JPS5825376B2 - Interlayer film composition for safety laminated glass - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polyvinyl butyral resin composition used as an interlayer film for safety laminated glass.

Polyvinyl butyral has been widely used as an interlayer film for safety laminated glass for automobiles, aircraft, building window glasses, etc. due to its excellent performance.

This polyvinyl butyral is plasticized by adding a plasticizer and used as an interlayer film formed into a sheet shape, and glass plates are bonded together with this interlayer film to make safety laminated glass. Even with laminated glass used as an interlayer film, performance such as penetration resistance is still insufficient, and various improvements have been attempted.

For example, it has been proposed to improve the penetration resistance of laminated glass by using an interlayer film in which metal salts of organic carboxylic acids or fluorides of alkali metals are kneaded into polyvinyl butyral. Even if it is possible to improve the penetration resistance in the temperature range of about 10 to 20 degrees Celsius,
It is difficult to improve the penetration resistance so as to cover the wide temperature range of -20°C to 40°C in which automobile windshields, aircraft window glasses, etc. are actually used.
Particularly at low temperatures, the above-mentioned strength decreases significantly.

In addition, when adding additives to polyvinyl butyral as described above to improve the penetration resistance, even if the penetration resistance is improved, the adhesion of the interlayer film to the glass decreases, making it more susceptible to damage by impact objects. This is undesirable because the broken glass fragments tend to scatter without being held by the interlayer film.

In view of the current situation of interlayer films using polyvinyl butyral as described above, the present invention is capable of preventing a large drop in penetration resistance even at low or high temperatures, has excellent penetration resistance over a wide temperature range, and at the same time It was developed with the aim of providing an interlayer film with excellent adhesion to glass, and its gist is that at least one unit of a monomer having a carboxyl group, which may be salt-modified or ester-modified, is mixed with at least 0. The present invention relates to an interlayer film composition for safety laminated glass comprising a polyvinyl butyral resin having a content of 3 mol % and a triethylene glycol ester plasticizer added thereto.

The degree of butyralization of the polyvinyl butyral resin used in the present invention is preferably 50 to 80 mol%, and
The degree of polymerization is preferably about 800 to 2,600.

However, the polyvinyl butyral resin used in the present invention has a small amount of carboxyl groups (both 0.3 mol%), and this carboxyl group may be salt-modified by replacing the hydrogen of the group with a metal. Alternatively, the group may be esterified to undergo ester modification.

In the case of the above-mentioned ester modification, it is preferable that a part of the carboxyl group is esterified with a lower alcohol.

The method for preparing the polyvinyl butyral resin having a carboxyl group as described above is not particularly limited, but for example, the following method may be used.

That is, one method is to copolymerize unsaturated carboxylic acids such as maleic acid, itaconic acid, crotonic acid, methacrylic acid, acrylic acid, etc. and their esters with vinyl acetate using alkali or acid. There is a method in which a carboxyl group-containing butyral resin, that is, an acid-modified butyral resin, is obtained by saponifying the polyvinyl alcohol to produce acid-modified polyvinyl alcohol, and then converting the polyvinyl alcohol into butyral with an aldehyde.

In addition, as another method, when polyvinyl alcohol is converted into butyral, an aldehyde having a carboxyl group,
For example, a method of butyralization using glyoxylic acid, mucochloric acid, etc. mixed with a small amount of butyraldehyde, or a method of carboxymethylating polyvinyl alcohol or polyvinyl butyral by reacting monochloroacetic acid etc. under an alkali catalyst to the hydroxyl group of polyvinyl alcohol or polyvinyl butyral. In this case, examples include a method in which the compound is then butyralized with an aldehyde.

As mentioned above, the polyvinyl butyral resin used in the present invention has at least 0.3 mol% of carboxyl groups, but this means that if the content of seven units containing carboxyl groups is less than this, the effects of the present invention will be reduced. On the other hand, if the content of monomer units having a carboxyl group is too high, the melting temperature tends to increase and processability tends to decrease, so the content is 15 mol%. It is preferable that it is below.

Therefore, having at least 0.3 mol% of one unit of a monomer having a carboxyl group in the polyvinyl butyral resin means one unit of all the monomers constituting the polyvinyl alcohol resin, which may be a copolymer with an unsaturated carboxylic acid. (However, for convenience, the number of monomer units is calculated assuming that the butyralized portion is not butyralized.)

