JPS61281118A - Crosslinked type polyurethane based resin sheet - Google Patents

Abstract

PURPOSE:The titled sheet, obtained from a polyester based polyol containing a diol and tri- or polyvalent polyol in a specific proportion, bivalent chain extender and bivalent polyisocyanate as raw materials, having transparency and smoothness and improved self-repairing properties and mechanical properties. CONSTITUTION:A sheet obtained by reacting (A) a polyol which is a mixture of a diol consisting essentially of a polyester based polyol and/or polycarbonate based polyol with a tri- or polyvalent polyol having 70-150 hydroxyl value and 0.1-0.6 equivalent ratio of the trivalent polyol to the diol and a relatively high molecular weight with (B) 0.4-1.8 equivalents, based on one equivalent component (A), bivalent chain extender and (C) 0.8-1.2 equivalents, based on one equivalent total of the components (A) and (B), bivalent alicyclic or aliphatic polyisocyanate compound to give a crosslinked polyurethane based resin and molding and the resultant resin and having transparency and smoothness and >=250% elongation and >=300kg/cm<2> breaking strength.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cross-linked polyurethane resin sheet having self-healing properties and high mechanical properties, and is particularly suitable as a penetration-resistant layer material for laminated safety glass. It concerns the seat.

Laminated safety glass, which has a sheet of inorganic glass (hereinafter simply referred to as glass) or a laminated glass sheet with a soft synthetic resin such as polyurethane resin on one side, is well-known. What is laminated glass sheet? Polyvinyl butyral resin A layer of cross-linked polyurethane resin (also called thermosetting polyurethane resin or reticulated polyurethane resin) on one side of a laminated glass sheet, which is a laminate made by laminating two glass sheets with an interlayer interposed between them. For example, laminated safety glass provided with
It is described in Publication No. 5. According to this publicly known information, the role of the cross-linked polyurethane resin layer of laminated safety glass is to prevent skin injury from broken glass pieces when a human body collides with laminated safety glass (a property called anti-laceration property). It is in. Further, while ordinary synthetic resins are easily damaged by scratches, this crosslinked polyurethane resin has self-repairing properties (also referred to as self-restoring properties).

Self-healing property refers to the property that when a scratch occurs on the surface of a cross-linked polyurethane resin, the scratch naturally disappears over time. Cross-linked polyurethane resins having this property are known and are described in the above publication. West German Patent No. 2 as described
It is described in the specification of No. 058504 (see Japanese Patent Publication No. 55J857). However, as described in these known examples, this crosslinked polyurethane resin has insufficient mechanical properties. Laminated safety glass requires mechanical properties such as energy absorption and penetration resistance in the event of a human body collision. Therefore, a laminated safety glass consisting of a layer of laminated glass and a layer of this cross-linked polyurethane resin is useful because the laminated glass has the mechanical properties required for laminated safety glass. Laminated safety glass cannot be constructed in place of glass sheets.

In promoting weight reduction of automobiles, laminated safety glass using a single glass sheet is more advantageous as an automobile window material than laminated safety glass using the above-mentioned laminated glass sheets. Even when used for other applications, such laminated safety glass is economical. In the case of laminated safety glass using a single glass sheet, in order to satisfy the mechanical properties of laminated safety glass, the laminated safety glass requires a layer of soft synthetic resin with high mechanical properties. Suitable synthetic resin materials include polyvinyl butyral resins and thermoplastic polyurethane resins. However, these materials tend to be easily scratched on the surface and do not have sufficient properties such as solvent resistance (hereinafter referred to as surface properties), so some kind of surface protection is required. It is known that a crosslinked polyurethane resin having the above characteristics is used for surface protection.
For example, Japanese Patent Publication No. 57-27050, Japanese Patent Application Publication No. 53-
It is described in Japanese Patent Application Laid-open No. 27871, Japanese Patent Application Laid-Open No. 17857-1987, and the like. In this known example, in a laminated safety glass using a single glass sheet, a relatively thick (approximately 0.5 mm or more) thermoplastic polyurethane resin layer functions as a mechanical property imparting layer, and the layer is approximately 0.5 mm thick. (1) The layer of the cross-linked polyurethane resin described above functions as a protective layer for the thermoplastic polyurethane resin layer (Japanese Patent Laid-Open No. 53-27
(See 871 Publication, page 17, upper right column et seq.) In a laminated safety glass of the same construction using a laminated glass sheet, the thermoplastic polyurethane resin layer functions as an adhesive layer.

It is specified that it may be a thin layer.

