JP2007169414A - Polyacetal carbonate block copolymer and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a novel polyacetal carbonate block copolymer having sufficient mechanical properties and the like and excellent heat resistance. <P>SOLUTION: The polyacetal carbonate block copolymer includes a continuous chain (A) mainly consisting of a repeating oxymethylene unit and a continuous chain (B) consisting of a repeating carbonate unit by the ring-opening polymerization of at least one cyclic carbonate compound selected from 1,3-dioxepan-2-one, 1,3-dioxan-2-one, and alkyl substituted compounds thereof. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a novel polyacetal carbonate block copolymer having sufficient mechanical properties and the like and excellent heat resistance, and a method for producing the same.

  Polyacetal resin has excellent balance of mechanical properties, chemical resistance, slidability, etc. and is easy to process, so it can be used as a representative engineering plastic for electrical / electronic parts, automobile parts and other various mechanical parts. Widely used as a center.

  With the expansion of such application fields, in recent years, there has been a tendency to demand a polyacetal resin material to which more advanced characteristics are added.

  In response to such demands, in general, selection of components to be blended with polyacetal resin, combination of blending components, adjustment of blending amount, etc., there are many cases where new functions are added or functions are optimized, Such improvements from the resin composition side are naturally limited, and basically, improvements from the polymer skeleton side of the polyacetal resin are also being studied.

  One of them is a polyacetal carbonate copolymer obtained by copolymerizing such a cyclic carbonate compound and trioxane by paying attention to a cyclic carbonate compound which has recently been attracting attention as a compound for fixing carbon dioxide which causes global warming. Has been proposed (Patent Document 1).

The polyacetal carbonate copolymer disclosed in this document is intended to impart degradability, particularly for disposal and decomposition / recovery processing. Although the copolymer disclosed in the above document can impart the target decomposability, the oxymethylene unit by trioxane ring opening and the carbonate unit by ring opening of the cyclic carbonate compound are randomly dispersed. It becomes a copolymer, and neither a crystal structure derived from polyoxymethylene nor a crystal structure derived from a ring-opened polymer of a cyclic carbonate compound is formed, and mechanical properties and heat resistance characteristics are greatly reduced.
JP 2005-320394 A

  In view of the actual situation, an object of the present invention is to provide a copolymer having sufficient mechanical properties and the like and excellent thermal stability.

  As a result of intensive studies to achieve the above object, the present inventors have found that the above-mentioned problems can be solved by a specific block copolymer, and have completed the present invention.

  That is, the present invention provides at least one selected from a continuous chain (A) mainly composed of repeating oxymethylene units, 1,3-dioxepan-2-one, 1,3-dioxan-2-one, and alkyl-substituted products thereof. The present invention relates to a polyacetal carbonate block copolymer having a continuous chain (B) composed of repeating carbonate units by ring-opening polymerization of a kind of cyclic carbonate compound, and a method for producing the same.

  The polyacetal carbonate block copolymer of the present invention has a crystal structure derived from polyoxymethylene and a crystal structure derived from polycarbonate, has sufficient mechanical properties when used as a molded product, and has heat resistance properties. Therefore, it is expected to be used for machine parts, housing parts, and packaging materials.

  The polyacetal carbonate block copolymer of the present invention comprises a continuous chain (A) mainly composed of repeating oxymethylene units, 1,3-dioxepan-2-one, 1,3-dioxan-2-one and alkyls thereof. It has a continuous chain (B) composed of repeating carbonate units by ring-opening polymerization of at least one cyclic carbonate compound selected from the substituents.

Continuous chain (A), in addition to oxymethylene units, it may include a small amount of oxyalkylene units of C ₂ ~ _6, known as the comonomer units of the polyacetal copolymer.
In the polyacetal carbonate block copolymer of the present invention, the ratio of the continuous chain (A) to the continuous chain (B) is preferably (A) / (B) = 10/90 to 70/30 (weight ratio). When the ratio of the continuous chain (A) is excessive, a random copolymer having a short continuous chain (B) is likely to be obtained, and the mechanical properties may be insufficient. Conversely, if the proportion of the continuous chain (B) is excessive, the thermal stability is impaired.

