JP3073524B2 - Multilayer glass laminates with enhanced resistance to penetration by high velocity projectiles - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a multilayer glass laminate having enhanced resistance to penetration by a high-speed projectile. More specifically, the present invention not only prevents the glass from breaking when a small to medium diameter bullet strikes, but also prevents the bullet or other small high velocity projectiles from penetrating. It relates to a thin glass laminate.

BACKGROUND ART A variety of transparent laminated constructions have been disclosed to protect persons from flying debris and debris of glass-containing materials generated when high velocity projectiles impact the construction. In U.S. Pat. No. 3,658,636, a thick plate of amorphous polyamide is formed in a structure sandwiched between silica glasses. U.S. Pat. No. 2,861,021 describes a structure in which a sheet of polymethyl methacrylate, together with polyvinyl butyral, is laminated face to face with a sheet layer of polyamide, polyester or regenerated cellulose. An arrangement in which multiple glass layers and polyvinyl butyral are used in combination with a plastic interlayer as a shock absorber in the structure is disclosed in U.S. Pat. No. 4,130,684.
Issue.

The crushing problem of the abrasion resistant layer using the polycarbonate sheet attached to the laminate is addressed in U.S. Pat. ing. A similar laminate having an intermediate elastic stretch core with a thin polycarbonate sheet covered with a replaceable antiwear agent is disclosed in US Pat. No. 4,879,183. British Patent No. 828,381 discloses two glass layers and two glass layers.
A five-layer laminate comprising a polyvinyl butyrate layer of one layer and one polyethylene interlayer is disclosed. British Patent Publication No. 2 156 736A discloses an impact-resistant laminate consisting of a number of glass sheets laminated on the back with a polycarbonate sheet which is said to have a shatterproof effect.

The problem with structures with the highest “bullet resistance” is
It is too thick for a normal glass-embedded product. Some structures, while effective in controlling shattering, have no effect in preventing projectiles from penetrating the stack. Most such structures rely on the incorporation of multiple layers of various materials into the laminated structure. This structure requires different lamination techniques for each material, which complicates manufacturing and increases costs.

Extremely thin composite material consisting of an adhesive layer and a dimensionally stable polyester film was permanently bonded to a number of glass layers sandwiching multiple layers of plasticized polyvinyl butyral, resulting in a significant reduction in thickness A glass laminate can be obtained, and this glass laminate can prevent the penetration of these high-speed projectiles even if small fragments are generated from the inner back surface of the laminate. found.

DISCLOSURE OF THE INVENTION The present invention provides a glass laminate, which can be coated with an adhesive energy absorbing layer, such as polyvinyl butyral, and a polysiloxane or other abrasion resistant coating. A tough, energy-absorbing, thin plastic composite consisting of a strong, dimensionally stable, chemical and abrasion resistant layer, such as a layer of polyester film, is provided. The thin plastic composite protects the surface of the glassware on which the composite is laminated from shattering. Surprisingly, in addition to preventing the glass from shattering, the composite material may have bullets or other projectiles opposite the composite stacking position of the structure on which the composite material is laminated. When the structure collides with the surface, the integrity of the structure and the penetration resistance are improved. By maintaining the surface glass and holding the structure together, and by other mechanisms that have not been fully elucidated, penetration resistance can be significantly greater than expected for such thin composite structures. To be improved.

According to the invention, a multilayer glass laminate consisting of at least three glass layers is prepared by interposing a plurality of plasticized polyvinyl butyral layers between the glass layers. Each of the plurality of glass layers has a thickness of about 1 /
It should be 8 to about 1/4 inch (3.175 to 6.35 mm) and the polyvinyl butyral layer should be about 15 to about 60 mils (0.381 to 1.524 mm) thick.
A 15 to 60 mil (0.381 to 1.524 mm) thick polyvinyl butyral adhesive layer and a 3 to 15 mil (0.07
A thin composite of 62 to 0.381 polyester film is permanently bonded to the outer layer of the glass layer. The total thickness of the composite is less than about 2 mm. A crush and penetration resistant structure having an overall reduced thickness of 20% or more compared to known bullet resistant glass-incorporated products is provided by the present invention. Preferably, three to seven glass layers adhered by a plurality of polyvinyl butyral adhesive layers are used. The relative thickness and number of layers of the multiple glass layers of the structure of the present invention are:
It is determined by the "threat level", i.e., the size and velocity of the projectile that is expected to be encountered.

The polyvinyl butyral adhesive sheet can be selected from a number of commercially available products of plasticized polyvinyl butyral. Moynihan US Patent No. 4,29
A particularly desirable product of the type disclosed in U.S. Pat. No. 2,372 is sold by E.I.Dubon de Nemours and Company under the trademark Butacite. Other known adhesive materials for glass laminates, such as polyurethane, can also be used. The polyester film is known from U.S. Pat.No. 4,072,779.
And may be coated with an abrasion resistant material as disclosed in that patent. The glass is in accordance with ASTM specifications (Designat
ion) C1172-91. The glass is
It may be quenched or annealed. Generally, hardened glass is desirable.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 and 2 are side sectional views of a projectile resistant laminate according to the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION As shown in FIG. 1, a projectile resistant laminate is composed of three glass sheets 10, 12, and 14.
The glass sheet 10 is positioned on the surface 11 in such a direction as to receive an impact from a projectile such as a bullet. Sheets 10, 12, and 14 should be 15 to 60 mils (0.381 to
It is adhered together by a polyvinyl butyral intermediate layer having a thickness of 1.528 mm). A 3 to 15 mil (0.0762 to 0.381 mm) thick polyethylene terephthalate film 24 is adhered to the glass sheet 14 by a polyvinyl butyral interlayer.