In laminated safety glass using one glass sheet,
The need for thick mechanical properties brings about various difficulties; the sheet for composing this layer must have an extremely smooth surface, a uniform thickness, and excellent optical properties. For example, the method of forming polyvinyl butyral resins or thermoplastic polyurethane resins into sheets by extrusion molding tends to cause minute surface irregularities and changes in sheet thickness, making it difficult to obtain sheets that fully satisfy optical properties. Cross-linked polyurethane resins can be easily made into sheets with excellent optical properties by cast molding, but thermoplastic polyurethane resins cannot be easily made into sheets by cast molding due to the high viscosity of the raw material mixture. Sheeting is a method of casting a raw material mixture onto a smooth surface and solidifying it to form a sheet.
In order to lower the viscosity of the raw material mixture of thermoplastic polyurethane resin, it is possible to dilute it with a solvent and then perform cast molding, but although a thin sheet can be obtained, it is difficult to obtain a relatively thick sheet.

If the soft synthetic resin layer of laminated safety glass could be composed of substantially one layer of synthetic resin material, it would be possible to
It is expected that it will be extremely advantageous economically. This material must have both the above-mentioned surface properties and mechanical properties, and is preferably one that can be formed into a sheet by cast molding. As a result of research and study to find a cross-linked polyurethane resin that is easy to cast and mold, we have found a cross-linked polyurethane resin that has such performance and is suitable for the production of laminated safety glass.

The present invention relates to a crosslinked polyurethane resin sheet having the above-mentioned characteristics.

A mixture of a diol whose main component is a polyester polyol and/or a polycarbonate polyol and a polyol having a valence of 3 or more, the average hydroxyl value of which is about 7.
0 to 150, (trivalent or higher polyol)/(diol)
A relatively high molecular weight polyol (A) in which the ml ratio of chain extender (B),
and a substantially divalent alicyclic or aliphatic polyisocyanate compound (C) in an amount of about 0.8 to 1.2 equivalents per total equivalent of the polyol (A) and chain extender (B).
It is a transparent and smooth sheet of cross-linked polyurethane resin obtained from the raw material.

Self-repairing property, elongation of about 250 dollars or more, and about 300 kg
A crosslinked polyurethane resin sheet having a breaking strength of /ca2 or more.

The crosslinked polyurethane resin of the present invention has self-repairing properties that are approximately the same or higher than those of known crosslinked polyurethane resins. In order to have self-healing properties, the measured value must be about 25 g or more as measured by the test described below. As described below, the measured value of the crosslinked polyurethane resin in the present invention is in the range of about 80 to 200 g. The above-mentioned Japanese Patent Publication No. 59-48775 discloses that the crosslinked polyurethane resin used therein has a self-repairing property of about 25 to 40 g.

The measurement method is considered to be almost the same as the measurement method of the present invention, but according to other materials (Sangopan Co., Ltd. technical data), the measurement conditions and the circular shape of the diamond tip may be slightly different. It has been revealed that when an inorganic glass surface is scratched with 18 to 20 g, scratches occur at about 5 g.

According to the above publication, the elongation (elongation at break) of the crosslinked polyurethane resin used therein is approximately 100
%, and the breaking strength is approximately 204 kg/cm2 (unit converted value). In contrast, the crosslinked polyurethane resin of the present invention has an elongation of about 250% or more and a breaking strength of about 300 kg/cm 2 or more. As shown in the Examples below, the crosslinked polyurethane resin in the present invention typically has an elongation of 300 to 5 oot and a breaking strength of about 500 to 800 kg/cm<2>. Moreover, the relationship between elongation and strength up to breakage (relationship represented by a stress strain curve) exhibits completely different behavior between the crosslinked polyurethane resin of the present invention and the above-mentioned known crosslinked polyurethane resin. The strain curve is shown in FIG. 1. As is clear from FIG. 1, the cross-linked polyurethane resin of the present invention exhibits behavior similar to that of thermoplastic polyurethane resins with excellent mechanical strength, and is superior to known cross-linked polyurethane resins. It exhibits completely different behavior from other resins.

Polyurethane resins are obtained by the reaction of a polyvalent active hydrogen-containing compound, particularly a polyol, and a polyvalent incyanate group-containing compound (hereinafter referred to as a polyisocyanate compound). When both of these two types of compounds are divalent, a thermoplastic polyurethane resin is obtained, and when at least one of them is more than divalent, a crosslinked polyurethane resin is obtained. The physical properties of crosslinked polyurethane resins are influenced by the type of active hydrogen-containing compound. Generally, polyurethane resin elastomers with high mechanical properties are obtained by using a high molecular weight active hydrogen-containing compound in combination with a low molecular weight active hydrogen-containing compound called a chain extender or a crosslinking agent. but.

