JP6427450B2 - Modified polyvinyl acetal resin - Google Patents

Description

The present invention relates to a modified polyvinyl acetal resin capable of producing a molded article having excellent crosslinkability and high strength, and a modified polyvinyl acetal resin composition using the modified polyvinyl acetal resin.

Polyvinyl acetal resin is a resin synthesized using polyvinyl alcohol as a raw material, and exhibits excellent toughness, adhesiveness, crosslinkability and hygroscopicity by having an acetyl group, a hydroxyl group and an acetal group in the side chain. Can. Moreover, it becomes possible to change resin physical properties by changing the ratio of side chain groups. Utilizing such characteristics, it is used in a wide range of applications such as laminated glass interlayers for automobiles and ceramic green sheets.

At present, attempts are being made to improve the physical properties of resins and to express new functions by introducing functional groups other than acetyl, hydroxyl and acetal groups into the side chain of polyvinyl acetal resin.
In Patent Documents 1 to 3, as an example of a technique for improving the characteristics of polyvinyl acetal resin, the crosslinking with the hydroxyl group of polyvinyl acetal resin is promoted by using in combination with a crosslinking agent such as an epoxy resin. A method of forming a body is disclosed.

JP, 2011-241294, A JP 2012-7134 A JP, 2012-7135, A

In the present invention, in view of the above-mentioned present conditions, a modified polyvinyl acetal resin having excellent crosslinkability and capable of producing a molded product having high strength, and a modified polyvinyl acetal resin composition using the modified polyvinyl acetal resin Intended to be provided.

The present invention is seen containing a structural unit having an imine structure, the content of the constituent unit having said imine structure is a modified polyvinyl acetal resin is 1.0 to 20.0 mol%.
The present invention will be described in detail below.

As a result of intensive investigations, the present inventors can express excellent crosslinkability when using a modified polyvinyl acetal resin having an imine structure alone or in combination with a crosslinking agent etc., and sufficient strength It has been found that a cross-linked product having the above is obtained, and the present invention has been completed.

The modified polyvinyl acetal resin of the present invention comprises a structural unit having an imine structure.
By containing such a modified polyvinyl acetal resin, it is possible to form a crosslinked structure with the crosslinking agent when self-crosslinking with the resin alone or in combination with the crosslinking agent. For this reason, the crosslinked body obtained after crosslinking has a moderate elasticity while having high mechanical strength.

In the present invention, the imine structure refers to a structure having a C = N bond.
As a structural unit which has the said imine structure, the structural unit shown to following formula (1) is mentioned, for example.

式（１）中、Ｒ^１は、単結合、又は、アルキレン基を表し、Ｒ^２は、イミン構造を有する基を表す。

In formula (1), R ¹ represents a single bond or an alkylene group, and R ² represents a group having an imine structure.

In the above formula (1), when R ¹ is an alkylene group, the preferable lower limit of the carbon number of the alkylene group is 1, and the preferable upper limit is 12. When the carbon number of the above-mentioned alkylene group exceeds 12, optimum strength may not be obtained. When said R < ¹ > is an alkylene group, the more preferable upper limit of carbon number of the said alkylene group is five.

In the above formula (1), when R ¹ is an alkylene group, examples of the alkylene group include methylene group, ethylene group, trimethylene group, tetramethylene group, pentamethylene group, hexamethylene group, octamethylene group, decamethylene group. , Linear alkylene groups such as methylmethylene, methylethylene, 1-methylpentylene, 1,4-dimethylbutylene, branched alkylene, cyclopropylene, cyclobutylene, cyclohexylene, etc. And cyclic alkylene groups of the following. Especially, linear alkyl groups, such as a methylene group, ethylene group, n-propylene group, n-butylene group, are preferable, and a methylene group and ethylene group are more preferable.

As the R ^2, it includes a functional group represented by the following formula (2).

式（２）中、Ｒ^３は水素原子又は炭素数１〜１８の炭化水素基を表し、Ｒ^４は炭素数１〜１８の炭化水素基を表す。

In the formula (2), ^{R 3} represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, ^{R 4} represents a hydrocarbon group having 1 to 18 carbon atoms.

As said hydrocarbon group, a saturated hydrocarbon group, an unsaturated hydrocarbon group, an aromatic hydrocarbon group etc. are mentioned. In addition, the said hydrocarbon group may consist only of a saturated hydrocarbon group, an unsaturated hydrocarbon group, and an aromatic hydrocarbon group, and 2 or more types of these may be used.

Examples of the saturated hydrocarbon group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, iso-butyl group, sec-butyl group, tert-butyl group, pentyl group and hexyl group. And heptyl group, 2-ethylhexyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, octadecyl group and the like. Among them, methyl group, ethyl group and n-propyl group are preferable.
As said aromatic hydrocarbon group, a phenyl group, toluyl group, xylyl group, t-butylphenyl group, a benzyl group etc. are mentioned, for example.

In the present invention, among the constituent units having the imine structure, R ¹ is preferably a single bond, R ³ is a hydrogen atom, and R ⁴ is a methyl group or an ethyl group.

As for the said modified polyvinyl acetal resin, the preferable minimum of content of the structural unit which has an imine structure is 0.1 mol%, and a preferable upper limit is 20.0 mol%.
When the content of the structural unit having an imine structure is less than 0.1 mol%, the viscosity stability with time may be deteriorated, and when it exceeds 20.0 mol%, acetalization may be difficult. . The more preferable lower limit of the content of the constituent unit having an imine structure is 1.0 mol%, and the more preferable upper limit is 15.0 mol%.

