JPH051109A - Polyvinyl butyral resin and interlayer film made of the same resin - Google Patents

Abstract

(57) [Summary] [Composition] Polyvinyl alcohol and butyraldehyde
A condensation product of ¹H nuclear magnetic resonance spectrum measurement
The butyralization degree in the range of 65 to 75 mol%
Yes, in the same measurement, the chain length of residual hydroxyl groups is 3 or more
One of the heterotactic triad type
~ 4.5 mol%, syndiotactic triad type
Of 1 to 4 mol% and isotactic try
Add type is 0.05 to 2 mol%, and
¹³In the C nuclear magnetic resonance spectrum measurement,
All syndiotactic hydroxyl groups with a chain length of 3 or more
When the integral value is 100%, three
50%, 4-40 chains are 30-40%, 5 chains or more
Of 10% to 40% of polyvinyl alcohol
Chiral resin Resin. [Effect] Improving the fluidity of the interlayer film at high temperature
It reduces the adhesiveness between membranes and has excellent moisture resistance.
An interlayer film for laminated glass is provided.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel polyvinyl butyral resin having a unique arrangement of hydroxyl groups. In addition, the present invention uses the compound of the same resin and the plasticizer as the intermediate film because of the unique arrangement of the hydroxyl groups as described above, and when the laminated film is manufactured by sandwiching the intermediate film with a pair of glass plates. , An interlayer film exhibiting excellent processability and good moisture resistance.

[0002]

2. Description of the Related Art Conventionally, a laminated glass obtained by sandwiching a plasticized polyvinyl butyral resin film as an intermediate film between glasses is excellent in impact energy absorption, transparency and adhesiveness with glass, and is also broken when broken. Since it does not scatter and is highly safe, it is widely used for window glass of transportation vehicles such as automobiles and window glass of buildings.
As the spread rate of laminated glass has increased, there has been a strong demand for improved laminated glass production efficiency. Especially in automobile windshields, the prevalence of laminated glass is high, and therefore an interlayer film having good laminating processability is desired. This is because the curvature of the windshield is increasing and the windshield is becoming a three-dimensional curved surface due to the emphasis on high speed performance of automobiles and the tendency toward larger size.

The conventional laminated glass interlayer film is difficult to cope with the recent changes in the shape of the windshield. That is, the conventional interlayer film is sandwiched between a pair of glass plates, and then subjected to a preliminary pressure bonding step of performing degassing while heating, and then finished in the final main pressure bonding step. Does not flow, so a so-called residual air phenomenon easily occurs. For this reason, there has been a problem that the rework ratio of the air residual laminated glass is increased.

Regarding the improvement of the fluidity of the resin in the main pressure-bonding step, for example, JP-A-2-182704 discloses that the polyvinyl butyral resin is chemically modified to improve the fluidity of the film at the time of stacking and the film-to-membrane property. Proposals have been made to achieve and eliminate the sticking problem. This is intended to improve the fluidity at the time of lamination by an ionomer type polyvinyl butyral, but since an ionic bond substance is introduced, the adhesive force between the glass and the polyvinyl butyral interlayer film can be arbitrarily adjusted. It has the difficulty that it is difficult to control.

Conventionally, the relationship between the tackiness of the interlayer film and the chain length of the hydroxyl group in the resin has been well studied, and it is said that the longer the chain length of the hydroxyl group is, the lower the tackiness of the resin is (for example, See JP-A-2-123103). Control of the resin physical property in the room temperature region of tackiness is related to the chain length of hydroxyl groups of 3 or more, but the detailed contribution of the hydroxyl groups in the high temperature region has not yet been clarified.

