JPH0330608B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to polyvinyl compounds, and its purpose is to use modified polyvinyl esters having an alkyl sulfoxide group and excellent adhesion to inorganic materials, particularly polyvinyl acetate esters or modified polyvinyl alcohols, which are saponified products thereof. It's about getting. Polyvinyl esters, especially polyvinyl acetate, are produced on a large scale industrially because the raw material monomers are easily available at low cost, and their polymerization can be easily carried out by methods such as solution polymerization and emulsion polymerization. Widely used in the field. In addition, polyvinyl alcohol obtained by saponifying these polyvinyl esters, especially polyvinyl acetate, can be used in molded products such as fibers and films, as well as in water-soluble adhesives, binder coatings, etc. by taking advantage of its strong film-forming ability and adhesive performance. Widely used in paper processing agents, textile glues, etc. In particular, polyvinyl acetate and its saponified product, polyvinyl alcohol, have adhesive properties for various materials and are used in large quantities as adhesives. For example, polyvinyl acetate is used in the form of an emulsion or a solution such as alcohol or acetone in adhesives or paints for a wide range of materials such as wood, paper, fibers, and plastics, and polyvinyl alcohol is in the form of an aqueous solution and is used for paper, Used in adhesives such as As described above, although polyvinyl acetate and polyvinyl alcohol have good adhesion ability to a wide range of materials, the adhesion strength may not always be high.
For example, adhesive strength to inorganic materials such as glass, asbestos, and concrete is insufficient, and materials with higher adhesive strength are desired. The present invention was made against these backgrounds, and includes the following () and (), () and ().
Or it contains copolymer units represented by (), () and (), and the copolymer composition is ()0.1
~60 mol%, ()0~99.9 mol%, ()0~
99.9 mol% and has an intrinsic viscosity of 0.1 dl/g or more when measured in acetone or water at 30°C. (Here, R ₁ is a lower alkyl group having 1 to 5 carbon atoms,
_R2 means a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. ) The polyvinyl compound of the present invention has a characteristic of excellent adhesion to inorganic materials, especially glass, as is clear from the examples described below. Embodiments of the polyvinyl compound of the present invention include modified polyvinyl acetate containing copolymer units represented by () and () above, and copolymer units represented by () and () or (), () and () above. It includes modified polyvinyl alcohol containing. The polyvinyl compound of the present invention must contain 0.1 to 60 mol% of the above vinyl sulfoxide units. If it is less than 0.1 mol%, it will not have excellent adhesion to inorganic substances. On the other hand, if it is more than 60 mol%, a product with a high degree of polymerization cannot be obtained, and therefore a product with high adhesive strength cannot be obtained. From the viewpoint of adhesion to inorganic substances, the content of vinyl sulfoxide units in () is more preferably 3 to 55 mol%. Polyvinyl compound is modified polyvinyl ester,
In particular, in the case of polyvinyl acetate, the vinyl sulfoxide units in () are 0.1 to 60 mol%, preferably 3 to 55 mol%, and the vinyl ester units in () are 40 to 60 mol%.
It is 99.9 mol%. When the polyvinyl compound is modified polyvinyl alcohol, the vinyl sulfoxide units in () are 0.1 to 60 mol%, preferably 3 to 55 mol%, and the vinyl ester units in () are 0.
-99.8, preferably 0-29.9 mol%, vinyl alcohol units of () 0-99.9 mol%, preferably
It is 70-99.9 mol%. _R1 of the vinyl sulfoxide unit in () is a lower alkyl group having 1 to 5 carbon atoms, preferably a methyl group, an ethyl group, or a propyl group. R in the vinyl ester unit () is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, preferably a methyl, ethyl, or propyl group. The polyvinyl compound of the present invention has an intrinsic viscosity [η] of 0.1 dl/
g or more. Intrinsic viscosity [η]
If it is less than 0.1 dl/g, it will not have sufficient performance for practical use. There is no particular upper limit on the upper limit, but those with an intrinsic viscosity of 3 or more are difficult to manufacture in practice. Note that if the polyvinyl compound is soluble in acetone, it is dissolved in acetone, and if it is insoluble in acetone but soluble in water, it is dissolved in water and its intrinsic viscosity is measured. Among the polyvinyl compounds of the present invention, modified polyvinyl acetate can be produced by the following method. In other words, vinyl acetate has CH ₂ =CH−
It is produced by mixing vinyl sulfoxide represented by SOR ₂ and a polymerization initiator and polymerizing the mixture. The polymerization method may be either a batch method or a continuous method, but in the case of a batch method, the monomer composition changes with the polymerization rate according to the comonomer reactivity ratio (γ ₁ , γ ₂ ). Although it is well known that
In order to obtain a copolymer having a uniform copolymer composition, it is desirable to adopt a so-called semi-batch method in which one or both monomers are added so that the monomer composition is constant. In the case of continuous multi-column copolymerization, for the same reason, it is desirable to add monomers to the second and subsequent columns so that the monomer composition in each column is constant. As a polymerization initiator, 2,2'-azobisisobutyronitrile (AIBN),
1,1'-azobis-(cyclohexane-1-carbonitrile), 2,2'-azobis-(2,4-dimethylvaleronitrile), 2,2'-azobis-(4-methoxy-2,4-dimethylvaleronitrile) Nitrile), 2,
2'-azobis-(2-amidinopropane) dibasic acid, benzoyl peroxide, potassium persulfate, ammonium persulfate, t-butyl hydroperoxide,
