JPH07103303B2 - Β-Methyl-δ-valerolactone polymer composition having improved thermal stability - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a β-methyl-δ-valerolactone-based polymer composition having improved thermal stability (hereinafter, β-methyl-δ-valerolactone-based polyester). Sometimes referred to as a polyol). The polymer containing β-methyl-δ-valerolactone is a liquid polyester and is not only easy to handle but also useful for imparting non-crystallinity to the crystalline polymer. Furthermore, a polyester diol obtained by using β-methyl-δ-valerolactone as an initiator with a diamine or a diol is useful as a soft segment of polyurethane, and in this case, it has a higher hydrolysis resistance than conventionally known polyester polyurethanes. It provides excellent properties such as degradability and high mold resistance.

[Conventional technology]

It is well known that the lactone ring-opening polymer is decomposed from the terminal to the original monomer by heating. This decomposition temperature remarkably depends on the type of lactone. For example, ε-caprolactone polymer shows a high decomposition temperature of 250 ° C. or higher,
Therefore, in the case of poly-ε-caprolactone, heat resistance is not a fatal problem in practical use. On the other hand, at the terminal obtained by subjecting β-methyl-δ-valerolactone to ring-opening polymerization reaction with glycol as an initiator, It is known that the thermal stability of a polymer having a is significantly low (JP-A-60-248727), but the thermal stability of such a β-methyl-δ-valerolactone-based polyester polyol is improved. This attempt has never been known before.

[Problems to be solved by the invention]

As described in JP-A-60-248727, β-methyl-δ-valerolactone-based polyester polyols release β-methyl-δ-valerolactone monomer from the ends by heating. For this reason, when used as a plasticizer such as vinyl chloride, bleeding and odor of the monomer become a problem, and even if an attempt is made to perform melt polymerization with an isocyanate compound during the production of polyurethane, the monomer is released and the molecular weight changes. This causes serious problems such as the viscosity not increasing. In order to make full use of the features such as high hydrolysis resistance of the β-methyl-δ-valerolactone-based polyester polyol, the thermal stability of the diol is increased and unless dissociation of the monomer due to heating is suppressed. The current situation is that the applications have to be very limited.

In general, various compounds have been developed as heat resistance improvers for polyesters, and organic phosphorus compounds, epoxy compounds, amine compounds, and phenol compounds are usually added.

However, these compounds have no effect on improving the thermal stability of the β-methyl-δ-valerolactone-based polyester polyol, or conversely have the problem of further lowering the thermal stability. I can't solve it.

An object of the present invention is β-methyl-δ- with improved thermal stability.
A valerolactone-based polymer composition is provided.

[Means for solving problems]

The inventors of the present invention have extensively studied a β-methyl-δ-valerolactone-based polymer composition having improved thermal stability and suppressed dissociation of a monomer due to heat. The inventors have found that a β-methyl-δ-valerolactone-based polymer having improved properties and suppressed dissociation of monomers due to heat is obtained, and completed the present invention.

That is, the present invention is a monoalcohol having 1 to 18 carbon atoms, a polyhydric alcohol having 2 to 22 carbon atoms, an alkylene group having 2 to 12 carbon atoms or an alkylene group having 4 to 10 carbon atoms. An initiator is an organic compound having an active hydrogen selected from the group consisting of polyoxyalkylene glycols having an average molecular weight of 200 to 2000, monoamines having 1 to 18 carbon atoms and polyamines having 2 to 12 carbon atoms, and is mainly β- Β obtained by ring-opening polymerization of methyl-δ-valerolactone
A stabilized β-methyl-δ-valerolactone polymer composition obtained by adding 0.01 to 5% by weight of an organic carbodiimide compound to a methyl-δ-valerolactone polymer.

The β-methyl-δ-valerolactone polymer used in the present invention can be produced by a conventionally known method for producing a lactone polymer. Monoalcohols having 1 to 18 carbon atoms and 2 to 22 carbon atoms can be produced. Polyhydric alcohols, alkylene groups having 2 to 12 carbon atoms or cycloalkylene having 4 to 10 carbon atoms, polyoxyalkylene glycols having an average molecular weight of 200 to 2000, monoamines having 1 to 18 carbon atoms, and carbon It can be obtained by ring-opening polymerization of β-methyl-δ-valerolactone in the presence of a catalyst using an organic compound having an active hydrogen selected from the group consisting of polyamines of the formulas 2 to 12 as an initiator. As the catalyst, known lithium, sodium, n-butyllithium, sulfuric acid, phosphoric acid, BF _3- (OC ₂ H ₅ ) ₂ or the like is 0.01 to 10 mol% with respect to the initiator.
Used in an amount of.

