JP3127174B2 - Ethylene copolymer laminate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminate comprising an ethylene copolymer and glass having excellent optical and mechanical properties. These laminates exhibit extremely high performance as laminated glass for windshields for automobiles or window glasses for buildings.

[0002]

2. Description of the Related Art In recent years,
As the level of safety of automobiles increases, safety measures for windshields have become an absolutely indispensable proposition to ensure passenger safety. In response to the demands of such an era, the fact is that the use of resin-reinforced double-layer safety glass for windshields is becoming legally obligatory in many countries around the world. Also, with the increasing number of buildings that use glass (windows) on the outer surface from the top of the design, from the viewpoint of ensuring safety in the event of a disaster such as an earthquake, the use of laminated glass as safety glass is also being promoted for building window glass. is there.

At present, safety glasses used for automobile windshields have extremely strict standards. For example, in Japan, JIS or JASO standards are set. However, it is necessary to satisfy these standards while satisfying cost requirements. Is a very difficult proposition.

Until now, polyvinyl butyral (hereinafter abbreviated as PVB) has been almost exclusively used as a material for the intermediate layer of laminated glass for automobiles. This laminated glass is characterized by its excellent transparency and high penetration resistance at around normal temperature, but its performance is not always satisfactory in the demands of the era. This PV
B shows high penetration resistance near normal temperature, but its penetration resistance is not always satisfactory in a temperature region of 0 ° C. or lower or a temperature region of 80 ° C. or higher. Further, since flexibility is achieved by adding a large amount of plasticizer (usually about 40% by weight), there are not a few disadvantages associated therewith.

[0005] In addition, PVB can be produced by polymerization of polyvinyl acetate, production of PVA by saponification of polyvinyl acetate, and PVB by partial butyralization of PVA.
The production process is complicated because of the multistage process of the production.

[0006] The present inventors have overcome the problems in PVB and have repeatedly studied a laminate using a material which can be easily manufactured industrially, and as a result, have reached the present invention.

[0007]

That is, the present invention relates to a copolymer of ethylene and at least a (meth) acrylamide derivative (hereinafter abbreviated as an ethylene-based copolymer), which contains a (meth) acrylamide derivative. Amount is 10-6
Provided is an ethylene-based copolymer laminate characterized by being laminated with 0% by weight of an ethylene-based copolymer and glass.

The (meth) acrylamide derivative contained in the ethylene copolymer used in the present invention includes (meth) acrylamide, N-alkyl (meth) acrylamide, N,
N-dialkyl (meth) acrylamide and the like, specifically, N-methylacrylamide, N-ethylacrylamide, Nn-propylacrylamide, Ni
so-propylacrylamide, Nn-butylacrylamide, N-iso-butylacrylamide, Nt
-Butylacrylamide, N, N-dimethylacrylamide, N, N-diethylacrylamide, N-ethylmethacrylamide, Nn-propylmethacrylamide, Nt-butylmethacrylamide, N, N-dimethylmethacrylamide, N, N-diethyl methacrylamide, acryloyl morpholine and the like, preferably acrylamide, methacrylamide, N-ethylacrylamide, N-iso-propylacrylamide, Nt-butylacrylamide, N, N-dimethylacrylamide, N, N- Diethylacrylamide, N
-N-propyl methacrylamide, Nt-butyl methacrylamide and the like. It is also possible to use a mixture of these.

In addition to the (meth) acrylamide derivative, the ethylene copolymer used in the present invention has other properties (eg, "adhesiveness" and "flexibility"). It is also possible to copolymerize other ethylenically unsaturated compounds for the purpose of imparting.