Known radical polymerization initiators such as peroxide di-t-butylcumene hydroperoxide and so-called redox initiators consisting of a peroxide and a reducing agent can be used. An appropriate temperature for the polymerization reaction is selected depending on the type of initiator, but 40 to 80°C is usually selected.
Further, a degree of polymerization regulator such as acetaldehyde or alkyl mercaptan can also be added to the polymerization system. The polymerization rate of the monomers is appropriately determined depending on the purpose, such as economical efficiency and adjustment of the degree of polymerization. In the present invention, bulk polymerization without using a solvent is preferred because of its high polymerization rate, but other methods such as solution polymerization, suspension polymerization, and emulsion polymerization can also be used. After the copolymerization is completed, if vinyl acetate remains in the reaction solution, it is necessary to separate and remove it by distillation or the like.
Even if vinyl sulfoxide remains, it is preferable to remove it, but in general, since the copolymerizability (γ ₂ ) of vinyl sulfoxide is higher than that of vinyl acetate (γ ₁ ), it is necessary to remove it from the polymerization system. The amount of vinyl sulfoxide remaining is small, and when carrying out such polymerization, in addition to vinyl acetate and vinyl sulfoxide, other unsaturated monomers that can be copolymerized with these monomers, such as ethylene and propylene, must be used. α-olefins such as (meth)acrylic acid,
Unsaturated acids such as crotonic acid, maleic anhydride, fumaric acid, and itaconic acid or their alkyl ester salts; Unsaturated amides such as (meth)acrylamide and N-methylolacrylamide; 2-acrylamido-2-methylpropanesulfonic acid or its alkyl ester salts; It is free to coexist with a sulfonic group-containing monomer such as a salt in an amount that does not impair the properties of the modified polyvinyl compound of the present invention during polymerization. Among the polyvinyl compounds of the present invention, modified polyvinyl alcohol is produced by the following method. That is, it can be obtained by saponifying the modified polyvinyl acetate obtained by the above method using a conventional method. It is usually advantageous to carry out the saponification reaction as a solution of the copolymer in alcohol, especially in methanol. Not only anhydrous alcohols but also those containing a small amount of water can be used depending on the purpose, and organic solvents such as methyl acetate and ethyl acetate may be optionally contained. As the saponification catalyst, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, alcoholates such as sodium methylate and potassium methylate, alkaline catalysts such as ammonia, or acidic catalysts such as hydrochloric acid and sulfuric acid can be used. Industrially, alkaline catalysts, particularly sodium hydroxide, are also desirable. The saponification temperature is usually selected from the range of 10 to 50°C. Through the saponification reaction, vinyl acetate units are partially or highly saponified and converted into vinyl alcohol units, but this conversion rate can be set to any value depending on the purpose of use of the modified polyvinyl alcohol of the present invention. can. The desired modified polyvinyl alcohol can be obtained by further pulverizing, washing and drying the saponified product as required. The modified polyvinyl esters thus obtained, particularly modified polyvinyl acetate and modified polyvinyl alcohol, have excellent adhesion to inorganic substances such as glass, and therefore can be used in applications that take advantage of these properties. For example, it can be effectively used as a binder, adhesive, or coating agent for inorganic materials such as gypsum boards, glass, glass fibers, rock wool, and ceramics, as well as as an additive for cement and mortar, or as a surface finishing agent. In addition, other fiber sizing agents, fiber processing agents, surface sizing agents for paper, binders for pigment coating, internal additives for paper making, improvers for amino resin adhesives, emulsion stabilizers for emulsion polymerization, emulsion stabilizers for suspension polymerization, etc. For use in polymerization dispersion stabilizers, wall materials for microcapsules, photosensitive resins, molded products (films, sheets, pipes, tubes, fibers, etc.), adhesives for wood, paper, aluminum foil, plastics, etc., binders for nonwoven fabrics, etc. can also be used. The modified polyvinyl acetate of the present invention is particularly suitable for inorganic materials among the above-mentioned applications, and modified polyvinyl alcohol is also suitable for ordinary polyvinyl alcohol applications such as textile glue and paper sizing, in addition to inorganic materials. is also suitable. Furthermore, the polyvinyl compound of the present invention has excellent affinity and permeability to the skin and epidermis of animals and plants, and is effective as a spreading agent for agricultural chemicals, for example. It can also be used as a so-called polymer drug. The present invention will be specifically explained below with reference to Examples, but the present invention is not limited thereto. Note that parts are by weight unless otherwise specified. Examples 1-4 Vinyl acetate (VAc), methylvinyl sulfoxide ( _CH2 = _CHSOCH3 ) (MVS) and 2,2'azobisisobutyronitrile (AIBN) in the reactor
was added, stirring at a temperature of 60°C (stirring speed
200 rpm), bulk polymerization was carried out. The obtained polymerization solution was poured into a large amount of petroleum ether to precipitate the polymer. Next, this polymer was dissolved in acetone, the solution was poured into petroleum ether, reprecipitated, and dried to obtain various modified polyvinyl acetates. Table 1 shows the manufacturing conditions, intrinsic viscosity, and solubility of this modified polyvinyl acetate.