The modified polyvinyl acetal resin preferably further contains a structural unit having an amino group or an amide structure. By having the above-mentioned amino group or amide structure, formation of a crosslinked structure with the above-mentioned crosslinking agent becomes still easier.
In the present invention, it is preferable to have the above amino group or amide structure in the side chain. The amino group or amide structure may be directly bonded to carbon constituting the main chain of the modified polyvinyl acetal resin, or may be bonded via a linking group such as an alkylene group. Furthermore, the amino group may be a primary amine or a secondary amine.
In particular, the amino group is preferably -NH ₂ .
In the present invention, an amide structure refers to a structure having —C (= O) —NH ₂ .
Especially, it is preferable that the structural unit which has the said amino group is a structure shown to following formula (3).
Moreover, it is preferable that the structural unit which has the said amide group is a structure shown to following formula (4).

式（４）中、Ｒ^５は水素原子又は炭素数１〜１０の炭化水素基を表す。
なお、上記炭化水素基としては、アルキル基、アルケニル基、シクロアルキル基、シクロアルケニル基が挙げられる。

In the formula (4), ^{R 5} represents a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms.
In addition, as said hydrocarbon group, an alkyl group, an alkenyl group, a cycloalkyl group, and a cycloalkenyl group are mentioned.

The preferable lower limit of the content of the structural unit having an amino group or an amide structure is 0.1 mol%, and the preferable upper limit is 20 mol%.
When the content of the structural unit having the amino group or the amide structure is less than 0.1 mol%, it may be difficult to develop additional properties, and when the content exceeds 20 mol%, the solubility is increased. Since it is too much, it may be difficult to take out the modified polyvinyl acetal resin powder by the precipitation method. The more preferable lower limit of the content is 0.5 mol%, and the more preferable upper limit is 10 mol%. In addition, content of the structural unit which has the said amino group or amide structure can be measured by NMR etc.
Further, the preferable lower limit of the total content of the structural unit having the amino group or the amide structure and the structural unit having the imine structure is 0.1 mol%, and the preferable upper limit is 20 mol%. The more preferable lower limit of the content is 0.5 mol%, and the more preferable upper limit is 10 mol%.

In the present invention, the ratio of the content of the structural unit having an imine structure to the structural unit having an amino group or an amide structure (structural unit having an imine structure / structural unit having an amino group or an amide structure) is 0.5 It is preferable that it is /99.5-99.5/0.5. When the above ratio is less than 0.5 / 99.5 and there are few constituent units having an imine structure, the viscosity stability over time may be inferior, and the above ratio exceeds 99.5 / 0.5, the imine structure When there are many structural units which have these, crosslinkability may fall. The more preferable lower limit of the above ratio is 5/95, and the more preferable upper limit is 75/25.

The degree of acetalization of the modified polyvinyl acetal resin is not particularly limited, but a preferable lower limit is 60 mol%, and a preferable upper limit is 90 mol%. If the degree of acetalization is less than 60 mol%, it may be difficult for the modified polyvinyl acetal resin to precipitate in the synthesis step by the precipitation method. If the degree of acetalization is more than 90% by mole, the solubility in the solvent is reduced. A more preferable lower limit is 65 mol%, and a more preferable upper limit is 85 mol%. The degree of acetal of the modified polyvinyl acetal resin can be measured by NMR or the like.

The amount of hydroxyl group in the modified polyvinyl acetal resin is preferably 15 to 35 mol%, and more preferably 17 to 25 mol%. If the amount of hydroxyl groups is less than 15 mol%, the toughness of the modified polyvinyl acetal resin may be impaired, and the strength of the resulting crosslinked product may be insufficient. When the amount of hydroxyl groups exceeds 35 mol%, the polarity of the modified polyvinyl acetal resin becomes too high, and problems such as cracking may occur in the obtained crosslinked product, and the removability may be reduced.

The amount of acetyl groups in the modified polyvinyl acetal resin is not particularly limited, and the preferable lower limit is 0.0001% by mol, and the preferable upper limit is 5% by mol.

Although the polymerization degree of the said modified polyvinyl acetal resin is not specifically limited, It is preferable that a preferable lower limit is 200 and a preferable upper limit is 4500. When the degree of polymerization of the modified polyvinyl acetal resin is less than 200, a modified polyvinyl acetal resin composition having a sufficient viscosity can not be obtained, and when the degree of polymerization of the modified polyvinyl acetal resin is greater than 4500, solubility in water And the viscosity of the aqueous solution becomes too high, which makes acetalization difficult. Moreover, since the viscosity at the time of melt | dissolving in an organic solvent becomes high too much, in the use which coats and uses a solution, coating properties fall etc. handling falls.

As a method of producing the said modified polyvinyl acetal resin, the polyvinyl alcohol obtained by saponifying the polyvinyl acetate obtained by copolymerizing the monomer which has the said imine structure, and vinyl acetate, for example is The method of carrying out acetalization by a well-known method is mentioned. Also, a method of introducing an imine structure by acetalizing a polyvinyl alcohol having a structural unit having an amino group or an amide structure by a conventionally known method may be used. The modified polyvinyl alcohol having an imine structure obtained by post-modifying a polyvinyl alcohol having a structural unit having an amino group or an amide structure may be acetalized by a conventionally known method.
Furthermore, the imine structure may be introduced by post-denaturing the unmodified polyvinyl acetal resin.
Among these, a method of obtaining a modified polyvinyl acetal resin having an imine structure by acetalizing a polyvinyl alcohol having a structural unit having an amino group or an amide structure is preferable. In particular, when such a method is used, an imine structure can be obtained by adding an excess amount of an aldehyde and an acid catalyst used for acetalization.
For example, it is preferable to add an acid catalyst at 1.0% by weight or more of the total.
In addition, in the case of using such a method, as a method of confirming a structural unit having an amino group or an amide structure and a constituent requirement having an imine structure, for example, using FT-IR, a spectrum of an amino group ( and how to determine the 1600cm around ^-1), and a method of confirming the spectrum of the imine structure (160～170Ppm) using 13 C-NMR and the like.