The ethylenically unsaturated compound means a compound having an unsaturated group copolymerizable with ethylene except for a (meth) acrylamide derivative, and includes a vinyl aromatic compound, an unsaturated nitrile compound, a vinyl ester compound,
It can be selected from (meth) acrylate compounds and the like. Specifically, the vinyl aromatic compound is
Styrene, α-methylstyrene, p-methylstyrene and the like, and the unsaturated nitrile compound is acrylonitrile, methacrylonitrile and the like. Vinyl ester compounds include vinyl acetate, vinyl propionate, and the like,
The (meth) acrylate compound includes methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, and the like. One or more of these compounds can be used for the purpose of imparting adhesiveness and flexibility properties to the ethylene copolymer as described above, and the type is selected according to other purposes and properties. It is possible to

The content of the (meth) acrylamide derivative contained in the ethylene copolymer used in the present invention is 10 to 60% by weight, preferably 20 to 50% by weight. If the amount is less than 10% by weight, the material strength of the copolymer is insufficient, which is not preferable. On the other hand, if it exceeds 60% by weight, the flexibility of the copolymer is gradually lost, and the mechanical properties of the laminated glass are inferior.

With respect to the content of the ethylenically unsaturated compound that can be contained in the ethylene copolymer used in the present invention, the present compound has an adhesive property or a flexibility to the ethylene copolymer. A small amount is sufficient since it is used for the purpose of imparting properties such as 0 to 30% by weight,
Preferably, it is 0 to 20% by weight. If it exceeds 30% by weight, the optical or mechanical properties inherent to the ethylene copolymer are impaired, which is not preferable.

[0013] Next, the fluidity of the ethylene copolymer is M
FR (JIS K7210: condition 4) is 0.01 to
100 g / 10 min, preferably 0.1 to 50 g / 10 min. If it is less than 0.01 g / 10 minutes, the fluidity is low and the moldability is poor, which is not preferable. On the other hand, if it exceeds 100 g / 10 minutes, the mechanical strength of the laminated glass is inferior because the material strength is low, which is not preferable. These ethylene-based copolymers can be produced by a high-pressure radical copolymerization method or a solution radical copolymerization method, but those produced by a high-pressure radical copolymerization method are preferable, and 500 to 200
It is preferred to produce under a pressure of 0 kg / cm ² . The polymerization temperature is preferably from 100 ° C to 300 ° C,
50 ° C to 250 ° C is more preferred. As the initiator to be used in the polymerization, it is possible to select and use a polymerization temperature, an initiator efficiency, and the like from the commonly used organic peroxides.

The ethylene-based copolymer thus obtained is added with various additives such as an antioxidant, an ultraviolet absorber and an antioxidant in order to secure its excellent various properties over a long period of time. It is possible. In addition, from the viewpoint of decorativeness when formed into a laminated body with glass, it is also possible to color in advance with a dye or the like.

These ethylene copolymers have, as optical and mechanical properties, sufficient properties to be bonded to glass as they are to form a laminated glass, but further increase their mechanical strength. In addition, it is also possible to bond with glass after performing a cross-linking treatment to impart heat resistance. As for the crosslinking treatment, a usual method such as peroxide crosslinking can be employed, but it is preferable to carry out the crosslinking treatment by ionizing radiation after forming the sheet.

In such treatment, it is possible to irradiate ionizing radiation such as an electron beam after forming the ethylene-based copolymer into a sheet using ordinary extrusion means or simultaneously with forming the sheet. When producing such a crosslinked sheet, the ethylene-based copolymer, prior to crosslinking,
It can be processed into a sheet by ordinary extrusion molding means. Here, the molding temperature is usually 60 to 150.
C., but preferably 80 to 130 C. The thickness of the sheet is usually from 0.2 to 1.0 mm. The irradiation dose of the ionizing radiation is expressed as a function of the irradiation time. Here, the required irradiation dose is 5 to 30 Mrad, and preferably around 10 Mrad. The objective criterion for determining the irradiation dose of the ionizing radiation is, when the crosslinked sheet is subjected to a high-speed impact tester to determine the absorbed energy at the time of penetration, the absorbed energy is around the irradiation dose showing a maximum value, Irradiation dose ±
3 Mrad is a preferred range. The device used for cross-linking, for example, an electron beam irradiation device, is almost characterized by the accelerating voltage of the electron beam. The accelerating voltage is 50 to 1000 kV.
0-800 kV is preferred.