By the way, recently, the moisture resistance of laminated glass is highly required. One of the reasons is the following changes in the method of mounting the windshield on the frame of the automobile. Conventionally, when the laminated glass as the windshield is bonded to the frame with an adhesive or the like, a method has been adopted in which the peripheral edge of the laminated glass is sealed with rubber, etc., which prevents the infiltration of moisture-containing air and rainwater. I was forced to. In addition, even if some change with time occurs in the interlayer film of the laminated glass due to the intrusion of water,
Since this portion was hidden by the seal, it did not spoil the appearance. However, recently, there has been a tendency to adopt a mounting method called a flush mount in which the peripheral portion of the windshield is only exposed by an adhesive and is left exposed to the outside. This method is expected to become more widespread in the future because it has the advantages of reducing the weight of the vehicle and simplifying the glass mounting process. Therefore, it is expected that the adoption of this method will strongly demand moisture resistance for the intermediate layer of the laminated glass. The reason is that when a laminated glass having poor moisture resistance is attached to the frame as a windshield by the above method, the water that has penetrated into the interlayer film of the laminated glass under high humidity cannot be completely contained in the composition of the resin and the plasticizer, and the water does not mix. This is because they are separated and whitening occurs by this.

[0007] Another reason why moisture resistance is required is the movement of adoption of laminated glass for side glass. Since the side glass has a structure that can be opened and closed as appropriate, its end face is always exposed. Therefore, a technical problem in using laminated glass for the side glass is to improve the moisture resistance of the end faces of the laminated glass.

Under the circumstances, attempts have been made to propose a sealing method for the end face of laminated glass and to develop a material having excellent moisture resistance. For the improvement of the sealing method for the edges of the laminated glass, see, for example, J.
And Japanese Utility Model Laid-Open No. 63-23027. A proposal of a laminated glass made of a material having excellent moisture resistance is described in JP-A-56-37154.

The proposal described in Japanese Utility Model Publication No. 61-98827 is as follows.
It is intended to improve the moisture resistance by sealing the end faces of the laminated glass with a moisture resistant layer. However, this is a problem that the long-term moisture resistance cannot be secured despite the complicated process. In addition, the actual exploitation Sho 63-2302
No. 7 aims to improve the moisture resistance by sealing the edges of the laminated glass with a specific adhesive, but this is also very complicated because the moisture resistance is not sufficient like the above-mentioned No. 61-98827. It requires steps and is not practical. For a proposal of a material having excellent moisture resistance, see JP-A-56-371.
54. This material is a laminated glass mainly composed of a polyvinyl acetal resin using a special plasticizer, and aims to improve moisture resistance by using tetraethylene glycol-di-n-heptanoate as a plasticizer. However, its moisture resistance level is
Not practically satisfactory. That is, the increase in water content due to the decrease in the amount of plasticizer made possible by using the above plasticizer has not reached a sufficient level.

[0010]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above circumstances, and a first object thereof is to provide a hydroxyl group chain length, in particular, a hydroxyl group chain length of 3 or more. By clarifying the relationship between the abundance and the morphology of the resin and the high temperature region of the resin, it is possible to improve the fluidity of the interlayer film at high temperature and is suitable for a laminated glass interlayer film that does not cause the air residue phenomenon as described above. Another object is to provide a polyvinyl acetal resin.

A second object of the present invention is to provide a polyvinyl butyral resin suitable for a laminated glass interlayer film, which can reduce the adhesiveness between interlayer films by elucidating the relationship as described above.

A third object of the present invention is to provide a polyvinyl acetal resin suitable for a laminated glass interlayer film having excellent moisture resistance, which does not require a special end surface treatment or a special end surface protection mechanism as described above. Especially.

[0013]

Means for Solving the Problems The present inventor has paid attention to the chain length of hydroxyl groups in a polyvinyl butyral resin and its morphology, and as a result of earnest studies on the relationship with the fluidity of the interlayer film at high temperature, The present invention has been completed.

[0014] That is, polyvinyl butyral resin of the present invention is a condensation product of polyvinyl alcohol and butyraldehyde, using proton as a resonance type ¹
In the H nuclear magnetic resonance spectrum measurement, the degree of butyralization is in the range of 65 to 75 mol%, and in the measurement, the chain length of residual hydroxyl groups is 3 or more and the heterotactic triad type is 1 to 4. 5 mol%, syndiotactic triad type 1 to 4 mol%, and isotactic triad type 0.05
.About.2 mol%, and isotope ¹³ C as a resonance species
In the measurement of ¹³ C nuclear magnetic resonance spectrum by using, when the total integral value of syndiotactic type hydroxyl groups in which the chain length of residual hydroxyl groups is 3 or more is 100%, that of 3 chains is 30-50%, and that of 4 chains 30% to 40% of those having 5 chains or more and 10% to 40% of those having 5 or more chains.