The acetalization can be carried out using a known method, and is preferably carried out in a water solvent, a mixed solvent of water and an organic solvent compatible with water, or in an organic solvent.
As the organic solvent compatible with water, for example, an alcohol-based organic solvent can be used.
Examples of the organic solvent include alcohol-based organic solvents such as methanol, ethanol, n-propanol, isopropanol, n-butanol and tert-butanol; aromatic organic solvents such as xylene, toluene, ethylbenzene and methyl benzoate; methyl acetate Aliphatic ester solvents such as ethyl acetate, butyl acetate, methyl propionate, ethyl propionate, methyl butyrate, ethyl butyrate, methyl acetoacetate, ethyl acetoacetate; acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl cyclohexanone, benzophenone Ketone solvents such as acetophenone; lower paraffin solvents such as hexane, pentane, octane, cyclohexane and decane; diethyl ether, tetrahydrofuran, ethylene glycol dimethyone Ether solvents such as ether, ethylene glycol diethyl ether, propylene glycol diethyl ether; amide solvents such as N, N-dimethylformamide, N, N-dimethyl tecetoamide, N-methyl pyrrolidone, acetanilide, ammonia, trimethylamine, triethylamine, Amine solvents such as n-butylamine, di-n-butylamine, tri-n-butylamine, aniline, N-methyl aniline, N, N-dimethyl aniline, pyridine and the like can be mentioned. These can be used alone or in combination of two or more solvents. Among these, ethanol, n-propanol, isopropanol, and tetrahydrofuran are particularly preferable from the viewpoint of solubility in a resin and ease of purification.

The acetalization is preferably performed in the presence of an acid catalyst.
The acid catalyst is not particularly limited, and hydrogen halide such as hydrochloric acid, mineral acid such as nitric acid, sulfuric acid, carboxylic acid such as formic acid, acetic acid, propionic acid, methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid, Examples thereof include sulfonic acids such as para-toluenesulfonic acid and phosphoric acid. These acid catalysts may be used alone or in combination of two or more. Among them, hydrochloric acid, nitric acid and sulfuric acid are preferable, and hydrochloric acid is particularly preferable.

Examples of the aldehyde used for the acetalization include aldehydes having a linear aliphatic group having 1 to 10 carbon atoms, a cyclic aliphatic group or an aromatic group. As these aldehydes, conventionally known aldehydes can be used. The aldehyde used for the acetalization reaction is not particularly limited. For example, formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, n-valeraldehyde, n-hexyl aldehyde, 2-ethylbutyraldehyde Aliphatic aldehydes such as 2-ethylhexyl aldehyde, n-heptyl aldehyde, n-octaldehyde, n-nonyl aldehyde, n-decyl aldehyde, amyl aldehyde and the like, benzaldehyde, cinnamaldehyde, 2-methyl benzaldehyde, 3-methyl benzaldehyde 4-Methylbenzaldehyde, p-hydroxybenzaldehyde, m-hydroxybenzaldehyde, phenylacetaldehyde, β-phenylpropionaldehyde, etc. Aromatic aldehydes, and the like. One of these aldehydes may be used alone, or two or more thereof may be used in combination. As aldehydes, among others, butyraldehyde, 2-ethylhexyl aldehyde, n-nonyl aldehyde which is excellent in acetalization reactivity and can provide a sufficient internal plasticizing effect to a resin to be formed, and as a result can impart good flexibility. Is preferred and butyraldehyde is more preferred.

The addition amount of the above-mentioned aldehyde can be appropriately set according to the acetalization degree of the target modified polyvinyl acetal resin. The addition amount of the above-mentioned aldehyde may be appropriately set according to the acetalization degree of the target modified polyvinyl acetal resin. In particular, when it is 60 to 95 mol%, preferably 70 to 90 mol% with respect to 100 mol% of polyvinyl alcohol, the acetalization reaction is efficiently performed, and unreacted aldehyde is easily removed, which is preferable.

The modified polyvinyl acetal resin composition is obtained by using the modified polyvinyl acetal resin of the present invention and the crosslinking agent in combination. Such modified polyvinyl acetal resin composition is also one of the present invention.
The modified polyvinyl acetal resin composition of the present invention contains a crosslinking agent. By containing the said crosslinking agent, it becomes possible to make it bridge | crosslink by applying energy by UV irradiation, heating, etc.