As an initiator, monoalcohols having 1 to 18 carbon atoms, polyhydric alcohols having 2 to 22 carbon atoms, and an average of an alkylene group having 2 to 12 carbon atoms or cycloalkyl having 4 to 10 carbon atoms 1 selected from the group consisting of polyoxyalkylene glycols having a molecular weight of 200 to 2000, monoamines having 1 to 18 carbon atoms and polyamines having 2 to 12 carbon atoms, 1
Alternatively, an organic compound having two or more active hydrogens in an amino group or a hydroxyl group is used. These may be low molecular weight compounds or high molecular weight compounds. Specific examples include methanol, ethanol, butanol, 2-ethylhexanol, 2,7-octadienol, lauryl alcohol, cyclohexanol, monoalcohols having 1 to 18 carbon atoms such as benzyl alcohol, ethylene glycol,
1,2-propanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 3-methyl-1,5-
C2 to C22 polyhydric alcohols such as pentanediol, neopentyl glycol, naphthalene diol, diethylene glycol, tetraethylene glycol, glycerin, trimethylolpropane, and triethanolamine, polyoxyethylene glycol or polyoxyethylene glycol having an average molecular weight of 200 to 2000. An alkylene group such as oxypropylene glycol having 2 to 12 carbon atoms or 4 to 10 carbon atoms
Polyoxyalkylene glycols having an average molecular weight of 200 to 2000 which are cycloalkylenes, butylamine, 2-
C2-C18 monoamines such as ethylhexylamine, laurylamine, diethylamine, dibutylamine, morpholine, ethylenediamine, 1,4-butanediamine, 1,6-hexanediamine, p-phenylenediamine, piperazine, etc. ~ 12 polyamines.

Polymers applicable to the present invention are those polymerized with β-methyl-δ-valerolactone alone by an initiator, but are copolymerized with other copolymerizable monomers in an amount of about 50 mol% or less. You can buy it. Δ for the copolymerizable monomer
Specific examples thereof include valerolactone, ε-caprolactone, formaldehyde and ethylene oxide.

The average molecular weight of the polymer is not particularly limited, but it is preferably in the range of 300 to 20,000.

The polymerization reaction is carried out in the presence of a catalyst, but depending on the type and amount of the catalyst, the hydrolysis resistance and storage stability of the polymer may be impaired, so the catalyst can usually be washed by a known method such as washing with water. It is desirable to remove as much as possible.

Since the ring-opening polymer of β-methyl-δ-valerolactone has low thermal stability, it is desirable to remove the solvent and unreacted monomers by shortening the heating time.

In the present invention, it is essential to add the organic carbodiimide compound in an amount of 0.01 to 5 weight percent to the β-methyl-δ-valerolactone-based polymer obtained by the above method. Addition amount of organic carbodiimide is 0.01
If it is less than weight percent, the effect of improving the thermal stability is hardly recognized. On the contrary, when it is used in an amount of more than 5% by weight, not only is it not so effective as in the case of less than 5% by weight, but the resin obtained by using the β-methyl-δ-valerolactone-based polymer is Therefore, the plasticizing effect appears and the physical properties are changed, which is not preferable. The most preferable addition amount is 0.05 to 1.0 weight percent.

Organic carbodiimide compound used in the present invention have the general formula _{A-R 1 N = C =} N-R 2 n B ( provided that Shikichu R ₁ and R ₂
Are the same or different hydrocarbon groups having 1 to 18 carbon atoms, and A
And B each represent H, --NHCONR ₃ R ₄ , or --NHCOOR ₅ . R ₃ and R ₄ are H or a hydrocarbon group having 1 to 18 carbon atoms, and R ₅ is a hydrocarbon group having 1 to 18 carbon atoms. N is an integer of 1 or more, preferably 1 or more and 10 or less). These organic carbodiimide compounds can be easily synthesized by reacting an isocyanate compound with a phosphoryl compound as a catalyst by a known method (TW Campbell, et.al, J. Amer. Chem. Soc., 8
4 , 3673 (1962)).

Specific examples of the organic carbodiimide compound used in the present invention include dicyclohexylcarbodiimide, diphenylcarbodiimide, di-p-tolylcarbodiimide, di-
p-nitrodiphenylcarbodiimide, di-2-methyl-4-nitrophenylcarbodiimide, bis-2,6-diisopropyl-4-hydroxyphenylcarbodiimide, bis-2,6-diisopropylcyclohexylcarbodiimide, average molecular weight 1000-5000 of A carbodiimide polymer having the structure of
Among them, dicyclohexylcarbodiimide is β-methyl-
It is suitable for improving the thermal stability of the δ-valerolactone polymer.

The addition of the organic carbodiimide compound in the present invention to the β-methyl-δ-valerolactone-based polymer is particularly preferably added after the monomer is removed, but after the polymerization reaction,
When water is used to remove the catalyst, it may be after the water is completely distilled off, before or during the distillation of unreacted β-methyl-δ-valerolactone. Absent. The organic carbodiimide compound is β-methyl-δ-
It is desirable that the polymer added to the valerolactone polymer is sufficiently stirred so that it is uniformly mixed.

