JP3034910B2 - Adhesive synthetic resin interlayer for laminated glass - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive synthetic resin interlayer and a laminated glass used for producing a laminated glass having excellent transparency and adhesiveness.

2. Description of the Related Art Conventional laminated glass is a window glass for automobiles, aircrafts, vehicles, and constructions for the purpose of preventing breakage, preventing danger due to breakage, improving crime prevention, imparting decorativeness, improving soundproofing, imparting various functions, and the like. It is widely used for entrances, bathrooms, other decorative glass, OA equipment and other laminated glass with functional properties. For example, it is also used for laminated glass consisting of CRT (CRT for display) and tempered glass.

Adhesive synthetic resin interlayers used in the production of laminated glass include plasticized polyvinyl butyral, partially saponified ethylene vinyl acetate copolymer (hereinafter abbreviated as HEVA-C), cross-linked EVA, polyurethane, poly Although vinyl chloride, acrylic resin and the like are used, each has advantages and disadvantages, and none of them is satisfactory for all uses.

For example, plasticized polyvinyl butyral has excellent transparency and is often used for transparent laminated glass for automobiles and buildings, but is inferior in water resistance. Further, when a film or sheet having decorativeness and functionality is inserted, the adhesiveness to these materials is not good. Adhesion to acrylic and polycarbonate plates is poor and cannot be used for these laminated glasses.

Furthermore, the polyvinyl butyral film itself has adhesiveness,
There are many disadvantages, such as difficulties in handling.

HEVA-C has excellent water resistance and can be applied to various materials, so it is used for decorative laminated glass, various functional laminated glass, laminated glass using various synthetic resin plates, etc. They are not used for windshields of automobiles and the like because they are not sufficient and their transparency is slightly inferior to glass itself.

Existing interlayers made of other resins are only slightly used for special purposes.

Problems to be Solved by the Invention There are no disadvantages of the conventional interlayer, and even when a laminated glass is used, it has the same transparency as glass itself, has excellent water resistance, and has various functions. There is a need for the development of an adhesive synthetic resin interlayer that has a wide range of good adhesive properties to materials and is easy to handle.

Means for Solving the Problems In order to achieve the above object, the present inventors have developed a partially saponified ethylene vinyl acetate copolymer (hereinafter referred to as HEVA) or an acid-modified product thereof (HEVA-
Focusing on C), it was found that adding a specific transparency modifier to this would not only provide the same level of transparency as the glass itself, but also provide a laminated glass with excellent durability. The present invention has been completed on the basis of the findings described above.

That is, the present invention contains at least one kind of a partially saponified ethylene vinyl acetate copolymer or an acid-modified product thereof, and a transparency modifier selected from rosins and polybrominated polycyclic aromatic compounds. The present invention relates to an adhesive synthetic resin interlayer for laminated glass and a laminated glass.

First, the HEVA and HEVA-C used in the present invention will be described. Methods for producing these compounds are known per se (JP-A-61-95007).

An ethylene-vinyl acetate copolymer (hereinafter abbreviated as EVA) as a raw material for producing the resin component is usually
A vinyl acetate content of 25 to 70% by weight is used,
Preferably, the one having the content of 30 to 60% by weight is used.

Such an EVA is produced by a known production method such as a high-pressure method and an emulsification method, and its melt index (g / 10
min: According to ASTM 1238-65T. The same applies below), but 0.1 to 500,
Preferably, one having from 1 to 300 can be used.

The EVA raw material is then subjected to a saponification reaction,
Partially saponified product (HEVA) is obtained. Degree of saponification is usually 30
~ 85 mol%, preferably 40-75 mol%, more preferably
45-70 mol%.

The saponification reaction may be performed by a method known per se.
For example, the reaction can be carried out in a system comprising a low-boiling alcohol such as methanol or ethanol and an alkali such as sodium hydroxide, potassium hydroxide or sodium methylate.

Next, HEVA-C having a carboxyl group can be produced using such HEVA.

Methods for acid-modifying HEVA include a method using a graft reaction and a method using an esterification reaction.

In order to utilize the graft reaction, it is usually carried out using an unsaturated carboxylic acid.

Such unsaturated carboxylic acids include acrylic acid,
Examples thereof include unsaturated monocarboxylic acids such as methacrylic acid, crotonic acid, and itaconic acid, and unsaturated dicarboxylic acids (or anhydrides) such as maleic acid. Usually, acrylic acid is used.

The grafting reaction may be performed under ordinary reaction conditions using a radical initiator such as benzoyl peroxide, lauroyl peroxide, α, α′-azobisisobutyronitrile and the like.

