JPH03402B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a novel polymer compound, alkylated cyclohexanecarbaldehyde-acetalized polyvinyl alcohol. More specifically, the present invention relates to a novel polymer compound, which is obtained by acetalizing polyvinyl alcohol with alkylated cyclohexanecarbaldehyde. It relates to polymer compounds. (Prior art) So-called polyvinyl acetals such as polyvinyl formal, polyvinyl acetal, and polyvinyl butyral, which are obtained by reacting polyvinyl alcohol with formaldehyde, acetaldehyde, and butyraldehyde, respectively, have been widely used as materials for synthetic fibers or synthetic resins. It is used. However, it has not yet been confirmed whether polyvinyl acetal can be obtained by reacting polyvinyl alcohol with alkylated cyclohexanecarbaldehyde. (Problems to be Solved by the Invention) As a result of actually reacting polyvinyl alcohol with alkylated cyclohexane aldehyde and confirming the properties of the obtained product, the present inventor found that alkylated cyclohexane carbaldehyde-acetalized polyvinyl alcohol Alcohol was obtained, and it was confirmed that this was a transparent synthetic resin with extremely excellent shape stability. The present invention was made based on this confirmation. (Structure of the Invention) The gist of the present invention is a compound obtained by a condensation reaction of alkylated cyclohexane carbaldehyde and polyvinyl alcohol in the presence or absence of a chain aliphatic, cyclopentane, cyclohexane or aromatic aldehyde. The following repeating units (a), (b), (c) and (d) are arranged randomly,

