Laminate and Method for Its Preparation

Preparation of a cross-linked polyurethane tvpe resin sheet

43.86 parts (by weight, the same applies hereinafter) of poly(1,6-hexane carbonate)diol having a hydroxyl value of about 122, 68.93 parts of poly(caprolactone)diol having a hYdroxyl value of about 90.5 and 12.54 parts of poly(caprolactone)triol having a hydroxy value of about 195.2 were heated and melted at 100.degree. C., stirred and mixed while dehydrated and deaerated under reduced pressure. This polyol mixture was cooled to 80.degree. C., and 6.0.times.10.sup.-3 part of dibutyltin dilaurate (hereinafter referred to as a catalyst), 10.02 parts of 1,4-butanediol and 64.5 parts of 4,4'-methylenebis(cyclohexylisocyanate) (hereinafter referred to H.sub.12 MDI) were sequentially added and mixed thereto under stirring. Heat generation was observed as the reaction started. When the system became uniform, defoaming under reduced pressure was conducted while stirring at 80.degree. C. for 3 minutes. This pre-polymerization solution was spread on a release-treated glass sheet (500.times.500 mm), and reacted for 15 hours in a nitrogen-purged furnace at 120.degree. C. to obtain a transparent sheet having a thickness of 0.7mm with a mirror surface. The average hydroxyl value of the above three polyols was about 112. This cross-linked polyurethane type resin sheet had an elongation of 374%, a breaking strength of 771 kg/cm and a tensile strength of 30 kg/cm.

Preparation of a double layered laminate with glass

On one side of the above sheet, a transparent thermoplastic polyurethane adhesive was coated in a uniform thickness (20 .mu.m), and then an embossed pattern was formed on the surface of this adhesive layer. Then, a sheet of glass of 3.times.300.times.300 mm was placed on the adhesive coating surface of this sheet, and the sheet was bonded to glass under a pressure of 13 atm at 120.degree. C.

Surface-reforming

The urethane sheet-glass double layered laminate thus obtained was dipped into the following solution at a speed of 50 cm/min., and then immediately pulled out at a withdrawal speed of 10 cm/min.

The laminate was dried in a oven at 60.degree. C. for one minute, and then the surface-reforming was conducted by means of a 120 cm/cm conveyer type high pressure mercury lamp irradiation apparatus by irradiating ultraviolet rays from a distance of 10 cm under a nitrogen stream at a conveyer speed of 5 m/min. The physical properties are shown in Table 1.

An embossed protective film (a polypropylene film) was laminated on the adhesive layer of the urethane sheet produced in Example 1. Then, this sheet was dipped into the following solution at a rate of 50 cm/min, and pulled out at a withdrawal speed of 10 cm/min.

The ultraviolet treatment was conducted in the same manner as in Example 1, and then the protective film was peeled off from the adhesive layer. Then, the sheet was laminated with a glass sheet in the same manner as in Example 1. The physical properties are shown in Table 1.

In the same manner as in Example 1, a transparent cross-linked polyurethane type resin sheet having a thickness of 1 mm was prepared.

Elongation: 474%

Breaking strength: 655 kg/cm.sup.2

Tensile strength: 33 kg/cm

Then, in the same manner as in Example 1, a surface-reformed laminated safety glass was prepared from the sheet. The physical properties are shown in Table 1.

A cross-linked polyurethane type resin sheet as obtained in Example 3 was subjected to surface-reforming in the same manner as in Example 2, and laminated with a glass sheet to obtain a laminated safety glass. The physical properties are shown in Table 1.

In the same manner as in Example 1, a transparent cross-linked polyurethane type resin sheet having a thickness of 0.7 mm was prepared.

Elongation: 415%

Breaking strength: 655 kg/cm.sup.2

Tensile strength: 38 kg/cm

In the same manner as in Example 1, a surface-reformed laminated safety glass was prepared from this sheet. The physical properties are shown in Table 1.

A cross-linked polyurethane type resin sheet as prepared in Example 5 was subjected to surface-reforming in the same manner as in Example 2, and then a laminated safety glass was prepared. The physical properties are shown in Table 1.

In the same manner as in Example 1, a transparent cross-linked polyurethane type resin sheet having a thickness of 1.1 mm was prepared.

Elongation: 495%

Breaking strength: 690 kg/cm.sup.2

Tensile strength: 35 kg/cm

In the same manner as in Example 1, a surface-reformed laminated safety glass was prepared from this sheet. The physical properties are shown in Table 1.

A surface-reformed laminated safety glass was prepared in the same manner as in Example 2 by using a cross-linked polyurethane type resin sheet as prepared in Example 7. The physical properties are shown in Table 1.

In the same manner as in Example 1, a transparent cross-linked polyurethane type resin sheet having a thickness of 0.7 mm was prepared.

Elongation: 399%

Breaking strength: 754 kg/cm.sup.2

Tensile strength: 53 kg/cm

In the same manner as in Example 2, a surface-reformed laminated safety glass was prepared from this sheet. The physical properties are shown in Table 1.

In the same manner as in Example 1, a transparent cross-linked polyurethane type resin sheet having a thickness of 0.7 mm was prepared.

Elongation:387%

Breaking strength:626 kg/cm.sup.2

Tensile strength:45 kg/cm

In the same manner as in Example 2, a surface-reformed laminated safety glass was prepared from this sheet. The physical properties are shown in Table 1.