The polyvinyl butyral resin of the present invention can be obtained, for example, by reacting polyvinyl alcohol obtained by saponification of polyvinyl acetate with butyraldehyde in the presence of an acid catalyst. More specifically, this resin is prepared by dissolving polyvinyl alcohol in water at 95 ° C or higher, lowering the temperature to 70 to 80 ° C, and then adding an acid catalyst and butyraldehyde to allow most of the reaction to proceed. It can be obtained by appropriately heating the reaction system by 5 ° C. or more above the above reaction temperature and keeping it at high temperature for aging to complete the reaction, and then neutralizing, washing with water and drying by a conventional method.

Further, a catalyst such as hydrochloric acid is added to an aqueous solution of polyvinyl alcohol, butyraldehyde is added dropwise to the solution in a cooled state to react with polyvinyl alcohol, followed by aging at a predetermined temperature, and then post-treatment as described above. You may obtain a polyvinyl butyral resin by doing.

The average degree of polymerization of polyvinyl alcohol as a raw material is preferably 800 to 3000.

The degree of saponification of polyvinyl alcohol is
In order to obtain a polyvinyl butyral resin excellent in transparency and heat resistance, the content is preferably 95 mol% or more.

The polyvinyl butyral resin thus obtained is a condensate of polyvinyl alcohol and butyraldehyde and has the above-mentioned specific physical properties.

Next, the relationship between the length and morphology of the hydroxyl chain and the fluidity of the resin at high temperatures will be described. The polyvinyl butyral resin according to the present invention is a condensation product of polyvinyl alcohol and butyraldehyde, and has a butyralization degree in the range of 65 to 75 mol% in ¹ H nuclear magnetic resonance spectrum measurement, and remains in the same measurement. Heterotactic triad type having 1 to 4.5 mol% of chain length of 3 or more hydroxyl groups, syndiotactic triad type having 1 to 4.5 mol%
4 mol% and 0.05 to 2 mol% of isotactic triad type and syndiotactic hydroxyl group having a residual hydroxyl chain length of 3 or more in ¹³ C nuclear magnetic resonance spectrum measurement. The total integrated value of 10
When set to 0%, 3 to 30 chains have 30 to 50%, 4 chains have 30 to 40%, and 5 chains or more have 10 to 4%.
Since it is 0%, the fluidity of the resin at high temperature is improved, and the adhesiveness between the interlayer films is controlled (reduced) in the room temperature region.

The form of the chain of the hydroxyl groups is as follows: a heterotactic type triad (hereinafter abbreviated as a hetero type) schematically shown in FIG. 4 (a), and a syndiotactic type triad (hereinafter referred to as a hetero type) shown in FIG. 4 (b). Syndio type) and an isotactic triad shown in FIG. 4C (hereinafter abbreviated as iso type). This syndio type is mainly involved in the temperature range of 120 to 150 ° C. in the main pressure bonding step described above as one of the steps for producing a laminated glass, and in particular, syndio type 3-chain, 4-chain and 5-chain or more hydroxyl groups are contained. It became clear that the identification of That is, in the case of controlling the adhesiveness between the interlayer films, detailed identification of each chain length of the syndio type hydroxyl group was not required, but in the temperature range of 120 to 150 ° C. of the main pressure bonding step, among the syndio type hydroxyl groups, It is necessary to specify the ratio of 3 chains, 4 chains and 5 chains or more. ¹³ C nuclear magnetic resonance spectrum measurement is a means for analyzing the relative relationship between the amounts of the 3-chain length, 4-chain length and 5-chain length or more of the syndio type hydroxyl group.

