JPH11323056A - Interlayer for glass laminate and laminated glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an interlayer having a good compatibility between a poly(vinyl acetal) resin and a plasticizer, and to provide laminated glass having a good adhesive property between an interlayer and plate glass using the interlayer. SOLUTION: This interlayer for laminated glass comprises (A) 100 pts.wt. poly(vinyl acetal) and (B) 20-60 pts.wt. plasticizer as main ingredients, wherein the plasticizer consists of triethylene glycol di-2-ethylhexanoate containing 0.3-5.0 wt.% triethylene glycol mono-2-ethylhexanoate. An average degree of conversion in poly(vinyl acetal) resin into acetal is pref. 40-75 mol.%. This laminated glass is produced by inserting the interlayer between at least two sheets of plate glass to glue them.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an interlayer for laminated glass and a laminated glass using the same, and more particularly, to an interlayer having good compatibility between a polyvinyl acetal resin and a plasticizer, and an interlayer. The present invention relates to a laminated glass having improved adhesion between a film and a glass plate.

[0002]

2. Description of the Related Art A laminated glass is formed by sandwiching an intermediate film made of a plasticized polyvinyl acetal resin composition between at least two glass plates, and has good transparency, weather resistance, adhesion, and penetration resistance. It is widely used, for example, for window glasses of automobiles and buildings because of its excellent properties such that glass is not easily scattered. This plasticized polyvinyl acetal resin composition contains a polyvinyl acetal resin and a plasticizer as main components, and further contains additives such as an ultraviolet absorber, an antioxidant, and an adhesion regulator. To obtain it, the compatibility between the polyvinyl acetal resin, which is the main component, and the plasticizer and the overall balance of each performance are important.

A plasticizer comprising triethylene glycol di-2-ethylhexanoate is known, has a high boiling point (219 ° C./5 mmHg), is hardly released into the atmosphere during high-temperature film formation, and has good handleability. It has advantages such as good hydrolyzability. On the other hand, since it has a low polarity, unless the acetalization degree of the polyvinyl acetal resin is increased, it tends to be inferior in compatibility with the polyvinyl acetal resin.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide an intermediate film having good compatibility between a polyvinyl acetal resin and a plasticizer, and to provide an intermediate film and a glass plate using this intermediate film. It is to provide a laminated glass having good adhesiveness.

[0005]

The inventors of the present invention have studied the compatibility of a polyvinyl acetal resin with a plasticizer composed of triethylene glycol di-2-ethylhexanoate. The compatibility with the polyvinyl acetal resin changes depending on the monoester content as an unreacted substance when 2-ethylhexanoate is produced, that is, the content of triethylene glycol / mono-2-ethylhexanoate. It has been found that the adhesive strength between an interlayer and a glass plate in glass changes.

The present invention has been completed based on such findings.

That is, the present invention provides an interlayer film for laminated glass comprising, as main components, 100 parts by weight of a polyvinyl acetal resin and 20 to 60 parts by weight of a plasticizer, wherein the plasticizer is triethylene glycol mono-2-ethylhexano. An interlayer film for laminated glass, comprising triethylene glycol di-2-ethylhexanoate containing 0.3 to 5.0% by weight of acetate.

[0008] The polyvinyl acetal resin preferably has an average degree of acetalization of 40 to 75 mol%.

A laminated glass is formed by sandwiching the above-mentioned intermediate film between at least two pieces of glass.

[0010] As described above, for example, Japanese Patent Publication No. 3-56545 discloses a monoester of unsaturated fatty acid multiesters of C16 to C20 which is effective in containing the monoester component in the multiester. It is disclosed that the combination with an ester improves the penetration resistance of the obtained laminated glass and the peel adhesion of the interlayer to the polycarbonate, but the plasticizer according to the present invention is a compound which is different from that described in the above publication. They differ in species and effects.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to obtain a plasticizer used in the present invention, triethylene glycol mono-2-ethylhexanoate is usually used in an esterification reaction between triethylene glycol and 2-ethylhexanoic acid. 0 inside.
A method of stopping the reaction at a required reaction rate without completely proceeding the reaction so that 3 to 5.0% by weight remains. Hereinafter, this esterification reaction will be described.

