阅读说明：本技术 聚缩醛共聚物和其制造方法 (Polyacetal copolymer and method for producing same ) 是由 喜来直裕 增田荣次 于 2020-04-10 设计创作，主要内容包括：本发明的目的在于,通过导入具有新结构的基团,从而提供生产率、机械特性优异的新型聚缩醛共聚物和其制造方法。通过聚缩醛共聚物和其制造方法来实现,所述聚缩醛共聚物是至少使三氧杂环己烷(A)、在环内具有碳数2以上的氧亚烷基的环状缩醛化合物(B)和有机聚硅氧烷(C)进行聚合反应而得到的,该有机聚硅氧烷(C)为选自下述式(1)所示的化合物中的一种以上的硅烷化合物的缩合物、且为具有烷氧基的化合物。R～(1)-(n)Si(OR～(2))-(4-n)(1)式(1)中R～(1)表示一价烃基,R～(2)表示碳数4以下的烷基。n为0～3的整数。(The present invention has an object to provide a novel polyacetal copolymer excellent in productivity and mechanical properties by introducing a group having a novel structure, and a method for producing the same. The polyacetal copolymer is obtained by polymerizing at least trioxane (A), a cyclic acetal compound (B) having an oxyalkylene group having at least 2 carbon atoms in the ring, and an organopolysiloxane (C) which is a condensate of at least one silane compound selected from compounds represented by the following formula (1) and has an alkoxy group, and a method for producing the same. R 1 n Si(OR 2 ) 4‑n (1) R in the formula (1) 1 Represents a monovalent hydrocarbon group, R 2 Represents an alkyl group having 4 or less carbon atoms. n is an integer of 0 to 3.)

1. A polyacetal copolymer obtained by polymerizing at least trioxane (A), a cyclic acetal compound (B) having an oxyalkylene group having at least 2 carbon atoms in the ring, and an organopolysiloxane (C) which is a condensate of at least one silane compound selected from compounds represented by the following formula (1) and has an alkoxy group,

R¹ _nSi(OR²)_4-n (1)

r in the formula (1)¹Represents a monovalent hydrocarbon group, R²Represents an alkyl group having 4 or less carbon atoms, and n is an integer of 0 to 3.

2. The polyacetal copolymer according to claim 1, wherein R in the formula (1)²Is at least one selected from the group consisting of methyl and ethyl.

3. The polyacetal copolymer according to claim 1 or 2, wherein R in the formula (1)¹Is at least one selected from methyl or phenyl.

4. A method for producing a polyacetal copolymer, which comprises polymerizing at least trioxane (A), a cyclic acetal compound (B) having an oxyalkylene group having at least 2 carbon atoms in the ring, and an organopolysiloxane (C) which is a condensate of at least one silane compound selected from the compounds represented by the following formula (1) and has an alkoxy group, in the presence of a cationic polymerization catalyst,

R¹ _nSi(OR²)_4-n (1)

r in the formula (1)¹Represents a monovalent hydrocarbon group, R²Represents an alkyl group having 4 or less carbon atoms, and n is an integer of 0 to 3.

Technical Field

The present invention relates to a novel polyacetal copolymer excellent in productivity and mechanical properties, and a method for producing the same.

Background

Polyacetal resins have excellent properties in terms of mechanical properties, thermal properties, electrical properties, slidability, moldability and the like, and are widely used mainly as structural materials, mechanical parts and the like for electrical equipment, automobile parts, precision machine parts and the like. However, as the field of application of polyacetal resins has expanded, the required properties have tended to be increasingly higher, more complex and more specialized. As such required properties, further improvement in mechanical strength is required while maintaining excellent slidability, appearance and the like inherent in polyacetal resins.

On the other hand, for the purpose of improving the rigidity, a method of filling a fibrous filler or the like into a polyacetal resin is generally used, but this method has problems such as poor appearance of a molded article, reduction in sliding characteristics, and the like due to filling of the fibrous filler or the like, and further has a problem of reduction in toughness.