With the introduction of this new measuring method, the deterioration (increase) of the adhesiveness in the normal temperature range is not caused,
Resins can be defined that achieve an increase in the fluidity of the interlayer at high temperatures. Since the iso-type and hetero-type hydroxyl groups are stereoregular with relatively weak hydrogen-bonding properties, their influence on the physical properties of the resin is dominant at room temperature. But 1
In the temperature range of 20 to 150 ° C., hydrogen bonding is weak due to molecular mobility due to heat. On the other hand, the syndio type hydroxyl group is
Because of the high stereoregularity of intermolecular hydrogen bonding,
Even in the temperature range of 120 to 150 ° C, the influence of the hydrogen bonding property is large. The intermolecular hydrogen bonding property of syndio type hydroxyl group is
It has a strong relationship with the chain length of the hydroxyl group, but especially 5
If there are many syndio-type hydroxyl groups that are longer than the chain, 150
Since strong intermolecular hydrogen bonding occurs even in a temperature range exceeding ℃, the fluidity of the interlayer film at high temperature does not increase. From this, the present invention was completed by studying the relationship between the amount and chain length of hydroxyl groups, the tackiness at room temperature, and the fluidity at high temperature.

Moreover, the polyvinyl butyral resin according to the present invention has excellent moisture resistance because it has the above-mentioned specific physical properties, and the layer separation of water due to local hydration is caused in the laminated glass interlayer film made of the resin. It is prevented, so that whitening does not occur.

The relation between the present invention and the technique for reducing tackiness in the room temperature range described in JP-A-2-123103 is as follows: In the above-mentioned known technique, the hetero-type hydroxyl group is 6 By setting -12 mol% and the syndio type hydroxyl group to 3-5 mol%, the tackiness is reduced. On the other hand, in the present invention, in addition to setting the hetero type hydroxyl group to 1 to 4.5 mol% and the syndio type hydroxyl group to 1 to 4%, the iso type hydroxyl group is set to 0.05 to 2 mol%. There is. In the present invention, the fluidity at high temperature is secured by reducing the amount of hetero type and syndio type hydroxyl groups. However, the tackiness increases in the room temperature range, which causes a problem in this respect. The present invention balances the physical properties at normal temperature and high temperature, and defines the relative ratio of 3 chain and 4 chain of syndio type hydroxyl groups, so that flow at high temperature can be achieved without increasing the adhesiveness at room temperature. It has achieved the improvement of sex.

Next, the laminated glass intermediate film according to the present invention will be described.

The laminated glass interlayer according to the present invention is a polyvinyl butyral resin having the above-mentioned structure, wherein the residual hydroxyl group has a chain length of 5 or more and the syndiotactic hydroxyl group has an integral value of 10 to 20%. It was obtained from a blend with a plasticizer.

As the above-mentioned plasticizer, a plasticizer which can be generally used for polyvinyl butyral resin is used.
For example, triethylene glycol-di (2-ethylbutyrate), triethylene glycol-di (2-ethylhexoate) and the like, triethylene glycol and a straight or branched chain having 4 to 8 carbon atoms. Esters with monobasic acids are preferably used. Since such a plasticizer has a proper compatibility with the resin, the phase separation of water can be effectively suppressed.

The carbon number of the monobasic acid is 4 from the relative balance between the propyl group which is the side chain of the butyral ring of the polyvinyl butyral resin and the plasticizer.
The range of -8 is suitable. When the carbon number is less than 4, the polyvinyl butyral resin cannot be sufficiently approached, and when the carbon number exceeds 8, the compatibility with the polyvinyl butyral resin is remarkably impaired, which is not preferable. On the other hand, regarding the glycol, in tetraethylene glycol, since the polarity of the plasticizer is too stronger than the polarity of the polyvinyl butyral resin, the water is strongly attracted to the plasticizer, resulting in the water as the entire composition of the resin and the plasticizer combined. The inclusion power is not sufficient and the moisture resistance is not good. With diethylene glycol,
On the contrary, since the polarity of the plasticizer is too weak to cause the water to be ubiquitous in the resin portion, the water inclusion capacity of the composition is not sufficient. Therefore, esters of triethylene glycol are preferred.

