three-layer structure.

In the present invention, the synthetic resin layer is composed of a surface layer made of a crosslinked synthetic resin and an inner layer made of at least one synthetic resin whose main portion is a thermoplastic resin. A crosslinked synthetic resin is a synthetic resin crosslinked by light or moisture, and will be described later. The inner layer may consist of at least one thermoplastic resin layer only or at least one thermoplastic resin layer and at least one thermoplastic resin layer.
It consists of a thin layer of synthetic resin other than thermoplastic resin, such as a synthetic resin that has been cured or crosslinked by heat, light, moisture, or the like. Synthetic resins other than thermoplastic resins in this inner layer are mainly used for the purpose of adhesion between multiple synthetic resin layers or between synthetic resin layers and hard substrate layers, but as long as the adhesive properties of thermoplastic resins are utilized. The presence of this layer is not essential, but rather its absence is preferred. The main part of the inner layer, particularly preferably the entire inner layer, consists of at least one layer of thermoplastic resin. This thermoplastic resin layer is preferably the main part of the entire synthetic resin layer. That is,
At least 1/2, preferably 2/3 or more of the total thickness of the synthetic resin layer is made of thermoplastic resin. The thickness of the crosslinked synthetic resin layer of the surface layer is preferably less than 1/2, particularly 1/3 or less, and more preferably 1/100 to 1/5 of the total thickness of the synthetic resin layer. The thickness of the surface layer is not particularly limited, but is 0.5mm.
It is preferably less than 0.2 mm, especially less than 0.2 mm. Although the thickness of the entire synthetic resin layer is not particularly limited, it is preferably 0.2 mm or more, particularly 0.4 to 10 mm. All or almost all of the synthetic resin layer is made of polyurethane synthetic resin, that is,
The surface layer is made of a crosslinked polyurethane synthetic resin crosslinked by an action other than heat, and the main part of the inner layer, especially all of the inner layer, is made of a thermoplastic polyurethane synthetic resin. These polyurethane-based synthetic resins will be described later.

In the present invention, the hard base layer is made of a sheet material harder than the synthetic resin of the synthetic resin layer, that is, a sheet of glass (i.e., inorganic glass), polycarbonate,
Consists of sheets of polymethyl methacrylate and other organic glasses. These hard substrates may have a single layer structure or a multilayer structure as described above. In the case of a multilayer structure, the space between the two hard substrates may consist of a soft material such as voripinyl butyral. In the case of a glass sheet, it may be strengthened, such as by air tempering or chemical strengthening, and may have a thin film layer, such as an anti-reflection coating, on its exposed surface. In the case of an organic glass sheet, a treatment such as stretching may be performed, and the exposed surface thereof may have a thin film layer such as a hard coat layer. Further, these hard substrates may be colored in whole or in part, or may have a pattern or a partially opaque portion. The overall thickness of these hard substrates is preferably 0.5 mm or more, particularly about 1 to 50 mm, but is not limited to this.

Although various methods can be considered for manufacturing the laminated safety glass of the present invention, the present inventor has found that the following three methods are particularly preferable. Of course, the method for manufacturing the laminated safety glass of the present invention is not limited to these three methods, but due to reasons such as the performance of the laminated safety glass to be manufactured, ease of manufacture, or economic efficiency, it is preferable to use any of these three methods. Either one is preferred.

A method in which an uncrosslinked synthetic resin and a thermoplastic resin are preliminarily laminated or simultaneously laminated on a hard substrate without prelaminating, and the uncrosslinked synthetic resin is crosslinked at the same time as or after the lamination.

A method of laminating a pre-laminated sheet having a crosslinked synthetic resin layer and a thermoplastic resin layer and a hard substrate, or laminating at least three of the crosslinked synthetic resin, the thermoplastic resin, and the hard substrate simultaneously.

A method of manufacturing a laminated safety glass by laminating a synthetic resin having a crosslinkable or non-crosslinked synthetic resin and a hard substrate, and then forming a layer made of a crosslinked synthetic resin on the surface of the synthetic resin of the laminated safety glass.

