JPH0259587A - Stabilized composition of dibenzylidene sorbitols - Google Patents

Abstract

PURPOSE:To obtain the subject composition developing little thermal discoloration or generating little aldehyde by thermal decomposition and having excellent thermal stability by adding an alkali metal compound for neutralization and a specific heat-stabilizer to purified dibenzylidene sorbitols. CONSTITUTION:The objective composition can be produced by compounding (A) purified dibenzylidene sorbitols of formula (X and X' are H, 1-3C alkyl, 1-3C alkoxy or halogen; m and n are 1-5; p is 0 or 1) with (B) an alkali metal compound and (C) an alkaline organic amine compound [preferably bis(2,2,6,6- tetramethyl-4-piperidyl) sebacate, etc.]. The component A is produced preferably by dispersing the compound of formula (a condensation product of an aromatic aldehyde and a >=5-hydric alcohol) in 6-15 times weight of a solvent such as methanol and maintaining at 40-80 deg.C for <=1hr to effect the purification of the compound.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to stabilized dibenzylidene sorbitol compositions.

[Prior Art] Dibenzylidene sorbitols (hereinafter referred to as rDBs) are used as modifiers for crystalline polyolefin resins, and are effective in improving rigidity and shortening molding cycles, and are effective in improving molded products. It has ground-breaking properties such as improving the transparency of (Kobunshi Kogyo, Vol. 35, No. 1, pp. 30-35 (1986)).

However, conventional DBSs tend to lack thermal stability. Therefore, when a resin composition made of a polyolefin resin mixed with DBS as a nucleating agent is heat-molded using a normal processing method, the DBS decomposes during heat-molding and generates an odor. Problems such as coloring of molded products were pointed out. In addition, such problems have been a major hindrance in terms of the working environment during molding and in applications where odorless products such as food packaging agents are desired.

As a countermeasure, for example, a heat stabilizer such as an aliphatic carboxylic acid metal salt may be added to the resin in advance or at the same time (JP-A-58-104933, JP-A-62-53360).
, a method of coating the surface with the heat stabilizer in a layer (JP-A-62-50355, JP-A-62-138545)
, method of adding non-aromatic organic amine (Japanese Patent Application Laid-open No. 62-4
No. 289) etc. have been proposed. As a result of the studies conducted by the present inventors, although a certain degree of improvement has been recognized by these methods, simply applying a heat stabilizer to the resin will not improve the DBS.
It has been difficult to sufficiently suppress the decomposition of

In addition, in fields of application such as food packaging materials where sufficient care must be taken in terms of hygiene, it is desirable that the amount of additives added be as small as possible, even if the additives are safe.

On the other hand, based on the knowledge that if mono-substituted or tri-substituted substances coexist with dibenzylidene sorbitol, the modification effect of polyolefin resins decreases, and as a way to solve this problem, the above-mentioned substituted substances are washed with aliphatic lower alcohol. A method for purifying dibenzylidene sorbitol by removing it has been proposed (Japanese Patent Application Laid-open No. 5165/1983). However, even with such a purified product, the thermal stability was still insufficient.

During the subsequent detailed examination, the following two important facts became clear. That is, (1) Strong acidic compounds such as sulfuric acid, phosphoric acid, p-toluenesulfonic acid, etc. used as catalysts when manufacturing DBS are almost neutralized and removed in the normal manufacturing process, but the products are powdered. Therefore, trace amounts remain that are not normally considered a problem, and these cannot be completely removed by simple solvent purification. Even if the amount of this strong acidic compound remaining in the product is small, it locally accelerates the hydrolysis of DBS under high temperature heating conditions and generates aromatic aldehydes on the order of ppm. The presence of these substances causes odor generation.

(2> DBS itself has a high melting point and is very stable. For example, 1.3:2.4-dibenzylidene sorbitol is used at 220°C, 1.3:2.4-bis(methylbenzylidene sorbitol) 260°C, and 138°C for non-target DBS where the raw material benzaldehyde is a mixture of benzaldehyde and cumylaldehyde.
It is ℃. On the other hand, conventional products contain small amounts of positional isomers such as 5-membered ring acetals such as 1.2:3.4-dibenzalized products or 1,2:3,4:5.6-dribenzated products. However, this substance is usually amorphous, and its melting point is as low as 80℃ or less.
This reduces the thermal stability of DBS products.

