JP2001164086A - Branched polyacetal resin composition - Google Patents

Abstract

(57) [Problem] To provide a resin material having improved impact resistance while maintaining various properties such as excellent appearance and rigidity of a polyacetal resin. SOLUTION: 100 parts by weight of a branched polyacetal copolymer (A) having an oxymethylene group as a main repeating unit and having a branching unit represented by the following general formula (I) is added to a thermoplastic polyurethane or a core-shell polymer. The impact modifier (B) is blended in an amount of 3 to 50 parts by weight. Embedded image (Wherein, m and n each represent an integer of 0 to 5, and m + n
Is 1 to 5. R represents a monovalent organic group having a molecular weight of 40 to 1,000. )

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a branched polyacetal resin composition having high rigidity and excellent impact resistance.

[0002]

2. Description of the Related Art Polyacetal resins have excellent properties in mechanical properties, fatigue resistance, thermal properties, electrical properties, slidability, moldability, etc., and are mainly used as structural materials and mechanical parts. Widely used for electrical equipment, automobile parts, precision machine parts, etc. However, with the expansion of the field in which polyacetal resins are used, the required characteristics tend to be increasingly sophisticated, complex, and specialized. The required properties often include impact resistance, and for the purpose of simply improving impact resistance, a method of adding a thermoplastic elastomer, a core-shell polymer, or the like to a polyacetal resin is generally used. However, in this method, the yield strength,
There is a problem that the elastic modulus decreases.

[0003] In view of such prior art, the inventor of the present invention has proposed modifying the polymer skeleton of the polyacetal resin in order to improve the impact resistance while maintaining the excellent properties inherent in the polyacetal resin. It has been speculated that the design of a resin composition having a polymer as a base is an important key to solving the problem. Regarding the modification of the polymer skeleton itself of such a polyacetal resin, JP-A-3-17052
No. 6 discloses trioxane and ethylene oxide,
3-dioxolan, 1,3-dioxepane, 1,3,5
Modified polyacetal copolymer obtained by copolymerizing at least one cyclic ether compound selected from trioxepane and 1,3,6-trioxocan and at least one compound selected from glycidyl phenyl ether, styrene oxide and glycidyl naphthyl ether Is disclosed. However, this modified polyacetal copolymer is intended to improve the moldability by increasing the crystallization rate, particularly for high cycle properties, and hardly discloses other properties.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a resin material having improved impact resistance while maintaining various properties such as excellent appearance and rigidity of a polyacetal resin. Is to do.

[0005]

Means for Solving the Problems In order to achieve the above object, the present inventors conducted detailed investigations into the molecular skeleton or resin physical properties of a polyacetal resin.
The present inventors have found a modification of a polymer skeleton effective for achieving the object and a compounding component effective for such a polymer, and have completed the present invention.

That is, according to the present invention, a thermoplastic polyurethane and a core-shell polymer are added to 100 parts by weight of a branched polyacetal copolymer (A) having an oxymethylene group as a main repeating unit and having a branching unit represented by the following general formula (I). A branched polyacetal resin composition containing 3 to 50 parts by weight of a selected impact modifier (B).

[0007]

Embedded image

Wherein m and n each represent an integer of 0 to 5, and m + n is 1 to 5. R has a molecular weight of 40 to 1000.
Represents a monovalent organic group. )

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. First, the branched polyacetal copolymer (A) used as the base resin in the present invention has an oxymethylene group (-
CH ₂ -O-) as the main repeating unit, and represented by the following general formula (I)
The presence of such a branch unit is one of the important elements for achieving the object of the present invention. If an ordinary polyacetal resin having no branching unit is used, the object of the present invention cannot be achieved even if an impact resistance imparting agent described later is blended.

[0010]

Embedded image

(M and n each represent an integer of 0 to 5, and m + n is 1 to 5. R represents a monovalent organic group having a molecular weight of 40 to 1000.) Formula (I) In the branching unit, R, which is a branching group, is a monovalent organic group having a molecular weight of 40 to 1,000. If the molecular weight of R is less than 40, no improvement in rigidity can be expected, and if the molecular weight exceeds 1,000, there is a problem of a decrease in crystallinity. Preferably, the molecular weight of R is between 50 and 500. Also,
As the monovalent organic group forming R, those having an aromatic ring are preferable, which have a remarkable effect on improving rigidity.