According to studies conducted by the present inventors, it has been found that the self-healing properties and high mechanical properties of crosslinked polyurethane resins tend to contradict each other. That is, crosslinked polyurethane resins with high mechanical properties have low self-healing properties, and therefore, crosslinked polyurethane resins that have both of these properties are a relatively limited type of crosslinked polyurethane resin. Specifically, the cross-linked polyurethane resin having self-healing properties is composed of a propylene oxide adduct of trimethylolpropane and has a molecular weight of about 450 ( It is limited to cross-linked polyurethane resins obtained by reacting approximately equal amounts of polyether triol with a hydroxyl value of 374) and a trivalent or higher polyisocyanate compound consisting of biuret of 1,8-hexamethylene diisocyanate.

On the other hand, the crosslinked polyurethane resin in the present invention must basically be a crosslinked polyurethane resin obtained using the following raw materials.

l. A relatively high molecular weight polyol (A) and a low molecular weight active hydrogen-containing compound (hereinafter referred to as chain extender (B)) must be used together.

If a chain extender (B) is not used in combination, a crosslinked polyurethane resin with high mechanical properties cannot be obtained.

2. The above-mentioned polyol (A) needs to be a combination of a diol and a polyol having a valence of 3 or higher, and the average hydroxyl value thereof is about 70 to 150. The equivalent ratio of (trivalent or higher polyol)/(diol) must be in the range of about 0.1 to 0.6. If the average hydroxyl value and the equivalent ratio of both polyols are higher than this, mechanical properties will deteriorate. However, if it is lower than this, the self-repairability will decrease.

3. The chain extender (B) must be a substantially divalent compound having a functionality of about 2.1 or less, and the polyisocyanate compound (C) must also be a substantially divalent compound having a functionality of about 2.1 or less. It must be an isocyanate compound; if the number of functional groups is higher than this, mechanical properties will deteriorate.

4. The amount of chain extender per equivalent of polyol is approximately 0.4
It must be ~1.8, higher than this will reduce the self-healing properties, lower than this will reduce the mechanical properties.

Incidentally, as a natural premise for producing crosslinked polyurethane resins, the total equivalent of the polyol and chain extender is approximately equal to the equivalent of the polyisocyanate compound, and in particular, 0.8 to 1.2 equivalents of the latter is suitable for 1 equivalent of the former. It is. Further, the polyisocyanate compound (C) needs to be an alicyclic or aliphatic non-yellowing polyisocyanate compound. Note that the hydroxyl value is used as a numerical value related to the molecular weight of the polyol. This is because when a diol and a trivalent or higher-valent polyol are used together, the influence of their molecular weights on physical properties cannot be expressed simply by the average value of their molecular weights.

The relationship between hydroxyl value and molecular weight is expressed by the following formula.

[0HV1-([al)(/[MW]) X5B, lX
103 [0HVI: Hydroxyl value (mgKOH/g) [
al: Number of functional groups [MW]: Molecular weight The above polyol (A) is a diol with a hydroxyl value of 40 to 250, particularly about 60 to 150, and a diol with a hydroxyl value of 50 to 300,
It is particularly preferable to consist of a combination of about 100 to 250 polyols having a valence of 3 or more. Note that the diol and the polyol of a valence of 3 or more may each be a combination of two or more types. In that case, each polyol may be outside the above range as long as the average hydroxyl value is within the above range. However, the upper limit of the hydroxyl value of each polyol does not exceed about 400 in order to distinguish it from the chain extender described below.
Preferred diols have a hydroxyl value of 90 to 100, and are a combination of a diol exceeding the upper limit and a diol below the upper limit, or a combination of a diol below the lower limit and a diol above the lower limit. The most preferred polyol (A) is at least two diols having an average hydroxyl value of 60 to 130 and an average hydroxyl value of 150 to 25.
It is a combination of at least one trivalent or higher valent polyol, especially triol, of 0. Also, those diols and 3
The chain extender (B
) is composed of at least one type of diol or diamine with a molecular weight of about 280 or less, and diols with a molecular weight of about 180 or less are particularly preferable. Although it is good, it usually consists only of divalent compounds. The amount of chain extender (B) relative to 1 equivalent of the polyol (A) is approximately 0.04
The most preferred amount is 7 to 1.3a. In addition, when the chain extender (B) is a low molecular weight polyol, the average hydroxyl value of the diol in the above specific polyol (A), the trivalent or higher valence polyol, and this low molecular weight polyol is not particularly limited. Approximately 120 to 250
In particular, it is about 150 to 220 that gives the best performance in both mechanical properties and self-healing properties. Among the above polyols, polyester polyols and/or polycarbonate polyols are selected as main polyols (ie, as the majority of all polyols). Polyoxypropylene polyols cannot be used in large amounts in view of the mechanical properties of the crosslinked polyurethane resin. Particularly preferred polyols consist essentially of polyester polyols and/or polycarbonate polyols.