2) The presence of at least 0.3% of one monomer unit modified by a carboxyl group.

Next, as the triethylene glycol ester plasticizer used in the present invention, for example, triethylene glycol di-2-ethyl butyrate, triethylene glycol di-2-ethyl hexoate, etc. can be suitably used.

The amount of the triethylene glycol ester plasticizer to be used is usually 20 to 80 parts by weight per 100 parts by weight of the polyvinyl butyral resin.

The interlayer film composition of the present invention can be obtained by adding and mixing a triethylene glycol ester plasticizer with the polyvinyl butyral resin having carboxyl groups, and at this time, colorants and other additives may be added as appropriate. I can't help it.

Then, the interlayer film composition of the present invention is formed into a sheet shape by a conventional method to form an interlayer film, and the interlayer film composition is sandwiched between multiple sheets of glass.
Heat and pressure is applied to laminated glass for automobiles, aircraft,
It can be used as safety glass for buildings, etc.

Since the interlayer film composition for safety laminated glass of the present invention has the above-mentioned structure, it is believed that the composition can improve the penetration resistance of the laminated glass used as an interlayer film in low-temperature and high-temperature regions. At the same time, it also improves the adhesion between the interlayer film and the glass surface, which has the effect of reducing the scattering of glass fragments broken by impact objects.

As described above, the composition of the present invention can simultaneously improve the penetration resistance and adhesion to the glass surface of the laminated glass in which the composition is used, thereby further improving the safety of the laminated glass. .

Next, examples of the present invention will be described.

In addition, in the following, parts mean parts by weight.

Example 1 Degree of polymerization 1700, degree of saponification 99.8 mol%, degree of acid modification 2
．． Butyralization was performed using 2 mol% maleic acid-modified polyvinyl alcohol, and the carboxyl group content was 2.
2 mol% polyvinyl butyral was obtained.

In addition, the degree of butyralization of this polyvinyl butyral is 63
It was mol%.

50 parts of triethylene glycol di-2-functional butyrate was added to 100 parts of the resin, and the mixture was heated to 130 parts using a roll press.
A 0.030 inch thick film was made at a temperature of ~150°C.

This film was sandwiched between two 3 mm thick glass plates and heated and pressurized to produce a laminated glass.

The ball falling height and pummel value of the obtained laminated glass were measured in the following manner.

The results were as shown in Table 1.

Falling ball height: A laminated glass is fixed to a 3oox3oomm support frame and held horizontally, and a 2.26 kg steel ball is freely dropped from above to the center of the test piece.

Gradually increasing the height of the steel ball, repeat the test at a constant height to find the distance the steel ball falls onto the glass surface that prevents the steel ball from penetrating in 50% of the tests, and use that distance as the falling ball height. Satoshi.

And in this test, the temperature of the laminated glass was -20℃, 20℃
The test was carried out at three different temperatures: and 40°C.

Therefore, the higher the falling ball height, the higher the penetration strength.

Pummel value: After keeping the laminated glass at -18°C for more than 1 hour to bring it to a constant temperature, it is crushed under a crushing test with a hammer (head weighing 1 pound) until the adhered glass particle size is 6 mm or less. do.

Shake off the broken glass pieces and remove the exposed part of the interlayer film.
It is divided into ~80 ranks, and the lower the degree of exposure, the higher the value.

Therefore, the adhesion of the interlayer film is good, and the degree of exposure at low degrees Celsius and the pummel value are high.

Example 2 Butyral with a carboxyl group content of 4.0 mol% prepared by butyralizing maleic acid-modified polyvinyl alcohol with a degree of polymerization of 1700, a degree of saponification of 96 mol%, and a degree of maleic acid modification of 4.0 mol%. Degree of oxidation: approx. 63 mol%
A composition was prepared by adding 60 parts of triethylene glycol di-2-functional butyrate to 100 parts of the polyvinyl butyral, and a laminated glass was produced in the same manner as in Example 1.

Further, when the same test as in Example 1 was conducted on the laminated glass obtained above, the results shown in Table 1 were obtained.