Examples of the plasticizer include triethylene glycol-di-butyrate, triethylene glycol-di-isobutyrate, triethylene glycol-di-pentylate, triethylene glycol-di-2-ethylbutyrate and triethylene. Glycol-di-caproate, triethylene glycol-di-n-heptanoate, triethylene glycol-di-2-ethylhexoate, triethylene glycol-di-n-octoate and the like are preferably used. The addition amount of the plasticizer is preferably 20 to 60 parts by weight with respect to 100 parts by weight of the polyvinyl butyral resin. If the added amount of the plasticizer is less than 20 parts by weight, the penetration resistance of the laminated glass is lowered, and if it exceeds 60 parts by weight, the plasticizer exudes from the interlayer film, so-called bleeding phenomenon occurs, and the transparency of the laminated glass is increased. Adversely affect.

In addition, an adhesiveness adjusting agent, an antioxidant, a stabilizer, an ultraviolet absorber, etc. are appropriately added in order to ensure the performance required for the laminated glass.

[0031]

EFFECTS OF THE INVENTION According to the present invention, it is possible to provide a laminated glass interlayer film having the above-mentioned constitution, which improves the fluidity of the interlayer film at high temperature and does not cause the residual air phenomenon.

Further, according to the present invention, it is possible to provide a laminated glass intermediate film in which the adhesiveness between the intermediate films is reduced.

Further, according to the present invention, it is possible to provide an interlayer film for laminated glass which does not require a special end surface treatment or a special end surface protection mechanism and has excellent moisture resistance.

Thus, the interlayer film according to the present invention does not cause deterioration of the adhesiveness in the room temperature region and does not affect the adhesiveness with the glass plate at all, and the laminated glass constituted is It is also excellent in transparency, penetration resistance and weather resistance.

[0035]

EXAMPLES The present invention will be specifically described below based on examples.

Example 1 a) Preparation of polyvinyl butyral resin In the reactor shown in FIG. 3, polyvinyl alcohol having a polymerization degree of 1500 and a saponification degree of 99.5 mol% was placed in a stainless steel dissolution layer (1) having a volume of 100 liters. The particles and pure water were charged, and the polyvinyl alcohol was dispersed in pure water so as to form a 10 wt% solution, the dispersion was heated to 95 ° C., dissolved and cooled to 75 ° C.

The first-stage loop reactor (2) composed of a glass lining tube with a volume of 2.5 liters and the second-stage loop reactor (3) communicating with this were filled with pure water and heated to 75 ° C. After that, a 10 wt% aqueous solution of polyvinyl alcohol was supplied to the first-stage loop reactor (2). Further, with respect to 100 parts by weight of the same aqueous solution, 1.5 parts by weight of hydrochloric acid having a concentration of 10% by weight and 5.6 parts by weight of butyraldehyde were used as catalysts in the first stage loop reactor.
It was put into (2) and the reaction proceeded. The flow velocity of the reaction solution is 6 m / sec in the first stage loop reactor (2), and the flow rate of the reaction liquid is 4 m / sec in the second stage loop reactor (3). Was adjusted to prevent the coalescence of particles.

To the aging tank (4) consisting of a glass lining container having a volume of 100 liters, was added pure water at 85 ° C. until the effect of a stirrer was exhibited to prevent particle agglomeration at the initial charging, and then it took about 1 hour. The reaction solution was received. During the reception, reflux was carried out to prevent volatilization and outflow of the aldehyde to the outside of the system. Also, to raise the aging temperature,
The tank was heated from the jacket to keep the temperature at 82 ° C.

After the completion of receiving, 90 parts by weight of 10% hydrochloric acid was additionally charged as an additional catalyst, and the temperature was kept at 82 ° C. for 4 hours. After completion of aging, the liquid was cooled to 40 ° C., neutralized with sodium bicarbonate at room temperature, and the produced resin was washed with water and dried.

Thus, a granular polyvinyl butyral resin was obtained.

In FIG. 3, (5) and (6) are electromagnetic flow meters, and (7)
Is a pressure gauge, (8) is a withdrawal valve, (9) (10) is a supply pump, and (11) (12) is a circulation pump.