【formula】

【formula】

[Formula] and

[Formula] And the number of repeating units, (a) is l, (b) is m,
An alkylated cyclohexanecarbaldehyde-acetalized polyvinyl alcohol, where (c) is represented by n and (d) is represented by p, where l is an integer of 1 or more, and m, n, and p are 0 or an integer of 1 or more. However, R is an alkyl group having 1 to 6 carbon atoms, g is a natural number of 3 or less, and R' is hydrogen or a chain aliphatic, cyclopentane, cyclohexane, or aromatic hydrocarbon group having 1 to 10 carbon atoms. represents, exists in. The compound of the present invention can be added to polyvinyl alcohol.
alkylated cyclohexanecarbaldehyde,
If necessary, add chain aliphatic, cyclopentane, cyclohexane or aromatic aldehyde,
It is obtained by performing a condensation reaction between these. In this condensation reaction, aldehydes are preferably added in a slight excess of up to twice the theoretically required amount. This condensation reaction may be carried out by either a precipitation method or a dissolution method. In the precipitation method, the raw material polyvinyl alcohol is dissolved in water using water as a solvent, and a catalyst such as an acid is added to perform a condensation reaction to produce the compound of the present invention (hereinafter referred to as polyvinyl acetal). ) is precipitated and the acid used as a catalyst is neutralized to obtain a solid powder. The dissolution method uses isoprobanol as a solvent,
The only difference is that an organic solvent such as butanol or tetrahydrofuran is used, but otherwise the same condensation reaction as in the precipitation method is carried out to obtain polyvinyl acetal dissolved in an organic solvent, which is then added to an insoluble liquid, e.g. In this method, polyvinyl acetal is obtained as a solid powder. In either method, the resulting powder contains impurities such as unreacted aldehyde and salts generated by neutralization, so ethyl alcohol is added to remove these impurities. Extract the impurities with a solvent such as
Pure polyvinyl acetal. The polyvinyl acetal is characterized in that it contains a moiety acetalized with alkylated cyclohexanecarbaldehyde (hereinafter referred to as an alkylated cyclo moiety). A moiety acetalized by a chain aliphatic, cyclopentane, cyclohexane, or aromatic aldehyde (hereinafter referred to as an aliphatic moiety) may or may not be included. Since this polyvinyl acetal contains an alkylated cyclo moiety, as the content of the alkylated cyclo moiety increases, its heat resistance and moisture absorption resistance tend to improve. This tendency has not been observed in conventional polyvinyl acetals having only aliphatic moieties, such as polyvinyl butyral. That is, in polyvinyl butyral and the like, when trying to improve heat resistance, there was a tendency for hygroscopicity to increase. Since the polyvinyl acetal of the present invention has an alkylated cyclo moiety, it has characteristics of improved moisture absorption resistance and improved heat resistance, and has good shape stability. In particular, when the composition fraction of the alkylated cyclo moiety of the polyvinyl acetal is 10% or more, that is, when 2(l+m)+n+p=t, l≧
In the case of 1/10×t, polyvinyl acetal has excellent moisture absorption resistance and heat resistance, and has a small photoelastic coefficient, so it is preferable. Especially, the case of l≧3/10×t is particularly preferable. In the cyclo cyclo moiety, R is a methyl group and g is preferably 1. R' in the aliphatic moiety may be a hydrogen atom, or may be a chain aliphatic group having 1 to 10 carbon atoms, cyclopentane, cyclohexane, or an aromatic hydrocarbon group. Although the aliphatic moiety is not essential, if it is included, the compositional fraction
30% or less, that is, when 2(l+m)+n+p=t, it is preferable that m≦3/10×t. The degree of acetalization is, in the above polyvinyl acetal, when 2(l+m)+n+p=t,
It is expressed as 2(l+m)÷t×100, and the degree of acetalization of the alkylated cyclo moiety is preferably higher. The degree of saponification is expressed as (100-p)÷t×100, and when the degree of saponification is 95 or more, the transparency of polyvinyl acetal is particularly good, and when p≦1/20×t. Preferably, p≦1/50×t is particularly preferable. In addition, the composition fraction of the polyvinyl alcohol part (hereinafter referred to as poval part) is 40% or less, that is, n
The case of ≦4/10×t is preferable. Therefore, the polyvinyl acetal of the present invention has 10% or more of alkylated cyclo moieties, 30% or less of aliphatic moieties, 40% or less of poval moieties, and 5% or less of vinyl acetate moieties, that is, 2(l+m )
When +n+p=t, moisture absorption resistance and heat resistance are good when l≧1/10×t, m≦3/10×t, n≦4/10×t, and p≦1/20×t. It is preferable because it has excellent shape stability, a small photoelastic coefficient, and excellent transparency.
In particular, when the alkylated cyclo moiety is 30% or more, the aliphatic moiety is 0, the poval moiety is 40% or less, and the vinyl acetate moiety is 2% or less, that is, l≧3/10×t, m = 0, n Particularly preferred cases are ≦4/10×t and p≦1/50×t. (Effects of the Invention) Since the alkylated cyclohexanecarbaldehyde-acetalized polyvinyl alcohol of the present invention contains an alkylated cyclo moiety, it has good moisture absorption resistance and heat resistance, and excellent shape stability. It is required to have a small photoelastic coefficient, excellent transparency, low birefringence, shape stability, and optical properties. It is expected to be used as a suitable material for various optical applications such as disk substrates and films for optical information recording media that utilize laser beams.
It has significantly better shape stability than polymethyl methacrylate, which has been supplied for similar purposes, and has significantly better optical properties than polycarbonate. (Example) Hereinafter, the present invention will be explained with reference to Examples. <Example 1> (a) Production of polyvinyl acetal 100 g of polyvinyl alcohol having a degree of saponification of 99% and a weight average degree of polymerization of 1700 was dissolved in 900 g of pure water. This aqueous solution was cooled to 13℃, and concentrated hydrochloric acid (purity 35
% by weight) was added thereto, and 143.1 g of methylcyclohexanaldehyde was added dropwise thereto over 10 minutes. A precipitate was deposited 21 minutes after the start of the dropwise addition. 10 minutes after precipitation, 51.3 g of concentrated hydrochloric acid (purity 35% by weight) was added, and the mixture was left to stand. After 2 hours, the temperature was raised to 60°C, and the temperature was maintained for 5 hours to obtain polyvinyl acetal. . This polyvinyl acetal was washed with pure water for 2 hours, and then polyvinyl acetal was added for neutralization.
It was dispersed in 800 g of pure water, the pH was maintained at 9.5, and stirring was continued for 4 hours. The polyvinyl acetal thus obtained was dehydrated, soaked, and extracted in an extractor using n-hexane as a solvent throughout the day to remove residual aldehyde, yielding 171 g of polyvinyl acetal. (b) Confirmation of physical properties of polyvinyl acetal The degree of acetalization, residual hydroxyl group, and residual acetyl group were measured for the above polyvinyl acetal. Furthermore, the glass transition point, water absorption, light transmittance, and photoelastic coefficient of the obtained polyvinyl acetal were measured. The results are shown in Table 1, showing excellent optical properties, particularly a high glass transition point and low water absorption. The glass transition point is determined by DSC (Differential
Scanning Calorimeter)
Measurement was carried out using type DSC-1B manufactured by PERKIN-ELMER in the measurement temperature range of 20 to 200°C. The water absorption rate was determined by immersing the dried material in pure water at 20°C for 24 hours and determining the weight change before and after. Light transmittance was measured according to ASTMD-1003. The photoelastic coefficient is determined by bending a resin plate with a thickness d of 1 mm and a width W of 4 mm in the width direction with a curvature b = 0.01 mm ^-1 , and bending the outer and inner peripheries with multiple bends (orders △P ₁ and △P ₂ ). Sodium lamp (wavelength λ is 5890 angstroms)
It was determined using a polarizing microscope using a light source. When the Poisson's ratio of the resin is σ, the coefficient of birefringence Cstrain for the unit length difference is calculated by the following formula. Cstrain (△P ₁ −△P ₂ )λ/(1+σ) Wbd ≒ (△P ₁ −△P ₂ )λ/1.5Wbd If the Young's modulus of the resin is E, the photoelastic coefficient
Cstress is calculated using the following formula. Cstress = 1 + σ / ECstrain = (△P ₁ - △P ₂ ) λ / EWbd In addition, an infrared absorption spectrum was taken for the polyvinyl acetal obtained above, and the unique absorptions in it are listed as follows. be. However, the unit is cm ^-1 . 3520, 2950, 2925, 2870, 1740, 1455, 1435, 1420, 1380, 1350, 1310, 1295, 1245, 1230, 1220, 1175, 1140, 1115, 1085, 1030, 1000, 950, 890, 830, 73 0, 710, 695, 620, 415. <Example 2> (a) Production of polyvinyl acetal Polyvinyl alcohol with a degree of saponification of 97% and a weight average molecular weight of 800 was dispersed in a mixed solution of 900 g of probanol, kept at 55°C with stirring, and concentrated hydrochloric acid (purity 35 Add 57.0g of methyl cyclohexanaldehyde and 71.7g of butyraldehyde.
40.9g was added and reacted for 12 hours. The obtained resin was dropped into 10 liters of pure water to obtain a white powder.
This powder was neutralized and purified in the same manner as in Example 1.
181 g of polyvinyl acetal was obtained. (b) Confirmation of polyvinyl acetal The physical properties of the above polyvinyl acetal were measured in exactly the same manner as in Example 1. The results are also shown in Table 1. <Comparative Example 1> Except that 81.7 g of butyraldehyde was used instead of methylcyclohexane aldehyde,
Butyralization was carried out in exactly the same manner as in Example 1, and this was further neutralized and purified to obtain 141 g of polyvinyl butyral. The physical properties of this polyvinyl butyral were measured in the same manner as in Example 1.
The results are also shown in Table 1. <Comparative Example 2> Glass transition point, water absorption, light transmittance, and photoelastic coefficient were measured for polymethyl methacrylate with a degree of polymerization of 2000. The results are also shown in Table 1. <Comparative Example 3> The same physical properties as in Comparative Example 2 were measured for a commercially available polycarbonate (trade name: Vanlite L-1250, manufactured by Teijin Chemicals). The results are also shown in Table 1.