The unsaturated carboxylic acid is used in an amount of 0.1 to 15% by weight, preferably 0.5 to 5% by weight based on the weight of HEVA.

The modified product having a carboxyl group obtained by such a reaction usually has an acid value of 0.1 to 40, preferably 0.5 to 40.
~ 15.

When an esterification reaction is used, dicarboxylic anhydride or the like is usually used. The reaction is carried out under esterification conditions known per se.

Examples of such dicarboxylic anhydrides include maleic anhydride, succinic anhydride, phthalic anhydride, hexahydrophthalic anhydride and the like.

The amount of the dicarboxylic anhydride to be used is usually an amount necessary to esterify 5 to 60 mol%, preferably 10 to 50 mol% of the hydroxyl groups in HEVA.

The thus obtained modified product having a carboxyl group usually has an acid value of 10 to 200, preferably 20 to 150.

The transparency modifier used in the present invention is at least one selected from rosins and polybrominated polycyclic aromatic compounds.

In general, rosins are thermoplastic resins containing abietic acid as a main component and include gum rosin, wood rosin, tall oil rosin and the like.

The rosins used in the present invention include modified rosins such as hydrogenated rosin (dihydroabietic acid, tetrahydroabietic acid), disproportionated rosin, disproportionated hydrogenated rosin, and polymerized rosin (including partially polymerized rosin); Rosin or modified rosins such as alkyl esters, glycol esters, glycerin esters, pentaerythritol esters, and rosin-modified polyesters in which rosin or modified rosin is used as a part of the polyester acid are exemplified. Such a rosin-modified polyester can also be obtained by reacting a rosin or a glycidyl ester of a modified rosin with a carboxylic acid-containing compound.

As the polybrominated polycyclic aromatic compound used in the present invention, for example, a polybrominated bisphenol A or diphenyl ether is preferable. Specific examples include tetrabromobisphenol A, decabromodiphenyl ether, octabromodiphenyl ether and the like.

The above-mentioned transparency modifiers can be used alone or as a mixture.

In particular, when a polybrominated polycyclic aromatic compound is used among the transparency modifiers, the refractive index of HEVA-C becomes close to the refractive index of glass, and it is possible to mask irregularities on the glass surface. it can. By this effect, even if the operation such as polishing of the surface of the tempered glass or the like is omitted and the tempered glass is used as it is, when the laminated glass is used, the irregularities on the tempered glass surface can be eliminated.

The amount of transparency modifier used is HEVA or HEVA-C
And 2 to 40% by weight, preferably 5 to 30% by weight, based on the total amount of the transparency modifier.

If necessary, stabilizers, ultraviolet absorbers, coloring agents, dyes, surfactants, and plasticizers may be added.

Further, in the present invention, by further blending a silane coupling agent with the above composition, an intermediate film having more excellent water resistance can be obtained.

As the silane coupling agent, epoxy silane, amino silane, and vinyl silane are used. In particular, epoxy silane, for example, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane,
γ-glycidoxypropylmethyldiethoxysilane, β
-(3,4-epoxycyclohexyl) ethyltrimethoxysilane and the like.

The silane coupling agent is used in an amount of usually 0.05 to 3 parts by weight, preferably 0.1 to 1.0 part by weight, based on 100 parts by weight of HEVA or HEVA-C.

In order to prepare the intermediate film according to the present invention, the components are usually melt-blended by an extruder, a kneader or the like, and then formed into a sheet using a T-die or the like. The temperature condition at the time of forming the sheet is usually about 100 to 150 ° C. for pelletizing by an extruder, and about 150 to 180 ° C. for forming a film by a T-die. Also. The sheet may be formed using a calendar roll. This sheeting itself may be performed by a known method (Japanese Patent Application Laid-Open No. 60-171253).

The thickness of the sheet is usually 50-2000μ, more preferably 100
~ 1000μ is used.

The surface of the sheet is preferably uneven to prevent bubbles from remaining during the production of the laminated glass, and a matte pattern or an embossed pattern is preferably provided by an embossing roll or the like.

In general, a known method such as a vacuum heat compression method, a thermocompression bonding method, a method using an autoclave, or the like can be suitably used for producing a laminated glass.

The laminated glass shown in the present invention is obtained by bonding a glass-like transparent body such as an inorganic glass, a template glass, a polycarbonate resin and an acrylic resin with an adhesive synthetic resin interlayer. In addition, one in which one of the overlapping parts is a transparent resin film is also included. At that time, the laminated glass may be a flat plate or a curved glass.