Examples of the crosslinking agent include epoxy compounds such as ethylene glycol diglycidyl ether and polyethylene glycol diglycidyl ether; halohydrin compounds such as epichlorohydrin and epibromohydrin; 1,2-dichloroethane and 1,3-dichloropropane Halogen compounds; Isocyanate compounds such as hexamethylene diisocyanate; Bisacrylamide compounds such as N, N'-methylenebisacrylamide, N, N'-ethylenebisacrylamide; Urea compounds such as urea and thiourea; and guanidine compounds such as guanidine and diguanide Dicarboxylic acid compounds such as oxalic acid and adipic acid; Unsaturated carboxylic acid compounds such as acrylic acid and methacrylic acid; Methyl acrylate, methyl methacrylate, 2-ethylhexyl acrylate, isoacrylate Unsaturated carboxylic acid ester compounds such as butyl, butyl acrylate, 2-ethylhexyl methacrylate, isobutyl methacrylate and butyl methacrylate; glyoxal, glutaraldehyde, malonaldehyde, succinaldehyde, adipinaldehyde, phthalaldehyde, isophthalaldehyde, The aldehyde compound etc. which contain dialdehydes, such as a terephthalaldehyde, are mentioned. These can be used alone or in combination of two or more. These crosslinking agents can be used by dissolving them in an organic solvent such as water or alcohol, if necessary.

Although the kind of epoxy resin as said crosslinking agent is not specifically limited, A bisphenol A epoxy resin, a bisphenol F epoxy resin, a resorcinol epoxy resin etc. will be mentioned specifically ,.

In the present invention, the mixing ratio of the modified polyvinyl acetal resin to the crosslinking agent is not particularly limited, but it is preferable to add 5 to 50 parts by weight of the crosslinking agent to 100 parts by weight of the modified polyvinyl acetal resin. When the addition amount of the crosslinking agent is less than 5 parts by weight, the crosslinking effect may be less likely to be exhibited, and when it exceeds 50 parts by weight, the compatibility with the modified polyvinyl acetal resin may be reduced. A more preferable lower limit of the addition amount of the crosslinking agent is 7 parts by weight, and a more preferable upper limit is 45 parts by weight.

The method of crosslinking the modified polyvinyl acetal resin composition of the present invention includes a method by UV light irradiation and heating. When heat-hardening by heating, although heating temperature is not specifically limited, It is preferable that it is 50-170 degreeC. If the heating temperature is less than 50 ° C., the desired strength may not be obtained due to insufficient crosslinking. In addition, if the heating temperature is higher than 170 ° C., the modified polyvinyl acetal resin may be thermally deteriorated and sufficient characteristics may not be obtained. The more preferable lower limit of the heating temperature is 60 ° C., and the more preferable upper limit is 150 ° C.
The heating time is also not particularly limited, but the preferable lower limit is 5 minutes, and the preferable upper limit is 10 hours. If the heating time is shorter than 5 minutes, crosslinking may be insufficient, so that sufficient strength may not be obtained. In addition, if the heating time is longer than 10 hours, the modified polyvinyl acetal resin may be thermally deteriorated and sufficient characteristics may not be obtained.

The modified polyvinyl acetal resin composition of the present invention can be suitably used for applications in which ordinary polyvinyl acetal resin is used, and for example, ceramic molded body, metal paste, heat developable photosensitive material, paint, ink, reflection A coating solution for producing a sheet or the like can be obtained. Moreover, it can be used for adhesives for films for displays, and interlayer adhesives of ceramic laminates.
Furthermore, since the modified polyvinyl acetal having an imine structure used in the modified polyvinyl acetal resin composition of the present invention is excellent in self-crosslinking property, a molded body having high strength can be produced.

According to the present invention, it is possible to provide a modified polyvinyl acetal resin composition capable of producing a molded article having excellent crosslinkability and high strength.
The modified polyvinyl acetal resin composition of the present invention is particularly excellent in adhesion to a resin and can be suitably used for adhesion to a resin which is difficult to adhere, and the change in viscosity is small even when stored for a long period of time And can be excellent in stability.
Furthermore, the molded object obtained using modified polyvinyl acetal resin composition becomes what was excellent in solvent resistance.

EXAMPLES The present invention will be described in more detail by way of the following examples, but the present invention is not limited to these examples.

Example 1
250 g of polyvinyl alcohol containing 3.5 mol% of a structural unit having a degree of polymerization of 800, a degree of saponification of 99 mol% and an amino group (-NH ₂ ) shown in the above formula (3) is added to 1800 g of pure water, and the temperature is 90 ° C. The mixture was stirred and dissolved for about 2 hours. The solution is cooled to 40 ° C., 170 g of 35% by weight hydrochloric acid and 130 g of n-butyraldehyde are added thereto, and the solution temperature is kept at 40 ° C. to carry out acetalization reaction to precipitate the reaction product The
Then, the liquid temperature was maintained at 40 ° C. for 3 hours to complete the reaction, and neutralization, washing with water and drying were performed by a conventional method to obtain a powder of a modified polyvinyl acetal resin.
The obtained modified polyvinyl acetal resin is dissolved in DMSO-d ₆ (dimethyl sulfoxide) and analyzed using ¹³ C-NMR (nuclear magnetic resonance spectrum) to find that it has an amino group represented by the above formula (3) Having a constituent unit (content: 0.5 mol%) and a constituent unit having an imine structure shown in the following formula (5) (content: 3.0 mol%, R ³ and R ⁴ are methyl groups) Was confirmed.
In addition, the acetalization degree measured using ¹³ C-NMR, the amount of acetyl groups, and the amount of hydroxyl groups are shown in Table 1.

A polyvinyl acetal resin solution was prepared by dissolving 9 g of the obtained modified polyvinyl acetal resin in 41 g of a solvent in which toluene and ethanol were mixed at a weight ratio of 1: 1.
An epoxy solution was prepared by dissolving 9 g of bisphenol F-type epoxy resin (jER 807, manufactured by Mitsubishi Chemical Corporation) as a cross-linking agent in the obtained polyvinyl acetal resin solution and 41 g of a solvent in which toluene and ethanol were similarly mixed at a weight ratio of 1: 1. A resin composition was prepared by mixing the polyvinyl acetal resin solution and the epoxy solution at a weight ratio of 5: 1.
The obtained mixed solution was coated on a release-treated polyethylene terephthalate (PET) film so that the film thickness after drying was 20 μm, and dried at 125 ° C. to produce a resin sheet.