The plasticizer used in the present invention is, for example, in the esterification reaction of triethylene glycol and 2-ethylhexanoic acid, the ratio of the raw materials is, for example, 2 to 2-ethylhexanoic acid per mole of triethylene glycol. .5
It is about a mole. The reaction proceeds even in the absence of a catalyst or a solvent.

The esterification reaction between triethylene glycol and 2-ethylhexanoic acid is carried out in the presence of a catalyst to increase the reaction rate and facilitate the reaction operation. A small excess of 2-ethylhexanoic acid itself can act as a catalyst. Examples of the acid catalyst used for the esterification include inorganic acids such as sulfuric acid, hydrochloric acid, and phosphoric acid; organic sulfonic acids such as paratoluenesulfonic acid and methanesulfonic acid; and organic metals such as tetraisopropyl titanate and tetrabutyl titanate. Is done. When a catalyst is used, the amount added is generally from about 0.01 to about 0.01% of the total reactants.
5.0% by weight. The esterification reaction can also be performed in a solvent. Solvents which are inert to the reactants and which form an azeotrope with the water formed during the reaction are preferred. Particularly suitable solvents are aromatic solvents such as toluene, xylene and benzene.

The above-mentioned esterification reaction can be carried out at normal temperature and normal pressure. However, in order to promote the reaction and to easily remove water generated as a result of the esterification reaction, the reaction should be carried out at 50 to 300 ° C.
It is preferably performed at a high temperature. A particularly preferred reaction temperature is a temperature equal to the boiling point of an azeotropic mixture of water and 2-ethylhexanoic acid or a solvent. The water generated by the esterification reaction is preferably removed from the reaction system during the reaction in order to increase the reaction rate and complete the reaction, and to know the progress of the reaction by measuring the amount of generated water. The removal of water is usually carried out by distillation of an azeotropic mixture of water and an acid or a solvent.

The esterification reaction is carried out while observing the progress of the reaction as described above.
When the reaction reaches, the reaction is stopped.

If the residual amount of the monoester is too small, the compatibility between the plasticizer and the polyvinyl acetal resin is reduced. If the residual amount is too large, the resin comprising the plasticized polyvinyl acetal resin obtained using the plasticizer is used. The adhesive force between the glass interlayer and the glass plate decreases with time.

Further, it is uneconomical because a large amount of energy is required to advance the esterification so that the residual amount of the monoester is less than the above range. If the reaction is stopped at a high reaction rate, the residual amount of the monoester increases, but it is difficult to determine the timing of stopping the reaction at the high reaction rate. Further, since the monoester component is a substance having a lower boiling point than that of the diester, it may be released into the atmosphere during high-temperature film formation. Therefore, it is not preferable that the residual amount of the monoester component is too large.

After terminating the reaction, the reaction product is subjected to a treatment such as neutralization, washing, dehydration, drying under reduced pressure or distillation to obtain triethylene glycol di-2 containing a monoester content of 0.3 to 5.0% by weight. Obtaining ethylhexanoate.

In order to obtain the plasticizer used in the present invention, in addition to the above method, for example, high-purity triethylene glycol di-
A method of mixing 2-ethylhexanoate with triethylene glycol di-2-ethylhexanoate containing a large amount of a monoester, or a method of mixing triethylene glycol di-2-ethylhexanoate with triethylene glycol di-2-ethylhexanoate. Ethylene glycol mono-2-ethylhexanoate in 0.
A method of adding 3 to 5.0% by weight may be used.

Using the above plasticizer, a plasticized polyvinyl acetal resin is prepared, an interlayer film for laminated glass is formed from this, and a laminated glass is produced using this.