From the viewpoint of maintaining or improving rigidity and toughness and maintaining other physical properties, the branching unit represented by the general formula (I) is preferably present at random in the polymer skeleton. 0.001 parts by weight is preferable with respect to oxymethylene units (-CH ₂ O-) 100 parts by weight, particularly preferably 0.01 to 3 parts by weight.

The production method of the branched polyacetal copolymer (A) used in the present invention is not particularly limited, but trioxane (a) 100 parts by weight, monofunctional glycidyl compound (b-1) 0.001 to Cyclic ether compound (c) 0 copolymerizable with 10 parts by weight and trioxane
Preferably, the copolymer is obtained by copolymerizing up to 20 parts by weight, and the branched polyacetal copolymer (A) comprising such a monomer component is characterized in that it is easy to produce and the properties of the obtained copolymer are excellent. The trioxane (a) used here is a cyclic trimer of formaldehyde, which is generally obtained by reacting an aqueous formaldehyde solution in the presence of an acidic catalyst, and which is purified by a method such as distillation. Used. Trioxane (a) used for polymerization
Is preferably free from impurities such as water, methanol and formic acid.

Next, the monofunctional glycidyl compound (b-1)
Is a general term for organic compounds having one glycidyl group in the molecule, for example, glycidol, aliphatic alcohol or aromatic alcohol, or their (poly)
Glycidyl ethers comprising an alkylene glycol adduct and glycidol, aliphatic carboxylic acids or aromatic carboxylic acids, or glycidyl esters comprising these (poly) alkylene glycol adducts and glycidol are mentioned as typical examples. Such a monofunctional glycidyl compound (b-1) is used as a branched constituent of the branched polyacetal copolymer (A) used in the present invention.

As the monofunctional glycidyl compound (b-1), glycidyl ether compounds represented by the above general formulas (II), (III) and (IV) are preferable.
Methyl glycidyl ether, ethyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, 2-methyloctyl glycidyl ether, phenyl glycidyl ether, p-tertiary butyl phenyl glycidyl ether, sec-butyl phenyl glycidyl ether, n-butyl phenyl glycidyl Ether, phenylphenol glycidyl ether,
Examples include cresyl glycidyl ether, dibromocresyl glycidyl ether, and glycidyl ether composed of (poly) ethylene glycol adduct of aliphatic alcohol or aromatic alcohol and glycidol. Further, specific examples of the glycidyl ester compound include glycidyl acetate, glycidyl stearate and the like.
Among such monofunctional glycidyl compounds, those having an aromatic ring are preferred. Among them, in the general formulas (II) and (III), the substituent R ¹ or R ³ is located at the ortho position.
Are preferred. As such a substituent, those having 4 or more carbon atoms are preferable, and those having an aromatic ring are particularly preferable. Specific examples include o-phenylphenol glycidyl ether.

In the production of the branched polyacetal copolymer (A) used in the present invention, the amount of the monofunctional glycidyl compound (b-1) to be copolymerized depends on the amount of trioxane 1 (a).
0.001 to 10 parts by weight to 00 parts by weight, preferably
It is 0.01 to 10 parts by weight, particularly preferably 0.1 to 5 parts by weight. If the copolymerization amount of the component (b-1) is too small, the effect of improving the physical properties, which is the main object of the present invention, cannot be obtained. Conversely, if the copolymerization amount is too large, the strength and rigidity are reduced due to a decrease in crystallinity. However, there is a possibility that a problem of moldability due to a decrease in fluidity may occur.

Further, the monofunctional glycidyl compound (b-1)
It is preferable to use those having a molecular weight of 100 to 1,000. If the molecular weight of the monofunctional glycidyl compound (b-1) is too large, the branched chain of the branched polyacetal copolymer (A) produced by the copolymerization becomes longer, disturbing the crystallinity of the resin and the like, and Undesirable effects may also occur on certain sliding characteristics. Conversely, if the molecular weight of the component (b-1) is too small, the effects of the present invention on improving impact resistance and maintaining rigidity, toughness, and the like become extremely small.