[Table] CDCl ₃ /CCl ₄ of polyvinyl acetate in Example 4
Figure 1 shows the proton nuclear magnetic resonance spectrum (NMR) of the mixture at a main frequency of 60 MHz. As the measuring device, JNM-PM×60 manufactured by JEOL Ltd. was used. Tetramethylsilane was used as a reference material. From Figure 1, -2.5ppm in the polymer.
Proton signal of SOCH ₃ , 2.1ppm −
A proton signal of OCOCH ₃ was observed, and VAc
It can be seen that it is a copolymer of and MVS. The MVS composition in the polymer was determined from this absorption and was found to be 24 mol%, which was almost in agreement with the S analysis value of 22.4 mol%. Examples 5-9 Adding VAc, MVS and AIBN into the reactor,
While stirring at a temperature of 60℃ (stirring speed 150r.pm),
Bulk polymerization was carried out. The obtained polymerization liquid was poured into a large amount of hexane to precipitate the polymer. Next, this polymer was dissolved in acetone, this solution was poured into hexane, reprecipitated, and then dried to obtain various modified polyvinyl acetates. Table 2 shows the manufacturing conditions, intrinsic viscosity, and solubility of this modified polyvinyl acetate.

[Table] Example 10 Bulk copolymerization with MVS was carried out under the same conditions as in Example 1 except that vinyl propionate was used instead of VAc in Example 1. The polymerization rate was 3%, the content of MVS in the polymer was 7.5 mol%, and [η] (measured in acetone at 30°C) was 0.36 dl/g. Example 11 Polymerization was carried out under the same conditions as in Example 1, except that 0.25% lauroyl peroxide was used as a polymerization initiator in place of AIBN in Example 1, and propyl vinyl sulfoxide was used in place of MVS. The polymerization rate is 3%, the propyl vinyl sulfoxide content in the polymer is 5.1 mol%,
(η) (determined in acetone at 30°C) was 0.41 dl/g. Example 12 1000 parts of VAc and 5.3 parts of ethyl vinyl sulfoxide were placed in a flask equipped with a stirrer, thermometer, dropping funnel, and reflux condenser, and after purging the system with nitrogen, the internal temperature was raised to 60°C. The temperature rose. A solution of 8 parts of AIBN dissolved in 100 parts of methanol was added to this system to initiate polymerization. During the polymerization time of 5 hours, 45.6 parts of a 25% methanol solution of ethyl vinyl sulfoxide was added dropwise at a constant rate. The solid content concentration in the system at the time of termination of polymerization was 38%. A gas introduction pipe and a vacuum distillation device were attached to the flask, and methanol vapor was blown into the polymerization reaction solution under reduced pressure.
After expelling the unpolymerized vinyl acetate monomer, a 35% methanol solution of the copolymer was obtained. It was confirmed by nuclear magnetic resonance analysis that this copolymer contained 3 mol% of ethyl vinyl sulfoxide units and 97 mol% of vinyl acetate units. While stirring 100 parts of a methanol solution of this copolymer at 40°C, add 1N
Add 10 parts by volume of caustic soda methanol solution of
After mixing well, it was left to stand. After 30 minutes, the solidified polymer was crushed using a crusher, washed with methanol, and dried.
A polymer powder was obtained. This copolymer was dissolved in water, and the viscosity was 0.45 at 30℃.
It was dl/g. Proton nuclear magnetic resonance spectroscopy analysis of a heavy aqueous solution of this copolymer revealed that the ethyl vinyl sulfoxide unit content was 2.9 mol%.
The degree of saponification of vinyl acetate units was 98 mol%. Example 13 Adding VAc, MVS and AIBN into the reactor,
Bulk polymerization was carried out at a temperature of 60°C with stirring. The obtained polymerization liquid was poured into a large amount of petroleum ether,
The polymer was precipitated. Next, this polymer was dissolved in acetone, the solution was poured into petroleum ether, reprecipitated, and dried to obtain various modified polyvinyl acetates. This modified polyvinyl acetate was dissolved in methanol to a concentration of 40%. While stirring 100 parts of this solution at 40° C., 4.7 parts by volume of 2N caustic soda methanol solution was added thereto, mixed well, and then allowed to stand. After 20 minutes, the solidified polymer was pulverized using a pulverizer, washed with methanol, and dried to obtain a polymer powder. The intrinsic viscosity of the obtained modified polyvinyl alcohol in water at 30°C was measured. In addition, the degree of saponification and the content of methyl vinyl sulfoxide units were measured and shown in Table 3. Then, the adhesion strength of modified polyvinyl acetate and modified polyvinyl alcohol to glass was evaluated by the following method. A 5% methanol solution of the obtained modified polyvinyl acetate and a 5% aqueous solution of modified polyvinyl alcohol were prepared, and the thickness of the film after drying was measured on a glass plate.
It was cast to a thickness of 50μ and dried at room temperature. After that, the humidity was controlled at 20℃ x 65% RH for more than 7 days, and the film was reinforced with cellophane tape, cut into 2cm wide pieces, and peeled off at 90° at a head speed of 100mm/min.
The peel stress is shown in Tables 4 and 5 in units of g/cm as adhesive strength. As can be seen from these results, modified polyvinyl acetate and modified polyvinyl alcohol into which sulfoxide groups have been introduced have superior adhesion to glass compared to unmodified polyvinyl acetate and polyvinyl alcohol, and this effect is thought to be due to the sulfoxide groups. It will be done. Note that the modified polyvinyl alcohol of Example 16
A KBr tablet was prepared by mixing 4% of KBr, and its infrared absorption spectrum was measured. The chart is shown in Figure 2. As a measuring device, an infrared spectrophotometer Model 260-10 manufactured by Hitachi, Ltd. was used.
From Figure 2, absorption based on sulfoxide is recognized at 1010 cm ^-1 , and absorption due to vinyl alcohol is observed at 1100 cm ^-1 .
Absorption based on alcohol was observed, indicating that this modified polyvinyl alcohol was modified with sulfoxide.