The polyvinyl acetal resin, which is the main component of the intermediate film, is prepared by dissolving polyvinyl alcohol in warm water, keeping the resulting aqueous solution at a predetermined temperature, for example, 0 to 95 ° C., and adding an acid catalyst to the solution. And an aldehyde (eg, acetaldehyde, butyraldehyde, etc.) to proceed the acetalization reaction, then raise the reaction temperature and ripen to complete the reaction, followed by neutralization, washing, drying and other treatments It is obtained by a precipitation method for obtaining a powder of a polyvinyl acetal resin. As the obtained polyvinyl acetal resin, for example, a polyvinyl butyral resin is suitably used. The polyvinyl alcohol used in the above method has an average degree of polymerization of 500 to 300.
0 is preferred, and those having an average degree of polymerization of 1000 to 2500 are more preferred. If the average degree of polymerization of polyvinyl alcohol is less than 500, the penetration resistance of the laminated glass thus produced is lowered, and if it exceeds 3000, production of the polyvinyl acetal resin tends to be difficult. Further, the saponification degree of the polyvinyl acetal resin is preferably 70 mol% or more from the viewpoint of transparency and heat resistance. The average acetalization degree of the resin is preferably 40 to 75 mol%. If the average degree of acetalization is less than 40 mol%, the compatibility between the resin and the plasticizer may be reduced, and 75 mol
If it exceeds 1%, the resin production process may take a long time, and both are not preferred.

The amount of the plasticizer for producing the interlayer film for laminated glass is preferably 20 to 60 parts by weight based on 100 parts by weight of the polyvinyl acetal resin. If the amount is less than this, the penetration resistance of the laminated glass decreases, and if the amount is too large, problems such as bleeding of the plasticizer and deterioration of the transparency and adhesiveness of the film may occur.

The composition for producing the interlayer film for laminated glass includes one of known additives such as an ultraviolet absorber, a light stabilizer, an antioxidant, an adhesion regulator, a surfactant and a coloring agent.
Seeds or two or more can be added.

Representative examples of the ultraviolet absorber include benzotriazole-based ones, and commercially available products such as "Tinuvin P", "Tinuvin 320", "Tinuvin 326", and "Tinuvin 328" manufactured by Ciba-Geigy Co., Ltd. Is exemplified.

As the light stabilizer, there is a hindered amine-based light stabilizer. Commercially available products include, for example, "ADK STAB LA-57" manufactured by Asahi Denka Co., Ltd.

As the antioxidant, a phenol type antioxidant, for example, “Sumilyzer BH” manufactured by Sumitomo Chemical Co., Ltd.
T "," Irganox 101 "manufactured by Ciba Geigy
0 "and the like.

Examples of the adhesion regulator include metal salts of organic acids such as carboxylic acid, for example, octanoic acid, hexanoic acid, butyric acid, and the like.
Examples thereof include potassium salts such as acetic acid and formic acid, sodium salts, and magnesium salts. In addition, metal salts of inorganic acids such as nitric acid and hydrochloric acid can also be used.

Examples of the surfactant include sodium lauryl sulfate and sodium alkylbenzene sulfonate.

As a method for producing an interlayer film for laminated glass,
The polyvinyl acetal resin is blended with a predetermined amount of a plasticizer and various additives as necessary, and after uniformly kneading them, the kneaded material is extruded, calendered, pressed,
A method of forming a film into a sheet by a casting method, an inflation method or the like is generally used. The obtained resin film is
A single layer may be used as an intermediate film, or two or more layers may be stacked to form an intermediate film.

The total thickness of the above intermediate film is preferably in the range of 0.3 to 1.6 mm in consideration of minimum penetration resistance and weather resistance required for a laminated glass.

Examples of the glass plate used in the production of laminated glass include an inorganic plate glass such as a float plate glass, a polished plate glass, a template plate glass, a mesh plate glass, a line plate glass, a heat absorbing plate glass, a colored plate glass, a polycarbonate plate, a polymethyl methacrylate plate, and the like. Can also be used.