Further, it is known that the rigidity of the polyacetal copolymer is improved without substantially impairing the slidability and the appearance by reducing the amount of the comonomer, but the method of reducing the comonomer causes problems such as not only a decrease in toughness but also a decrease in thermal stability of the polymer, and thus the method is not always satisfactory.

However, depending on the kind of the comonomer, when a cationic polymerization catalyst, particularly a protonic acid, is used as the polymerization catalyst, the initiation of polymerization may be delayed, and the polymerization may suddenly and explosively occur, and there is a problem in view of production stability.

For example, as for the polyacetal copolymer, a copolymer obtained by copolymerizing trioxane with a compound having 2 or more glycidyl ether groups in 1 molecule has been proposed (patent document 1). However, when a compound having a plurality of epoxy groups represented by glycidyl ether groups and ether oxygen groups as functional groups is used in polymerization, there remains a problem in polymerization stability. In particular, when a protonic acid is used as a polymerization catalyst, polymerization does not occur at a low catalyst amount, and when the catalyst amount is increased, a phenomenon occurs in which a sharp polymerization reaction suddenly occurs after an irregular induction period, and it is difficult to control the polymerization.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent application No. 2001-163944

Disclosure of Invention

Problems to be solved by the invention

An object of the present invention is to provide: a process for producing a novel polyacetal copolymer excellent in productivity and mechanical properties.

Means for solving the problems

The object of the present invention is achieved as follows.

1. A polyacetal copolymer obtained by polymerizing at least trioxane (A), a cyclic acetal compound (B) having an oxyalkylene group having at least 2 carbon atoms in the ring, and an organopolysiloxane (C) which is a condensate of at least one silane compound selected from compounds represented by the following formula (1) and has an alkoxy group.

R¹ _nSi(OR²)_4-n (1)

R in the formula (1)¹Represents a monovalent hydrocarbon group, R²Represents an alkyl group having 4 or less carbon atoms. n is an integer of 0 to 3.

2. The polyacetal copolymer according to 1, wherein R in the formula (1)²Is at least one selected from the group consisting of methyl and ethyl.

3. The polyacetal copolymer according to 1 or 2, wherein R in the formula (1)¹Is at least one selected from methyl or phenyl.

4. A method for producing a polyacetal copolymer, which comprises polymerizing at least trioxane (A), a cyclic acetal compound (B) having an oxyalkylene group having at least 2 carbon atoms in the ring, and an organopolysiloxane (C) which is a condensate of at least one silane compound selected from the compounds represented by the following formula (1) and has an alkoxy group, in the presence of a cationic polymerization catalyst.

R¹ _nSi(OR²)_4-n (1)

R in the formula (1)¹Represents a monovalent hydrocarbon group, R²Represents an alkyl group having 4 or less carbon atoms. n is an integer of 0 to 3.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, there can be provided: a novel polyacetal copolymer excellent in productivity and mechanical properties, and a method for producing the polyacetal copolymer.

Detailed Description

The present invention is not limited to the following embodiments, and can be carried out with appropriate modifications within the intended scope of the present invention.

< polyacetal copolymer >

The polyacetal copolymer of the present invention is a copolymer obtained by polymerizing trioxane (a), a cyclic acetal compound (B) having an oxyalkylene group having at least 2 carbon atoms in the ring, and organopolysiloxane (C) which is a condensate of at least one specific silane compound and has an alkoxy group.

The polyacetal copolymer of the present invention is considered to be excellent in mechanical properties because it has a structure in which a plurality of polyacetal molecules are bonded at their ends to an organopolysiloxane.

Trioxane (A)

Trioxane (a) used in the present invention is a cyclic trimer of formaldehyde, and is usually obtained by reacting an aqueous formaldehyde solution in the presence of an acidic catalyst, and is purified by a method such as distillation.

Cyclic acetal compound (B) having oxyalkylene group having 2 or more carbon atoms in the ring

In the present invention, a cyclic acetal compound (B) having an oxyalkylene group having 2 or more carbon atoms in the ring can be used as a comonomer.