When laminating synthetic resins together, or when laminating synthetic resins and hard substrates, heating and pressing is usually the most common and easiest method, and this lamination method is often used in the above methods as well. preferable.
If the uncrosslinked crosslinkable synthetic resin has thermoplasticity and is difficult to crosslink by heating and pressurizing, this crosslinking synthetic resin can be handled almost in the same way as a thermoplastic resin, and by heating and pressurizing it. It becomes possible to use a method of laminating (hereinafter also referred to as thermocompression bonding). In this sense, a necessary condition for the crosslinkable synthetic resin is that it can be crosslinked by light or moisture. However, it is also possible to manufacture the laminated safety glass of the present invention using a crosslinked synthetic resin crosslinked by light or moisture, and the method for manufacturing the laminated safety glass of the present invention involves using a crosslinked synthetic resin that is not crosslinked. Thermocompression bonding is not always necessary. For example, a pre-laminated sheet having a layer of cross-linkable synthetic resin cross-linked by light or moisture and a layer of thermoplastic resin is produced by a method other than thermo-compression bonding, and this pre-laminated sheet and a rigid substrate are laminated by thermo-compression bonding. It is also possible to produce the laminated safety glass of the invention by the method (an example of the first method described above). However, in the case of the first method, it is usually advantageous to manufacture the pre-laminated sheet by thermo-compression bonding, and it is preferable to manufacture the pre-laminated sheet by thermo-compression bonding using an uncrosslinked crosslinkable synthetic resin. preferable. The first two of the above three manufacturing methods can be further divided into the following two types depending on whether preliminary lamination of synthetic resin is performed or not.

[First method] -a A pre-laminated sheet having an uncrosslinked light- or moisture-crosslinkable crosslinkable synthetic resin layer and a thermoplastic resin layer and a hard substrate are laminated by thermocompression bonding or the like, and at the same time this lamination is performed. Alternatively, laminated safety glass can be manufactured by crosslinking the crosslinkable synthetic resin after this lamination. Pre-laminated sheets can be prepared by laminating at least two sheets or films of crosslinkable synthetic resin and thermoplastic resin by heating and pressing, or by laminating the crosslinkable synthetic resin and thermoplastic resin together. It can be manufactured by a method of directly forming a pre-laminated sheet by extrusion molding or the like, but of course it can also be manufactured by a method of casting one sheet or film on the other. Crosslinking of the crosslinkable synthetic resin is preferably carried out after laminating the pre-laminated sheet and the hard substrate, but a transparent mold material such as a glass sheet, which will be described later, is used as the mold material and is irradiated with light such as ultraviolet rays during lamination. It is possible to carry out crosslinking at the same time.

-b It is possible to use a method in which at least three of a crosslinkable synthetic resin sheet or film, a thermoplastic resin sheet or film, and a hard substrate are simultaneously laminated without using a pre-laminated sheet. After that, as in the case of a, the crosslinkable synthetic resin is crosslinked at the same time as this lamination or after this lamination.

[Method] -a Laminated safety glass can be manufactured by a method of laminating a pre-laminated sheet having a crosslinked synthetic resin layer crosslinked by light or moisture and a hard substrate. This pre-laminated sheet can be produced by the method of cross-linking a pre-laminated sheet having a cross-linkable synthetic resin layer as explained in -a above, or by lamination or co-extrusion using a cross-linked synthetic resin, its sheet or film. I can do it.

-b Laminated safety glass can be manufactured by simultaneously laminating at least three materials: a crosslinked synthetic resin sheet or film, a thermoplastic resin sheet or film, and a hard substrate, without using a preformed sheet. can.

The third method also includes a method of forming a crosslinkable synthetic resin layer on the thermoplastic resin surface of the laminated safety glass and then crosslinking it, a method of directly forming a crosslinked synthetic resin layer, and a method of directly forming a crosslinked synthetic resin layer on the thermoplastic resin surface of the laminated safety glass. The crosslinked synthetic resin layer of the surface layer is formed by laminating a preliminary laminate having a synthetic resin layer and a thermoplastic resin and then crosslinking them if they are not crosslinked to form a crosslinked synthetic resin layer. can be formed.