  The polyacetal carbonate block copolymer of the present invention contains at least one cyclic compound selected from trioxane (a), 1,3-dioxepan-2-one, 1,3-dioxan-2-one, and alkyl-substituted products thereof. The carbonate compound (b) can be produced by ring-opening copolymerization based on the production method described later.

  The trioxane (a) used in the present invention is a cyclic trimer of formaldehyde and is generally obtained by reacting an aqueous formaldehyde solution in the presence of an acidic catalyst. Used after purification by the method.

  At least one cyclic carbonate compound (b) selected from 1,3-dioxepan-2-one, 1,3-dioxan-2-one and their alkyl-substituted products used in the present invention is Macromolecules Chem. Phys. 199,97 (1998), Journal of Polymer Science Part A, Polym. Chem. 31,581 (1993), etc., and can be synthesized and used after purification by recrystallization or the like. The

  The polyacetal carbonate block copolymer of the present invention first undergoes ring-opening polymerization of trioxane (a), and then 1,3-dioxepan-2-one, 1,3-dioxan-2-one, and alkyl substitution thereof. It can manufacture by adding at least 1 type of cyclic carbonate compound (b) chosen from a body, and carrying out ring-opening polymerization. Such two-stage polymerization is a particularly preferable method for stably obtaining the block copolymer of the present invention. As the polymerization method, a conventionally known method can be applied as a polymer production method such as a bulk polymerization method using the monomer directly, a solution polymerization method using a solvent, and a suspension polymerization method. Among these, in the present invention, a solution polymerization method using a solvent is preferable. As the solvent, aliphatic hydrocarbons such as n-pentane, n-hexane, n-heptane, n-octane, cyclohexane, cyclopentane, benzene, toluene, Aromatic hydrocarbons such as xylene, halogenated aliphatic hydrocarbons such as dichloromethane, chloroform, carbon tetrachloride, ethylene chloride and trichloroethylene, halogenated aromatic hydrocarbons such as chlorobenzene and o-dichlorobenzene, dimethyl sulfoxide, etc. Sulfur-containing compounds, nitrogen-containing compounds such as nitrobenzene, ether compounds such as diethyl ether, dibutyl ether, and tetrahydrofuran. The polymerization reaction is preferably performed at a temperature of 50 ° C. or lower. As described later, the polymerization rate of trioxane (a) and the cyclic carbonate compound (b) varies depending on the reaction temperature, but in the two-stage polymerization, particularly in the two-stage polymerization in a solvent, the difference in the polymerization speed is taken into consideration. The reaction temperature is not particularly required to be controlled. For example, ring-opening polymerization of trioxane (a) is performed at 0 to 50 ° C., and then the cyclic carbonate compound (b) is added and the ring-opening polymerization is performed at 0 to 50 ° C. As a result, a polyacetal carbonate block copolymer can be obtained. The apparatus used for the polymerization is not particularly limited, and any of batch type, continuous type and the like is possible.

  The ratio of trioxane (a) and cyclic carbonate compound (b) used in the polymerization reaction is preferably (a) / (b) = 20/80 to 80/20 (weight ratio). When the proportion of trioxane (a) is excessive, the continuous chain (A) becomes large, and when the proportion of the cyclic carbonate compound (b) is excessive, the proportion of the continuous chain (B) increases, both of which are mechanical properties and thermal stability. It becomes difficult to obtain a block copolymer having both properties.

  In the polymerization reaction, the method for adding the cyclic carbonate compound (b) is not particularly limited, but it is preferable to add gradually. The time from the start of polymerization of trioxane (a) to the addition of cyclic carbonate (b) is preferably 30 minutes to 2 hours, more preferably 1 hour to 1 hour 30 minutes.

  The block copolymer of the present invention can also be obtained by methods other than the two-stage polymerization as described above. For example, the difference in polymerization rate between trioxane (a) and the cyclic carbonate compound (b), that is, the polymerization rate of the cyclic carbonate compound (b) is higher than that of trioxane at a temperature lower than 50 ° C., and that of trioxane (a) is higher than 50 ° C. If appropriate temperature control is performed using the property that the polymerization rate is faster than that of the cyclic carbonate compound (b), even if the polymerization is carried out in the state where the trioxane (a) and the cyclic carbonate compound (b) coexist, Coalescence can be obtained.