Example 3 100 parts of polyvinyl alcohol with a degree of saponification of 99.6 mol% and a degree of polymerization of 1700 was dissolved in water, the system was kept at 10°C, 64 parts of concentrated hydrochloric acid and 9 parts of glyochilic acid were added, and then butyraldehyde was dissolved. Add 50 parts and react.

The product obtained by the reaction was washed with water and dried.

In this way, polyvinyl butyral containing 9.4 mol% of acid-modified dust and a degree of butyralization of 56 mol% was obtained.

It was also confirmed that almost no glyoxylic acid and butyraldehyde remained adsorbed on this polyvinyl butyral.

A laminated glass was made in the same manner as in Example 1 except that the glyoxylic acid-modified polyvinyl butyral obtained above was used, and the same tests were conducted.

The results were as shown in Table 1.

Example 4 100 parts of polyvinyl alcohol with a degree of saponification of 99.6 mol% and a degree of polymerization of 1700 was dissolved in a 5% aqueous sodium hydroxide solution, 50 parts of monochloroacetic acid was added, and the reaction system was maintained at 0°C and reacted for 20 hours. , excess hydrochloric acid was added to obtain acid-modified polyvinyl alcohol.

To this system, 55 parts of butyraldehyde was added to 100 parts of polyvinyl alcohol, and the system was kept at 35° C. and reacted for 5 hours to obtain acid-modified polyvinyl butyral.

By analyzing the water-washed and dried polyvinyl butyral, it was found that the polyvinyl butyral contained 11 mol% of acid-modified dust and a degree of butyralization of 5.
It was found to be 5 mol%.

Moreover, almost no unreacted monochloroacetic acid was present in the resin after washing with water and drying.

A laminated glass was prepared in the same manner as in Example 1, except that the carboxymethylated polyvinyl butyral obtained above was used, and the same tests were conducted.

The results were as shown in Table 1.

Example 5 The acid-modified polyvinyl butyral obtained in Example 1 was added to 0.01
After being immersed for 20 hours in a specified NaO'E solution (a mixed NaOH solution with a water:ethyl alcohol volume ratio of 8:2), it was washed with water and dried.

In this way, acid-modified polyvinyl butyral in which 1.2 mol% of the 2.2 mol% carboxyl groups was neutralized with sodium to become salt-modified carboxyl groups was obtained.1 Using this resin, the same procedure as in Example 1 was carried out. Laminated glass was made and similar tests were conducted.

The results were as shown in Table 1.

Example 6 The acid-modified polyvinyl butyral obtained in Example 1 was immersed in a 0.2N NaOH solution (NaOH solution with a volume ratio of water: ethyl alcohol of 8:2) for 20 hours, and then washed with water. Dry.

In this way, a modified polyvinyl butyral in which most of the carboxyl groups (2.2 mol %) were neutralized with sodium was obtained.

A laminated glass was made using this resin in the same manner as in Example 1, and the same tests were conducted.

The results were as shown in Table 1.

Example 7 To 100 parts of the acid-modified polyvinyl butyral obtained in Example 1, 6 parts of triethylene glycol di-2-functional methyl hekynate was added.
0 parts was added to prepare a composition, and thereafter a laminated glass was made and tested in the same manner as in Example 1.

The results were as shown in Table 1.

Comparative Example 1 Triethylene glycol di-
A laminated glass was made in the same manner as in Example 1 using plasticized polyvinyl butyral to which 40 parts of 2-ethyl butyrate had been added, and the same tests were conducted.

The results were as shown in Table 1.

Claims (1)

[Claims] 1. A safety compound made by adding a triethylene glycol ester plasticizer to a polyvinyl butyral resin having at least 0.3 mol% of one monomer unit having a carboxyl group which may be salt-modified or ester-modified. Interlayer film composition for glass. 2 The first polyvinyl butyral resin has a carboxyl group-containing monomer unit content of 0.3 to 15 mol%
An interlayer film composition for safety laminated glass as described in . 3 Butyralization degree of polyvinyl butyral resin is 50
2. The interlayer film composition for safety laminated glass according to item 1, which has a content of 80 mol %. 4 Polyvinyl butyral resin has a polymerization degree of 800 to 26
00. The interlayer film composition for safety laminated glass according to item 1. 5 The amount of triethylene glycol ester plasticizer added is 20 to 100 parts by weight of polyvinyl butyral resin.
80 parts by weight of the interlayer film composition for safety laminated glass according to item 1.