As mentioned above, when laminating a rigid substrate and a pre-laminated sheet or a thermoplastic resin sheet or film, or simultaneously laminating other crosslinked or crosslinked synthetic resin sheets or films. In this case, thermocompression bonding is the most preferred method. In the case of this thermocompression bonding, the surface in contact with the hard substrate may be made of thermoplastic resin. Thermocompression bonding in the lamination of at least two materials is usually carried out by stacking the thermoplastic resin and the hard substrate to remove air, etc. Room temperature to 100℃
This is carried out through a preliminary press-bonding step in which the pressure is reduced and degassed at temperatures below .degree. C., and a main press-bond step in which the laminated assembly is thermocompression bonded under heat and pressure. Specifically, for example, one or more sheets or films of thermoplastic resin are layered on a hard substrate, and then a mold material with a smooth surface, such as a glass sheet, rubber sheet, or plastic sheet that has been subjected to mold release treatment, is layered on top of that. , metal sheets, etc. are stacked, the laminated assembly is placed in a rubber preliminary crimping bag, the inside of the crimping bag is evacuated and preliminary crimping is performed, and then the pre-crimped laminate is placed with or without separating the form material. Thermocompression bonding is performed by placing the material in an autoclave and applying heat and pressure to perform main compression bonding. Such pre-crimping is usually carried out at a temperature of about 700 mmHg or less, for example 200 mmHg or less, within the pre-crimping bag.
After reducing the pressure to 650 mmHg, it is heated to about 100°C or less, for example, room temperature to 90°C. In addition, this crimping is usually performed at temperatures ranging from about 60°C to melting of the thermoplastic resin, especially at temperatures of about 80 to 150°C, and at pressures of 2 kg/cm ² or higher, especially at pressures of about 7 to 20 kg/cm ^2. under,
It is preferable that the process be carried out in These conditions can vary depending on the type of thermoplastic resin or hard substrate, the thickness and size of each structural unit, and other factors.

The above-mentioned preliminary crimping is not limited to the method using the preliminary crimping bag as described above. for example,
A method for pre-crimping the laminated assembly by passing it between rolls and pressing it with a roll, a method for pre-pressing the laminated assembly by pressing it with a platen, a method for pre-pressing the laminated assembly by pressing the laminated assembly with a platen, and a method for pre-pressing the laminated assembly by pressing the laminated assembly with a platen, and a method for pre-pressing the laminated assembly by pressing the laminated assembly with a platen. It was placed,
It can also be carried out by a double vacuum crimping method, in which the outer vacuum chamber is first degassed, then the inner vacuum chamber is evacuated, and then the vacuum in the outer vacuum chamber is released and the pressure is bonded at atmospheric pressure. Similarly, the actual compression bonding is not limited to the method of thermocompression bonding using autoclave.
For example, a method in which the laminated assembly is placed in a heated oil tank and pressurized, a method in which the laminated assembly is passed between rolls under heating and pressed with rolls, a method in which the laminated assembly is pressed under heating, a method in which the laminated assembly is pressed under heating, and a method in which the laminated assembly is pressed under heating. It can also be carried out by a method such as a double vacuum pressure bonding method.
In addition, during thermocompression bonding, especially in the pre-compression bonding process, it is preferable to place the above-mentioned mold material on top of the thermoplastic resin to ensure sufficient crimping and to obtain a smooth surface, but the crimping method Depending on the type and purpose, the use of such a mold material may be omitted. In addition, thermocompression bonding between a thermoplastic resin and a hard substrate is most commonly carried out through a preliminary compression bonding process and a main compression bonding process. Depending on conditions such as the thickness and size of the unit, thermocompression bonding can be performed in one step without going through both the preliminary compression bonding process and the main compression bonding process.

Lamination by thermocompression bonding as described above is not the only method of manufacturing laminated safety glass. However, compared to other methods, it is possible to obtain higher adhesive strength between the thermoplastic resin and the hard substrate, and because the thermoplastic resin can be formed into a sheet or film in advance, it is smooth and has good optical properties. There are various advantages such as being able to obtain a smooth thermoplastic resin layer, and obtaining a smoother surface by pressing the thermoplastic resin layer or the crosslinkable synthetic resin layer thereon with a mold material during thermocompression bonding.

In the present invention, the thermoplastic resin is a polyurethane-based thermoplastic resin from the viewpoint of transparency, impact resistance, penetration resistance, and other physical properties. A polyurethane-based thermoplastic resin is a thermoplastic synthetic resin having a large number of urethane groups. In addition to the urethane group, this synthetic resin may have a group formed by a reaction between an isocyanate group and an active hydrogen-containing group such as a urea group, an allophanate group, or a biuret group. Further, it may have an isocyanurate group, a carbodiimide group, or another group derived from an isocyanate group. Furthermore, the ester group, ether group, which the high molecular weight polyol itself has,
It may of course have a carbonate group or other group, but it may also have a group resulting from a compound such as a chain extender or a crosslinking agent.

