JPS5857406A - Production of polyvinyl butyral having improved autohesion - Google Patents

Abstract

PURPOSE:To produce a polyvinyl butyral which, when plasticized, is capable of providing laminated glass interlayer membranes having excellent autohesion, by treating a polyvinyl butyral in a state of an aqueous dispersion in the presence of a water-soluble salt of a specified acid in the strongly acidic range. CONSTITUTION:An acid catalyst is added to an aqueous PVA solution heated above 20 deg.C, saponification degree of PVA >=90mol%, average polymerization degree of PVA 800-3,000. After cooling the reaction system, butyraldehyde is added and condensed. Then, a polyvinyl butyral dispersed in water phase is obtained by precipitating a polyvinyl butyral, butyralization degree of 60-75mol%, at below 20 deg.C. This is mixed with 2-100pts.wt. per 100pts.wt. polyvinyl butyral, water-soluble salt of hydrochloric acid, nitric acid or hydrobromic acid (e.g., calcium bromide). The mixture is further reacted at above 30 deg.C in the strongly acidic region. Then, the catalyst is neutralized.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing polyvinyl butyral, and more specifically, when a Nakaoka membrane for laminated gas is produced by adding a polyvinyl butyral, the adhesiveness of the interlayer films at room temperature (hereinafter referred to as self-adhesion of the interlayer film) Polyvinyl butyral 01 allows you to obtain a medium ceramic for laminated glass that has greatly improved It is related to the manufacturing method.

Polyvinyl butyral O sludge, which is widely used industrially today, can be roughly divided into precipitation methods and dissolution methods. In this internal precipitation method, for example, methylaldehyde is added to an aqueous solution of polyvinyl alcohol in the presence of an acid catalyst and a butycooling reaction is carried out at a relatively low temperature below 20°C to produce fine precipitates of polyvinylgutifur. This method involves stirring and heating for a long time. The dissolution method is, for example, a method in which a fraction of 11' IJ vinyl alcohol is added to an organic solvent such as isopropyl alcohol, gtyraldehyde is added in the presence of an acid catalyst, and the mixture is heated and reacted for a long period of time.

However, polyvinyl butyral KjJ produced by these conventional methods can be obtained by adding a plasticizer for use in laminated glass. , ** There was a problem that the 1-made W11 m simultaneous KM comrades with strong adhesion stuck to each other, and to prevent such adhesion, a heavy lR111 soda 410 anti-stick agent was sprayed on the membrane surface), below 20 ° C. The interlayer film is cooled to a temperature of .

However, the method of spraying the anti-adhesion agent has IIK, which involves bonding the polyvinyl butyral film and glass, and 1IIA, which requires a washing process and drying process to remove the anti-adhesion in advance. The interlayer film has the drawback that it requires a refrigeration system from production to packaging, transportation, storage, and use, making it very expensive, and the emergence of an interlayer film that is substantially free of self-adhesion at room temperature has been awaited.

In view of the above-mentioned current state of the method for producing polyvinyl butyral, the present invention has been proposed to produce an interlayer film for laminated glass by adding a plasticizer to the obtained polyvinyl butyral, and the self-adhesion is greatly improved. The purpose of this is to provide a method for producing polyvinylguticool that can obtain a membrane, and its gist is to form a fraction of polyvinyl butyral obtained by acetalizing polyvinyl alcohol into an aqueous phase, and to prepare a polyvinyl butyral film using hydrochloric acid, A process for producing polyvinyl butyral OH with improved self-adhesive properties, characterized by maintaining the temperature at 30°C or higher in a strongly acidic region in the presence of at least one of hydrobromic acid and nitric acid, each with zero water latent filler O. Exists.