The sheet or crosslinked product of the ethylene copolymer thus obtained can be formed into a laminate with glass in the same autoclave laminating step as in the production of ordinary laminated glass. In that case, the conventional PV
As compared with the temperature and time employed in B, lamination can be performed at a lower temperature or in a shorter time. Also,
Without using an autoclave, lamination can be carried out using a hot press at 100 to 150 ° C. or equivalent conditions.

The laminate of the ethylene copolymer and glass thus obtained has excellent optical properties, excellent mechanical strength such as penetration resistance, and has a small temperature dependence of mechanical strength and is wide. It can be used in the temperature range and can be applied to various laminated glass applications including automobile windshields.

The ethylene copolymer used in the present invention has high adhesiveness to various thermoplastic resins other than glass, and can be bonded at a low temperature. It can also be applied as an intermediate layer of a laminate of transparent resins such as polymethyl methacrylate or an intermediate layer between glass and a transparent resin. Hereinafter, the present invention will be described more specifically in embodiments.

[0020]

Next, the present invention will be described in more detail with reference to Examples and Comparative Examples.

Example 1 (1) Production of ethylene / N, N-dimethylacrylamide copolymer A 2 liter autoclave equipped with a stirrer was set to a temperature of 200 ° C. and a pressure of 1
Under a condition of 200 kg / cm ² , ethylene and N, N-dimethylacrylamide were fed simultaneously with t-butylperoxypivalate to produce a copolymer. After separating the monomer from the obtained copolymer, a thin film was formed using a hot press, and the amount of N, N-dimethylacrylamide in the copolymer was quantified by IR measurement of the film. As a result, the amount of N, N-dimethylacrylamide was 37.5% by weight. The fluidity is 3.7 g
/ 10 minutes (190 ° C., 2.16 kg load). (2) Production and evaluation of laminated glass The ethylene / N, N-dimethylacrylamide copolymer obtained as described above was heated and pressed at 120 ° C. using a mold whose surface was coated with Teflon. ,
It was formed into a sheet having a thickness of 0.76 mm under a pressure of 20 kg / cm ² . Using the sheet thus prepared, a laminated glass (laminated glass) having this as an intermediate layer was prepared, and its physical properties were measured. That is, the above-mentioned sheet was sandwiched between two glass sheets having a thickness of 2 mm, and heated and pressed by a press at 10 kg / cm ^2.
Under a pressure of 120 ° C. for 10 minutes to perform lamination, taken out of the press and cooled by natural cooling to produce a laminated glass. The laminated glass thus produced was subjected to a penetration resistance test in accordance with JIS R 3212. As a result, it was confirmed that the laminated glass did not penetrate at all in a steel ball drop test from a height of 4 m and satisfies the JIS standard sufficiently. Was done. The transparency of this laminated glass is Haz
The e value was 0.5%, and it was confirmed that the transparency was also sufficiently satisfied.

Example 2 The ethylene / N, N-dimethylacrylamide copolymer used in Example 1 was formed into a sheet having a thickness of 0.76 mm by a heat compression press, and then an electron beam irradiator (Nissin) Using a scanning type, EPS750 type (manufactured by High Voltage Co., Ltd.), an electron beam was irradiated in air at an acceleration voltage of 750 kV to an irradiation dose of 10 Mrad to prepare a crosslinked sheet. Using the crosslinked sheet thus prepared, according to the method of Example 1,
A laminated glass (laminated glass) having this as an intermediate layer was prepared, and its physical properties were measured. The laminated glass thus produced was subjected to a penetration resistance test in accordance with JIS R 3212. As a result, it was found that the laminated glass did not penetrate at all in a steel ball drop test from a height of 5 m and had a performance exceeding the JIS standard. confirmed. The transparency of this laminated glass is Haz
The e value was 0.5%, and it was confirmed that the transparency was also sufficiently satisfied.