Polyurethane thermoplastic resins are basically linear polymers obtained by reacting high molecular weight diols, chain extenders, and diisocyanate compounds.
However, a small amount of branching may be present, for example by using trifunctional or higher functional polyols, cross-linking agents or polyisocyanates in combination with the above bifunctional compounds. It may be a polymer of the form. In addition to the three main raw materials of a high molecular weight diol, a chain extender, and a diisocyanate compound, a polyurethane thermoplastic resin can be obtained using various auxiliary raw materials as necessary. A catalyst is usually required as an auxiliary feedstock. Depending on the purpose, crosslinking agents, colorants, stabilizers, ultraviolet absorbers, flame retardants, and other additives may be used as auxiliary raw materials.

As high molecular weight diols, polyester diols, polyether diols, polyether ester diols, polycarbonate diols, and other high molecular weight diols can be used, especially polyester diols obtained from dihydric alcohols and dihydric carboxylic acid compounds, or cyclic ester compounds. Polyester diols obtained by ring-opening polymerization are preferred, such as poly(1,4-butylene adipate), poly(ethylene adipate), poly(1,3-butylene azelate), poly(ε-caprolactone), etc. Can be used. In addition, water, dihydric alcohol, dihydric phenol, and other initiators include epoxides such as alkylene oxide,
Alternatively, polyether diols and polycarbonate diols obtained by adding other cyclic ethers having four or more members are often preferable. These high molecular weight diols are suitably low melting point compounds that are liquid at room temperature or can become liquid during reaction, and the molecular weight is not particularly limited, but
~8000, particularly preferably 800-4000.
The chain extender is a relatively low molecular weight divalent compound, such as a diol, diamine, divalent alkanolamine, or other compound having two hydroxyl groups or two amino groups. Although its molecular weight is not particularly limited, it is preferably 400 or less, particularly 200 or less. As the diol, dihydric alcohols, polyester diols, polyether diols, etc. can be used, and dihydric alcohols having 2 to 6 carbon atoms are particularly preferred. As the diamine, aliphatic, alicyclic, aromatic, and other diamines can be used.
As the alkanolamine, divalent alkanolamines such as N-alkyldiethanolamines can be used. In the combination of these high molecular weight diols and chain extenders, other divalent compounds, such as diols having a molecular weight intermediate between the two, may be used in combination. Of course, two or more compounds of each of the high molecular weight diol and the chain extender can be used in combination.

As the diisocyanate compound, aliphatic, alicyclic, aromatic, and other diisocyanates and modified products thereof can be used, and it is also possible to use two or more of them in combination. Since an isocyanate group directly bonded to an aromatic nucleus may cause yellowing of the obtained polyurethane, a diisocyanate without such an isocyanate group, usually called a non-yellowing type diisocyanate, is preferred. For example, preferred diisocyanates include hexamethylene diisocyanate, methylene bis(cyclohexyl isocyanate), cyclohexylmethane diisocyanate, isophorone diisocyanate, xylylene diisocyanate, and modified diisocyanates obtained by modifying these with various compounds or treatments.

The crosslinkable synthetic resin is made of polyurethane-based synthetic resin as described above. Particularly preferred is a polyurethane synthetic resin obtained by introducing a crosslinkable group that can be crosslinked by light or moisture into the polyurethane thermoplastic resin. Some crosslinkable polyurethane synthetic resins that can be crosslinked by light or moisture are known, such as photocrosslinkable polyurethane synthetic resins. This photocrosslinkable polyurethane synthetic resin is a liquid resin such as acrylic modified polyurethane or an acrylic monomer in which polyurethane is dissolved (for example, see Japanese Patent Application Laid-open No. 149348/1983), and is crosslinked by curing with light irradiation. Polyurethane is obtained. This crosslinkable synthetic resin, which becomes a crosslinked synthetic resin from this liquid resin without passing through an uncrosslinked solid resin having thermoplastic properties, may be applicable to the above-mentioned first method and the second method, and in the present invention. You can also use this. Moreover, as mentioned above, it is preferable to use an uncrosslinked solid resin having thermoplastic properties, and this crosslinkable synthetic resin will be mainly explained below.

