JPH0210785B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel resin for safety laminated glass interlayer film, and in detail, the following general formulas (), (), (),
At least one copolymer unit selected from the copolymer units represented by (), (), or () is 0.1
The present invention relates to a resin for safety laminated glass interlayer film comprising a cation group-modified polyvinyl acetal resin containing mol% to 10 mol%. (Here, A means a group that connects the nitrogen atom in B and the nitrogen atom of the amide group, and B is

[Formula] Also teeth

[Formula], D means an alkylene group connecting the nitrogen atom in B and the oxygen atom of the ether group, and R ¹ , R ² , R ¹⁰ , and R ¹¹ each represent a hydrogen atom or a lower alkyl group. , R ³ , R ⁴ ,
R ⁵ each means a hydrogen atom or a lower alkyl group (which may contain a substituent), R ⁶ , R ⁷ , R ⁸
each means a hydrogen atom, a lower alkyl group or a phenyl group, R ⁹ and R ¹² each mean a lower alkyl group, and X ⁻ means an anion. The resin for safety laminated glass interlayer film of the present invention exhibits excellent performance as an interlayer film for safety laminated glass used for windows of automobiles, aircraft, buildings, etc. Traditionally, interlayer films for safety laminated glass have been made of polyvinyl acetal obtained by acetalizing polyvinyl alcohol (hereinafter abbreviated as PVA), especially polyvinyl butyral, with a plasticizer added and molded into a sheet shape. . The quality requirements for the strength performance of safety laminated glass have become higher and higher in recent years, and in particular, conventional products have a large drop in penetration resistance at low or high temperatures.In order to improve this point, interlayer resins or additives for them Although many studies have been conducted on
At present, nothing satisfactory has been found. The present inventors have extensively investigated the chemical modification of PVA, which is the raw material for polyvinyl acetal resin, and have produced and evaluated polyvinyl acetal resin using the resulting modified PVA. derived from denatured PVA,
The inventors have discovered that a modified polyvinyl acetal resin containing a specific cationic group exhibits excellent performance for such purposes, and have also established an industrially advantageous method for introducing cationic groups, thereby completing the present invention. It is something. Until now, the concept of using polyvinyl acetal modified with cationic groups as an interlayer film for safety glass has been completely unknown. Although several methods have been proposed to introduce cationic groups into PVA, all of them had drawbacks in their modification methods and were difficult to produce industrially. This is presumably because it has not been considered to apply acetal resins modified with cationic groups to interlayer films for safety laminated glass. The present invention will be explained in more detail below. The cationic group contained in the modified polyvinyl acetal resin used in the present invention refers to the primary amine, secondary amine, or tertiary amine contained in the copolymerized unit represented by the general formula (), (), or (). quaternary ammonium salt contained in the copolymerized unit represented by the general formula (), () or (); imidazole contained in the copolymerized unit represented by the general formula (); and the At least one type of cationic group selected from imidazolinium contained in the copolymerized unit represented by the general formula (), and these cationic groups have a chemical structure that dissociates in an aqueous solution and becomes positively charged. It is a unit. To explain cation-modified PVA, which is the raw material for cation-modified polyvinyl acetal, the cation-modified
PVA can be produced by copolymerizing vinyl pyridine and vinyl acetate, followed by saponification, or by copolymerizing N-vinyl phthalimide or N-vinyl succinimide and vinyl acetate, followed by saponification, and then decomposing the imide group with alkali or hydrazine. , A method of converting PVA into aminoacetal or aminobenzacetal under an acid catalyst, A method of reacting PVA with alkoxydimethylamine, glycidyltrimethylammonium hydrochloride or 3-chloro-2-hydroxypropyltrimethylammonium hydrochloride, PVA A method is known in which an amino group is introduced by Michael addition of acrylamide to and then Hofmann decomposition. However, these methods for producing cation-modified PVA have various problems in the cationization step itself, which are difficult to implement industrially. On the other hand, the general formula (), (), ()