Example 3 According to the method of Example 1- (1), polymerization was carried out by changing the feed amounts of ethylene and N, N-dimethylacrylamide to obtain a copolymer. After separating the monomer from the obtained copolymer, the amount of N, N-dimethylacrylamide was quantified by IR according to the method of Example 1. As a result, the amount of N, N-dimethylacrylamide was 28.2% by weight. The liquidity is 3.
5 g / 10 minutes (190 ° C., 2.16 kg load).
Using this ethylene / N, N-dimethylacrylamide copolymer, a laminated glass (laminated glass) was prepared in the same manner as in Example 1, and the physical properties were measured. as a result,
Laminated glass using this copolymer as an intermediate layer is JIS R
In contrast to the penetration resistance test shown in No. 3212, it did not penetrate at all in a steel ball drop test from a height of 4 m, and it was confirmed that the steel satisfies the JIS standard. The transparency of this laminated glass was 0.8% in Haze value, and it was confirmed that the transparency was sufficiently satisfied.

Example 4 The ethylene / N, N-dimethylacrylamide copolymer used in Example 3 was formed into a sheet having a thickness of 0.76 mm by a heat compression press. -A crosslinked sheet was prepared by irradiating an electron beam under the same conditions and methods as in the method. A laminated glass (laminate glass) having this as an intermediate layer was prepared using the crosslinked sheet thus prepared in the same manner as in Example 2, and the physical properties thereof were measured.
In contrast to the penetration resistance test shown in Table 2, the steel ball drop test from a height of 5 m did not penetrate at all, and it was confirmed that the steel ball had a performance higher than the JIS standard. The transparency of this laminated glass was 0.8% in Haze value, and it was confirmed that the transparency was sufficiently satisfied.

Example 5 Polymerization was carried out according to the method of Example 1- (1) while feeding ethylene and N, N-dimethylacrylamide and vinyl acetate as an ethylenically unsaturated compound to obtain a copolymer. Was. After separating the monomer from the obtained copolymer, the amount of N, N-dimethylacrylamide was quantified by IR according to the method of Example 1. As a result, the amount of N, N-dimethylacrylamide was 24.1% by weight, and the fluidity was 4.4 g / 10 minutes (190 ° C., 2.16 kg load). The vinyl acetate content was 3.4% by weight. This ethylene / N,
Using N-dimethylacrylamide / vinyl acetate copolymer, a laminated glass (laminated glass) was prepared in the same manner as in Example 1, and the physical properties were measured. As a result, a laminated glass having this copolymer as an intermediate layer is JIS R 321
In contrast to the penetration resistance test shown in No. 2, it did not penetrate at all in a steel ball drop test from a height of 4 m, and it was confirmed that the steel satisfies the JIS standard. The transparency of this laminated glass was 1.0% in Haze value, and it was confirmed that the transparency was sufficiently satisfied.

Example 6 The ethylene / N, N-dimethylacrylamide / vinyl acetate copolymer used in Example 5 was formed into a sheet having a thickness of 0.76 mm by a hot compression press. Conditions and methods similar to those shown
A crosslinked sheet was prepared by irradiating an electron beam by the method. A laminated glass (laminate glass) having this as an intermediate layer was prepared using the crosslinked sheet thus prepared in the same manner as in Example 2, and its physical properties were measured.
In contrast to the penetration resistance test shown in 3212, it did not penetrate at all in a steel ball drop test from a height of 5 m, and it was confirmed that the steel ball had a performance higher than the JIS standard. The transparency of this laminated glass was 1.0% in Haze value, and it was confirmed that the transparency was sufficiently satisfied.