Preferably, the uncrosslinked solid synthetic resin has thermoplasticity. This is because sheets and films can be easily manufactured by extrusion molding due to thermoplasticity. Furthermore, a sheet or film having at least two layers can be obtained by coextruding the thermoplastic resin and this uncrosslinked thermoplastic crosslinkable synthetic resin. The above-mentioned polyurethane-based synthetic resin is preferable as this cross-linkable synthetic resin, which can be obtained by introducing a functional group that can be cross-linked by light or moisture, that is, a cross-linkable group, into the polyurethane-based thermoplastic resin. . The polyurethane-based thermoplastic resin has a reactive functional group such as a urethane group, and a crosslinkable group can be introduced into it, but preferably a more active group,
That is, it is preferable to use a synthetic resin having a functional group into which a crosslinkable group can be easily introduced. For example, a polyurethane thermoplastic resin can be manufactured by using a diol having a carboxylic acid group in part, and the carboxylic acid group makes it easier to introduce a crosslinking group. Dimethylolpropionic acid is particularly preferred as the diol having a carboxylic acid group, and is used as part of the chain extender. Further, a polyurethane thermoplastic resin having a crosslinkable group can also be produced using a compound having a group having active hydrogen such as 1 or 2 hydroxyl groups or amino groups and a crosslinkable group. For example, a polyurethane-based thermoplastic resin is created using mono- or di(meth)acrylic acid ester of trimethylolpropane as a chain extender, and a sensitizer is added to this to create a thermoplastic polyurethane-based resin that has photocrosslinkability. Synthetic resins can be produced. In the case of the above-mentioned polyurethane thermoplastic resin having a carboxylic acid group, it has a functional group that can easily react with a carboxylic acid group such as an epoxy group or a glycidyl group, and a crosslinkable group such as a cinnamic acid group or an alkoxysilyl group. A thermoplastic polyurethane synthetic resin that can be crosslinked by light, moisture, etc. can be obtained by reacting the compounds.

The laminated safety glass of the present invention is suitable as a windshield for an automobile, but is not limited thereto, and is suitable as a window material for automobiles, other vehicles, buildings, etc. The present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples.

Reference example [A] Production example of moisture-crosslinkable polyurethane Polybutylene adipate 1500 with a hydroxyl value of 54.3
g was dehydrated for 2 hours at 110° C. under 3 mmHg vacuum. To this were added 642 g of 4,4'methylene-bis(cyclohexyl isocyanate) and 0.33 g of di-n-butyltin dilaurate, and the mixture was reacted for 15 minutes at 80 DEG C. under a nitrogen stream. Next, 121 g of 1,4-butanediol and 45 g of dimethylolpropionic acid were added to this reaction mixture, and the mixture was rapidly stirred and mixed. An exotherm was observed with the onset of the reaction and a substantially homogeneous mixture was obtained. Pour this liquid reaction mixture into a Teflon-coated vat 110
℃ for 12 hours. The resulting polymer was mixed with 79 g of γ-glycidoxypropyltrimethoxysilane and 0.7 g of N,N'-dimethylanili.
The mixture was kneaded in a double-arm kneader at 180°C under a nitrogen atmosphere. The kneaded material was then crushed and granulated using a crusher. Hereinafter, this moisture-crosslinkable polyurethane will be referred to as polyurethane (A).

[B] Production example of photocrosslinkable polyurethane Polybutylene adipate 1500 with hydroxyl value 56
g, isophorone diisocyanate 908g, 1,
A polyurethane was prepared in the same manner as in Reference Example A using 244 g of 4-butanediol, 75 g of dimethylolpropionic acid and 0.16 g of di-n-butyltin dilaurate. Add this to 110g of glycidyl cinnamate, 30g of triethylamine, 2.
2-dimethoxy 2-phenylacetophenone 45g
The mixture was kneaded in a double-arm kneader in the same manner as in the reference example to obtain a granulated product. Hereinafter, this crosslinkable polyurethane will be referred to as polyurethane (B).

[C] Production example of photocrosslinkable polyurethane 1500g of polybutylene adipate with a hydroxyl value of 73
was dehydrated at 110° C. for 2 hours under a vacuum of 3 mmHg. To this, 950 g of 4,4'-methylene-bis(cyclohexyl isocyanate) and 0.16 g of di-n-butyltin dilaurate were added, and the mixture was heated to 80°C under a nitrogen stream.
The reaction was carried out for 15 minutes. This reaction mixture contains 1,
After adding 203 g of 4-butanediol, 75 g of acrylic acid monoester of trimethylolpropane, and 30 g of benzoin methyl ether and reacting for several minutes, the liquid reaction mixture was poured into a Teflon-coated vat and the urethane reaction was completed at 100°C. I let it happen. The product was ground and granulated in a grinder.
Hereinafter, this photocrosslinkable polyurethane will be referred to as polyurethane.
It is called (C).