The branched polyacetal copolymer (A) used in the present invention is preferably a copolymer obtained by further adding a cyclic ether compound (c) copolymerizable with trioxane as a copolymerization component. Such a cyclic ether compound (c) is not particularly essential for improving the properties aimed at by the present invention, but stabilizes the polymerization reaction when producing the branched polyacetal copolymer (A). In addition, in order to enhance the thermal stability of the resulting branched polyacetal copolymer (A), it is extremely effective to use such a cyclic ether compound as a copolymer component. Examples of the cyclic ether compound (c) copolymerizable with trioxane include ethylene oxide, propylene oxide, butylene oxide, epichlorohydrin, epibromohydrin, styrene oxide, oxetane, 3,3-bis (chloromethyl) oxetane, tetrahydrofuran, Trioxepane, 1,3-dioxolan, propylene glycol formal, diethylene glycol formal, triethylene glycol formal, 1,4-butanediol formal, 1,5-pentanediol formal,
1,6-hexanediol formal and the like.
Among them, ethylene oxide, 1,3-dioxolan, diethylene glycol formal, and 1,4-butanediol formal are preferred. In the branched polyacetal copolymer (A) used in the present invention, the copolymerization amount of the cyclic ether compound (c) is 0 to 20 parts by weight, preferably 0.05 to 100 parts by weight of the trioxane (a). ~ 15
Parts by weight, particularly preferably 0.1 to 10 parts by weight. If the copolymerization ratio of the cyclic ether compound (c) is too small, the copolymerization reaction becomes unstable and the thermal stability of the resulting branched polyacetal copolymer becomes poor. When the polymerization ratio is excessive, mechanical properties such as rigidity and strength, which are one of the object characteristics of the present invention, are reduced and become insufficient.

The branched polyacetal copolymer (A) used in the present invention basically comprises the above trioxane (a), monofunctional glycidyl compound (b-1) and cyclic ether compound (c), if necessary. Then, an appropriate amount of a molecular weight modifier is added, and bulk polymerization is performed using a cationic polymerization catalyst.

Examples of the molecular weight modifier include low molecular weight acetal compounds having an alkoxy group such as methylal, methoxymethylal, dimethoxymethylal, trimethoxymethylal, and oxymethylene di-n-butyl ether; and alcohols such as methanol, ethanol and butanol. Kind,
Ester compounds and the like are exemplified. Among them, a low molecular weight acetal compound having an alkoxy group is particularly preferable. The amount of these molecular weight modifiers is not particularly limited as long as the effects of the present invention are not impaired.

As the cationic polymerization catalyst, 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, trifluoride Boron trifluoride coordination compound such as boron trifluoride triethylamine complex compound, boron trichloride, t-butyl perchlorate, t-butyl perchlorate, hydroxyacetic acid, trichloroacetic acid,
Trifluoroacetic acid, inorganic and organic acids such as p-toluenesulfonic acid, triethyloxonium tetrafluoroborate, triphenylmethylhexafluoroantimonate,
Complex salt compounds such as allyldiazonium hexafluorophosphate and allyldiazonium tetrafluoroborate,
Alkyl metal salts such as diethylzinc, triethylaluminum, diethylaluminum chloride and the like, heteropoly acids, isopoly acids and the like can be mentioned. Among them, boron trifluoride, boron trifluoride diethyl etherate, boron trifluoride dibutyl etherate, boron trifluoride dioxanate, boron trifluoride acetic anhydrate, boron trifluoride triethylamine complex compound, etc. Boron fluoride coordination compounds are preferred. These catalysts can be used after being diluted with an organic solvent or the like in advance.

The branched polyacetal copolymer (A) used in the present invention has a structural unit derived from the monofunctional glycidyl compound (b-1) and the cyclic ether compound (c) in the molecular chain of the polyacetal copolymer. It is desirable that the glycidyl compound (b-1), the cyclic ether compound (c) and the catalyst are uniformly mixed in advance in the production of the polyacetal copolymer (A) by polymerization. A method in which this is added to a melt of trioxane (a) separately supplied to a polymerization machine to carry out polymerization, or a method in which the uniform mixture is further mixed with trioxane (a) and then supplied to a polymerization machine to carry out polymerization. It is valid. Particularly, the reaction rate of the glycidyl compound (b-1) is often slower than that of the other components (a) and (c), and it is extremely effective to previously mix the component (b-1) and the catalyst. . In this way, by preliminarily mixing and maintaining a uniform solution state, the dispersion state of the branched structure derived from the glycidyl compound is improved.

In producing the polyacetal copolymer (A) used in the present invention, the polymerization apparatus is not particularly limited, and a known apparatus may be used, and any method such as a batch type or a continuous type may be used. It is. The polymerization temperature is 65
It is preferred to keep it at ~ 135 ° C. Deactivation after polymerization is the product reactant discharged from the polymerization machine after the polymerization reaction, or
The reaction is performed by adding a basic compound or an aqueous solution thereof to the reaction product in the polymerization machine.