As a method of manufacturing a laminated glass, for example, 2
An interlayer film for laminated glass is sandwiched between two glass plates, which is placed in a rubber bag and suctioned under reduced pressure at about 70 to 110 ° C.
At a temperature of about 120 to 150 ° C. and a temperature of about 10 to 15 ° C. using an autoclave or a press.
A method of performing the actual bonding at a pressure of kg / cm ² is generally used.

[0033]

EXAMPLES Examples will be described below, but the present invention is not limited to the following examples.

Example 1 (1) Synthesis of plasticizer In a reactor equipped with a Gene Stark type oil / water separator, 360.0 g (2.50 mol) of 2-ethylhexanoic acid and 150.0 g of triethylene glycol (1. (00 mol) and 1.0 g of sulfuric acid, the degree of reduced pressure was adjusted so as to slowly reflux, and the mixture was reacted at a set temperature of 100 ° C. while stirring. During the esterification reaction, the reaction solution was sampled every predetermined time, and the conversion of triethylene glycol to an ester was determined using a gas chromatograph. The reaction was terminated when the monoester content in the reaction solution reached 3.4% by weight in terms of product. After completion of the reaction, the remaining acid was removed by distillation, the reaction product was neutralized, washed with water, and dehydrated. Then, activated carbon was added and the mixture was filtered to obtain a plasticizer product.
The composition of the final product was confirmed by gas chromatography.

(2) Synthesis of polyvinyl acetal resin An average degree of polymerization of 1700 and a degree of saponification of 99.000 in 2700 g of pure water.
250 g of 0% polyvinyl alcohol was added and heated to 95 ° C. to dissolve. Then, the solution was cooled to 11 ° C., and while stirring, 173 g of 35% hydrochloric acid and 141 g of n-butyraldehyde were added and the temperature was maintained to precipitate a reaction product. Thereafter, the temperature of the reaction system was raised to 60 ° C., and maintained at this temperature for 2 hours to complete the reaction. Reaction solution 3
After cooling to 0 ° C. and neutralizing with sodium hydroxide, the reaction product was separated by filtration, washed with excess water for 12 hours, and dried to obtain a polyvinyl butyral resin powder. The average degree of butyralization of this resin was 67.5 mol%.

(3) Production of interlayer film for laminated glass For 100 parts of the polyvinyl butyral resin obtained in the step (2), 40 parts of the plasticizer obtained in the step (1) and Ciba-Geigy as an ultraviolet absorber 0.2 parts of "Tinuvin 328" manufactured by Sumitomo Chemical Co., Ltd., 0.2 parts of "SUMILIZER BHT" manufactured by Sumitomo Chemical Co., Ltd. as an antioxidant, and 0.08 parts of magnesium 2-ethylhexanoate as an adhesion regulator were added. After melt-kneading the mixture with a mixing roll, the kneaded product was press-formed with a press-forming machine at 150 ° C. and 100 kg / cm ² for 30 minutes to obtain an interlayer film for laminated glass having a thickness of 0.8 mm. The compatibility was evaluated in the state of the intermediate film.

(4) Production of laminated glass The interlayer film for laminated glass obtained in (3) is sandwiched between float plate glasses from both sides, and this is placed in a rubber bag for 20 Torr.
, And then kept in an oven at 90 ° C. for 30 minutes while maintaining a vacuum. The adhesive taken out of the vacuum bag is autoclaved at a temperature of 150 ° C and a pressure of 13k.
Under the condition of g / cm ² , hot pressing was performed to obtain a laminated glass.

Example 2 In the synthesis step (1) of the plasticizer in Example 1, except that the reaction was terminated when the monoester content in the reaction solution reached 0.4% by weight in terms of product. A plasticizer was obtained in the same manner as in Example 1.

Using this plasticizer, an intermediate film and a laminated glass were produced in the same manner as in Example 1.

Example 3 In the synthesis step (1) of the plasticizer in Example 1, except that the reaction was terminated when the monoester content in the reaction solution reached 1.7% by weight in terms of product. A plasticizer was obtained in the same manner as in Example 1.

Using this plasticizer, an interlayer film and a laminated glass were produced in the same manner as in Example 1.