Effect of the present invention When a laminated glass is produced using the adhesive synthetic resin interlayer of the present invention, it adheres well to glass, decorative printed polyester films, polarizing films, acrylic plates, polycarbonate plates and the like.

Further, a laminated glass which is hardly peeled off at the time of use and has excellent durability can be obtained, and a glass having transparency equivalent to that of the glass itself can be obtained.

Production Examples and Examples Production Example Production of Resins (HEVA-C) A and B (i) Melt Index 30 g / 10 min Vinyl acetate content
33% of ethylene vinyl acetate copolymer is saponified with 50 mol% of sodium methoxide catalyst in the presence of methanol, and then acrylic acid is grafted with benzoyl peroxide, and the product is precipitated with water. A was obtained. The obtained resin A was a 0.2% by weight acrylic acid grafted product.

(Ii) Melt index 55g / 10min vinyl acetate content
Resin B was obtained by preparing a 55 mol% saponified product of 40% ethylene vinyl acetate copolymer according to (i), and further grafting 0.2% by weight of acrylic acid.

[Examples 1 to 10] Interlayer and laminated glass Resin A or B obtained in Production Example and transparency modifier are shown in Table 1.
In Example 8, a silane coupling agent was further added, and the mixture was charged into a tumbler and rotated for 20 minutes to mix.

Next, the mixture is melted at 120 ° C. by an extruder, extruded into strands, and pelletized by a pelletizer.

Thereafter, the pellets were extruded into a sheet at 170 ° C. with a T-die, and subsequently, a 400 μm-thick resin film (intermediate film) was obtained with a take-up roll having an embossed pattern.

The obtained intermediate film was sandwiched between two pieces of 3 mm float glass, placed in a bag, and placed in a heating furnace while reducing the pressure in the bag, and heated at 100 ° C. for 30 minutes to produce a laminated glass.

The disproportionated hydrogenated rosin polyester adducts A and B used in Examples 9 and 10 were produced by the following method known per se.

For example, polyester adduct A of disproportionated hydrogenated rosin
Is charged into a reactor with 50 parts by weight of a polyester composed of 2 mol of neopentyl glycol, 1 mol of hydrogenated bisphenol A and 4 mol of hexahydrophthalic anhydride and 50 parts by weight of glycidyl ester of disproportionated hydrogenated rosin. One obtained by reacting at 180 ° C. for 2 hours was used. The polyester adduct B of disproportionated hydrogenated rosin is composed of 45 parts by weight of a polyester comprising 1 mol of neopentyl glycol, 1 mol of hydrogenated bisphenol A and 3 mol of hexahydrophthalic anhydride, and disproportionated hydrogenated rosin. Of a glycidyl ester was charged into a reactor and reacted at 180 ° C. for 2 hours.

Table 1 shows the process of measuring the properties of the obtained laminated glass. In particular, in the present invention, visual transparency is excellent.

The measurement of the total light transmittance and the measurement of Haze were performed in accordance with the test method specified in JISR3212.

Further, the boiling water immersion test was performed in accordance with a test method specified in JISR3205 heat resistance.

[Test Examples 1 to 12] Adhesion test Each of the interlayer films obtained in Examples 1 to 10 and Comparative Examples 1 and 2 was placed on glass, and a 50 µ polyester film was placed thereon, and placed thereon for holding down. The glass was placed, and the glass and the polyester film were bonded in the same manner as in Example 1.

Next, the adhesive strength between the glass and the interlayer and between the interlayer and the polyester film was examined, and the water resistance of the adhesion was examined. Table 2 shows the results.

The measurement of the adhesive strength and the water-resistant adhesive strength was carried out in accordance with the test method specified in JIS K6854 (180 ° peel test: pulling speed 200 mm / min).

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-63-151649 (JP, A) JP-A-59-78958 (JP, A) JP-A-58-79850 (JP, A) JP-A-61-78 44741 (JP, A) JP-B 63-33784 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) C03C 27/12

Claims (4)

(57) [Claims] 1. A partially saponified ethylene-vinyl acetate copolymer or an acid-modified ethylene-vinyl acetate copolymer, and at least one transparency modifier selected from rosins and polybrominated polycyclic aromatic compounds. Adhesive synthetic resin interlayer for laminated glass. 2. The adhesive synthetic resin interlayer according to claim 1, further comprising a silane coupling agent. 3. The amount of the transparency modifier is 2 to 40% by weight based on the total amount of the partially saponified ethylene vinyl acetate copolymer or the acid-modified product thereof and the transparency modifier. Or the adhesive synthetic resin interlayer according to 2). 4. A laminated glass using the adhesive synthetic resin interlayer according to claim 1 as an adhesive.