Example 1 1500 g of polyethylene adipate with a hydroxyl value of 56,
173 g of 4,4'-methylenebis(cyclohexyl isocyanate), 327 g of 1,4-butanediol,
A polyurethane was produced in the same manner as in Reference Example A using 0.18 g of di-n-butyltin dilaurate, and this was granulated to produce a thermoplastic polyurethane. This thermoplastic polyurethane and Reference Example A
A laminate sheet with a thickness of 0.6 mm and having a moisture crosslinkable layer of 0.05 mm on one side was produced by coextrusion using the polyurethane (A) granules obtained in .
This sheet was then used to create a two-layer laminate of glass-plastic sheets in the following manner. First, the sheet was placed between two glass plates. At this time, polydimethylsiloxane was uniformly coated in advance on the glass surface in contact with the moisture-crosslinkable surface of the sheet, and heat treated at 350°C. This non-adhesive glass laminate was placed in a rubber bag, and the bag was placed in an autoclave. Initially, both the rubber bag and the autoclave were evacuated to remove the air between the glass and the sheet. Next, the autoclave was heated to 100°C, and while the inside of the rubber bag was kept in a vacuum, only the inside of the autoclave was returned to atmospheric pressure, thereby applying a pressure of 1 kg/cm ² . After keeping this state for 15 minutes, the autoclave was set to 140°C and 13 Kg/cm ² and kept for 20 minutes. After removing the glass laminate from the autoclave, the polydimethylsiloxane-treated glass was removed to create a bilayer with a glass-like smooth exposed surface of the polyurethane sheet and good adhesion to the glass.

Next, this bilayer glass is placed in hot water at 90℃.
It was immersed for 30 minutes, then transferred to a dryer at 120°C and dried for 15 minutes under a nitrogen atmosphere.

Ethanol/methanol = 10/1 (V/V) on the polyurethane sheet surface of this bilayer glass.
When felt was dyed with carbon tetrachloride, kerosene, and gasoline and a rubbing test was performed, no change was observed even after 1000 rubbings, and no increase in haze was observed.

Furthermore, when a taper test was conducted based on JIS R3212, the increase in haze after 100 cycles was 2.3%. Also, in a falling ball test based on JIS R3212, the steel balls did not penetrate, demonstrating sufficient penetration resistance.

Comparative Example In Example 1, a bilayer glass was made using only the thermoplastic polyurethane made in Example 1 without using polyurethane (A), and the same heat treatment as in Example 1 was performed. When we conducted a rubbing test with ethanol/methanol = 10/1 (V/V) on the surface of the polyurethane sheet of this bilayer glass, the film was damaged after 1000 times.35
An increase in % haze was observed.

Example 2 The thermoplastic polyurethane produced in Example 1,
Using the granulated polyurethane (B) obtained in Reference Example B, a layer of a 0.6 mm polyurethane sheet having a 0.05 mm photocrosslinkable layer was formed on the exposed surface of the polyurethane sheet in the same manner as in Example 1. We created bilayer glass containing

Next, the surface of the polyurethane sheet of this bilayer glass was irradiated with light for 20 minutes from a distance of 5 cm from a high-pressure mercury lamp. This bilayer glass showed the same performance as Example 1 in the other tests, except that the haze increase in the taper test was 2.8%.

Example 3 Using a granulated product of the thermoplastic polyurethane produced in Example 1 and the polyurethane (C) obtained in Reference Example C, a granulated product of 0.05 mm was formed on one side by the same coextrusion method as in Example 1.
A 0.6 mm polyurethane sheet with a photocrosslinkable layer of Using this polyurethane sheet, bilayer glass was produced in the same manner as in Example 1, and then irradiated with light in the same manner as in Example 2. Haze increase in taper test is 3.0%
A bilayer glass having the same performance as Example 1 was obtained except for the following.