However, the use of only polyester polyols tends to cause problems with the water resistance of cross-linked polyurethane resins.
Polycarbonate polyols have a high viscosity and may cause problems when formed into a sheet by cast molding.

Therefore, most preferably both are used in combination. However, polycarbonate polyols have the above-mentioned problems because there are only a few types of commercially available polycarbonate polyols; however, if a suitable low-viscosity polyol can be obtained, it would be possible to use only polycarbonate polyols. at present,
The ratio of the polycarbonate polyol to the total polyol is at least about 15% by weight, preferably about 25% by weight.Currently, there are no commercially available polycarbonate polyols with a valence of 3 or higher, but of course they can be used if they are available. sell. Therefore, at present, due to viscosity problems and problems in obtaining polycarbonate polyols, the best crosslinked polyurethane resin is a combination of trivalent or higher polyester polyols, polycarbonate diols, and polyester diols. However, if such restrictions are removed, the combination is not limited to this combination, and the currently preferred hydroxyl value of the polycarbonate diol is approximately 40 to 200.
, its proportion to the total diol is about 25-75ii%,
Particularly suitable is about 25 to θO weight percent.

Examples of polycarbonate polyols include ethylene glycol, diethylene glycol, dipropylene glycol, 1,4-butanediol, neopentyl glycol, 1. Polycarbonate diols obtained by using θ-hexane diol, cyclohexane dimetatool, and other aliphatic or alicyclic dihydric alcohols, and diols exceeding dihydric ones obtained by using a small amount of trihydric or higher alcohols together. Polycarbonate polyols can be used.

Ring-opened polymers of cyclic carbonate compounds may also be used. It is well known that polyurethane resins using polycarbonate polyols are applied to laminated safety glass; for example, Japanese Patent Publication No. 55-19249 and Japanese Unexamined Patent Application Publication No. 1983-1989 disclose
In the present invention, polycarbonate polyols as described in these known examples are used. can be used. The most preferred polycarbonate polyols are poly(1,8-hexane carbonate) diol and poly(1,8-hexane/1,4-dimethylenecyclohexane carbonate) diol.

As the polyester polyol, a polyester polyol having a polyhydric alcohol residue and a polycarboxylic acid residue or a polyester polyol having a hydroxycarboxylic acid residue is suitable. The former is preferably a polyester polyol having a dihydric alcohol residue, or both it and a small amount of a trihydric or higher alcohol residue, and a dibasic acid residue, such as ethylene glycol,
Residues such as diethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, neopentyl gelcol, 1,8-hemosandiol, glycerin, trimethylolpropane, hexanetriol, and adipic acid, azelaic acid, sebacin Polyester polyols having acid, phthalic acid, etc. residues are suitable. The latter is preferably a polyester polyol obtained by adding a cyclic ester such as ε-caprolactone (hereinafter referred to as caprolactone) or hydroxycaproic acid to the polyhydric alcohol, water, or other polyvalent compound; , especially JP-A-53-27
Polyester polyols described in F171 and JP-A-57-17111157 can be used. Furthermore, the types of polyesters generally described in "Plastic Materials Course [2] Polyurethane Resins" published by Nikkan Kogyo Shimbun, pages 58 to 61 and pages 133 to 188, etc. Examples include polyols based on polyols. The most preferred polyester polyols are poly(1,4-butylene adipate) polyols, poly(ethylene adipate) polyols, poly(1,4-butylene azelate) polyols, and poly(captolactone) polyols. Poly(captolactone) polyols are particularly preferred as trivalent or higher polyols, especially triols.

Poly(oxytetramethylene)-based polyols are often inferior to the former two in terms of mechanical properties and weather resistance, but their water resistance is superior to polyester-based polyols, so they can be used as a partial substitute for polyester-based polyols. Can be used. However, other polyols other than these (for example, polyoxypropylene polyols and polybutadiene polyols) are usually not used, but even if they are used for some purpose, they are not used as the main polyol. Of course, as long as there is a polyol that is excellent in terms of mechanical properties, weather resistance, water resistance, viscosity, etc., the combination use thereof is not prohibited.