The cyclic acetal compound having an oxyalkylene group having 2 or more carbon atoms in the ring according to the present invention means: specific examples of the compound generally used as a comonomer in the production of the polyacetal copolymer include 1, 3-dioxolane, 1,3, 6-trioxane, 1, 4-butanediol formal, and the like.

In the present invention, the component (B) is preferably used in an amount within a range of 0.01 to 20 parts by mass, more preferably 0.05 to 5 parts by mass, based on 100 parts by mass of trioxane.

Organopolysiloxane (C) having alkoxy groups, obtained by condensing one or more silane compounds selected from silane compounds represented by formula (1)

R¹ _nSi(OR²)_4-n (1)

R in the formula (1)¹Represents a monovalent hydrocarbon group, R²Represents an alkyl group having 4 or less carbon atoms. n is an integer of 0 to 3.

Examples of the silane compound represented by the formula (1) include phenyltrimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, methylphenyldimethoxysilane, trimethylmethoxysilane, trimethylethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, and diphenyldiethoxysilane.

The organopolysiloxane (C) of the present invention can be obtained by condensing at least one silane compound selected from the silane compounds represented by formula (1) with a known condensation reaction catalyst, specifically, an acid catalyst, a base catalyst, an organometallic compound catalyst, and the like.

Specifically, for example, the (alkoxy) silane compound is partially hydrolytically condensed by the method described in japanese patent No. 2904317 and japanese patent No. 3389338, and the alkoxy group is contained to such an extent that the effect of the present invention is produced.

The organopolysiloxane (C) of the present invention has an alkoxy group, which can be determined by quantifying the alkoxy group in the organopolysiloxane. For example, can be made of²⁹Si-NMR measurement and quantification of the amount of alcohol produced when KOH was added for thermal decomposition.

The organopolysiloxane (C) of the present invention is a compound containing an alkoxy group and, as the case may be, a hydrocarbon group and having a siloxane skeleton. Specific examples of the alkoxy group include methoxy, ethoxy, propoxy and butoxy.

Specific examples of the hydrocarbon group include saturated hydrocarbon groups such as methyl group, ethyl group, and propyl group, and aromatic hydrocarbon groups such as phenyl group and naphthyl group.

R in the formula (1) relating to the organopolysiloxane (C) of the present invention is R in the present invention from the viewpoint of the mechanical properties of the resulting polyacetal copolymer²Preferably at least 1 selected from methyl and ethyl.

In addition, from the viewpoint of the mechanical properties of the resulting polyacetal copolymer, R in the formula (1) relating to the organopolysiloxane (C)¹Preferably at least one selected from methyl or phenyl.

Examples of commercially available products of the organopolysiloxane (C) of the present invention include "SR 2402 Resin", "AY 42-163", "DC-3074 interlayer", and "DC-3037 interlayer" (manufactured by Dow Toray Co., Ltd., "KC-89S", "KR-500", "X-40-9225", "X-40-9246", "X-40-9250", "KR-9218", "KR-213", "KR-510", "X-40-9227", "X-40-9247", and "KR-401N" (manufactured by shin-Etsu chemical Co., Ltd.).

In the present invention, it is considered that the component (C) functions as a chain transfer agent in the polymerization reaction. As a result, it is considered that when the polymerization reaction of the trioxane (a), the cyclic acetal compound (B) having an oxyalkylene group having 2 or more carbon atoms in the ring, and the organosiloxane (C) is carried out, the control of the polymerization becomes easy, and the productivity is improved.

In the present invention, the component (C) is preferably used in an amount within a range of 0.01 to 5 parts by mass, more preferably 0.03 to 1 part by mass, based on 100 parts by mass of the trioxane (A).

< cationic polymerization catalyst >

As the cationic polymerization catalyst, a polymerization catalyst known for cationic copolymerization using trioxane (A) as a main monomer can be used. Typical examples thereof include protonic acids and Lewis acids. Protic acids are particularly preferred.

