JPH04332717A - Polyurethane-based resin precursor composition - Google Patents

Abstract

PURPOSE:To obtain a composition providing a novel resin having excellent transparency and impact resistance suitable as a bilayer resin layer of laminated safety glass, comprising a specific polycarbonate diol, a chain extender and a diisocyanate compound free from yellowing. CONSTITUTION:The objective composition comprising (A) a polycarbonate diol containing 10-50mol% 2-substituted 1,3-propanediol shown by the formula (R<1> and R<2> are H, 2-6C alkyl with the proviso that R<1> and R<2> are not H at the same time) as a diol compound, (B) a chain extender (preferably ethylene glycol or hexamethylenediamine) and (C) a diisocyanate compound (preferably isophorone diisocyanate), reacting under heating to give a polyurethane resin suitable as a bilayer resin layer, etc. For example, 2-butyl-2-ethyl-1,3-propanediol may be cited as the diol shown by the formula of the component A, etc.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a new polyurethane resin. More specifically, the present invention relates to a precursor composition that can provide a polyurethane resin that has excellent transparency and impact resistance and is particularly useful as a resin layer of laminated safety glass called a bilayer.

0002

[Prior Art] Laminated safety glass, which has a structure of at least two layers, one of which is an inorganic glass (hereinafter simply referred to as glass) layer and the other is a synthetic resin layer, is bilayer glass or simply bilayer glass. It is called a "layer" and is attracting attention as an automotive window material in place of so-called laminated glass, which is a laminate of two glasses with an interlayer interposed between them.

[0003] Polyurethane-based synthetic resins, particularly thermoplastic polyurethane-based synthetic resins, are generally used as the synthetic resin layer constituting the bilayer. Also known is one consisting of two layers of curable polyurethane synthetic resin (see JP-A-53-27671). However, thermoplastic polyurethane resins determine the main mechanical properties desired for bilayers, such as impact resistance and penetration resistance.Although thermosetting polyurethane resins are effective in improving surface properties, other This does not necessarily contribute to improving mechanical properties.

Conventionally, thermoplastic polyurethane resins for bilayers have mainly been known as those obtained by reacting three components: a high molecular weight polyester diol, a chain extender, and a non-yellowing diisocyanate compound. The use of thermoplastic polyurethane resins using high molecular weight polycarbonate diols instead of molecular weight polyester diols has also been proposed (see JP-A-49-98818).

However, these conventional thermoplastic polyurethane resins have some disadvantages in terms of physical properties such as transparency, hydrolytic stability, and weather resistance, mechanical properties such as impact resistance and penetration resistance, and ease of production. However, the results are still not fully satisfactory.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned drawbacks of the prior art and to provide a precursor that can provide a polyurethane resin that has excellent transparency and impact resistance and is useful as a bilayer resin layer. An object of the present invention is to provide a composition.

[0007]

[Means for Solving the Problems] As a result of intensive research to achieve the above object, the present inventors discovered that a certain specific diol is effective as a component for producing polycarbonate diol, and in order to complete the present invention. It's arrived.

That is, the present invention is constructed as follows. 1. A composition containing (A) a polycarbonate diol, (B) a chain extender, and (C) a non-yellowing diisocyanate compound, which reacts under heating to give a polyurethane resin suitable for a bilayer resin layer, etc. ) The diol component of polycarbonate diol is the following ■ formula

[Formula 2] [Here, R1 and R2 are hydrogen or carbon number 2
A polyurethane resin precursor composition comprising 10 to 50 mol% of 2-substituted 1,3-propanediol, which is an alkyl group of -6 (provided that R1 and R2 are not hydrogen). 2. Polycarbonate diol has an average molecular weight of 500
5,000 and a hydroxyl value of 20 to 230.

[0009] Polycarbonate diol (A), which is one component of the composition of the present invention, can be obtained by any known method capable of producing it. It is obtained by reacting in the presence of a catalyst and at elevated temperatures.

0010

[Math 1]

[0011]

[Chemical formula 3]

0012

[C4]

[0013]

[C5]

[0014]

embedded image [In the above formula, R is a diol residue, and R' is a lower alkyl group or aryl group containing 1 to 4 carbon atoms. ]

[0015] It is important in the present invention to use 2-substituted-1,3-propanediol represented by the above formula (2) as the diol component (2).
Butyl-2-ethyl-1,3-propanediol (hereinafter abbreviated as DMH), 2,2-diethyl-1,3-propanediol (hereinafter abbreviated as DMP), 2-pentyl-2
-Propyl-1,3-propanediol (hereinafter referred to as DMN
), etc.

Although it is essential to use these diols mentioned above, other aliphatic diols include 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,10
-Decanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, etc. Also, as alicyclic diols, 1,3-cyclohexanediol, 1 ,4-
Cyclohexanediol, 1,3-dimethylolcyclohexane, 1,4-dimethylolcyclohexane, 1,
3-dihydroxyethylcyclohexane, 1,4-dihydroxyethylcyclohexane, etc. may also be included.