B) Molding of intermediate film 100 g of the above polyvinyl butyral resin was used as a plasticizer for triethylene glycol-di (2-ethyl butyrate).
40 g, and the mixture was mixed with a roll of 6 inches in diameter for 8 hours.
After kneading at 0 ° C for 5 minutes, the kneaded product is heated at 150 ° C for 20 minutes.
Press molding was carried out for a minute to prepare a film having a smooth surface and a thickness of about 0.76 mm. Thus, an intermediate film was prepared.

Example 2 As an additional catalyst, 150 parts by weight of 10% hydrochloric acid was additionally charged, the temperature was kept at 87 ° C. for 1 hour, and otherwise the same operation as in Example 1 was carried out to obtain a polyvinyl butyral resin. .

Then, an intermediate film was prepared using this resin in the same manner as in Example 1.

Comparative Example 1 Polyvinyl alcohol having a degree of polymerization of 1500 and a degree of saponification of 99.5 mol% was dispersed in pure water to form a 10 wt% solution, and the dispersion was heated to 95 ° C. and then to 30 ° C. Cooled. After adding 0.6 part by weight of 35% hydrochloric acid as a catalyst to 100 parts of a 10% by weight polyvinyl alcohol solution at 30 ° C., 1.6 parts by weight of butyraldehyde were added. The liquid was further cooled, and when the temperature reached 10 ° C, 3.9 parts by weight of butyraldehyde was added to precipitate particles, and then the reaction liquid was heated at 50 ° C while adding 5.4 parts by weight of 35% hydrochloric acid as an additional catalyst. The temperature was raised to.

After leaving the reaction solution at 50 ° C. for 3 hours,
The mixture was cooled to ℃ and neutralized with sodium bicarbonate at room temperature. The product was washed with water and dried to obtain a powdery polyvinyl butyral resin.

Then, using this resin, an intermediate film was prepared in the same manner as in Example 1.

Example 3 a) Preparation of polyvinyl butyral resin In Example 1, the heating temperature in the aged layer (4) was 82 ° C.
And the holding temperature of 82 ° C. for 4 hours is 85 ° C.
Other operations were performed in the same manner as in Example 1 to prepare a polyvinyl butyral resin.

B) Molding of interlayer film 100 g of the above polyvinyl butyral resin was used as a plasticizer for triethylene glycol-di (2-ethylbutyrate).
40 g was added, and further, 0.1 g of potassium acetate as an adhesion control agent, 0.2 g of dibutylhydroxytoluene as an antioxidant, and 0.15 g of "Tinuvin P" manufactured by Ciba-Geigy Co. as an ultraviolet absorber were added. Then, the mixture was kneaded with a roll having a diameter of 6 inches at 80 ° C. for 5 minutes, and the kneaded material was press-molded at 150 ° C. for 20 minutes to form a film having a smooth surface and a thickness of about 0.76 mm. did. Thus, an intermediate film was prepared.

C) Preparation of laminated glass The above interlayer film was sandwiched between a pair of 30 cm square float glasses, and this sandwich was degassed in a rubber gag at a vacuum degree of 20 torr and a temperature of 90 ° C. for 20 minutes. Vacuum pressing was performed while maintaining this temperature. The preliminary pressure-bonded product thus obtained was then subjected to a main pressure-bonding treatment at a pressure of 12 kg / m ² and a temperature of 135 ° C. in an autoclave to prepare a laminated glass.

Example 4 In Example 2, a polyvinyl butyral resin was prepared in the same manner as in Example 2, except that the temperature for maintaining the aged layer (4) for one hour at 87 ° C was 89 ° C. Then, using this resin, an intermediate film was prepared in the same manner as in Example 3, and further a laminated glass was prepared.

Comparative Example 2 (Preparation of Polyvinyl Butyral Resin) The cooling temperature of the dispersion liquid of Comparative Example 1 was 30 ° C. and the reaction temperature of 30 ° C. was 26 ° C. A resin was prepared.