Proton acid

Examples of the protonic acid include perfluoroalkanesulfonic acid, heteropolyacid, and isopoly acid. Specific examples of perfluoroalkanesulfonic acids include trifluoromethanesulfonic acid, pentafluoroethanesulfonic acid, heptafluoropropanesulfonic acid, nonafluorobutanesulfonic acid, undecafluoropentanesulfonic acid, tridecafluorohexanesulfonic acid, pentadecafluoroheptanesulfonic acid, and heptadecafluorooctanesulfonic acid.

The heteropoly acid is a polyacid produced by dehydration condensation of various kinds of oxo acids, and has a single-core or multi-core complex ion in which a specific different element is present in the center and an oxygen atom is shared to enable condensation of a condensed acid group. Isopoly acids, also known as isopoly acids, homonuclear condensation acids, isopoly acids, refer to high molecular weight inorganic oxoacids formed from the condensation of inorganic oxoacids of a single type of metal having a valence of V or VI.

Specific examples of the heteropoly-acid include phosphomolybdic acid, phosphotungstic acid, phosphomolybdotungstic acid, phosphomolybdovanadic acid, phosphomolybdotungstovanadic acid, phosphotungstovanadic acid, silicotungstic acid, silicomolybdic acid, silicomolybdotungstic acid, silicomolybdotungstovanadic acid, and the like. In particular, from the viewpoint of polymerization activity, the heteropoly-acid is preferably selected from the group consisting of silicomolybdic acid, silicotungstic acid, phosphomolybdic acid, and phosphotungstic acid.

Specific examples of the isopoly acid include tungsten isopoly acids exemplified by paratungstic acid, metatungstic acid, and the like; molybdenum isopolyacids exemplified by paramolybdic acid, metamolybdic acid, and the like; metavanadate, vanadium isopoly acid, and the like. Among them, tungsten isopoly acid is preferable from the viewpoint of polymerization activity.

Lewis acid

Examples of the lewis acid include halides of boron, tin, titanium, phosphorus, arsenic and antimony, and specifically, boron trifluoride (and its ether complex), tin tetrachloride, titanium tetrachloride, phosphorus pentafluoride, phosphorus pentachloride, antimony pentafluoride, and complexes or salts thereof.

The amount of the polymerization catalyst is not particularly limited, but is preferably 0.1ppm to 50ppm, more preferably 0.1ppm to 30ppm, based on the total amount of all monomers.

In the present invention, in addition to the above-mentioned components, a component for adjusting the molecular weight may be used in combination to adjust the amount of the terminal group. Examples of the component for adjusting the molecular weight include compounds having an alkoxy group such as methylal, monomethoxymethylal, dimethoxymethylal, which are chain transfer agents not forming an unstable terminal.

The polymerization apparatus used in the present invention is not particularly limited, and any known apparatus may be used, and any method such as a batch method or a continuous method may be used. Further, the polymerization temperature is preferably maintained at 65 ℃ or higher and 135 ℃ or lower.

The cationic polymerization catalyst is preferably used by diluting with an inactive solvent which does not adversely affect the polymerization.

The deactivation of the polymerization catalyst after the polymerization can be carried out by a conventionally known method. For example, the polymerization may be carried out by adding a basic compound or an aqueous solution thereof to the reaction product discharged from the polymerization reactor or the reaction product in the polymerization reactor after the polymerization reaction.

The basic compound used for neutralizing and deactivating the polymerization catalyst is not particularly limited. After polymerization and deactivation, washing, separation and recovery of unreacted monomers, drying, and the like are further performed by a conventionally known method as needed.

The polyacetal copolymer obtained as described above preferably has a weight average molecular weight corresponding to methyl methacrylate determined by size exclusion chromatography of 10000 to 500000, particularly 20000 to 150000. In addition, for the terminal groups, from¹The amount of the terminal group of the hemiformal to be detected by H-NMR (for example, according to the method described in Japanese patent application laid-open No. 2001-11143) is preferably 0 to 4mmol/kg, and particularly preferably 0 to 2 mmol/kg.

In order to control the hemiformal end group content within the above range, impurities, particularly water, in the total amount of monomers and comonomers to be polymerized are preferably 20ppm or less, and particularly preferably 10ppm or less.