(Example 2)
Same as Example 1 except that polyvinyl alcohol is changed to 260 g of polyvinyl alcohol having a polymerization degree of 800, a saponification degree of 99 mol%, and a constituent unit having an amino group represented by the above formula (3) of 6.6 mol%. A modified polyvinyl acetal resin was obtained by the method.
The obtained modified polyvinyl acetal resin is dissolved in DMSO-d ₆ (dimethyl sulfoxide) and analyzed using ¹³ C-NMR (nuclear magnetic resonance spectrum) to find that it has an amino group represented by the above formula (3) Having a structural unit (content: 0.6 mol%) and a structural unit (content: 6.0 mol%, R ³ and R ⁴ are methyl groups) having the imine structure shown in the above formula (5) Was confirmed.
In addition, the acetalization degree measured using ¹³ C-NMR, the amount of acetyl groups, and the amount of hydroxyl groups are shown in Table 1.
Using the obtained modified polyvinyl acetal resin, a polyvinyl acetal resin solution, a resin composition and a resin sheet were produced in the same manner as in Example 1.

(Example 3)
The polyvinyl alcohol is changed to 250 g of polyvinyl alcohol having a polymerization degree of 600, a saponification degree of 98 mol%, and a structural unit having an amino group represented by the above formula (3) of 9 mol%, and the addition amount of n-butyraldehyde is 150 g A modified polyvinyl acetal resin was obtained by the same method as in Example 1 except for the above.
The obtained modified polyvinyl acetal resin is dissolved in DMSO-d ₆ (dimethyl sulfoxide) and analyzed using ¹³ C-NMR (nuclear magnetic resonance spectrum) to find that it has an amino group represented by the above formula (3) Having a structural unit (content: 0.7 mol%) and a structural unit having an imine structure shown in the above formula (5) (content: 8.3 mol%, R ³ and R ⁴ are methyl groups) Was confirmed.
In addition, the acetalization degree measured using ¹³ C-NMR, the amount of acetyl groups, and the amount of hydroxyl groups are shown in Table 1.
Using the obtained modified polyvinyl acetal resin, a polyvinyl acetal resin solution, a resin composition and a resin sheet were produced in the same manner as in Example 1.

( Reference Example 4)
By the same method as in Example 1 except that polyvinyl alcohol is changed to 240 g of polyvinyl alcohol having a polymerization degree of 800, a saponification degree of 99 mol%, and a constituent unit having an amino group shown in the above formula (3) is 1 mol%. A modified polyvinyl acetal resin was obtained.
The obtained modified polyvinyl acetal resin is dissolved in DMSO-d ₆ (dimethyl sulfoxide) and analyzed using ¹³ C-NMR (nuclear magnetic resonance spectrum) to find that it has an amino group represented by the above formula (3) Having a structural unit (content: 0.3 mol%) and a structural unit having an imine structure shown in the above formula (5) (content: 0.7 mol%, R ³ and R ⁴ are methyl groups) Was confirmed.
In addition, the acetalization degree measured using ¹³ C-NMR, the amount of acetyl groups, and the amount of hydroxyl groups are shown in Table 1.
Using the obtained modified polyvinyl acetal resin, a polyvinyl acetal resin solution, a resin composition and a resin sheet were produced in the same manner as in Example 1.

(Example 5)
The polyvinyl alcohol is changed to 250 g of polyvinyl alcohol having a polymerization degree of 600, a saponification degree of 99.5 mol%, and a constituent unit having an amino group shown in the above formula (3) 15 mol%, and the addition amount of n-butyraldehyde is A modified polyvinyl acetal resin was obtained by the same method as in Example 1 except that 250 g was used.
The obtained modified polyvinyl acetal resin is dissolved in DMSO-d ₆ (dimethyl sulfoxide) and analyzed using ¹³ C-NMR (nuclear magnetic resonance spectrum) to find that it has an amino group represented by the above formula (3) Having a structural unit (content: 0.8 mol%) and a structural unit having an imine structure shown in the above formula (5) (content: 14.2 mol%, R ³ and R ⁴ are methyl groups) Was confirmed.
In addition, the acetalization degree measured using ¹³ C-NMR, the amount of acetyl groups, and the amount of hydroxyl groups are shown in Table 1.
Using the obtained modified polyvinyl acetal resin, a polyvinyl acetal resin solution, a resin composition and a resin sheet were produced in the same manner as in Example 1.

(Example 6)
Polyvinyl alcohol is changed to 250 g of polyvinyl alcohol containing a structural unit having a degree of polymerization of 800, a degree of saponification of 99.5 mol%, and an amino group represented by the above formula (3) and 250 mol%. A modified polyvinyl acetal resin was obtained by the same method as in Example 1 except that 150 g was used.
The obtained modified polyvinyl acetal resin is dissolved in DMSO-d ₆ (dimethyl sulfoxide) and analyzed using ¹³ C-NMR (nuclear magnetic resonance spectrum) to find that it has an amino group represented by the above formula (3) Having a constituent unit (content: 0.9 mol%) and a constituent unit having an imine structure shown in the above formula (5) (content: 19.1 mol%, R ³ and R ⁴ are methyl groups) Was confirmed.
In addition, the acetalization degree measured using ¹³ C-NMR, the amount of acetyl groups, and the amount of hydroxyl groups are shown in Table 1.
Using the obtained modified polyvinyl acetal resin, a polyvinyl acetal resin solution, a resin composition and a resin sheet were produced in the same manner as in Example 1.