Among the diol components, 2-substituted-1,3-
The proportion of propanediol used must be 10 to 50 mol%. That is, when the composition is made into a resin, if it is less than 10 mol %, transparency and impact resistance will be impaired, and if it exceeds 50 mol %, it will become too flexible and it will be difficult to obtain a desired bilayer.

The polycarbonate diol thus obtained has an average molecular weight of 500 to 5,000, preferably 5.
50 to 2,500, and the hydroxyl value is 20 to 23
0, preferably 40 to 210. Note that the average molecular weight can be determined from hydroxyl end group analysis and the following formula.

[0019]

[Math 2]

Next, as the chain extender (B) which is another component of the composition of the present invention, low molecular weight diols and diamines having a molecular weight of about 400 or less, particularly about 250 or less are suitable. The diol is preferably an aliphatic diol having 2 to 15 carbon atoms, such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, or 1,6-hexanediol, particularly 1,4-butanediol. is most suitable. In some cases, dihydric alcohols containing carboxyl groups, such as α,α-dimethylolpropionic acid and dimethylolacetic acid, can also be used, but in this case, when the composition is made into a thermoplastic polyurethane resin, hydration is added. There is a fear that it will be easily disassembled. In addition, examples of the diamine include hexamethylene diamine, tolylene diamine, diaminodiphenylmethane, isophorone diamine,
MOCA and other diamines can be shown. These chain extenders can also be used in combination with small amounts of crosslinking agents (low molecular weight alcohols and amines having a valence of 3 or more). This crosslinking agent must not be used in such a large amount that the resulting polyurethane resin loses its thermoplasticity. Examples of crosslinking agents include trimethylolpropane, glycerin, and triethanolamine.

As the non-yellowing diisocyanate compound (C) which is another constituent component, aliphatic or alicyclic diisocyanates having no aromatic group and modified products thereof are widely suitable. Specifically, 4,4'-methylenebis(cyclohexyl isocyanate), 1,6-
Cyclohexane diisocyanate, 1-methyl-2,4
(or 2,6) cyclohexane diisocyanate,
Isophorone diisocyanate, hexamethylene diisocyanate, urea modified product, prepolymer type modified product,
Examples include carbodiimide modified products and Biuret modified products. Among these, 4,4'-methylenebis(cyclohexyl isocyanate) and isophorone diisocyanate are particularly preferred. These non-yellowing diisocyanate compounds are generally used alone, but two or more types may be used in combination.

[0022] In addition to the three components mentioned above, the composition of the present invention may also contain other components, such as a catalyst for producing polyurethane, if necessary. Examples of the catalyst include tertiary amine catalysts, organotin compounds such as dibutyltin dilaurate, and other organometallic compound catalysts. Furthermore, if necessary, ultraviolet absorbers, light stabilizers, antioxidants, and other stabilizers may be added during or after the production of the polyurethane resin, thereby improving weather resistance. Furthermore, coloring agents and the like may be added at any stage if necessary.

The polyurethane resin precursor composition of the present invention is converted into a resin by any known polycondensation method including a prepolymer method, a quasi-prepolymer method, or a one-shot method, and the use of a prepolymer method is particularly preferred. Although the bilayer can also be manufactured by the so-called direct casting method in which the composition is directly cast between the glass and the mold, it is preferable to first manufacture a thermoplastic polyurethane resin sheet or film from the composition, It can be manufactured by laminating it with glass or other materials (laminated method). Note that sheets and films of thermoplastic polyurethane resin can be manufactured by applying the thermoplastic polyurethane resin once manufactured to an extrusion molding method, but they can also be manufactured directly by casting the composition into a flat surface. You can also.

The bilayer using the polyurethane resin precursor composition of the present invention is suitable for automobile window materials, particularly windshields, but is not limited thereto, and is also suitable for example as architectural window materials. used for.

[0025]

EXAMPLES The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited thereto. Note that parts used in Examples and Comparative Examples are based on weight.

Example of production of polycarbonate diol 775 parts of diethyl carbonate, 662 parts of 1,6-hexanediol, 224 parts of DMH, and tetra- Charge 0.66 parts of n-butoxy titanium,
It was refluxed under a nitrogen atmosphere at 0 to 170°C. Then, as the reaction progressed, ethanol was distilled off. When almost no ethanol was distilled out, a vacuum operation was started, and further ethanol was distilled off under a final vacuum of 200° C. and 20 mmHg to obtain a reaction product. As is clear from Table 1, the obtained polycarbonate diol a had a hydroxyl value of 92.7 and a molecular weight of 1210.

Polycarbonate diols b to g were obtained in the same manner as above except that the type and/or amount of the diols used in combination were changed, and the hydroxyl values and molecular weights were determined in the same manner. The results are shown in Table 1 together with the above results. The composition of the obtained polycarbonate diol was determined by analyzing the hydrolyzed product using a gas chromatograph, and the results were almost the same as the diol charge ratio.