Example 4 In the synthesis step (1) of the plasticizer in Example 1, except that the reaction was terminated when the monoester content in the reaction solution reached 4.6% by weight in terms of product. A plasticizer was obtained in the same manner as in Example 1.

Using this plasticizer, an interlayer film and a laminated glass were produced in the same manner as in Example 1.

Comparative Example 1 In the plasticizer synthesis step (1) in Example 1, the content of triethylene glycol / mono-2-ethylhexanoate in the reaction solution reached 0.1% by weight in terms of product. At this point, a plasticizer was obtained in the same manner as in Example 1 except that the reaction was completed.

Using this plasticizer, an intermediate film and a laminated glass were produced in the same manner as in Example 1.

Comparative Example 2 In the synthesis step (1) of the plasticizer in Example 1, except that the reaction was terminated when the monoester content in the reaction solution reached 5.5% by weight in terms of product. A plasticizer was obtained in the same manner as in Example 1.

Using this plasticizer, an interlayer film and a laminated glass were produced in the same manner as in Example 1.

Table 1 shows the compounding ratios of the interlayer films for laminated glass of the above Examples and Comparative Examples.

Evaluation test Compatibility: The interlayer films for laminated glass obtained in the above Examples and Comparative Examples were allowed to stand at 20 ° C. and 25% humidity for 3 days, and the film surfaces were blotted with blotting paper and stained. Was examined. Table 3 shows the results.

Adhesion: In the laminated glasses obtained in the above Examples and Comparative Examples, the adhesion between the interlayer and the glass plate was evaluated by Pummel value. That is, the laminated glass obtained in the step (4) was left at a temperature of −18 ° C. ± 0.6 ° C. for 16 hours, and the head was hit with a hammer of 0.45 kg to reduce the particle diameter of the glass to 6 mm or less. Crushed until it became. The degree of exposure of the film after the glass was partially peeled was determined based on a preliminarily graded limit standard (Table 2), and the result was defined as a Pummel value. As shown in Table 2, the higher the Pummel value, the greater the adhesion to glass. Furthermore, the same evaluation test was performed after the laminated glass after the test was left at 50 ° C. for 4 weeks. Table 3 shows the evaluation results.

[0051]

[Table 1]

[0052]

[Table 2]

[0053]

[Table 3]

As can be seen from Table 3, the intermediate films obtained by using the plasticizers synthesized in Examples 1 to 4 have no stain on the film surface and have good compatibility between the polyvinyl acetal resin and the plasticizer. Met. Moreover, the adhesiveness with the glass plate of the laminated glass obtained using the plasticizer synthesized in Examples 1 to 4 showed a Pummel value of 6, which was also good. Further, the adhesiveness of the laminated glass to the glass plate after long-term storage also had a Pummel value of 6, confirming that there was no change with time.

On the other hand, when the monoester content in the plasticizer was too small as in Comparative Example 1, the compatibility was poor. As in Comparative Example 2, the monoester content in the plasticizer was too high. The adhesion between the glass plate and the glass plate decreased with time.

[0056]

According to the present invention, an interlayer having good compatibility between a polyvinyl acetal resin and a plasticizer can be provided. Further, according to the present invention, it is possible to provide a laminated glass having good adhesion between an interlayer film and a glass plate and being useful for automobiles and buildings.

Claims (3)

[Claims] 1. An interlayer film for laminated glass comprising, as main components, 100 parts by weight of a polyvinyl acetal resin and 20 to 60 parts by weight of a plasticizer, wherein the plasticizer is triethylene glycol mono-2-ethylhexanoate. 3 ~
An interlayer film for laminated glass, comprising triethylene glycol di-2-ethylhexanoate containing 5.0% by weight. 2. The interlayer film for laminated glass according to claim 1, wherein the average acetalization degree of the polyvinyl acetal resin is 40 to 75 mol%. 3. A laminated glass comprising the interlayer film for laminated glass according to claim 1 sandwiched between at least two sheets of glass.