[Table] As is clear from Table 1, the polyvinyl acetal of the present invention has a higher glass transition point than polyvinyl butyral, has a lower water absorption rate, has a lower water absorption rate than polymethyl methacrylate, and is more transparent than polycarbonate. is excellent.

Claims (1)

[Scope of Claims] 1. A compound obtained by a condensation reaction of alkylated cyclohexane carbaldehyde and polyvinyl alcohol in the presence or absence of a chain aliphatic, cyclopentane, cyclohexane, or aromatic aldehyde, comprising: Repeating units (a), (b), (c)
and (d) are arranged randomly, [formula] [formula] [formula] and [formula] and the number of repeating units is 1 for (a), m for (b),
An alkylated cyclohexanecarbaldehyde-acetalized polyvinyl alcohol, where (c) is represented by n and (d) is represented by p, where l is an integer of 1 or more, and m, n, and p are 0 or an integer of 1 or more. However, R is an alkyl group having 1 to 6 carbon atoms, g is a natural number of 3 or less, and R' is hydrogen or a chain aliphatic, cyclopentane, cyclohexane, or aromatic hydrocarbon group having 1 to 10 carbon atoms. represents. 2 When 2(l+m)+n+p=t, l≧
1/10×t, m≦3/10×t, n≦4/10×t, p≦1
/20×t, the alkylated cyclohexanecarbaldehyde-acetalized polyvinyl alcohol according to claim 1. 3 When 2(l+m)+n+p=t, l≧
3/10×t, m=0, n≦4/10×t, p≦1/50×t
The alkylated cyclohexanecarbaldehyde-acetalized polyvinyl alcohol according to claim 1. 4. The alkylated cyclohexanecarbaldehyde-acetalized polyvinyl alcohol according to claim 1, wherein g=1 and R is a methyl group.