【table】

【table】

【table】 [Brief explanation of drawings]

Figure 1 is a proton nuclear magnetic resonance spectrum with a main frequency of 60 MHz (using JNM-PM x 60 manufactured by JEOL Ltd.)
and the CDCl ₃ / of the polyvinyl acetate of Example 4
This is a measurement of a CCl ₄ mixed solution. Tetramethylsilane was used as a reference material, and the horizontal axis shows the chemical shift ppm from the reference material. Figure 2 shows the infrared absorption spectrum of KBr tablets prepared by mixing 4% of the modified polyvinyl alcohol of Example 16 with KBr.
This is a chart where measurements were taken using Model 260-10.

Claims (1)

[Claims] 1. The following () and (), () and ()
Or it contains copolymer units represented by (), () and (), and the copolymer composition is ()
0.1-60 mol%, () 0-99.9 mol%, () 0
-99.9 mol%, and has an intrinsic viscosity of 0.1 dl/g or more when measured in acetone or water at 30°C. (Here, R ₁ is a lower alkyl group having 1 to 5 carbon atoms,
_R2 means a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. ) 2 The polyvinyl compound according to claim 1, wherein R ₁ is a methyl group. 3. The polyvinyl compound according to claim 1 or 2, wherein R ₂ is a methyl group. 4 Contains copolymerized units represented by () and (), and () is 0.1 to 60 mol% and () is 40
~99.9 mol% Claims 1 and 2
The polyvinyl compound according to item 1 or 3. 5 () and () or (), ()
and (), and the content of () is 0.1 to 60 mol%, the content of () is 0 to 29.9 mol%, and the content of () is 70 to 99.9 mol%. The polyvinyl compound according to item 2 or 3.