[Problems to be Solved by the Invention] The present inventors suppressed the thermal decomposition of DBS that occurs during thermoforming of resin by applying a relatively small amount of stabilizer, thereby improving the working environment and improving hygiene. As a result of intensive studies to develop BSs that can produce molded products with no problems in terms of surface properties and have good thermal stability, we have developed purified DBSs obtained by washing and removing impurities such as positional isomers with a specific solvent. By completely neutralizing strong acidic substances mixed in the substance and turning them into neutral chlorides, the desired purpose can be achieved by adding a specific substance as a heat stabilizer. The present invention was completed based on this finding.

That is, an object of the present invention is to provide a DB8m composition with excellent thermal stability.

[Means for Solving the Problems] The stabilized DBS composition according to the present invention is a purified product of DBS represented by the general formula (I>) in which an alkali metal compound and an alkaline organic amine compound are added. It is characterized by being mixed.

(The following is a blank space) (X') m [In the formula, x and x'' are the same or different, a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms,
Represents a halogen atom. m and n are the same or different,
Represents an integer from 1 to 5. p represents 0 or 1. ] The purified product of DBS according to the present invention refers to a compound represented by the following general formula (I), which is a condensate of aromatic aldehydes and a polyhydric alcohol having a valence of 5 or more, and is washed with a specific solvent. By doing so, the purified product is obtained by removing the mono- or tri-substituted product and the positional isomer, which is usually contained in an amount of about 1.0 to 2.5% by weight.

Here, the aromatic aldehydes include benzaldehyde, a benzaldehyde substituted product substituted with 1 to 5 alkyl groups having 1 to 3 carbon atoms, a benzaldehyde substituted product substituted with 1 to 5 halogen atoms, and a benzaldehyde substituted product substituted with 1 to 5 halogen atoms; Examples include benzaldehyde substituted products having 1 to 5 alkoxy groups and mixtures thereof in arbitrary proportions.

Examples of polyhydric alcohols include sugar alcohols such as sorbitol and xylit, and mixtures thereof in arbitrary proportions.

The resulting compounds include not only asymmetric types with different types and numbers of aromatic substituents, symmetric types with the same aromatic substituents, and mixtures thereof, but also arbitrary mixtures of sorbitol derivatives and xylitol derivatives. Ru.

Solvents suitable as cleaning solvents have the following properties: (1) relatively high volatility and good drying properties;
) Does not gel even after heat treatment and rapid cooling; (3)D
Any material that satisfies conditions such as being able to disperse BS well and (4) being a good solvent for isomers is sufficient. Specifically, (A) methanol, ethanol, isopropanol, etc. Aliphatic lower alcohols for tools, etc., carbon atoms of 6 or more such as n-hexane, etc.
One or more solvents selected from the group consisting of 12 saturated hydrocarbons, alicyclic hydrocarbons such as cyclohexane, and aromatic hydrocarbons such as toluene, or together with these (8)
Examples include a mixed solvent with one or more selected from the group consisting of ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone.

In this case, there is no problem with the presence of water in the system as long as it does not impair the cleaning effect, and it is more realistic.

As a specific purification treatment method, DBS combinations are
It is dispersed in about 20 times the amount (by weight) of a solvent, preferably 6 to 15 times the amount (by weight), and heated at room temperature or under heating conditions, preferably at about 40 to 80°C, for about 1 minute to 3 hours, preferably about 1 hour.
The content of the positional isomer in the purified product is reduced to about 0.2% by weight or less by holding for a few hours, cooling to near room temperature, and filtering.

Naturally, this method can also be applied as a liquid flow purification method.

However, even with such purification treatment, it is not possible to completely remove the strong acidic substance used as an acid catalyst.
A strongly acidic substance of about 10 to 1100 pD usually remains in the purified product.

This phenomenon is unique to the compound and is presumed to occur because it has strong liquid adsorption properties, but the cause is not completely clear.

In the present invention, the alkali metal compounds applied to neutralize the purified product include sodium hydroxide,
Inorganic alkalis such as potassium hydroxide, citric acid, abietic acid, lactic acid, lactic acid dimer stearate, succinic acid, benzoic acid and their nuclear substitutes, stearic acid, isostearic acid, hydroxystearic acid, dihydroxystearic acid, tetrahydroxystearic acid , fatty acids such as dimer acid, oleic acid, and behenic acid, and ethylenediaminetetraacetic acid (hereinafter abbreviated as rEDTAJ).

), organic acids such as boric acid, and inorganic weak acids such as boric acid, lithium,
Examples include alkali metal salts such as sodium and potassium.

The amount of the above alkali metal compound added is preferably at least enough to completely neutralize the remaining strong acidic compound, and unlike normal neutralization, it is added in an amount of about 10 to 20 times the equivalent of the acidic compound. .