As the chain extender, diols are preferred as mentioned above, such as ethylene glycol, diethylene glycol,
．． 3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-bentanediol, 1
．． 8-hexanediol, cyclohesandimeta tool, etc. can be used. Dihydroxycarboxylic acids and diamines such as dimethylol acetic acid, dimethylol propionic acid, diaminodicyclohexylmethane, and inphorondiamine can be used instead of or together with these. Preferred chain extenders are aliphatic diols having 2 to 6 carbon atoms, with 1,4-butanediol and ethylene gelcol being particularly preferred.

As the polyisocyanate compound, divalent alicyclic or aliphatic polyisocyanate is used as described above. Specifically, for example, methylene bis(cyclohexyl isocyanate), inholodiisocyanate, cyclohexane diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, and divalent modified products thereof (for example, prepolymer type modified products, urea modified products, etc.) A particularly preferred polyisocyanate compound is 4,4-methylene-bis(cyclohexylisocyanate)X. Although a small amount of trivalent or higher non-yellowing polyisocyanate can be used in combination, only divalent polyisocyanate compounds are usually used.

Crosslinked polyurethane resins often require small amounts of other auxiliary raw materials in addition to the above-mentioned main raw materials.

In particular, catalysts and stabilizers are often essential raw materials. As the catalyst, an organometallic compound catalyst such as an organotin compound is suitable. As the stabilizer, it is preferable to use one or more of antioxidants, ultraviolet absorbers, and light stabilizers, such as hindered phenol compounds, hinterate amine compounds, phosphate ester compounds, and benzophenone compounds. compounds, benzotriazole compounds, etc. can be used. In addition, depending on the purpose, colorants and flame retardants, 1
Use a small amount of llI type agent, adhesion improver, etc. In some cases, small amounts of diluents such as solvents may be used, but are usually unnecessary.

The crosslinked polyurethane resin is manufactured using the above-mentioned raw materials by a method such as a one-shot method, a prepolymer method, or a quasi-prepolymer method. Forming into sheets is carried out by the casting method.

Particularly preferred is a method in which raw materials are mixed by a one-shot method, the mixture is cast onto a smooth surface, and solidified to form a sheet.

In addition to the above-mentioned known examples, forming a sheet by the casting method is disclosed in Japanese Patent Application Laid-open No. 5
Publication No. 5-105534, JP-A-58-1132ft1
As a method for forming the sheet of the present invention described in Publication No. 8, these known methods can be employed.

The crosslinked polyurethane resin sheet of the present invention needs to be transparent and smooth. An extremely smooth sheet can be obtained by molding using the above-mentioned Cath I method. on the other hand,
A highly transparent sheet can usually be obtained by using the above-mentioned raw materials.The thickness of the sheet of the present invention is not particularly limited, but is approximately 0.2 to 2.0 layers, particularly approximately The thickness is preferably from 0.4 to 1.2 cm. If the sheet is too thin, it will lack mechanical strength such as penetration resistance when used in laminated safety glass. Moreover, unnecessarily thick ones are not economical.

The crosslinked polyurethane resin sheet of the present invention is particularly suitable as a material for laminated safety glass used in automobile window materials and the like. In particular, 0 used as a material for manufacturing laminated safety glass using one glass sheet.
When laminating the crosslinked polyurethane resin sheet of the present invention on a glass sheet, it is preferable to interpose a layer of an adhesive material, that is, an adhesive layer, between the glass sheet and the crosslinked polyurethane resin sheet of the present invention. The type polyurethane resin sheet is hereinafter referred to as a pre-laminated sheet, and a pre-laminated sheet is manufactured by applying an adhesive solution or the like to the surface of the cross-linked polyurethane resin sheet that has been solidified to a certain extent during sheet formation by cast molding. I can do it. Of course, an adhesive layer can be formed on one side of the sheet of the crosslinked polyurethane resin obtained after the crosslinked polyurethane resin is formed into a sheet. The adhesive used in this preliminary tank layer sheet is thermoplastic polyurethane resin,
The adhesive is preferably selected from polyvinyl butyral resin or EVA resin. EVA resin refers to a resin consisting of a co-electrical resin of ethylene and vinyl acetate or a partial hydrolyzate thereof. These adhesives are thermoplastic. When pressed against a glass sheet, it can deform to follow the surface of the glass sheet. Therefore, the adhesive layer may have irregularities on its surface and may have a non-uniform thickness to some extent. In order to prevent the formation of bubbles due to residual space heat during lamination with a glass sheet, it is an effective means to provide fine irregularities on the surface of the adhesive layer to prevent air from remaining. Incidentally, it goes without saying that the adhesive is not necessarily limited to the above-mentioned synthetic resins.