or Modifications containing copolymerized units shown in parentheses
PVA not only exhibits cationic activity, but also allows for the introduction of cationic groups and the achievement of a desired degree of saponification in an industrially stable and easy manner. The production of modified PVA containing copolymerized units represented by the above general formulas () to () is carried out using vinyl esters, especially vinyl acetate, and the following formulas (a) to (d). (Here, the meanings of R ¹ , R ² , R ⁶ to ^{R 9} , X, A, B, and D are the same as above.) in the presence of a radical polymerization initiator. After that, the alcohol solution of the copolymer is treated with an alkali or acid catalyst to partially or highly saponify the vinyl ester units in the copolymer depending on the purpose, resulting in vinyl alcohol units. It can be produced effectively and easily by In the monomer represented by general formula (a), R ¹ is a hydrogen atom or a lower alkyl group, but a hydrogen atom or a methyl group is usually preferred, and furthermore, the polymerization rate in the copolymerization reaction with vinyl acetate is high. and is preferably a hydrogen atom. R ² is also a hydrogen atom or a lower alkyl group, but usually a hydrogen atom or a methyl group is preferred. B is an amino group

[Formula] or quaternary ammonium salt

[Formula], and R ³ , R ⁴ , and R ⁵ are a hydrogen atom or a lower alkyl group that may contain a substituent,
X indicates an anion. R ³ , R ⁴ , and R ⁵ are preferably all methyl groups for normal purposes, but for special purposes they may be lower alkyl groups such as ethyl or propyl groups, or methylol groups or cationic groups for the purpose of imparting reactivity. Lower alkyl groups containing substituents such as aminoalkyl groups are also used for the purpose of improving density. X is a halogen atom such as chlorine, silium, iodine, or CH ₃ OSO ₃
Alternatively, CH ₃ C ₆ H ₄ SO ₃ is preferable, but chlorine atoms are especially preferred for economic, safety, or modification reasons.
This is preferable in terms of the physical properties of PVA. When B is in the form of a quaternary ammonium salt, the effects of the present invention can be exhibited even with primary to tertiary amines, which are preferable for ease of handling in the production of modified PVA. A is a group that connects the nitrogen atom in the amino group B and the nitrogen atom of the amide group
Any group containing a stable bond can be used, but a linear or branched aliphatic group is usually used. Among the monomers represented by the above general formula (A), the following are specific examples of monomers in the form of tertiary amines. N-(2-dimethylaminoethyl)acrylamide, N-(2-dimethylaminoethyl)methacrylamide, N-(3-dimethylaminopropyl)acrylamide, N-(3-diethylaminopropyl)acrylamide, N-(3-dimethyl aminopropyl) methacrylamide, N-(3-
diethylaminopropyl) methacrylamide, N
-(1,1-dimethyl-3-dimethylaminopropyl)acrylamide, N-(1,1-dimethyl-3-dimethylaminopropyl)methacrylamide, N-(1,1-diethyl-3-dimethylaminobutyl)acrylamide , N-(1-methyl 1,
3-diphenyl-3-diethylaminopropyl)
Methacrylamide, N-(3-dimethylaminohexyl)acrylamide, N-(3-methylethylaminopropyl)methacrylamide, N-methyl-N-(3-dimethylaminopropyl)acrylamide. Among the monomers represented by the above general formula (a), those in the form of quaternary ammonium can be easily obtained by quaternizing the above-mentioned tertiary amine type monomer with the following quaternizing agent. be able to. Dialkyl sulfate, e.g. dimethyl sulfate, diethyl sulfate, dipropyl sulfate, alkyl or aryl sulfonic acid C ₁ ~
C ₄ -esters, e.g. methyl-, ethyl-, propyl- or butyl esters, such as methanesulfonic acid, benzenesulfonic acid or toluenesulfonic acid, benzyl halides, e.g. benzyl chloride or benzyl bromide, alkyl halides, e.g. methyl chloride. , methyl bromide, methyl iodide, ethyl chloride, ethyl bromide or ethyl iodide. The following four types of monomers among the various examples mentioned above as monomers represented by the above general formula (A). N-(1,1-dimethyl-3-dimethylaminopropyl)acrylamide Trimethyl-(3-acrylamido-3,3-dimethylpropyl)ammonium chloride N-(3-dimethylaminopropyl)methacrylamide Trimethyl-(3-methacrylamidopropyl)