Example 7 According to the method of Example 1- (1), polymerization was carried out while feeding ethylene and N-isopropylacrylamide and vinyl acetate as an ethylenically unsaturated compound to obtain a copolymer. Note that N-isopropylacrylamide is a solid having a melting point of 60 ° C.
The solution was fed in a form dissolved in vinyl acetate. After the monomer was separated from the obtained copolymer, the amount of N-isopropylacrylamide was quantified by IR according to the method of Example 1. As a result, the amount of N-isopropylacrylamide was 15.1% by weight, and the fluidity was 1.2 g / 10 minutes (190 ° C., 2.16 kg load). The vinyl acetate content was 20.4% by weight. This ethylene / N
-A laminated glass (laminated glass) was prepared using isopropylacrylamide / vinyl acetate copolymer in the same manner as in Example 1, and the physical properties were measured. As a result, the laminated glass having this copolymer as an intermediate layer is JIS R 32
In contrast to the penetration resistance test shown in FIG. 12, the steel ball did not penetrate at all in a steel ball drop test from a height of 4 m, and it was confirmed that the steel satisfies the JIS standard. The transparency of this laminated glass was 1.0% in Haze value, and it was confirmed that the transparency was sufficiently satisfied.

Example 8 The ethylene / N-isopropylacrylamide / vinyl acetate copolymer used in Example 7 was formed into a sheet having a thickness of 0.76 mm by a heat compression press. Conditions and conditions similar to those for conditions and methods
A crosslinked sheet was prepared by irradiating an electron beam by the method. A laminated glass (laminate glass) having this as an intermediate layer was prepared using the crosslinked sheet thus prepared in the same manner as in Example 2, and its physical properties were measured.
In contrast to the penetration resistance test shown in 3212, it did not penetrate at all in a steel ball drop test from a height of 5 m, and it was confirmed that the steel ball had a performance higher than the JIS standard. The transparency of this laminated glass was 1.0% in Haze value, and it was confirmed that the transparency was sufficiently satisfied.

[Comparative Example] [Comparative Example 1] As a comparative example with respect to the embodiment, the embodiment 1-
According to the method of (1), an ethylene / N, N-dimethylacrylamide copolymer having an N, N-dimethylacrylamide content of 8.6% by weight was produced. Its fluidity was 7.0 g / 10 min (190 ° C., 2.16 kg load). Using this ethylene / N, N-dimethylacrylamide copolymer, a laminated glass (laminated glass) was prepared in the same manner as in Example 1, and the physical properties were measured. As a result, the transparency was poor as a Haze value of 6.2%, and it was impossible to use as a laminated glass.

Comparative Example 2 According to the method of Example 1- (1), the feed amount of N, N-dimethylacrylamide was gradually increased, and finally, the amount of N, N-dimethylacrylamide was 62.5% by weight. Was prepared. The fluidity of this was 250 g / 10 min (190
(° C., 2.16 kg load), and it was confirmed that the molecular weight was not sufficiently increased. In addition, the physical properties of the copolymer were hard and brittle, and the copolymer could not be uniformly bonded to glass. The Haze value was as high as 10.2%, and it could not be used as a laminated glass.

[0031]

As shown in the examples, the laminate of the ethylene-based copolymer and glass disclosed in the present invention has a performance sufficiently applicable as an automobile windshield,
The development is expected.

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-2-14855 (JP, A) JP-B-62-28105 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) B32B 17/10 C03C 27/12

Claims (6)

(57) [Claims] 1. A laminated glass comprising an ethylene-based copolymer comprising ethylene and at least a (meth) acrylamide derivative, wherein the content of the (meth) acrylamide derivative is 10 to 60% by weight. An ethylene copolymer laminate, comprising: 2. The ethylene-based copolymer laminate according to claim 1, wherein the (meth) acrylamide derivative is an N-alkyl-substituted acrylamide. 3. The ethylene-based copolymer laminate according to claim 1, wherein the (meth) acrylamide derivative is N, N-dimethylacrylamide. 4. The ethylene-based copolymer laminate according to claim 1, wherein the ethylene-based copolymer has been subjected to a crosslinking treatment. 5. An ethylene copolymer laminate according to claim 4, wherein the crosslinking in the ethylene copolymer laminate is caused by ionizing radiation. 6. The ethylene copolymer laminate according to claim 5, wherein the ionizing radiation in the ethylene copolymer laminate is an electron beam.