The edge layer safety glass is preferably manufactured by laminating the above-mentioned pre-laminated sheet and one glass sheet. In the case of a flat glass sheet, an adhesive is first applied to the glass surface, and then a cross-linked polyurethane resin is applied. Although sheets can be laminated, it is difficult to use this method in the case of bent glass sheets such as automotive window materials. It is also possible to simultaneously laminate the crosslinked polyurethane resin sheet of the present invention and the adhesive sheet on a glass sheet, but handling the thin adhesive sheet and removing air from the laminated surface is complicated, and the lamination process is complicated. It also becomes more complicated. Therefore, it is most preferable to use the above-mentioned pre-fabricated sheet.Heating and pressing is usually employed as a method for laminating a relatively soft synthetic resin sheet and a glass sheet. An autoclave is usually used for heating and pressurizing, and it is preferable to first remove air between the sheets under reduced pressure and then apply pressure to press both sheets.

Both sheets can be pressed by only reduced pressure, or laminated by only pressure. The specific lamination method is as follows:
For example, Japanese Patent Publication No. 58-12140 and Special Publication No. 55-
It is described in Publication No. 14074.

It is preferable to pre-treat the adhesive surface of the glass sheet in order to improve adhesion, and a suitable pre-treatment agent is a silane compound such as an alkoxysilane containing an amine 7 group or a glycide group. .

The thickness of the glass sheet layer in laminated safety glass is approximately 1x
lhm, especially about 2 to 6 cm, is suitable. When used as an automobile window material, the thickness of the glass sheet layer is particularly about 3~3
5■ is preferable.

As mentioned above, the thickness of the crosslinked polyurethane resin sheet layer is suitably about 0.2 to 2.0 mm, particularly about 0.4 to 1.5 mm. In the case of laminated safety glass used as a window material for automobiles, a thickness of 0.6 to 1.2 m is particularly preferable.

Suitably, the thickness of the adhesive layer is less than about 0.2 parts, particularly less than about 0.1 mm, and particularly preferably less than 0.05 parts.

The lower limit of the thickness of this layer is not particularly limited, but approximately 0.01 a square is appropriate.

Laminated safety glass is most suitable for automobile window materials, especially windshields. However, it is not limited to this use; for example, it can also be used as architectural window glass where safety is required. The laminated safety glass of the present invention is usually a colorless or colored transparent body. Further, some portions may be opaque.

EXAMPLES The present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples. The physical properties of the present invention were measured by the following method.

[Method for measuring physical properties] Self-healing property: Scratch the cross-linked polyurethane resin surface with a loaded JOILmφ diamond tip,
Disappearance of scratches was determined visually, expressed as the maximum load at which scratches generated within 10 minutes at .degree. C. could be eliminated. In the case of inorganic glass that does not have self-healing properties, this method caused scratches under a load of approximately 5 g.

Elongation, breaking strength, tensile strength: According to JIS K13301.

Light transmittance, taper wear: According to JIS K8301.

Light Example 1 Poly(1,6-hexane carbonate) diol with a hydroxyl value of 122° 43.88 parts [parts by weight, the same applies hereinafter], poly(caprolactone) diol with a hydroxyl value of 90.5 6
After heating and melting 8.93 parts of poly(caprolactone) triol having a hydroxyl value of 195.2 at 100° C., the mixture was stirred and mixed while being dehydrated and degassed under reduced pressure. After cooling this polyol mixture to 80°C, add diptyltin diurarate [hereinafter referred to as catalyst] 8. OX10
-3 parts, 10.02 parts of 1,4-butanediol, and 184.5 parts of 4,4'-methylenebis(cyclohexyl isocyanate) [hereinafter referred to as HI2 MDI] were sequentially added and mixed with stirring. He had a fever. When the system became homogeneous, it was degassed under reduced pressure while stirring at 80° C. for 3 minutes. This prepolymerization solution was cast onto a glass sheet (500×500m+e) which had been subjected to mold release treatment, and reacted for 15 hours in a nitrogen purge oven at 120° C. to obtain a sheet having a thickness of 0.7+u+ and having a transparent mirror surface.

The average hydroxyl value of the three polyols mentioned above is about 112. The obtained crosslinked polyurethane resin sheet is hereinafter referred to as A-1, and the elongation of this crosslinked polyurethane resin sheet was 374z, the breaking strength was 771 kg/c layer, and the tear strength was 30 kg/am. Also, self-repairability is 150
g, light transmittance: 91%, taper abrasion: A crosslinked polyurethane resin sheet was produced in the same manner as above. The name of each sheet (from A-2 to A-4), the raw material, sheet thickness, and average hydroxyl value of the polyol (without chain extender) are shown below.