ammonium chloride In producing the modified PVA of the present invention, the polymerization rate,
It is excellent in terms of stability of the amide group and economic efficiency during monomer production. In addition, examples of the monomer shown in (b) above include the following. 1-vinylimidazole,
1-vinyl-2-methylimidazole, 1-vinyl-2-ethylimidazole, 1-vinyl-2-
Phenylimidazole, 1-vinyl-2,4,5
-Trimethylimidazole. Further, the monomer represented by the above general formula (c) can be easily obtained by quaternizing the monomer represented by the above general formula (b) with the above-mentioned quaternizing agent. Examples of the monomer represented by the above general formula (2) include dimethylaminoethyl vinyl ether, dimethylaminopropyl vinyl ether, quaternized products thereof, and vinyloxyethylamine. It has also been found that a cationic group-modified polyvinyl acetal resin containing a copolymerized unit represented by the general formula () or () is also effective in the present invention. The method for synthesizing modified PVA containing vinylamine units is described in Industrial Chemistry Journal 59 , 658.
(1956) or 60 , 353, 1188 (1957), after copolymerizing N-vinylphthalimide or N-vinylsuccinimide with vinyl acetate, the vinyl acetate portion is saponified, and then an alkali or hydrazine is used to copolymerize the vinyl acetate. A method of decomposing the imide group has been shown, but for both imide monomers, the imide group is decomposed to the amide group, but it is difficult to proceed with the decomposition reaction to the amino group. As the above literature shows, it is difficult to manufacture. It was more difficult than expected to incorporate vinylamine copolymer units into the PVA molecule, and no effective method was known yet. In light of such circumstances, the present inventors have developed a stable and effective method.
As a result of exploring the manufacturing method of incorporating vinylamine units into PVA, we found that vinyl esters, especially vinyl acetate and N-vinyl alkylamide, especially N-
- By copolymerizing vinylacetamide, N-vinyl-N-methylacetamide, N-vinyl-N-methylformamide, etc. in the presence of a radical polymerization initiator, and then hydrolyzing the copolymer, N- - All of the amide groups in the vinylalkylamide units can be hydrolyzed to vinylamine units, and it has thus been possible to successfully produce modified PVA containing any desired amount of vinylamine units. In the hydrolysis of a copolymer of vinyl acetate and N-vinylalkylamide, the hydrolysis rate of the amide group in the N-vinylalkylamide unit is slower than that of the ester group in vinyl acetate, so the hydrolysis is usually carried out in two steps. It is desirable to carry out a decomposition reaction. That is, an alcoholic solution of a copolymer of vinyl acetate and N-vinylalkylamide is treated with an alkali or acid catalyst to saponify the vinyl acetate units in the copolymer, thereby producing modified PVA containing N-vinylalkylamide units. One example is a method in which after synthesizing, water is dissolved under heating to form an aqueous solution, an alkali or acid is added, and a hydrolysis reaction is carried out at 90°C to 100°C. In this case, the alkali is sodium hydroxide, potassium hydroxide, etc., and the acid is sulfuric acid, hydrochloric acid, etc. If the hydrolysis of the N-vinylalkyl amides is carried out using acids, modified PVA is obtained in which the vinylamine units are in the form of the salts of the acids used. Also,
The above-mentioned quaternizing agent was applied to the aqueous solution of modified PVA obtained by decomposing the amide group, and the above ()
It can also be in the form of a quaternary ammonium salt as shown in the formula. The above general formula () in the cation-modified PVA that is the raw material in the modified polyvinyl acetal resin of the present invention
The content of the copolymerized units represented by ~() is essential to have a lower limit of 0.1 mol% or more and an upper limit of 10 mol% or less since the effect is exhibited even at a relatively small content. Generally, the saponification degree is preferably selected from the range of 70 to 100 mol %, and the polymerization degree is selected from the range of 800 to 3000. The cationically modified PVA thus obtained is then acetalized to produce polyvinyl acetal resin. Among polyvinyl acetals, polyvinyl butyral resins are preferred for the purpose of the present invention.