The polyvinylguticool used in the present invention is obtained by acetalizing polyvinyl alcohol, and the starting material may be polyvinyl acetate, and when a plasticizer is added, it forms an interlayer film with self-adhesive properties. 10 is widely used. However, since it is dispersed in the aqueous phase, it is preferred to use polyvinyl butyral which is also produced in the main phase. In this case, it is particularly preferred industrially to react polyvinyl alcohol and butyraldehyde in the presence of an acid catalyst to precipitate polyvinyl butitur in the aqueous phase, and then separate the Il fat from the anti-15 system. Afterwards, leave it in the same aqueous phase without any problems! & Understand. but,
Of course, it is also possible to use polyvinyl guccicool powder obtained by the above-mentioned precipitation method or dissolution method 4IO and dried.

The polyvinyl guchicool used in the present invention has a temperature of 36°C.
When using the polyvinyl butyral obtained by keeping the above O temperature as an interlayer film for laminated glass, it is desirable that the degree of crosslinking is as small as 60 to 75 mol%, and the degree of crosslinking is preferably 95 mol% or more. , or those made from polyvinyl alcohol with a content of 98 mol % or more are preferable in that a resin with good transparency can be obtained in the final fiber. Also, if the average degree of polymerization of polyvinyl alcohol at this time is too low, the effect of improving self-adhesion when binding an interlayer film by adding a plasticizer will be poor; if it is too high, the viscosity will be high and it will be difficult to acetalize it industrially. Since this is inconvenient, one with an Fi of 800 to 300G is usually used.

Preferred examples of the water-soluble salts of hydrochloric acid, hydrobromic acid and nitric acid in the present invention include magnesium, calcium, zinc, aluminum, iron,
Examples include those having a valence of 2, such as titanium. These resins are used alone or in appropriate combinations, and the amount used is usually fractional polyvinyl resin.The fractional liquid concentration of polyvinylguticool in the present invention is the concentration at which the resin is dispersed in the aqueous phase. Although not particularly limited,
The content is 113 to 11% by weight. At this time, a trace amount of aldehyde may be present in the dispersion, and the amount is set to be 1% by weight or less of the normal dispersion of Fi.

In order to prevent the coarsening of melivinylguticool particles, it is best to add the above-mentioned water-soluble salt to the polyvinyl butyral dispersion before a too long period of time has elapsed at a high temperature after acetalizing the polyvinyl alcohol. Delicious.

In the present invention, K for obtaining a polyvinyl butyral dispersion in a strongly acidic region is added to a strongly acidic main phase obtained using a conventionally known high acid, an inorganic acid such as sulfuric acid, nitric acid, or an organic acid such as para-toluenesulfonic acid. Dry polyvinylguticool may be added, the acid may be added after the polyvinylguticool is dispersed in the aqueous phase, or the polyvinylguticool may be precipitated into the gII acidic main phase. good.

The strongly acidic region in the present invention refers to polyvinyl gutilyl A
/Myokin liquid O Although it depends on the temperature, the pH is usually 2 or less, preferably #1 PH1 or less.

In addition, for pigeon houses where it is necessary to increase the degree of butyralization of polyvinyl butyral, the degree of butyralization can be increased by allowing a predetermined amount of butyraldehyde to be present in the dispersion.

In addition, the upper limit of the lII skin of polyvinyl butyral is not particularly determined, but it is generally set to 90°C or less, and 30°C
The time for maintaining the above temperature is usually 1 to 20 hours, including the time for the external temperature of the dispersion liquid and the time for cooling the dispersion liquid.

Ka for producing polyvinyl butyral by the method of the present invention
Usually, an acid catalyst is added to the main polyvinyl alcohol solution at a temperature of over 20°C, then the anti-I15 system is cooled, and butyraldehyde is added to cause a binding reaction to precipitate polyvinyl butyral at a low temperature such as 20°C or lower. Don't let it out,
Provide polyvinyl butyral dispersed in an aqueous phase.

In this way, the temperature of the reaction system is kept low during precipitation, and O is used to obtain the precipitate in the form of fine particles or powder. As long as it's the temperature (
Although not particularly limited, usually -6℃ or higher O11
degree is adopted.

Next, if the PH of the reaction system is 2 or less, the above woodcutter is at least 41
The reaction system was heated externally and kept at a temperature of 30°C or higher.
After the reaction has proceeded further, the catalyst is neutralized with a base, and the reaction product is taken out and washed and purified in a conventional manner.