FIG. 2 shows a polyethylene terephthalate film 24
The laminate of FIG. 1 is shown having a wear resistant coating 26 adhered to the outer surface of the laminate. Coating 26 is disclosed in U.S. Pat.
1 to 20 microns thick silanol coating of the type disclosed in US Pat. No. 3,177,315 and US Pat. No. 4,177,315.

The laminated structure of the present invention can be prepared by a known laminating method. The polyvinyl butyral film is sandwiched between the glass sheets 10, 12, and 14. A composite consisting of the polyethylene terephthalate film 24 and the polyvinyl butyral film 22 is then placed on the back of the glass sheet 14. A cover plate is placed on the assembly, the assembly is taped at the ends, placed in an airtight bag, and exposed to vacuum. The evacuated assembly is then autoclaved while the bag is maintained under reduced pressure.

 Hereinafter, the present invention will be further described with reference to examples.

EXAMPLE A 30 mil (0.762 mm) thick polyvinyl butyral sheet was placed on a 1 foot (304.8 mm) square nominal 100 mil (0.76 mm) sheet.
A laminated glass test panel was prepared by sandwiching between 2 mm) thick glass layers. Selected panels have a 15 mil (0.381m) bonded to one outer layer of a number of glass layers
m) thick butasite® polyvinyl butyrate layer and a 0.007 inch (0.178 m) thick polyester film composite. One shot from a 38 caliber pistol was fired into the center of each panel from a distance of 15 feet (4.572 m). Crushing was measured in grams of glass that protruded from the back of the laminate. The crush indication "++++" indicates a crush that cannot be measured but is estimated to be in the range of about 50 to 100 grams, the indication "++" indicates a crush in the range of 10 to 15 grams, and the indication "+" Indicates a crush of less than about 0.2 grams. The test results are shown in the following table.

Results similar to those obtained with the four glass layers with the composite added are shown above, with a total thickness of about 12.5 with the composite added.
Obtained with 3 mm glass layers.

In Table 2, the data from Table 1 was summarized and reconstructed to show the structure of the samples, the percentage of penetration to the thickness, and the ratio of penetration to the number of samples tested for each type. . Looking at each sample of the four glass layers, the standard laminate was penetrated, but only the sample with the same number of layers and the composite shielding material was added penetrated.
25%. For specimens where the composite was not penetrated,
No spalling occurred. This improvement is about 0.5 inches (12.7m
m) compared to a glass laminate with a thickness of only 22 mils (0.559 mm) thick, with the addition of a polyethylene terephthalate and polyvinyl butyral adhesive film (an increase of 6.4% in thickness). It is. A similar pattern appears in each sample including five glass layers with a larger number of data settings. In this case, the addition of composite reduces the frequency of penetration from 40% to 0%, while only increasing the thickness by 3.3%.
Compared to a five-layer standard glass laminate, it is clear that the composite glass laminate of the present invention provides higher protection even when four glass layers of the same thickness are used. Even if the thickness of the laminate is increased to 0.6 inches (15.24 mm), the actual penetration will be at most 40 (for a five-layer laminated glass).
% (Thickness increases by 27.7%). To obtain 0% penetration in the standard structure, the glass layer should be 6
Layer needed.

INDUSTRIAL APPLICABILITY The multilayer glass laminate of the present invention not only prevents the glass from breaking when a small to medium diameter bullet collides with little increase in thickness, but also the bullet or other small bullet. It is also possible to prevent a high-speed projectile from penetrating.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-248347 (JP, A) JP-A-1-63419 (JP, A) JP-A 64-41420 (JP, U) 10964 (JP, B2) JP-B-60-39546 (JP, B2) JP-T-Hei 1-500653 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B32B 17/10 C03C 27 / 12

Claims (3)

(57) [Claims] 1. A glass layer comprising three to seven glass layers sandwiching a plasticized polyvinyl butyral resin layer, each of said glass layers having a thickness of 3.175 to 6.35 mm. A thin composite of an adhesive energy absorbing layer and a dimensionally stable and chemically resistant polyester film is permanently adhered to one outside of the glass layer, said composite having a thickness of less than about 2 mm. Yes, the thickness of the polyester film is about 0.0762
Wherein the adhesive energy absorbing layer has a thickness of about 0.381 mm to about 1.524 mm. 2. The multilayer glass laminate for high-speed flying objects according to claim 1, wherein the adhesive energy absorbing layer is a plasticized polyvinyl butyral. 3. The multilayer glass laminate for high-speed flying objects according to claim 2, wherein said polyester film is coated with a wear-resistant coating agent.