In the neutralization treatment according to the present invention, it is desirable to stir and mix the DBS in a state where it is sufficiently swollen in the solvent under the above-mentioned temperature conditions. is substantially neutralized, and the local hydrolysis-promoting effect of this substance can be eliminated.

As the alkaline organic amine compound used as a heat stabilizer in the present invention, a compound having a melting point lower than that of DBS is preferable because it exhibits an alkali stabilizing effect during heating, and specifically, N, N- Jetanol alkyl (012-24 which may have a hydroxyl group) amine, N,N-dibrobanol alkyl (C12-24 which may have a hydroxyl group) amine, N,N-polyethoxy (polymerization degree -1 ~20>Alkyl (
In addition to aliphatic amines such as C12-24) amines, N,N-polypropoxy (degree of polymerization = 1-20>alkyl (C12-24) amines, bis(
2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis(1,2,2,6,6-bentamethyl-4-piperidyl) sebacate, tetrakis(2,2,6,6-tetramethyl-4 -piperidyl)butanetetracarboxylate, tetrakis(
1,2,2,6,6-・pentamethyl-4-piperidyl)butanetetracarboxylate, poly[[6-(1,1,3,3-tetramethylbutyl)
imino-1,3,5-triazine-2,4-diyl]
[2,2,6,6-tetramethyl-4-piperidyl)
imino]hexamethylene[(2゜2.6,6-tetramethyl-4-piperidyl(imino)], dimethyl succinate-1-(2- and droxyethyl)-4
-Hydroxy-2,2,6,6-titramethylpiperidine polycondensate, dimethyl succinate-2-(4-hydroxy-2°2.6
．． 6-titramethylpiperidine) ethanol polycondensate, 2-(2″-hydroxy-5′-methylphenyl)benzo-1-riazole, 2-(2″-hydroxy-3-tert-butyl-5)
'-Methylphenyl)benzotriazole, "Sanol LS-770J, [Sanol LS2626J" manufactured by Sankyo@
, rHA-70GJ, and other hindered amine compounds.

Although the above alkaline organic amine compound is not limited to the following, it is usually 10 ppm relative to DBS.
About 10% by weight, more preferably 1100Dp to 6% by weight. If it is less than 10 ppm, it is difficult to obtain the desired hardening, and if it is more than 10% by weight, no significant difference is observed in terms of effectiveness, and on the contrary, it may cause discoloration during heating, which is not preferable.

If desired, the DBS according to the present invention may further contain a radical inhibitor of 100 to 50%. It can also be blended in an amount of about OOppm.

Specifically, the applicable radical inhibitors include bisphenol A1 butylhydroxyanisole (hereinafter abbreviated as rBHAJ), 2,6-tert-butylhuman former xytoluene (hereinafter abbreviated as rBHTJ), and 2.6-sheet
rt-butyl-p-cresol, 2.6-sheet tert
-butyl-phenol, 4.4-methylenebis(2,
6-tert-butylphenol), 2.6-tert-butyl-α-dimethylamino-
p-Cresol, 2.6-tert-butyl-p-ethylphenol, 2.4.6-tert-butylphenol, tris(3,5-tert-butyl-4-hydroxybenzyl)isocyanurate, tris[ β-(3,5-tert-butyl-4-hydroxyphenyl>propionyl-oxyethyl]isocyanurate, 1.3.5-trimethyl-2,4,6-tris(3,'
5-tert-butyl-4-hydroxybenzyl)
Benzene, 1,6-hexanethiol bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 6-(4-hydroxy-3,5-di-tert-butylanilino)-2, 4-bisoctyl-thio-1゜3.5
-triazine, tetrakis[methylene-3-(3,5-di-tert-
Butyl-4-hydroxyphenyl) propionate comethane (hereinafter referred to as [Irganox'l010J, manufactured by Ciba Geigy, trade name), n-octadecyl-3-
(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, N,N''-hexamethylenebis(3,5-di-tert-butyl-4-hydroxy-hydrocinnamamide, 3,5-di-tert- Phenols such as polymeric hindered phenols such as butyl-4-hydroxy-benzyl phosphonate diethyl ester, 2,2-thio-diethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] compounds, tris(nonylphenyl)phosphite, tris(2
, 5-di-tert-butylphenyl) phosphite, and tris(2,4-di-tert-butylphenyl) phosphite.

The above-mentioned alkali metal compounds, alkaline organic amine compounds, and radical inhibitors may be used alone or in combination of two or more.