In this case, in a state in which 9-polyvinyl buticol obtained by the 7-tarization of d-lipinyl alcohol is dispersed in the aqueous phase φ, at least 1 % of each of hydrochloric acid, hydrobromic acid and nitric acid is added to the water-soluble solution. If an interlayer film for laminated glass is manufactured by adding an analizing agent and maintaining the temperature of the dispersion liquid at 30°C or higher in a strongly acidic region in the presence of a substance, an interlayer film with virtually no self-adhesion at room temperature can be obtained. Although it is not yet fully clear why vinyl butty tools with improved self-adhesive properties are produced in this way, it is speculated that the following reasons may arise.

Since the reaction I5 is an equilibrium reaction, the reaction progresses to the extent that it reaches a state of great equilibrium, and the degree of reaction #i becomes constant. In conventional production methods, the reaction was generally stopped before the degree of butycooling reached a certain level; therefore, the hydroxyl groups in the polyvinyl guccicool at this time were arranged in a random order. it is conceivable that. However, if the lever-O polyvinyl tail is dispersed in an aqueous phase and the dispersion liquid is kept at 30 degrees Celsius or higher in a strongly acidic region in the presence of a woodcutter, the product is formed by a reverse butycooling reaction that occurs in a strongly acidic region. Hydroxyl groups that do tend to exhibit complete hydrogen bonding, while butyralization (t) is more likely to occur selectively for hydroxyl groups that do not have a strong tendency to eclipse than for hydroxyl groups that have a strong tendency to eclipse. Therefore, as the final equilibrium state approaches, the tendency for hydroxyl groups to be chained in the molecule increases, which increases the rigidity of the obtained polyvinylguticool, which increases its self-reliance when used as an interlayer film. It is thought that this contributes to reducing or improving adhesion.

This J1 review shows that even in the absence of the above-mentioned soil, self-adhesion is improved by adding polyvinyl butyral dispersion liquid maintained at a relatively high temperature for a long time in a strongly acidic region. Although it has already been found that a film can be obtained, the use of the above-mentioned salt in the present invention significantly relaxes the above-mentioned temperature and time conditions, which is advantageous in terms of the process.

In addition, for example, if fine particles of polyvinylguticool are precipitated in the precipitation method and kept at high temperature for a long time in the absence of the above salt after death, coarsening due to agglomeration of precipitated particles is likely to occur. However, the above * has the effect of preventing the coarsening of fine particles, as the acid catalyst and the ring groups used for its neutralization remain and reduce the transparency and thermal stability of Ti. There is almost no reduction in transparency or thermal stability.

The agent used in the polyvinyl butylene tool obtained by the method of the present invention is conventionally used in polyvinyl butylene.
General-purpose plasticizers such as triethylene glyco-A/-di2-ethyl butyrate and triethylene glyco-A/-di-ethylhexoate are commonly used as additives. can be mentioned. Furthermore, dibutoxydiethylene glycol adipate and the like are preferably used.

The amount of plasticizer added is 30 to 60 parts by weight per 1110 sK of polyvinyl butylene ff-! I love it. If the plasticizer is 30 parts by weight, the penetration resistance will decrease when used as an interlayer film for laminated glass, and if the plasticizer exceeds 60 parts by weight, a so-called bleed phenomenon will occur in which the plasticizer seeps onto the film surface, resulting in poor lamination. This is because it has an adverse effect on the transparency and adhesiveness when used as a Nakaoka membrane for glass.

The method of the present invention has the above-mentioned configuration, and according to the present invention, when a plasticizer is added to produce a middle plate for laminated glass, the self-adhesion at room temperature is significantly improved. The polyvinyl butytool from which the membrane is obtained can be obtained under industrially advantageous temperature and time conditions compared to the case 6 when none of the water-soluble salts of hydrochloric acid, hydrobromic acid, and nitric acid are used. It can be done.