Example 2 ≧ 43.53 parts of poly(1,6-hexane carbonate) diol with a hydroxyl value of 54.52, a hydroxyl value of about 7
0.79 poly(caprolactone) diol
88.41 parts Poly(
caprolactone) triol 12.
44 parts catalyst 8
．． OXl0-3 part 1,4-butanediol
12.44 parts H12MDI 63
．． Average hydroxyl value of 18 parts polyol: 88.5 Sheet thickness: 0.7++ m elongation
415z
Breaking strength: 855kg/cm2 Tear strength: 38kg/am Self-healing property: 120g Light transmittance
91z taper wear
134z Example 3 Poly(l,6-hexane carbonate) diol with a hydroxyl value of 57 63.07 parts Hydroxyl value approximately 90
．． 5 poly(caprolactone) diol
99.12 parts Poly(caprolactone) triol with a hydroxyl value of about 195.2 18.02
Part catalyst 8.2
5X 10-3 parts 1,4-butanediol
14.42 parts H12MDI 80
．． 3°? Average hydroxyl value of polyol: 89.2
5 Sheet thickness 1 layer elongation 474z
Breaking strength [155kg/cm
2 Tear strength: 33kg/c layer Self-healing property: 130g Light transmittance
90X taper wear
1.4% Example 4 Poly(1,6-hexane carbonate) diol with a hydroxyl value of 54.52 35.88 parts Hydroxyl value approximately 9
0.79 poly(caprolactone) diol
124.87 parts Poly(
caprolactone) triol 17.
84 parts catalyst 8
．． 25X 10-3 parts 1,4-butanediol
14.27 part HI2MDI
82.34 parts Average hydroxyl value of polyol 94.
0 Sheet thickness: 1.1mm
435
Z breaking strength f190kg/c
m2 tear strength 35kg/cm
Self-healing property 130g light transmittance SOW taper wear
0.8% Example 5 Poly(1,6-hexane carbonate) diol with a hydroxyl value of 53.3 44.54 parts Hydroxyl value approximately 9
1.1 poly(caprolactone) diol
69.99 parts Poly(
caprolactone) triol 12.
73 parts catalyst
8. OX 1G-3 part 1,4-butanediol
11.45 parts HI2MDI
81.30 parts Average hydroxyl value of polyol
88.3 Sheet thickness 0.
7-layer intestinal elongation
504% breaking strength 707k
g/cm2 tear strength 48kg
/am Self-healing property 180g light transmittance 90% taper wear
0.9z Example 6 Poly(l,6-hexane carbonate) diol with a hydroxyl value of 53.3 43.44 parts Hydroxyl value approx. 9
1.1 poly(caprolactone) diol
88.27 parts Poly(caprolactone) triol with a hydroxyl value of about 1!95.2 12
．． 41 parts catalyst El, OX 10 bow parts 1.4
-Butanediol 12.41 parts H12M
DI f (3,48 parts Average hydroxyl value of polyol 88.3 Thickness of sheet
0.7m shoe extension
52oz breaking strength
E137kg/cm2 tear strength
58kg/am self-healing property
130g light transmittance 90
% Taper wear 1.1z Example 7 Poly(1,8-hexane/1.1z) with a hydroxyl value of 128.8.
4-dimethylene cyclohexane carbonate) diol [1,8-hexane diol, cyclohexane dimetatool, and polycarbonate diol obtained as raw material diol] 43.44 parts Poly(1,8-hexane carbonate) diol with a hydroxyl value of 55°87 22.40 parts Poly(caprolactone) diol with a hydroxyl value of about 91.1
70.41 parts Poly(caprolactone) triol with a hydroxyl value of about 195.2
12.80 parts catalyst
8. OXl0-3 part 1,4-butanediol
10.24 parts H12MDI
81.74 parts Average hydroxyl value of polyol 1
01.9 Sheet thickness 0.7m
m elongation
388z breaking strength 754kg
/cm2 tear strength 53kg/
cm Self-healing property 150° light transmittance 91X taper wear
1.0g Example 8 Poly(1,8-hexane 11,
4-dimethylenecyclohexane carbonate) diol 21.85 parts Hydroxyl value approximately 55
．． 87 poly(l,6-hexane)bonate) diol 21.85 parts Poly(caprolactone) triol with a hydroxyl value of about 91.1
H, 88 parts Poly(caprolactone) triol having a hydroxyl value of about 195.2 12.48 parts Catalyst 8.0 parts 10 parts 1,4-butanediol 11.24 parts H
I2MDI [13.93 parts Average hydroxyl value of polyol 101.9 Sheet thickness
0.7% wear/elongation
387z breaking strength
8213kg/cm2 tear strength
45kg/am self-healing property
120g light transmittance
90% taper wear 1.3%
[Comparison sheet] Poly(l,6-hexane carbonate) diol with a hydroxyl value of 122 52.8% 1 part Hydroxyl value approx. 8
0.5 poly(caprolactone) diol
7!11.30 parts catalyst
6.0XIO-: 1 part 1,4-butanediol 10.57 parts) 112 MOI
ft 3.87 parts Using the above raw materials, a one-layer sheet having a thickness of 1 layer was produced by a casting method in the same manner as the crosslinked polyurethane resin sheet A-1. The surface of the obtained thermoplastic polyurethane resin sheet was orange-skinned and could not be optically applied to laminated safety glass at all. This crosslinked polyurethane resin sheet had an elongation of 88 oz, a breaking strength a of 400 kg/crs2, and a tear strength of 41 kg/am.