The DBS according to the present invention is prepared by adding and mixing an alkaline organic amine compound dissolved or dispersed in a solvent similar to the above-mentioned cleaning solvent to the purified product containing a predetermined amount of an alkali metal compound, and then evaporating the solvent. Manufactured by removing. However, the method is not limited to the above method as long as a predetermined effect can be obtained.

The DBS composition according to the present invention is useful as a nucleating agent applied to polyolefin resins and the like.

Here, polyolefin resins include high-density polyethylene, medium-density polyethylene, low-density polyethylene including linear polyethylene, copolymers with a polyethylene content of 50% or more, homopolypropylene, random polypropylene, block polypropylene, and polypropylene-containing Examples include copolymers in which the amount is 50% or more.

For molding, commonly used molding methods can be widely applied, and conventionally known additives such as pigments, fillers, antistatic agents, foaming agents, lubricants, plasticizers, crosslinking agents, etc. are appropriately blended as necessary. be able to.

Furthermore, it functions not only as a gelling agent, but also as a viscosity modifier, thixotropic agent, anti-sagging agent, oil/water separator, flocculant, etc., and is useful for modifying adhesives, paints, resins, aromatics, water treatment agents, etc. Solidification and recovery of spilled oil, fragrances, cosmetics, civil engineering, building materials, lubricants,
It is similarly applied in fields where conventional products have been used, such as rust preventives, agricultural chemicals, medicines, pharmaceutical products, fuels, inks, and glues.

[Example code] Hereinafter, the present invention will be described in detail with reference to Examples.

Example 1 [A] 1.3:2.4-bis(methylbenzylidene)sorbitol (hereinafter abbreviated as rMe-DBSJ)
10 g of the mixture (containing 30 ppm of acid catalyst) was dispersed in 150 d of cyclohexane/acetone (8/2: by volume, same hereinafter) mixed solvent, 800 ppm of sodium stearate was added as an alkali metal compound, and the mixture was heated under reflux conditions. Stir at room temperature for 1 hour, cool to room temperature, filter and
A purified product of e-DBS was obtained. For such purified product, N
, N-jetanol tallow alkylamine 1% and 150
150 d of a solution prepared by preliminarily dissolving Irganox 1010J in an amount equivalent to ppm in the above solvent was added, and the solution was stirred and heated to evaporate and remove the solvent. In addition, in each of the above conditions, the blending amount of each additive is based on Me-DBS.

The amount of aldehyde generated when this product was heated in a nitrogen atmosphere at 260° C. in an oil bath for 5 minutes was extracted with acetone and analyzed by GLC, and found to be 10 ppm. Further, the residual amount of isomer measured by n-hexane extraction method was 0.05% by weight.

[B] To 100 parts by weight of polypropylene resin, 0.2 parts by weight of the above treated product, 0.1 parts by weight of calcium stearate, and 1 part by weight of BHTo were added, and melted at 230°C using a twin-screw laboratory plastomill. The mixture was mixed and continuously extruded, and a sheet having a thickness of 0.5 m was continuously prepared by an air cooling method over a period of 30 minutes. At this time, the odor caused by the decomposition of aldehyde was significantly suppressed compared to the case where Me-DBS, which was prepared as [A] except that sodium stearate was not blended, was applied.

Example 2 Cyclohexane/acetone (515) as the purification solvent and potassium benzoate as the alkali metal compound
ppm, bis(1,
Stabilized Me-DBS was prepared according to Example 1, except that 5,000 ppm of 2,2,6,6-bentamethyl-4-piperidyl) sebacate and 200 ppm of BHA were used.

The amount of aldehyde generated in this product was 15[)m, and the amount of isomer was 0.06%.

Example 3 Toluene/ethanol (7/3) as the purification solvent and 500p of lithium behenate as the alkali metal compound
pm and EDTA at 300 ppm.

N,N-dibrobanolstearylamine was used as an alkaline organic amine compound, and BHT was added at 40% aooppm.
Stabilized Me-
DBS was prepared. The amount of aldehyde generated in this product is 10
ppm, and the amount of isomer was 0.1%.

Example 4 Methanol was used as a purification solvent, potassium hydroxide was used at 1 ooppm as an alkali metal compound, and N,N-polyethoxy (degree of polymerization = 15>) was used as an alkaline organic amine compound.
Stabilized Me-DBS was prepared according to Example 1 except that 5% by weight of -12-hydroxystearylamine was used. The amount of aldehyde generated in this product was 10 ppm,
The amount of isomer was 0.05%.