[0028]

[Table 1]

Example 1 Polycarbonate diol a with hydroxyl number 92.7
632 parts were stirred, degassed, and dehydrated at 110° C. under a reduced pressure of 3 mmHg. To this were added 531 parts of 4,4'-methylenebis(cyclohexyl isocyanate) and 0.01 part of dibutyltin dilaurate, and the mixture was reacted at 80° C. for 20 minutes under a nitrogen atmosphere. Next, 135 parts of 1,4-butanediol was added to this reaction mixture and rapidly stirred and mixed. An exotherm was observed upon initiation of the reaction, and a substantially homogeneous mixture was obtained. This liquid reaction mixture (composition of the present invention) was charged into a drying container coated with a fluororesin and left standing in a purge oven at 130° C. for 15 hours until the reaction was completed. The produced polyurethane resin is pulverized into granules, and then granulated by an extruder in the usual way to a maximum cylinder temperature of 180°C.
It was made into a sheet and formed into a transparent sheet with a thickness of 0.5 mm. Next, bilayer glass was manufactured using this sheet by thermocompression bonding. In other words, the sheet is 30cm x 30cm
It was placed between two glass plates of m size and bonded under heat in an autoclave. At this time, a release agent was applied in advance to the surface of one piece of glass that would come into contact with the sheet. The autoclave was initially evacuated to remove air between the glass and the sheet, and then heated to 120° C. in vacuum for preliminary pressure bonding. Furthermore, autoclave at 150℃ and 13kg
/cm2 for 30 minutes. Thereafter, the glass laminate was taken out of the autoclave and the release layer was removed to obtain a bilayer glass. The impact resistance of the bilayer glass thus obtained, the manufacturing workability of the polyurethane resin in the preceding stage, and the transparency, elongation, hydrolytic stability, and weather resistance of the polyurethane resin sheet were evaluated. . The results are shown in Table 2.

Examples 2 to 4 and Comparative Examples 1 to 3 Bilayer glasses were produced in the same manner as in Example 1, except that the types and/or amounts of the constituent components of the composition were changed, and various properties were measured in the same manner. Or evaluated. The results are shown in Table 2 together with Example 1.

[0031]

[Table 2] As is clear from Table 2, it is known that the polyurethane resins of the Examples of the present invention are superior in all properties to those of the Comparative Examples.

[0032] In each of the Examples and Comparative Examples, various properties were measured or evaluated by the following methods.

Workability: Ease of handling during production of polyurethane resin was visually judged. ○: Foam comes out smoothly and is easy to handle. △: The bubbles are slightly difficult to remove. ×: Difficult to remove bubbles and difficult to handle.

Transparency: Judgment was made visually. ○: Transparent. △: Slightly opaque. ×: Opaque.

[0035] Breaking strength/elongation: width 10mm, length 20m
m sheet test piece at 25°C at a tensile speed of 300 mm/m
A tensile test was conducted, and the breaking strength and elongation were determined from the load at which the test piece broke and the length of the test piece.

[0036] Hydrolytic stability: sheet test piece was heated to 70°C,
After being left in an atmosphere with a relative humidity of 98% for 50 days, a tensile test was conducted to determine the ratio of the breaking strength to the value before the hydrolytic stability test.

Weather resistance: 1 in accelerated weathering tester (QUV)
After being exposed for 1,000 hours, a tensile test was conducted to determine the ratio of the breaking strength to the value before the weathering test.

Impact resistance: Bilayer glass is fixed in a frame and impacted from the sheet side with a 5 pound (2.27 kg) free-falling ball at 20°C. The velocity required for the ball to penetrate the bilayer glass or cause it to burst was determined from the height at which the ball fell.

[0039]

Effect of the invention: 10 to 50 mol% of the diol component is
This is a polyurethane resin precursor composition containing polycarbonate diol obtained as substituted 1,3-propanediol as one of its constituent components.With this composition, it has excellent manufacturing workability, extremely high transparency and impact resistance, and is highly durable. A polyurethane resin useful as a layer resin layer can be provided.

Claims (2)

[Claims] Claim 1: (A) polycarbonate diol, (
B) A composition containing a chain extender and (C) a non-yellowing diisocyanate compound, which reacts under heating to give a polyurethane resin suitable for a bilayer resin layer, etc., wherein the diol component of the polycarbonate diol (A) is , the following formula [Formula 1] [Here, R1 and R2 are hydrogen or carbon number 2
A polyurethane resin precursor composition comprising 10 to 50 mol% of 2-substituted 1,3-propanediol, which is an alkyl group of -6 (provided that R1 and R2 are not hydrogen). 2. The polyurethane resin precursor composition according to claim 1, wherein the polycarbonate diol has an average molecular weight of 500 to 5,000 and a hydroxyl value of 20 to 230.