In addition to the organic carbodiimide compound of the present invention, conventionally known additives such as an ultraviolet absorber and an antioxidant may be appropriately added to the β-methyl-δ-valerolactone polymer of the present invention.

The β-methyl-δ-valerolactone-based polymer composition of the present invention has improved thermal stability and can be used as a plasticizer such as vinyl chloride or as a raw material for polyurethane by melt polymerization, and has a high hydrolysis resistance. It can be applied to a wide range of applications by utilizing its excellent properties such as degradability.

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

[Example] Synthesis example 1 A three-necked flask having a thermometer, a dropping funnel and a stirrer with a content of 1 was charged with 15 g of anhydrous ethylene glycol and 571 g of anhydrous β-methyl-δ-valerolactone and stirred under a nitrogen atmosphere. Meanwhile, 1.0 ml of a hexane solution of n-BuLi (concentration: 1.5 mole / l) was added dropwise. The reaction was carried out at a reaction temperature of 60 ° C for 2 hours. The obtained polymerization solution was dissolved in 600 ml of toluene and washed twice with 300 ml of water each time. Toluene was distilled off from the toluene layer with a rotary evaporator. The polymerization liquid containing unreacted monomer was treated under reduced pressure of 140 ° C. and 3 Torr using a wiper type thin film evaporator to distill off the monomer. The physical properties of the obtained β-methyl-δ-valerolactone type polyester diol are as follows. Average molecular weight 2040, acid value 0.15, β-methyl-δ-valerolactone monomer 0.2 wt%, water content 0.02 wt%, viscosity by E-type viscometer 20.6 poise (40 ° C).

Comparative Example 1 30 g of the β-methyl-δ-valerolactone polyester diol obtained in Synthesis Example 1 was placed in a pressure-resistant glass container, sealed, and heated at 200 ° C. for 1 hour. After cooling, the polymer was analyzed by liquid chromatography to find that the amount of β-methyl-δ-valerolactone monomer was 54 wt%, and the average molecular weight of the polymer analyzed by gel permeation chromatography was 950. Atsuta In addition, as a result of analyzing the end group structure of this polymer by nuclear magnetic resonance spectrum,
The end groups were all polyester diols that maintained hydroxyl groups.

The β-methyl-δ-valerolactone polyester diol was heated in a sealed tube at 110 ° C for 4 hours. After cooling, the viscosity at 40 ° C. was measured using an E-type viscometer to determine the rate of change in viscosity. The results are shown in Table 1.

Example 1 To 50 g of the β-methyl-δ-valerolactone-based polyester diol obtained in Synthesis Example 1, 0.05 wt% of dicyclohexylcarbodiimide was added and uniformly dissolved. This polymer 30
g was heated in the same manner as in Comparative Example 1 at 200 ° C. for 1 hour. After cooling, the polymer was analyzed by liquid chromatography to find that the amount of β-methyl-δ-valerolactone monomer was
It was 3.0 wt%, and the average molecular weight of the polymer analyzed by gel permeation chromatography was 2010. In addition, as a result of analyzing the end group structure of this polymer by nuclear magnetic resonance spectrum analysis, all the end groups remained hydroxyl groups.

Examples 2 to 4 and Comparative Examples 2 to 9 A predetermined amount of the organic carbodiimide compound or other compound shown in Table 1 was added to 20 g of each β-methyl-δ-valerolactone-based polyester diol obtained in Synthesis Example 1,
Heated at 110 ° C. in a sealed tube for 4 hours. After cooling, the viscosity at 40 ° C. was measured using an E-type viscometer to determine the rate of change in viscosity. The results are shown in Table 1.

Example 5 The same reactor as in Example 1 was charged with 14.75 g of anhydrous 3-methylpentane-1,5-diol, 28 g of ε-caprolactone and 253 g of β-methyl-δ-valerolactone and stirred under a nitrogen atmosphere. While n-BuLi in hexane (concentration 1.
5mole / l) 0.5 ml was added dropwise. The reaction was carried out at a reaction temperature of 60 ° C. for 2 hours. The obtained polymerization liquid was dissolved in 500 ml of toluene and washed twice at room temperature with 200 ml of water each time. Toluene was distilled off from the toluene layer with a rotary evaporator. 0.2 wt% of dicyclohexylcarbodiimide was added to a polymerization liquid containing unreacted monomer and undistilled toluene. Using this wiper type thin film evaporator
Unreacted monomer and undistilled toluene were distilled off by treatment under reduced pressure of 150 ° C. and 5 Torr.