Example 5 1.3:2.4-dibenzylidene sorbitol (hereinafter “
It is abbreviated as "DBS". ), cyclohexane/acetone (7/3) was added as a purification solvent, 600 ppm of potassium hydroxide was added as an alkali metal compound, and bis(2,2,6,6-tetramethyl-4-piperidyl) was added as an alkaline organic amine compound. ) Sebaket 5. OOOpp
Stabilized DBS was prepared according to Example 1 except that m was used.

The amount of aldehyde generated in this product was 12 Dpm, and the amount of isomer was 0.13%.

Example 6 Methanol /
Except for using water (9/1), 500 m of potassium hydroxide as the alkali metal compound, and 5% by weight of Sanol S-770J as the alkaline organic amine compound.
Stabilized DBSs were prepared according to Example 1. The amount of aldehyde generated in this product was 5 ppm, and the amount of isomer was 0.
It was 0.8%.

Example 7 1.3: Methanol/water (9/
1) as an alkali metal compound, oleic potassium 1. OOOppm as an alkaline organic amine compound, 2-(2”-hydroxy-5′-methylphenyl)
Example 1 except that 8% by weight of benzotriazole was used.
Stabilized DBSs were prepared according to . The amount of aldehyde generated in this product was 7 ppm, and the amount of isomer was 0.05%.

Example 8 1.3: For a combination of 2.4-bis(chlorobenzylidene) sorbitol, n-hexane/methyl ethyl ketone (6/4) was used as a purification solvent, 1,000 ppm of potassium stearate was added as an alkali metal compound, and alkaline As an organic amine compound [Sanol LS2626J 2]
Stabilized DB according to Example 1 except for 00ppm use.
Class S was prepared. The amount of aldehyde generated in this product is 7pp.
The amount of isomer was 0.05%.

Example 8 Methanol/water (9
/1) as an alkali metal compound, and lithium benzoate 1. Stabilized DBS was prepared according to Example 1, except that N,N-jetanol-12-hydroxystearylamine was used as the alkaline organic amine compound in 3% of OOOppm. The amount of aldehyde generated in this product was 1 oppm, and the amount of isomer was 0.01%.

Comparative Example 1 A Me-DBS crude composition without solvent purification treatment and addition of no alkali metal compound or alkaline organic amine compound was measured according to Example 1, and the amount of aldehyde generated was 1.400 ppm. The amount of isomer is 0.9
% was rare.

Comparative Example 2 Me, -DBS purified product was subjected to only solvent purification treatment according to Example 1, and no alkali metal compound and alkaline organic amine compound were added. When measured according to Example 1, the amount of aldehyde generated was 1,1100 pp. The amount of isomer was 0.02%.

Comparative Example 3 A Me-DBS crude composition to which 5% by weight of N,N-jetanolstearylamine was added as an alkaline organic amine compound without solvent purification was measured according to Example 1, and the amount of aldehyde generated was measured according to Example 1. is 1,250pl
)m, and the amount of isomer was 0.95%.

Comparative Example 4 A Me-DBS crude mixture prepared according to Example 1 except that the solvent purification treatment was not performed was measured, and the amount of aldehyde generated was 1,300 Dom, and the amount of isomer was 0.95%. Met.

Comparative Example 5 Cyclohexane/acetone (8/2>
0 g of Me-DBS crude composition was dispersed in 150 d, 800 ppm of potassium stearate was added, and the mixture was stirred at 60° C. for 1 hour, then topped and dried. The amount of aldehyde generated in this product was 990 ppm and the amount of isomer was 0.95% in a heating test.

Comparative Example 6 The mixture was dispersed in a solvent in the same manner as in Comparative Example 5, potassium stearate was added, and the mixture was further filtered and dried. The amount of aldehyde generated in this product is necessarily 385 pDm, and the amount of isomer is 0.05%.
Met.

[Effects of the Invention] The DBS composition according to the present invention shows little coloring even when heated, suppresses generation of aldehyde due to decomposition, and is extremely stable. Therefore, for example, when this product is applied as a nucleating agent for crystalline resin, the production of odors is greatly suppressed when molding the resin, improving the working environment, and it can also be used for tableware containers with no uneven brown color. Molded products can be obtained.

Patent applicant: Shin Nihon Rika Co., Ltd.

Claims (1)

[Claims] 1. A stabilized dibenzylidene sorbitol compound represented by the general formula (I), which is characterized by blending an alkali metal compound and an alkaline organic amine compound with the purified dibenzylidene sorbitol compound represented by the general formula (I). Benzylidene sorbitol composition. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) [In the formula, X and X' are the same or different, and represent a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms,
Represents a halogen atom. m and n are the same or different,
Represents an integer from 1 to 5. p represents 0 or 1. ]