Example 4 A 0.6 mm thick polyurethane sheet having a moisture-crosslinkable layer on one side obtained in Example 1 was
It was immersed in hot water at 120°C for 60 minutes and then dried at 120°C for 15 minutes. The obtained polyurethane sheet having a crosslinked layer on one side was laminated with a sheet of glass using the same lamination method as in Example 1 to produce bilayer glass. This bilayer glass was tested in the same manner as in Example 1 and had the same performance as the bilayer glass of Example 1, except that the haze increase due to the taper test was 2.7%.

Example 5 The photocrosslinkable layer of the 0.6 mm thick polyurethane sheet having the photocrosslinkable layer on one side obtained in Example 2 was irradiated with light for 5 minutes using a 100W high pressure mercury lamp. Using this polyurethane sheet, a bilayer glass was manufactured using the same lamination method as in Example 1. This bilayer glass had properties similar to the bilayer glass of Example 1, except for a 2.8% haze increase in the taper test.

Example 6 Using a 0.6 mm thick polyurethane sheet having a photocrosslinkable layer on one side obtained in Example 3,
After photo-crosslinking was carried out in the same manner as in Example 5, it was laminated with glass to produce bilayer glass. This bilayer glass had properties similar to the bilayer glass of Example 1, except that the haze increase by the taper test was 3.0%.

Example 7 A 0.05 mm film was produced from polyurethane A obtained in Reference Example [A] by extrusion molding. This film and the thermoplastic polyurethane sheet produced in Example 1 were laminated by thermocompression bonding, and using this laminated sheet, a bilayer was formed using the same method as in Example 1 so that the polyurethane A film was exposed. Glass was made, treated with hot water, and dried. This bilayer glass exhibited similar performance to Example 1.

Example 8 From polyurethane B obtained in Reference Example [B],
A 0.05 mm film was produced by extrusion molding. This film and the thermoplastic polyurethane sheet produced in Example 1 were laminated by thermocompression bonding, and using this laminated sheet, a bilayer was formed using the same method as in Example 1 so that the polyurethane B film was exposed. I made glass. Next, the surface of the polyurethane sheet of the bilayer glass was irradiated with light for 20 minutes from a distance of 5 cm using a high-pressure mercury lamp.
This bilayer glass showed the same performance as the bilayer glass in Example 2.

[Brief explanation of drawings]

Figures 1 to 3 are cross-sectional views showing schematic cross sections of the laminated safety glass of the present invention, in which Figure 1 is a laminated safety glass having a two-layered synthetic resin layer, and Figure 2 is a three-layered safety glass. FIG. 3 shows a laminated safety glass having a two-layered synthetic resin layer and a three-layered hard base layer. 1...Synthetic resin, 2...Hard base layer, 3...Crosslinked synthetic resin layer, 4...Thermoplastic resin layer.

Claims (1)

[Claims] 1. A transparent or translucent laminated safety glass having two surface layers and at least one inner layer between them, one of which is a hard substrate made of inorganic glass or organic glass. , the other surface layer is a thin layer of polyurethane-based crosslinked synthetic resin crosslinked by light or moisture, and the main part of the inner layer is a layer of polyurethane-based thermoplastic resin. A transparent or translucent laminated safety glass characterized in that the layer is in contact with the thin layer of the crosslinked synthetic resin. 2. Using a laminated synthetic resin having a thin layer of a polyurethane-based crosslinkable synthetic resin that can be crosslinked by light or moisture and a layer of a polyurethane-based thermoplastic resin in contact with the layer, such laminated synthetic resin and inorganic glass or organic glass are used. A hard substrate consisting of a laminated synthetic resin is laminated with the surface of the laminated synthetic resin where the thin layer of the crosslinkable synthetic resin is not present either directly or via a second synthetic resin, and the crosslinking is performed during or after the lamination. 1. A method for producing transparent or translucent laminated safety glass, characterized in that one surface layer is a hard substrate layer and the other surface layer is a crosslinked synthetic resin layer. 3. Using a laminated synthetic resin having a thin layer of a polyurethane-based crosslinked synthetic resin cross-linked by light or moisture and a layer of a polyurethane-based thermoplastic resin in contact with the layer, the laminated synthetic resin is made of such a laminated synthetic resin and inorganic glass or organic glass. A hard substrate is laminated directly or via a second synthetic resin with the surface of the laminated synthetic resin where the thin layer of the crosslinked synthetic resin is not present as the laminated surface, wherein one surface layer is of the hard substrate. A method for producing transparent or translucent laminated safety glass, the other surface layer of which is a layer of crosslinked synthetic resin.