The obtained polymer was a polyester diol having an average molecular weight of 2000, β-methyl-δ-valerolactone monomer of 0.15 wt% and an acid value of 0.05.

Charge 20 g of this polymer into a sealed tube in the same manner as in Example 1
It heat-processed at 00 degreeC for 1 hour. The polymer after the treatment has an average molecular weight of 1990, β-methyl-δ-valerolactone monomer 2.1w
The polyester diol had t% and an acid value of 0.05.

Comparative Example 10 A copolymer was synthesized in the same manner as in Example 5 except that dicyclohexylcarbodiimide was not added. The polymer obtained has an average molecular weight of 1985 and is a β-methyl-δ-valerolactone monomer.
The polyester diol had an acid value of 0.22 and an acid value of 0.22.

Charge 20 g of this polymer into a sealed tube in the same manner as in Example 1
It heat-processed at 00 degreeC for 1 hour. The polymer after the treatment has an average molecular weight of 1100, β-methyl-δ-valerolactone monomer 4.5w
The polyester diol had t% and an acid value of 0.12.

Reference Example β-Methyl-δ-having an average molecular weight of 2040 obtained in Synthesis Example 1
Valerolactone-based polyester diol (PMVL), PMVL and polycaprolactone (average molecular weight 2300, obtained by adding 0.4 wt% of dicyclohexylcarbodiimide to this)
Polyurethane was synthesized from acid value of 0.21) and its hydrolysis resistance was compared. Polyurethane is polyester diol / 1,4-
It was synthesized by using butanediol / 4,4'-diphenylmethane diisocyanate in a molar ratio of 1/2/3 and reacting in dimethylformamide at 70 ° C. The polyurethane concentration in the solution was 25 wt%. With this solution, a thickness of 100
A dry film of μ was obtained. This film was left in water at 100 ° C. for 12 days, the film before and after the test was dissolved in dimethylformamide, and the change in viscosity was measured. As a result, Synthesis Example 1
The viscosity retention (viscosity after test / viscosity before test × 100) of the polyurethane prepared from PMVL obtained in 1. was 89%, and it was prepared from PMVL obtained by adding dicyclohexylcarbodiimide to the PMVL obtained in Synthesis Example 1. The viscosity retention of the obtained polyurethane was 89%. The viscosity retention of polyurethane made from polycaprolactone was 20%. Thus, it has been found that PMVL has essentially higher hydrolysis resistance than conventional polycaprolactone-based ones, regardless of the addition of carbodiimide.

〔The invention's effect〕

The stabilized β-methyl-δ-obtained according to the invention
With the valerolactone-based polymer composition, β-methyl-
The dissociation of β-methyl-δ-valerolactone monomer from the δ-valerolactone polymer was suppressed, and the thermal stability of the polymer was highly improved.

 ─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-60-248727 (JP, A) JP-A-61-241354 (JP, A) Kurt C. Frisch, Sidney L .; Reegen edited “KINETI CS AND MECHANISM OF POLYMERIZATION” Vol. II (1969) MARCEL DE KKER, INC. P. 278-282

Claims (5)

[Claims] 1. A monoalcohol having 1 to 18 carbon atoms, a polyhydric alcohol having 2 to 22 carbon atoms and an alkylene group having 2 to 2 carbon atoms.
Selected from the group consisting of polyalkylenes having an average molecular weight of 200 to 2000, which are 12 alkylenes or cycloalkylenes having 4 to 10 carbons, monoamines having 1 to 18 carbons, and polyamines having 2 to 12 carbons. Using an organic compound having an active hydrogen as an initiator, 0.01 to 0.01% of an organic carbodiimide compound with respect to a β-methyl-δ-valerolactone-based polymer obtained mainly by ring-opening polymerization of β-methyl-δ-valerolactone. A stabilized β-methyl-δ-valerolactone polymer composition obtained by adding 5% by weight. Wherein the organic carbodiimide compound has the general formula _{A-R 1 - (N =} C = N-R 2) n-B ( provided that Shikichu R ₁ and R ₂ are the same or different carbon atoms from 1 to 18
Is a carbon-hydrogen group of A and B are H and -NHCONR ₃ R, respectively.
Represents either ₄ or --NHCOOR ₅ . R ₃ and R ₄ are H or a hydrocarbon group having 1 to 18 carbon atoms, and R ₅ is a hydrocarbon group having 1 to 18 carbon atoms. n represents an integer of 1 or more. The composition according to claim 1, which is a compound represented by the formula (1). 3. The composition according to claim 2, wherein n is an integer of 1 or more and 10 or less. 4. The composition according to claim 3, wherein the organic carbodiimide compound is dicyclohexylcarbodiimide. 5. The addition amount of the organic carbodiimide compound is 0.05.
The composition according to any one of claims 1 to 4, which is about 1.0% by weight.