In producing the polyacetal carbonate block copolymer of the present invention, as the polymerization initiator used, perfluoroalkylsulfonic acid and its anhydride, perchloric acid, acetyl perchlorate, t-butyl perchlorate, hydroxyacetic acid, Inorganic and organic acids such as trichloroacetic acid, trifluoroacetic acid and p-toluenesulfonic acid, complex salt compounds such as triethyloxonium tetrafluoroborate, triphenylmethylhexafluoroantimonate, allyldiazonium hexafluorophosphate, allyldiazonium tetrafluoroborate Alkyl metal salts such as diethyl zinc, triethylaluminum, diethylaluminum chloride, heteropolyacid, isopolyacid, lead tetrachloride, tin tetrachloride, titanium tetrachloride, aluminum trichloride, zinc chloride Vanadium trichloride, antimony trichloride, phosphorus pentafluoride, antimony pentafluoride, boron trifluoride, boron trifluoride diethyl etherate, boron trifluoride dibutyl etherate, boron trifluoride dioxanate, boron trifluoride acetate One type or two or more types of boron trifluoride coordination compounds such as tic anhydrate and boron trifluoride triethylamine complex can be used. In particular, perfluoroalkylsulfonic acid, its anhydride, and its derivatives are preferably used. Specific examples of perfluoroalkylsulfonic acid include trifluoromethanesulfonic acid, pentafluoroethanesulfonic acid, heptafluoropropanesulfonic acid, Nonafluorobutanesulfonic acid, undecanefluoropentanesulfonic acid, perfluoroheptanesulfonic acid and the like can be mentioned. Specific examples of the perfluoroalkylsulfonic acid anhydride include trifluoromethanesulfonic acid anhydride, pentafluoroethanesulfonic acid anhydride, heptafluoropropanesulfonic acid anhydride, and the like. Specific examples of the perfluoromethanesulfonic acid derivative include methyl trifluoromethanesulfonate, ethyl trifluoromethanesulfonate, methyl pentafluoroethanesulfonate, methyl heptafluoropropanesulfonate, and the like.

  The polyacetal carbonate block copolymer of the present invention is obtained by ring-opening copolymerization of trioxane (A) and a cyclic carbonate compound (B) as described above. In addition to these main components, a cyclic ether In addition, conventionally known reaction components such as a cyclic formal, a glycidyl ether compound, and a component for adjusting the molecular weight can be used in combination.

  Examples of cyclic ethers and / or cyclic formals that can be used in the present invention include ethylene oxide, propylene oxide, butylene oxide, epichlorohydrin, epibromohydrin, styrene oxide, oxetane, and 3,3-bis (chloromethyl) oxetane. , Tetrahydrofuran, trioxepane, 1,3-dioxolane, ethylene glycol formal, propylene glycol formal, diethylene glycol formal, triethylene glycol formal, 1,4-butanediol formal, 1,5-pentanediol formal, 1,6-hexanediol formal Among them, ethylene oxide, 1,3-dioxolane, diethylene glycol formal, and 1,4-butanediol formal are preferable. Moreover, the addition amount or addition method of these cyclic ethers and / or cyclic formals is not limited at all as long as the effects of the present invention are not impaired.

Examples of glycidyl ether compounds that can be used in the present invention include methyl glycidyl ether, ethyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, octyl glycidyl ether, 2-ethylhexyl glycidyl ether, decyl glycidyl ether, dodecyl glycidyl ether, stearyl glycidyl ether, Ethoxybutyl glycidyl ether, 1-allyloxy-2,3-epoxypropane, 1- (1 ′, 1′-dimethylpropargyloxy) -2,3-epoxypropane, phenyl glycidyl ether, cresyl glycidyl ether, butylphenyl glycidyl ether , Naphthyl glycidyl ether, phenylphenol glycidyl ether, benzyl alcohol glycidyl ether, ethylene glycol Le diglycidyl ether, propylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, hexamethylene glycol diglycidyl ether, resorcinol diglycidyl ether, bisphenol A
Examples include diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, polybutylene glycol diglycidyl ether, trimethylolpropane triglycidyl ether, glycerol triglycidyl ether, pentaerythritol tetraglycidyl ether and the like. Moreover, the addition amount of these glycidyl ether compounds or the addition method will not be limited at all, if it is a range which does not impair the effect of this invention.