In addition, in the present invention, by using fine polyvinyl butyral particles, it is possible to obtain polyvinyl butyral with good transparency, high stability, and almost no coarse particles.

Examples of the present invention are shown below. % simply means weight %
means. The following measurement methods were used for each physical property value in the examples.

A sample obtained by sandwiching the transparent polyvinyl butyral between two glass plates 0111 was placed in a heated open chamber to melt the polyvinyl butyral and allowed to cool at room temperature. The obtained sample was observed under white light, and those without bluishness, turbidity, etc. were evaluated as good.

2 A test tube containing thermostable polyvinyl butytail was heated to
! Pigeon houses in which the medivinylbutytool did not change color even after being immersed in water and heated at 120° C. for a predetermined period of time were considered to have good thermal stability.

Generally, if neutralization or washing with water is incomplete, a catalyst such as hydrochloric acid remains in the KFi polyvinyl butytool, and when this test is performed, the polyvinyl buthytool is colored yellow.

Add 100 parts by weight of self-adhesive polyvinyl guchi tool and 42 parts by weight of a plasticizer with tcIvr constant, mix for 1 second using a Raikai machine, knead for 1 minute at 120'CK using a roll, and then mix at 150°C for 4 minutes.
Press at 0/- for 3 minutes to obtain a smooth surface with a thickness of a76M.
A uniform film was created. ζ0 film 3 am
X 1 Oam O was cut into a rectangular shape, two sheets were superimposed, and the shape 1, which was immediately loaded, was placed in a desiccator kept at xo''co temperature for 48 hours.

One end of the sample obtained at 01K was peeled off from each other, and the peeled film was bent in a 90°C direction to form a T-shape.
Grasp both ends of the peeled film with a tensile tester for 20 minutes.
Tl1ll-strength was measured at a tensile rate of 50 m/min.

Table: Impact resistant finish: Add 42 parts by weight of 100% K11r lubricant to ribinyl rubber, mix and mix with an extruder to a thickness of α76 cod 0W.
A qIl-containing bolibi; lugutilal was obtained, and this film was sandwiched between two 11tO cod, SOam If the laminated glass is kept at the specified temperature for more than 8 hours, the outer frame will be 31611 x 31ms and the inner frame will be 26mm.
X 26 cm, height 2 @ alO Placed horizontally on the iron frame of a mass restaurant, a λ268 (5〆nd) 0m ball was placed from the specified height and lowered to the center of the glass O.

The height at which the percentage of steel balls penetrating the laminated glass becomes SO-% is defined as the penetration resistance strength.

In addition, by using Fi as a combined gaff O test sample and ffi # mixed with a suitable amount of soap in advance, the bummel value described later can be obtained as a product with 1lIl (>6
I used the one that was firmly established.

Adhesiveness to glass.

A piece of laminated glass was adjusted to 8℃±Q6℃Os 1 degree by heating at 16:00, and Ken S. pounded it with an A4140 hammer until 10 pieces of glass became 6jI11 or less. The degree of exfoliation of the dead stone film caused by the exfoliation of the glass was determined using limit samples that had been graded in advance, and the results were expressed as pummel values according to Table 1.

Table 1 Example 1 Degree of conversion: 916 mol%, degree of polymerization! 10 (10Posibiel Alf~011j6 water JII solution 1@・Immediately add 1 portion of concentrated hydrochloric acid (concentration 3!%), 13'CK and stir while stirring 3 minutes. When the mixture was added dropwise, fine white particles of polyvinylbutycous #O were precipitated.

Further, 3J11gI6 concentrated acid 7g was added and stirred to bring the reaction system OPml to below L5, and a 16% aqueous solution of Calf bromide was added (the amount of Calf bromide was determined by the final amount obtained). 14) 2 to 0 parts by weight
It was 0 parts by weight. )20℃/40' at Tokioka O temperature increase shielding rate
Warm to iI+ to c, then maintain that temperature for 6 hours to ripen for 6 hours. After 6 hours of aging, add sodium hydroxide to neutralize the anti-fI5 system and make PH*tL@9.Kutokioka, which is kept at a temperature of 30℃ or above. It was ttts*m.