(Examples 7 to 9, Reference Example 10, Examples 11 to 12)
Examples 1 to 3, Reference Example 4, Example 5 except that 9 g of oxalic acid (manufactured by Mitsubishi Chemical Corporation) was used instead of 9 g of bisphenol F-type epoxy resin (jER 807, manufactured by Mitsubishi Chemical Corporation) as the crosslinking agent. A resin composition and a resin sheet were produced in the same manner as in.

(Examples 13 to 15, Reference Example 16, Examples 17 to 18)
Examples 1 to 3, Reference , except that 2-methacryloyloxyethyl isocyanate (Kalens MOI, manufactured by Showa Denko KK) was used instead of 9 g of bisphenol F-type epoxy resin (jER 807, manufactured by Mitsubishi Chemical Corporation) as the crosslinking agent. A resin composition and a resin sheet were produced in the same manner as in Example 4 and Examples 5 to 6.

(Examples 19 to 21, Reference Example 22, Examples 23 to 24)
Resin compositions and resin sheets were produced in the same manner as in Examples 1 to 3, Reference Example 4 and Examples 5 to 6 except that no crosslinking agent was added.

(Example 25)
Polyvinyl alcohol is changed to 240 g of polyvinyl alcohol containing a structural unit having a degree of polymerization of 600, a degree of saponification of 99 mol%, and an amino group represented by the above formula (3) 1.7 mol%, and the amount of n-butyraldehyde added A modified polyvinyl acetal resin was obtained in the same manner as in Example 1 except that the amount was 275 g.
The obtained modified polyvinyl acetal resin is dissolved in DMSO-d ₆ (dimethyl sulfoxide) and analyzed using ¹³ C-NMR (nuclear magnetic resonance spectrum) to find that it has an amino group represented by the above formula (3) Having a constituent unit (content: 0.2 mol%) and a constituent unit having an imine structure shown in the above formula (5) (content: 1.5 mol%, R ³ and R ⁴ are methyl groups) Was confirmed.
In addition, the acetalization degree measured using ¹³ C-NMR, the amount of acetyl groups, and the amount of hydroxyl groups are shown in Table 1.
A polyvinyl acetal resin solution was produced in the same manner as in Example 1 using the resulting modified polyvinyl acetal resin.

( Reference Example 26)
Polyvinyl alcohol is changed to 240 g of polyvinyl alcohol having a polymerization degree of 600, a saponification degree of 99 mol%, and a structural unit having an amino group represented by the above formula (3) of 0.2 mol%, and the amount of n-butyraldehyde added A modified polyvinyl acetal resin was obtained in the same manner as in Example 1 except that the amount was 275 g.
The obtained modified polyvinyl acetal resin is dissolved in DMSO-d ₆ (dimethyl sulfoxide) and analyzed using ¹³ C-NMR (nuclear magnetic resonance spectrum) to find that it has an imine structure represented by the above formula (5) It was confirmed that the polymer had a constituent unit (content: 0.2 mol%, R ³ and R ⁴ are methyl groups).
In addition, the acetalization degree measured using ¹³ C-NMR, the amount of acetyl groups, and the amount of hydroxyl groups are shown in Table 1.
A polyvinyl acetal resin solution was produced in the same manner as in Example 1 using the resulting modified polyvinyl acetal resin.

(Example 27)
Polyvinyl alcohol is changed to 240 g of polyvinyl alcohol containing 1.7 mol% of a structural unit having a degree of polymerization of 1700, a degree of saponification of 99 mol% and an amino group shown in the above formula (3), and the amount of n-butyraldehyde added A modified polyvinyl acetal resin was obtained in the same manner as in Example 1 except that the amount was 275 g.
The obtained modified polyvinyl acetal resin is dissolved in DMSO-d ₆ (dimethyl sulfoxide) and analyzed using ¹³ C-NMR (nuclear magnetic resonance spectrum) to find that it has an amino group represented by the above formula (3) Having a constituent unit (content: 0.2 mol%) and a constituent unit having an imine structure shown in the above formula (5) (content: 1.5 mol%, R ³ and R ⁴ are methyl groups) Was confirmed.
In addition, the acetalization degree measured using ¹³ C-NMR, the amount of acetyl groups, and the amount of hydroxyl groups are shown in Table 1.
A polyvinyl acetal resin solution was produced in the same manner as in Example 1 using the resulting modified polyvinyl acetal resin.

(Example 28)
The polyvinyl alcohol is changed to 240 g of polyvinyl alcohol containing a structural unit having a degree of polymerization of 3300, a degree of saponification of 99 mol%, and an amino group represented by the above formula (3) 1.7 mol%, and the amount of n-butyraldehyde added A modified polyvinyl acetal resin was obtained in the same manner as in Example 1 except that the amount was 275 g.
The obtained modified polyvinyl acetal resin is dissolved in DMSO-d ₆ (dimethyl sulfoxide) and analyzed using ¹³ C-NMR (nuclear magnetic resonance spectrum) to find that it has an amino group represented by the above formula (3) Having a constituent unit (content: 0.2 mol%) and a constituent unit having an imine structure shown in the above formula (5) (content: 1.5 mol%, R ³ and R ⁴ are methyl groups) Was confirmed.
In addition, the acetalization degree measured using ¹³ C-NMR, the amount of acetyl groups, and the amount of hydroxyl groups are shown in Table 1.
A polyvinyl acetal resin solution was produced in the same manner as in Example 1 using the resulting modified polyvinyl acetal resin.