  Examples of the component for adjusting the molecular weight (molecular weight regulator) usable in the present invention include a low molecular weight acetal compound having an alkoxy group, alcohols such as methanol, ethanol, butanol, ethylene glycol and polyalkylene glycol, water, and ester compounds. Illustrated. Among them, a low molecular weight acetal compound having an alkoxy group is preferred, and specific compound names include methylal, methoxymethylal, dimethoxymethylal, trimethoxymethylal, oxymethylene di-n-butyl ether and the like. Moreover, the addition amount of these molecular weight modifiers or the addition method will not be limited at all, if it is a range which does not impair the effect of this invention.

  The molecular weight or melt viscosity of the block copolymer of the present invention thus obtained is not limited at all.

  About the copolymer superposed | polymerized as mentioned above, the deactivation process of an initiator is further performed as needed. Regarding the method of catalyst deactivation, a method using a large amount of a basic solution, a method of adding and mixing a basic compound or a small amount of a solution containing a basic compound, a method of contacting a product with a basic gas, etc. Conventionally known methods can be used. As the deactivator used, any known basic substance is effective. For example, ammonia, various amine compounds, alkali or alkaline earth metal oxides, hydroxides, organic acid salts or inorganic acid salts. And trivalent phosphorus compounds. Amine compounds include primary, secondary and tertiary aliphatic amines and aromatic amines such as methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, butylamine, dibutylamine, tributylamine and the corresponding alcohols. Examples include amines (such as triethanolamine), aniline, diphenylamine, heterocyclic amines, hindered amines (various piperidine derivatives), and the like. Examples of the alkali or alkaline earth metal compound include inorganic weak acid salts such as alkali metal or alkaline earth metal oxides, hydroxides, carbonates, bicarbonates, phosphates, borates, and silicates. , Acetate, oxalate, formate, benzoate, terephthalate, isophthalate, phthalate, fatty acid salt and other organic acid salts, methoxide, ethoxide, n-butoxide, sec-butoxide, tert-butoxide And alkoxides such as phenoxide. A combination of two or more of these is also a preferred method.

  After the polymerization method and the deactivation method, if necessary, further separation of solvent, washing, separation and recovery of unreacted monomers, drying, and the like are performed by a conventionally known method. In addition, the obtained crude polymer is further subjected to terminal stabilization treatment such as decomposition removal of unstable terminals or sealing of unstable terminals with a stable substance, if necessary, and various stabilizers and additions depending on the purpose. Agents and reinforcing materials can also be blended.

  As the known stabilizer, one or more of hindered phenol compounds, nitrogen-containing compounds, alkali or alkaline earth metal hydroxides, inorganic salts, carboxylates and the like can be mentioned. . Furthermore, as long as the purpose and effect of the present invention are not impaired, general additives for thermoplastic resins, for example, colorants such as dyes and pigments, lubricants, mold release agents, antistatic agents, surfactants, if necessary. Alternatively, one or more organic polymer materials, inorganic or organic fibrous, powdery, and plate-like fillers can be added.

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples. In addition, the method used for characteristic evaluation in the Example is as follows.
(1) Identification of cyclic carbonate compound and determination of copolymer composition NMR measurement was performed using a nuclear magnetic resonance apparatus.
(2) Determination of the number average molecular weight (Mn) and molecular weight distribution (Mw / Mn) of the copolymer
Using Tosoh HLC-8220GPC, GPC measurement was performed with eluent THF (tetrahydrofuran) at a flow rate of 1.0 ml / min and 40 ° C. The molecular weight was calculated from a calibration curve using polystyrene as a standard.
(3) Thermal loss of copolymer It measured using Seiko Instruments TG / DTA6200.
(4) Crystallinity
The determination was made based on the presence or absence of a diffraction peak using RINT 2500HL manufactured by Rigaku Corporation.
(5) Tensile modulus
The sample was packed in a 1 mm thick spacer with a hot press machine at 170 ° C., kept at 10 MPa for 5 minutes, then cooled, and a 1 mm thick film sample was taken out from the spacer. Cut into 5 mm width and 50 mm length strips and measured with a tensile tester to calculate the tensile modulus in the initial deformation region.
(6) Tensile modulus retention after thermal history The strip specimen was subjected to thermal history at 100 ° C. for 2 days, measured for tensile modulus, and calculated as the retention rate compared with the initial modulus.
Reference Example 1 (Synthesis of 1,3-dioxepan-2-one)
It was synthesized according to Macromolecules Chem. Phys. 199, 97 (1998), recrystallized from diethyl ether / hexane and purified. The yield was 23% and the melting point was 75.5-76.5 ° C.
Example 1
A glass container equipped with a nitrogen flow tube is charged with trioxane and nitrobenzene as a solvent, trifluoromethanesulfonic acid is added as an initiator at 10 ° C., and polymerization is performed with stirring at the same temperature for 1 hour, and then 1,3-dioxepane 2-one was added dropwise in the same weight as trioxane, and the temperature was controlled at 40 ° C., and polymerization was performed for 2 hours. Triethylamine was added as a quencher to stop the reaction. The reaction mixture was added dropwise to diethyl ether, and the resulting precipitate was filtered and dried under reduced pressure to obtain a copolymer in a yield of 40%.