The acetalization method is carried out similarly to conventional polyvinyl acetal resins. The above description has focused on the method of acetalizing cationic group-modified PVA after creating it. However, even if the saponification reaction and acetalization are carried out simultaneously in the saponification step during the production of cationic modified PVA, the modification of the present invention will still be effective. A polyvinyl acetal resin can be obtained. The degree of acetalization is usually selected from the range of 50 to 80 mol%. In order to use the thus obtained modified polyvinyl acetal resin containing a specific cationic group in the molecule as a safety laminated glass interlayer film, a plasticizer is added to the resin in the same way as with conventional polyvinyl acetal resin.
Use 20 to 80 parts per 100 parts. Preferred plasticizers include those commonly used, such as triethylene glycol di-2-ethyl butyrate and triethylene glycol di-2-ethylhexoate. Other additives such as colorants and silicone oil may be added as appropriate. The interlayer film is created by molding a resin into a sheet shape using a conventional method, which is sandwiched between glass plates and heated and pressurized to be used as a safety laminated glass. When the resin of the present invention is used as an interlayer film,
Safety laminated glass is characterized by its excellent penetration resistance not only at room temperature but also at low or high temperatures. The reason why such performance is exhibited is not fully understood, but it is believed that it is due to the improved adhesion between the interlayer film and glass due to the action of the cationic groups in the modified polyvinyl acetal resin of the present invention. Presumed. The present invention will be described in more detail with reference to Examples. In addition, in the following, parts mean parts by weight. Example 1 Trimethyl-(3-acrylamide-3,3-
A copolymer of dimethylpropyl) ammonium chloride and vinyl acetate is saponified to contain 2 mol% of trimethyl-(3-acrylamido-3,3-dimethylpropyl) ammonium chloride units as copolymerized units containing a cationic group, Saponification degree of vinyl acetate unit is 99.8 mol%, 4% aqueous solution at 20℃
A cationic group-modified PVA with a viscosity of 30 cp (centipoise) (as measured by a Bruckfield viscometer; the same applies hereinafter) was obtained. Next, this modified PVA was reacted with butyraldehyde to perform butyralization, resulting in a butyralization degree of 63 mol% and trimethyl-(3
-acrylamide-3,3-dimethylpropyl)
A modified polyvinyl butyral resin containing 2 mol % of ammonium chloride units was obtained. This resin
50 parts of triethylene glycol di-2-ethyl butyrate was mixed with 100 parts of the mixture, and after kneading with a roll at 70°C, an interlayer film with a thickness of 0.7 mm was produced at 140°C and 30 kg/cm ² . Glass plate (300 x 300 x 2 mm) 2
This interlayer film was sandwiched between the sheets to obtain a safety laminated glass laminated at 120° C. and 10 Kg/cm ² . The penetration resistance of this safety glass was measured by a falling ball test, and the results are shown in Table 1. Examples 2 to 9 A modified polyvinyl butyral resin was obtained in the same manner as in Example 1 except that the following cationic group-modified PVA was used in place of the cationic group-modified PVA of Example 1, and evaluated as a safety laminated glass interlayer film. carried out.