The obtained resin was washed with water and dried according to a conventional method to obtain a white fine powder. The degree of polyvinylbutytool O-butytoolization was 6 to 496.

The polyvinyl butytool obtained by this process, the polyvinyl butycoal 1001f obtained by adding triethylene glycol 2-rouge 2-ethyl butyrate 42 as a plasticizer, and the intermediate layer obtained from the The physical properties of the glass were as shown in Table 2.

Example 2 A polyvinyl butyral powder was obtained by repeating the same procedure as in Example 1 except that ferric seeding was used instead of calcium bromide C1 in Example I.

Its physical properties were as shown in Fi No. 2.

Example 3 In the same manner as in Example 1, white fine particles were packed in anti-J6 system. Furthermore, a powder of polyvinyl buticool was obtained in the same manner as in Example 1, except that magnesium bromide was added instead of Calref^ bromide, and then the temperature was raised to 60°C and kept at that temperature for 3 hours.

Its physical properties were as shown in the second barley.

Example 4 Polyvinyl butyral O powder was obtained in the same manner as in Example 1 and W4 except that zinc nitrate was used in place of calcium bromide.

Its physical properties 4I were as shown in No. 21.

Example 5 Concentrated hydrochloric acid (concentration 3
5%) was added thereto, and while stirring at 13° C., gtyraldehyde a7Q was added over a period of 30 minutes to obtain polyvinyl butyral O precipitate in the form of white fine particles. Furthermore, he added concentrated hydrochloric acid 7F4, stirred the reaction system, raised the temperature to 40°C at a rate of 20°C/1 hour IIO temperature increase, and kept it at that temperature for 3 hours.He then neutralized it using a conventional method and converted it to butyral through a water washing process. degree 65
．． 8 mol%, σ average particle size 17 - Moderately dry polyvinyl butyral.

Zinc bromide 012g 6 aqueous solution & 4 sides 35% O citric acid 6
F4 was added to fractionate 10 pieces of the dried mejivinylgutitool (the pH of the fraction was less than α5), and the fraction was kept at 48°C for 5 hours and neutralized by adding sodium hydroxide. A powder of polyvinyl Guchicool was obtained in the same manner as in Example 1 using rat-as. Its physical properties etc. are the 21st
It was as shown in k.

Comparative Example 1 A powder of polyvinylguchicool was obtained in the same manner as in Example 1, except that no bromide was added in Example 5. Its physical properties ◆ were as shown in Table 2.

Comparative Example 2 Polyvinyl Guticool powder was obtained in the same manner as in Example 3 except that magnesium bromide was not added. Its physical properties were as shown in the second barley.

Comparative Example 3 Polyvinyl butyral O powder in the latter stage was obtained in the same manner as in Example 5 except that zinc bromide was not used. Its physical properties *Fi were as shown in Table 2.

Claims (1)

[Scope of Claims] L A polyvinylguticool obtained by acetalization of polyvinyl alcohol-kO is fractionated into an aqueous phase,
A polyvinyl glutinous resin with improved self-adhesive properties, characterized in that it is maintained at a temperature of 30°C or higher in a strongly acidic region in the presence of at least 1% water-soluble salts of hydrobromic acid and nitric acid. kOIl production method. λ The amount of water-soluble salt in the dispersion of polyvinylgtyralt
The manufacturing method according to item 1 or 2, wherein the amount of at least one of zinc, aluminum, iron, and titanium is 0 parts by weight or more based on the amount of ool. The manufacturing method according to any one of Items 1 to 13JJK, wherein the temperature is maintained at 435°C or higher for a time of 1 to 20 hours. Items 1 to 4 Jj where the pH of the strongly acidic region is 2 or more
[Any manufacturing method described in 111K. Kame A method for producing any of IJJK Kiki O, which comprises boiling and aging polyvinylguchicool obtained by acetalization in the same aqueous phase without separating it from the anti-15 system.