The copolymer was identified by ¹ H-NMR (solvent: deuterated hexafluoroisopropanol). The peak derived from acetal was around 4.99 ppm, the peaks derived from carbonate were around 1.74 ppm and 4.20 ppm, When carbonate was ring-opened, peaks decarbonated to ether units appeared at 1.74 ppm and 3.17 ppm, confirming the formation of a copolymer. Further, by calculating these integral ratios, the composition of acetal part: carbonate part: ether part = 3: 5: 2 was calculated. The resulting copolymer had a number average molecular weight of 2.1 × 10 ⁴ and a molecular weight distribution (Mw / Mn) of 1.8. According to the measurement of heat loss at the time of temperature increase, the weight was reduced by 54% by 200 ° C, and then there was no weight loss by 230 ° C. Further, the material heated at 200 ° C. was 0.8 × 10 ⁴ as the acetal continuous chain length by the same measurement as described above. This revealed that the polymer obtained was not a random copolymer but a block copolymer.

According to X-ray diffraction measurement, the peak of 1,3-dioxepan-2-one ring-opening polymer appearing at 20 to 21 degrees coexists with the peak of polyoxymethylene appearing at 22 degrees. It turned out to have. The results are shown in Table 1.
Example 2
The same polymerization and evaluation as in Example 1 were performed except that the charging ratio of trioxane and 1,3-dioxepan-2-one was 3: 1. The results are shown in Table 1.
Example 3
The same polymerization and evaluation as in Example 1 were performed except that the charging ratio of trioxane and 1,3-dioxepan-2-one was 1: 3. The results are shown in Table 1.
Comparative Example 1
The same polymerization and evaluation as in Example 1 were conducted except that trioxane and 1,3-dioxepan-2-one were charged simultaneously into a nitrobenzene solution. The results are shown in Table 1.

Claims (7)

  At least one cyclic carbonate compound selected from a continuous chain (A) mainly composed of repeating oxymethylene units, 1,3-dioxepan-2-one, 1,3-dioxan-2-one, and alkyl-substituted products thereof. A polyacetal carbonate block copolymer having a continuous chain (B) consisting of repeating carbonate units by ring-opening polymerization.   The ratio of the continuous chain (A) consisting mainly of repeating oxymethylene units and the continuous chain (B) consisting of repeating carbonate units is (A) / (B) = 10/90 to 70/30 (weight ratio). The polyacetal carbonate block copolymer according to claim 1.   First, ring-opening polymerization of trioxane (a) is performed, and then at least one cyclic carbonate compound (b) selected from 1,3-dioxepan-2-one, 1,3-dioxan-2-one, and alkyl-substituted products thereof (b) ) Is added to perform ring-opening polymerization. A method for producing a polyacetal carbonate block copolymer.   The method for producing a polyacetal carbonate block copolymer according to claim 3, wherein the polymerization catalyst is selected from perfluoroalkylsulfonic acid, its anhydride and derivatives thereof.   The method for producing a polyacetal carbonate block copolymer according to claim 3 or 4, wherein the polymerization reaction is carried out in a solvent.   The method for producing a polyacetal carbonate block copolymer according to claim 5, wherein the polymerization reaction is carried out at a temperature of 50 ° C or lower.   The ratio of a trioxane (a) and a cyclic carbonate compound (b) is (a) / (b) = 20 / 80-80 / 20 (weight ratio), The polyacetal carbon in any one of Claims 3-6 A method for producing a naruto block copolymer.