Poly(butylene 7 dipate) diol with a bihydroxyl value of approximately 80.5 87°09 parts Hydroxyl value approximately 80.5
poly(caprolactone) triol
87.09 parts catalyst
8.25X 10-3 parts 1,4-butanediol 10.45 parts H12MDI
93.37 parts A sheet having a mirror surface and having a thickness of 1.1 ff1m was obtained in the same manner as the A-1 sheet. The average hydroxyl value of the polyol is 142.9 (however, the triol/diol output ratio is 1.44), and the elongation of this crosslinked polyurethane resin sheet is 230.
L breaking strength is 380kg/cm2, tearing strength is 27k
A cross-linked polyurethane resin sheet (thickness: 0.8 m+e) having a known self-healing property was obtained. This cross-linked polyurethane resin sheet is recognized to be the cross-linked polyurethane resin sheet described in Japanese Patent Publication No. 58-48775 (for the composition, see Examples in Japanese Patent Publication No. 55-6657) (physical property measurements, chemical analysis, etc.) (Depends on the results.) Poly(butylene adipate) diol with a hydroxyl value of about 56 38.00 parts Poly(caprolactone) triol with a hydroxyl value of about 54
3B, 00 part touch 11N
? , 2X10-3 parts 1,4-butanediol 9.71 parts H12MDI
38.29 parts Using the above raw materials, produce a block of thermoplastic polyurethane resin by a prepolymer method,
This was granulated and then extruded to produce a thermoplastic polyurethane resin sheet with a thickness of 0.5 mm.

The elongation of this thermoplastic polyurethane resin sheet is 480
$, breaking strength 845kg/cm2. Tear strength 98kg/
It was cm. Note that this thermoplastic polyurethane resin sheet is an example of a thermoplastic polyurethane resin sheet with excellent mechanical properties, and has almost no self-healing property [stress strain curve] A-1- above. The stress strain curves of the crosslinked polyurethane resin sheet A-4 and the sheets X-3 and X-4 are shown in FIG.

[Brief explanation of the drawing]

FIG. 1 shows stress strain curves of crosslinked polyurethane resin sheets A-1 to A-4 produced in Examples, a known crosslinked polyurethane resin sheet X-3, and thermoplastic polyurethane resin sheet x-4. This is a graph showing.

Claims (1)

[Scope of Claims] 1. A mixture of a diol containing a polyester polyol and/or a polycarbonate polyol as a main component and a polyol having a valence of 3 or more, the average hydroxyl value of which is about 70 to 150; A relatively high molecular weight polyol (A) in which the equivalent ratio of polyol)/(diol) is about 0.1 to 0.8, and about 0.4 to 1.8 equivalents per equivalent of the polyol (A). Substantially divalent chain extender (B
), and about 0.8 to 1.2 equivalents of a substantially divalent alicyclic or aliphatic polyisocyanate compound (
A transparent and smooth sheet of cross-linked polyurethane resin obtained using C) as a raw material, and has self-healing properties, an elongation of about 250% or more, and a breaking strength of about 300 kg/cm^2 or more. Polyurethane resin sheet. 2. The polyol (A) is a polyol with an average hydroxyl value of about 80 to 140, consisting of at least one diol with a hydroxyl value of about 80 to 130 and at least one trivalent or higher polyol with a hydroxyl value of about 150 to 250. , the sheet according to claim 1. 3. The sheet of claim 1, wherein the diol comprises at least 15% by weight of a polycarbonate diol. 4. The sheet according to claim 1, wherein the equivalent ratio of (trivalent or higher polyol)/(diol) in the polyol (A) is about 0.15 to 0.35. 5. The sheet according to claim 1, wherein the amount of chain extender (B) is about 0.7 to 1.3 equivalents per equivalent of polyol (A).