Then, using this resin, an intermediate film was prepared in the same manner as in Example 3, and further a laminated glass was prepared.

Physical Properties Test <Measurement of Nuclear Magnetic Resonance Spectrum> The ¹ H nuclear magnetic resonance spectrum of polyvinyl butyral resin was measured as follows.

A 2% by weight solution of polyvinyl butyral resin in deuterated dimethyl sulfoxide (DMSO-d ₆ ) was prepared and a small amount of tetramethylsilane [(CH ₃ ) ₄ S was prepared.
i] was added as a standard substance, and the spectrum was measured at a temperature of 28 ° C. One example is shown in FIG.

The horizontal axis in the figure is the chemical shift (ppm) based on the resonance frequency of the standard substance tetramethylsilane used, and the vertical axis is the resonance absorption intensity of the proton (hydrogen). Corresponds to quantity. From the measurement chart of FIG. 1, from the attribution and integrated intensity of each absorption peak described in Table 1,
By substituting the integrated intensity into the following calculation, the butyralization degree,
The amount of each of the hetero type, syndio type, and iso type of the hydroxyl group was calculated.

[0057]

[Table 1]

[0058] [a formula]   Butyral degree (D_B) = {2I_A/ (3I_B-4I_A)} × 100 (mol% ) Hetero-type hydroxyl group = {I_D-(I_A/ 3-I_F)} × (3D_B/ 2I _A ) (Mol%)   Syndio type hydroxyl group = (I_C-I_F) × (3D_B/ 2I_A) (Mol%)                           (Mol%)   Iso-type hydroxyl group = I_E× (3D_B~ 2I_A) (Mol%) In addition, polyvinyl butyral resin¹³C nuclear magnetic resonance spectroscopy
The cuttle was measured as follows. Polyvinyl butyra
10 to 12% by weight of the resin
Xide (DMSO-d₆) Prepare a solution and add a small amount of
Methylsilane [(CH₃)_FourSi] as a standard substance
Then, the spectrum was measured at a temperature of 100 ° C. That
An example is shown in FIG.

The horizontal axis in the figure represents DMSO-d ₆ 3
Chemical shift (ppm) based on the resonance frequency of 9.5 ppm
), And the vertical axis represents the resonance absorption intensity, which corresponds to the amount of carbon. From this measurement chart, the amount of syndio-type hydroxyl groups of 3 or more chains was measured by substituting the integrated intensity into the following calculation formula from the attribution of each absorption peak and the integrated intensity shown in Table 2.

The measurement mode of ¹³ C nuclear magnetic resonance spectrum was SGBCM mode.

[0061]

[Table 2]

[0062] [equation] syndiotactic type 3 Streptococcus _{= I G / (I G +} I H + I I) * 100 ( mol%) syndiotactic type 4 chain _{= I H / (I G +} I H + I I) * 100 ( mol% ) Syndio type 5 chain = I _I / (I _G + I _H + I _I ) * 100 (mol%) As described above, regarding the polyvinyl butyral resins of Examples 1 and 2 and Comparative Example 1, the degree of butyralization and the type The amount of hydroxyl groups was calculated. The results are shown in Table 3.

Also for the polyvinyl butyral resins of Examples 3 and 4 and Comparative Example 2, the degree of butyralization and the amount of each type of hydroxyl group were calculated. The results are shown in Table 4.

<Adhesion Measurement> The adhesion of the interlayer film sheet was measured as follows.

A rectangular test piece having a width of 30 mm and a length of 100 mm was cut out from the film obtained in Example 1 and two test pieces were superposed and placed in a desiccator kept at 20 ° C. under a load of 6 kg. Left for hours. One end of one film of the obtained laminated body was peeled from the other film at a 90 degree angle with respect to the other film in a thermostatic chamber at 20 ° C., and the T-type peel strength was measured at a peeling speed of 500 mm / min. .

With respect to the films of Example 2 and Comparative Example 1, the T-type peel strength was measured by the same operation as described above.

The measurement results are shown in Table 3.