(Example 29)
Polyvinyl alcohol is changed to 240 g of polyvinyl alcohol containing a structural unit having a degree of polymerization of 300, a degree of saponification of 99 mol%, and an amino group represented by the above formula (3) 1.7 mol%, and the amount of n-butyraldehyde added A modified polyvinyl acetal resin was obtained in the same manner as in Example 1 except that the amount was 275 g.
The obtained modified polyvinyl acetal resin is dissolved in DMSO-d ₆ (dimethyl sulfoxide) and analyzed using ¹³ C-NMR (nuclear magnetic resonance spectrum) to find that it has an amino group represented by the above formula (3) Having a constituent unit (content: 0.2 mol%) and a constituent unit having an imine structure shown in the above formula (5) (content: 1.5 mol%, R ³ and R ⁴ are methyl groups) Was confirmed.
In addition, the acetalization degree measured using ¹³ C-NMR, the amount of acetyl groups, and the amount of hydroxyl groups are shown in Table 1.
A polyvinyl acetal resin solution was produced in the same manner as in Example 1 using the resulting modified polyvinyl acetal resin.

(Example 30)
Polyvinyl alcohol is changed to 240 g of polyvinyl alcohol containing a structural unit having a degree of polymerization of 600, a degree of saponification of 99 mol%, and an amino group represented by the above formula (3) 1.7 mol%, and the amount of n-butyraldehyde added A modified polyvinyl acetal resin was obtained by the same method as in Example 1 except that the amount was 135 g.
The obtained modified polyvinyl acetal resin is dissolved in DMSO-d ₆ (dimethyl sulfoxide) and analyzed using ¹³ C-NMR (nuclear magnetic resonance spectrum) to find that it has an amino group represented by the above formula (3) Having a constituent unit (content: 0.2 mol%) and a constituent unit having an imine structure shown in the above formula (5) (content: 1.5 mol%, R ³ and R ⁴ are methyl groups) Was confirmed.
In addition, the acetalization degree measured using ¹³ C-NMR, the amount of acetyl groups, and the amount of hydroxyl groups are shown in Table 1.
A polyvinyl acetal resin solution was produced in the same manner as in Example 1 using the resulting modified polyvinyl acetal resin.

(Example 31)
Polyvinyl alcohol is changed to 240 g of polyvinyl alcohol containing a structural unit having a degree of polymerization of 600, a degree of saponification of 85 mol%, and an amino group represented by the above formula (3) 1.7 mol%, and the amount of n-butyraldehyde added A modified polyvinyl acetal resin was obtained by the same method as in Example 1 except that 150 g was used.
The obtained modified polyvinyl acetal resin is dissolved in DMSO-d ₆ (dimethyl sulfoxide) and analyzed using ¹³ C-NMR (nuclear magnetic resonance spectrum) to find that it has an amino group represented by the above formula (3) Having a constituent unit (content: 0.2 mol%) and a constituent unit having an imine structure shown in the above formula (5) (content: 1.5 mol%, R ³ and R ⁴ are methyl groups) Was confirmed.
In addition, the acetalization degree measured using ¹³ C-NMR, the amount of acetyl groups, and the amount of hydroxyl groups are shown in Table 1.
A polyvinyl acetal resin solution was produced in the same manner as in Example 1 using the resulting modified polyvinyl acetal resin.

(Reference Example 32)
The polyvinyl alcohol is changed to 240 g of polyvinyl alcohol having a polymerization degree of 600, a saponification degree of 99 mol%, and a structural unit having an amide group shown in the above formula (4) (R ⁵ is hydrogen atom) 1.7 mol%, A modified polyvinyl acetal resin was obtained in the same manner as in Example 1 except that the amount of addition of butyraldehyde was changed to 275 g.
The obtained modified polyvinyl acetal resin is dissolved in DMSO-d ₆ (dimethyl sulfoxide) and analyzed using ¹³ C-NMR (nuclear magnetic resonance spectrum) to find that it has an amide group shown in the above formula (4) Structural unit (content: 1.0 mol%, R ⁵ is a hydrogen atom), and structural unit having an imine structure shown in the above formula (5) (content: 0.7 mol%, R ³ and R ⁴ are It could be confirmed that it had a methyl group).
In addition, the acetalization degree measured using ¹³ C-NMR, the amount of acetyl groups, and the amount of hydroxyl groups are shown in Table 1.
A polyvinyl acetal resin solution was produced in the same manner as in Example 1 using the resulting modified polyvinyl acetal resin.

(Comparative example 1)
Change the polyvinyl alcohol to a mixture of 140 g of polyvinyl alcohol having a degree of polymerization of 570 and 98 mol% saponification, 50 g of a polyvinyl alcohol having a degree of polymerization of 790 and 98 mol% saponification, and 60 g of polyvinyl alcohol having a degree of polymerization of 1700 and 99% saponification A polyvinyl acetal resin was obtained in the same manner as in Example 1 except for the above.
The obtained polyvinyl acetal resin was dissolved in DMSO-d ₆ (dimethyl sulfoxide) and analyzed using ¹³ C-NMR (nuclear magnetic resonance spectrum) to find that the structural unit having an amino group and the imine structure It could not be confirmed that it had a structural unit.
In addition, the acetalization degree measured using ¹³ C-NMR, the amount of acetyl groups, and the amount of hydroxyl groups are shown in Table 1.
Using the obtained polyvinyl acetal resin, in the same manner as in Example 1, a polyvinyl acetal resin solution, a resin composition and a resin sheet were produced.