The evaluation results are also shown in Table 1. The cationic group-modified PVA trimethyl-(3-acrylamide-3,3
A cationic group-modified PVA containing 0.5 mol% of (dimethylpropyl) ammonium chloride units, a degree of saponification of vinyl acetate units of 99.6 mol%, and a viscosity of 4% aqueous solution at 20°C of 28 cP. Cationic group-modified PVA used in Example 3 Cationic group-modified PVA containing 1 mol% of N-(1,1-dimethyl-3-dimethylaminopropyl)acrylamide units, having a saponification degree of 99.6 mol% and a viscosity of 28 cP . Cationic group-modified PVA used in Example 4 A cationic group-modified PVA containing 0.8 mol% of trimethyl-(3-methacrylamidopropyl)ammonium chloride units, having a saponification degree of 99.8 mol% and a viscosity of 29 cP. Cationic group-modified PVA used in Example 5 A cationic group-modified PVA containing 0.5 mol% of 1-vinyl-2,3-dimethylimidazolinium chloride units, a saponification degree of 99.9 mol%, and a viscosity of 30 cP.
PVA. Cationic group-modified PVA used in Example 6 A cationic group-modified PVA containing 1 mol% of 1-vinyl-2-methylimidazole units, having a saponification degree of 99.6 mol% and a viscosity of 27 cP. Cationic group-modified PVA used in Example 7 A cationic group-modified PVA containing 0.4 mol% of trimethyl-(vinyloxyethyl)ammonium chloride units, a saponification degree of 99.6 mol%, and a viscosity of 28 cP.
PVA. The copolymer of the cationic group-modified PVA N-vinylacetamide and vinyl acetate used in Example 8 was saponified, and the amide group was further decomposed with caustic soda.It contained 2 mol% of vinylamine units, and the degree of saponification was 100. Mol%, 4% aqueous solution at 20℃
Cationically modified PVA with a viscosity of 30 cP. 1 mol% of N-methylvinylamine units obtained by saponifying the copolymer of cationic group-modified PVA N-vinyl-N-methylformamide and vinyl acetate used in Example 9 and further decomposing the amide group with sulfuric acid. Contains, saponification degree 100 mol%, 4
% aqueous solution with a viscosity of 30 cP at 20°C. Comparative Example 1 A polyvinyl butyral resin was obtained in the same manner as in Example 1, except that PVA with a saponification degree of 99.9 mol% and a 4% aqueous solution having a viscosity of 28 cP at 20°C was used in place of the cationic group-modified PVA of Example 1. We conducted an evaluation as an interlayer film for safety laminated glass. The evaluation results are shown in Table 1.

【table】

[Table] A safety laminated glass sample (300 x 300 mm) is held horizontally by supporting its edges, and a 2.26 kg steel ball is freely dropped from above the safety glass to the center of the sample at the specified temperature. The height of the steel ball was varied in 1-foot increments, and the highest falling ball height that resulted in penetration resistance of 50% or more in repeated tests was measured. The larger the value of the falling ball height, the higher the penetration resistance.

Claims (1)

[Claims] 1 The following general formulas (), (), (), (), (
)
A resin for a safety laminated glass interlayer film comprising a cationic group-modified polyvinyl acetal resin containing 0.1 mol% to 10 mol% of at least one copolymerized unit selected from the copolymerized units represented by (). (Here, A means a group connecting the nitrogen atom in B and the nitrogen atom of the amide group, B means [formula] or [formula], and D means the nitrogen atom in B and the oxygen of the ether group. means an alkylene group that connects atoms, R ¹ , R ² , R ¹⁰ , and R ¹¹ each represent a hydrogen atom or a lower alkyl group; R ³ , R ⁴ ,
R ⁵ each means a hydrogen atom or a lower alkyl group (which may contain a substituent), R ⁶ , R ⁷ , R ⁸
each means a hydrogen atom, a lower alkyl group or a phenyl group, R ⁹ and R ¹² each mean a lower alkyl group, and X ^- means an anion)