<Melt Viscosity> After adjusting the humidity of the test piece prepared by the above-mentioned adhesion measurement at a temperature of 30 ° C. and a relative humidity of 25% for 24 hours, 1.5 g of the sample was weighed and melted by a flow tester (Shimadzu Corporation). The viscosity was measured. The measurement conditions are load = 20 kg, die diameter = 1 mm, length = 1.0 mm,
Preheating time = 300 seconds, temperature = 120 ° C. and 150 ° C.

Table 3 shows the measurement results of the intermediate films of Examples 1 and 1 and Comparative Example 2.

<Moisture resistance test> a) Whitening distance The laminated glass obtained in Example 3 was kept under conditions of a temperature of 50 ± 3 ° C. and a relative humidity of 95 to 98% for 4 weeks, and then whitening from the edge of the laminated glass. The distance was measured with the naked eye. Example 4
The whitening distance of the laminated glass of Comparative Example 2 was measured by the same operation as above. The results are shown in Table 4.

B) Peeling distance After holding the laminated glass obtained in Example 3 for 4 weeks under the above-mentioned conditions, the presence or absence of peeling between the glass and the film at the edge of the laminated glass was examined. The maximum distance of peeling from the edge was measured as the peeling distance. Example 4
With respect to the laminated glass of Comparative Example 2, the peeling distance was measured by the same operation as above. The results are shown in Table 4.

C) Adhesion Test of Edges According to the Pummel test, the adhesion of the edges of the laminated glass was measured by the following method. After the laminated glass was cooled at -18 ° C for 2 hours or more, it was crushed with a 0.5 lb iron hammer on a supporting iron plate that can hold an angle of 45 degrees, and the glass adhered state, that is, the glass adhered to the film. The presence / absence of a part that was not checked was examined. When there was a glass non-adhesive portion, the maximum distance of the non-adhesive portion on the entire circumference was measured as "distance with no adhesive force". With respect to the laminated glass of Example 4 and Comparative Example 2, the peel distance was measured by the same operation as above. The results are shown in Table 4.

[0073]

[Table 3]

[0074]

[Table 4]

As is clear from Tables 3 and 4, it is recognized that the interlayer film made of the polyvinyl butyral resin of the example and the laminated glass are superior in melt viscosity, tackiness and moisture resistance to those of the comparative example. .

[Brief description of drawings]

FIG. 1 is a ¹ H nuclear magnetic resonance spectrum.

FIG. 2 is a ¹³ C nuclear magnetic resonance spectrum.

FIG. 3 is a flowchart showing a reaction process of an example.

FIG. 4 is a schematic diagram showing a three-dimensional structure of a chain of hydroxyl groups, (a)
Shows hetero type, (b) shows syndio type, and (c) shows iso type.

[Explanation of symbols] (1) Melting tank (2) First stage loop reactor (3) Second stage loop reactor (4) Aging tank (5) Electromagnetic flow meter (6) Electromagnetic flow meter (7) Pressure gauge (8) Extraction valve (9) Supply pump (10) Supply pump (11) Circulation pump (12) Circulation pump

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Claims (2)

[Claims] 1. A condensation product of polyvinyl alcohol and butyraldehyde, which has a degree of butyralization in the range of 65 to 75 mol% in ¹ H nuclear magnetic resonance spectrum measurement, and a chain of residual hydroxyl groups in the measurement. Heterotactic triad type with a length of 3 or more is 1 to 4.5 mol%, syndiotactic triad type is 1 to 4 mol%, and isotactic triad type is 0.05%. ˜2 mol% and, in ¹³ C nuclear magnetic resonance spectrum measurement, 3 chains having a residual hydroxyl group chain length of 3 or more when the total integral value of syndiotactic hydroxyl groups is 100%. Is 3
A polyvinyl butyral resin characterized by 0 to 50%, 4 to 30% of 40%, and 5 to 10% of 40% or more. 2. The polyvinyl butyral resin according to claim 1, wherein the polyvinyl butyral resin having a syndiotactic hydroxyl group having a chain length of 5 or more residual hydroxyl groups has an integral value of 10 to 20% and a plasticizer. An intermediate film for laminated glass obtained from a product.