< other ingredients >

The polyacetal copolymer produced in the present invention is preferably blended with various known stabilizers selected as necessary. The stabilizer used here may be any one of 1 or 2 or more of hindered phenol compounds, nitrogen-containing compounds, hydroxides, inorganic salts, and carboxylates of alkali metals or alkaline earth metals.

Further, to the polyacetal copolymer produced in the present invention, 1 or 2 or more kinds of additives commonly used for thermoplastic resins, for example, coloring agents such as dyes and pigments, lubricants, nucleating agents, mold release agents, antistatic agents, surfactants, or organic polymer materials, inorganic or organic fibrous, powdery, and plate-like fillers, may be added as necessary.

Examples

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

< polymerization >

300g of trioxane (A) was placed in a closed autoclave having a jacket through which a heat medium can flow and a stirring blade, and the compound shown in Table 1 as the component (C) and 1, 3-Dioxolane (DO) as the component (B) were further added in the proportions of the parts by mass shown in Table 1. These contents were stirred, hot water at 80 ℃ was passed through the jacket, and after the internal temperature was maintained at about 80 ℃, phosphotungstic acid (PWA) was added as a catalyst in the form of a methyl formate solution at 4.5ppm relative to the sum of the masses of (a) and (B) or trifluoromethanesulfonic acid (TfOH) was added as a cyclohexane solution at 1.0ppm relative to the sum of the masses of (a) and (B), thereby carrying out polymerization. Example 6 is TfOH, except PWA was used.

The component (C) used in the examples was (C-1) KR-500 (R)¹: methyl, R²: methyl group), (C-2) KR-401N (R)¹: methyl/phenyl, R²: methyl) (all manufactured by shin-Etsu chemical industries, Ltd.). The components of the examples and comparative examples are shown in table 1.

After 5 minutes, 300g of water containing 0.1% triethylamine was added to the autoclave, the reaction was stopped, the contents were taken out, pulverized to 200 mesh or less, washed with acetone and dried, and then the yield of the polyacetal copolymer (the ratio of the mass of the obtained copolymer to the sum of the masses of (A), (B) and (C) used in the polymerization (% by mass)) was calculated. The results are shown in Table 2.

For comparison, a comparative polyacetal copolymer was obtained by using the following diglycidyl compounds (X-1 and X-2) in place of the component (C) of the present invention for polymerization.

X-1: butanediol diglycidyl ether

X-2: trimethylolpropane triglycidyl ether

To 100 parts by mass of the polyacetal copolymer obtained in the above-mentioned manner, 0.35 part by mass of pentaerythritol-tetrakis [ 3- (3, 5-di-t-butyl-4-hydroxyphenyl) propionate ] (trade name: Irganox1010 BASF corporation) and 0.15 part by mass of melamine were added as stabilizers, and the mixture was melt-kneaded at 210 ℃ in a small twin-screw extruder to obtain a polyacetal resin composition in the form of pellets.

These pellets were used for the following evaluation. The results are shown in Table 2.

< tensile Strength >

The tensile strength of the ISOType1A test piece was measured in accordance with ISO527-1, 2. The measuring chamber was kept in an atmosphere of 50% RH at 23 ℃.

< flexural Strength and flexural modulus >

The flexural strength and flexural modulus were determined in accordance with ISO 178. The measuring chamber was kept in an atmosphere of 50% RH at 23 ℃.

[ Table 1]

[ Table 2]

It is clear that: in examples 1 to 7, a polyacetal copolymer was obtained in a high yield with a low amount of catalyst, and the polyacetal copolymer was excellent in mechanical properties. In comparative examples 2 and 3, no polymerization was observed at the same catalyst amount as in example. In comparative examples 2 and 3, when the amount of the catalyst was set to 20ppm, a sudden reaction occurred, but the final yield was as low as about 50 mass%.

As is clear from the results in table 2, the present invention can provide a novel polyacetal copolymer excellent in production stability and mechanical properties, and a method for producing the polyacetal copolymer.