(Comparative example 2)
A resin composition and a resin sheet in the same manner as Comparative Example 1 except that 9 g of oxalic acid (manufactured by Mitsubishi Chemical Corp.) is used instead of 9 g of bisphenol F-type epoxy resin (jER 807, manufactured by Mitsubishi Chemical Corp.) as a crosslinking agent. Was produced.

(Comparative example 3)
Same as Comparative Example 1 except that 9 g of 2-methacryloyloxyethyl isocyanate (Karenz MOI, manufactured by Showa Denko KK) was used in place of 9 g of bisphenol F-type epoxy resin (jER 807, manufactured by Mitsubishi Chemical Corporation) as the crosslinking agent. The resin composition and the resin sheet were produced.

<Evaluation>
The following evaluation was performed about the polyvinyl acetal resin solution, resin composition, and resin sheet which were obtained by the Example , the reference example, and the comparative example. The results are shown in Table 1.

(Base material adhesion evaluation)
The resulting polyvinyl acetal resin solution was applied to various plastic substrates, and then dried at 125 ° C. to produce a resin laminate.
The stress (N / 25 mm) of the obtained resin laminate was measured at a tensile speed of 20 mm / min using TENSILON (manufactured by ORIENTEC Co., Ltd.) in accordance with JIS K 6829.
In the table, PET represents polyethylene terephthalate, PC represents polycarbonate, COP represents a cycloolefin polymer, and AC represents an acrylic polymer (polymethyl methacrylate).

(Temporal viscosity stability)
10 g of the resin composition is added to and dissolved in 90 g of a solvent in which toluene and ethanol are mixed at a weight ratio of 1: 1, and a solution sample is prepared. With respect to the obtained solution sample, the viscosities immediately after preparation of the solution sample and one month after were measured using a B-type viscometer, the rate of change of the solution viscosity was confirmed, and evaluation was made according to the following criteria.
:: less than 10% ○: 10% or more, less than 20% Δ: 20% or more, less than 30% x: 30% or more

(Upper yield point stress measurement)
About the obtained resin sheet, upper yield point stress (N / mm < ² >) was measured on condition of 20 mm / min of tensile velocity using TENSILON (made by ORIENTEC) based on JISK7113.
In addition, the upper yield point stress of the sheet obtained in Comparative Example 1 was normalized as 1.0, and the “normalized conversion efficiency” was determined.
:: normalized conversion efficiency is 1.1 or more ○: normalized conversion efficiency is 1.0 or more and less than 1.1 ×: normalized conversion efficiency is less than 1.0

(Measurement of gel fraction)
To about 0.1 g (w1) of a sample of the resin sheet, 40 g of a solvent in which toluene and ethanol are mixed at a weight ratio of 1: 1 was added, and re-dissolved by stirring for 24 hours. Perform solid-liquid separation with wire mesh (w2). Thereafter, the stainless steel mesh was taken out and vacuum dried at 100 ° C. for 1 hour to measure the mass (w3), and the gel fraction was calculated by the following formula.
Gel fraction (%) = {(w3-w2) / w1} × 100
The gel fraction obtained was evaluated according to the following criteria.
:: 80% or more ○: 40% or more, less than 80% Δ: 10% or more, less than 40% ×: less than 10%

(Solvent resistance)
One drop (about 0.02 g) of a solvent in which ethanol and toluene are mixed at a weight ratio of 1: 1 is dropped on the obtained resin sheet with a spoiler, and after drying at 60 ° C. for 5 minutes, the state of the resin sheet is visually observed. It observed and evaluated in the following procedures.
◎: There was no change in the shape of the sheet, and neither perforation was observed.
○: Swelling was observed in the sheet, but no perforation was observed.
X: Perforation was observed in the sheet.

According to the present invention, it is possible to provide a modified polyvinyl acetal resin composition capable of producing a molded article having excellent crosslinkability and high strength.

Claims (9)

Look containing a structural unit having an imine structure, modified polyvinyl acetal resin, wherein the content of the constituent unit having said imine structure is 1.0 to 20.0 mol%. The modified polyvinyl acetal resin according to claim 1, further comprising a constituent unit having an amino group or an amide structure. The modified polyvinyl acetal resin according to claim 1 or 2, which has an amino group or an amide structure in a side chain. Claim 1, 2 or 3, wherein the modified polyvinyl acetal resin acetalization degree is characterized in that 60 to 90 mol%. Modified polyvinyl acetal resin, claims 1, 2, 3 or 4, wherein the modified polyvinyl acetal resin is made by acetalizing a polyvinyl alcohol having a constituent unit having an amino group or an amide structure. Claim 1, 2, 3, 4 or modified polyvinyl acetal resin composition characterized by containing a modified polyvinyl acetal resin and the crosslinking agent according 5. Crosslinking agents, epoxy compounds, halohydrin compounds, isocyanate compounds, bisacrylamide compound, guanidine compound, according to claim 6, wherein the at least one selected from the group consisting of unsaturated carboxylic acid ester compound and an aldehyde compound Modified polyvinyl acetal resin composition. Claim 1, 2, 3, 4 or 5, wherein the modified polyvinyl acetal resin, or coating solution characterized in that it is obtained by using the claim 6 or 7 modified polyvinyl acetal resin composition. Claim 1, 2, 3, 4 or 5, wherein the modified polyvinyl acetal resin, or bonding agent characterized in that it is obtained by using the claim 6 or 7 modified polyvinyl acetal resin composition.