Examples of the basic compound for neutralizing and deactivating the polymerization catalyst include ammonia, amines such as triethylamine, tributylamine, triethanolamine and tributanolamine;
Alkaline earth metal hydroxide salts and other known catalyst deactivators are used. After the polymerization reaction, it is preferable to add these aqueous solutions to the product promptly to deactivate the product.
After such a polymerization method and a deactivation method, if necessary,
Washing, separation and recovery of unreacted monomers, drying and the like are performed by a conventionally known method.

The degree of polymerization of the polyacetal copolymer (A) obtained as described above and used in the present invention is not particularly limited, and can be adjusted according to the purpose of use and the molding means. However, when used for molding, the temperature
The melt index (MI) measured at 190 ° C. under a load of 2.06 kg is preferably from 1 to 100 g / 10 min, particularly preferably from 2 to 90 g / 10 min. In order to adjust the viscosity, a small amount of a crosslinking agent such as a diglycidyl compound may be copolymerized.

In the above process for producing the polyacetal copolymer (A) and in the monomer constitution, a cyclic formal compound (b-2) capable of forming a branch may be used in place of the monofunctional glycidyl compound (b-1). In the same manner as described above, a preferable polyacetal copolymer (A) is obtained. Examples of cyclic formal compounds capable of forming a branch include:
4-methyl-1,3-dioxolan, 4-ethyl-1,
3-dioxolan, 4-isopropyldioxolan, 4
-Phenyl-1,3-dioxolane and the like.

Next, the impact modifier (B) which is a characteristic component of the present invention will be described. The resin composition of the present invention,
It is characterized in that an impact resistance improver is blended with the branched polyacetal copolymer (A) as described above. A branched polyacetal copolymer modified by simply introducing a branched structure alone improves the rigidity but does not have sufficient impact resistance. Conversely, even when these impact resistance improvers are used, if they are blended with a general polyacetal resin having no branched structure, the impact resistance is improved but the rigidity is insufficient. On the other hand, by blending such a branched polyacetal copolymer (A) with an impact resistance improver (B),
It is quite unexpected and surprising that an excellent resin composition having both rigidity and impact resistance can be obtained, and it was found for the first time as a result of intensive studies by the present inventors.

Impact modifier (B) used in the present invention
Is selected from thermoplastic polyurethanes and core-shell polymers. Thermoplastic polyurethane has a higher affinity for polyacetal resin than other elastomers, and has features such as improvement in impact resistance and improvement in hinge properties of the composition. The thermoplastic polyurethane used in the present invention is basically an isocyanate compound,
Short-chain polyol having a molecular weight of 40 to 62 to 350 and a soft component of 40
It is a copolymer comprising 0 to 500 long-chain polyols. Particularly preferably, a thermoplastic polyurethane having a glass transition temperature of −15 ° C. or lower is used. The glass transition temperature of a thermoplastic polyurethane is usually defined as the peak of the loss modulus obtained by a dynamic viscoelasticity measuring device. Examples of the dynamic viscoelasticity measuring device include Leo Vibron manufactured by Orientec Co., Ltd. The lower the glass transition temperature, the higher the toughness of the thermoplastic polyurethane, and accordingly the higher the impact resistance of the composition mixed with the polyacetal resin. As the isocyanate compound constituting the thermoplastic polyurethane, diphenylmethane diisocyanate, 2,4- and 2,6-tolylene diisocyanate, m- and p-phenylene diisocyanate, hexamethylene diisocyanate and the like are preferably used. As the short-chain polyol component, 1,2-ethanediol,
1,2-propanediol, 1,4-butanediol,
Butenediol, 1,6-hexanediol, 1,10
-Decamethylene diol and the like are preferably used. As the long-chain polyol as the soft component, polyalkylene adipate, polyalkylene ether and the like are preferable, and polyethylene-butylene adipate, polybutylene adipate, polynonanediol adipate, polytetramethylene glycol and the like are more preferable. Each of the components may be suitably used alone or as a mixture of two or more.

The core-shell polymer used in the present invention is a polymer having a structure in which a rubber-like polymer core is covered with a glass-like polymer shell. Since this core-shell polymer is not thermoplastic but in the form of particles, it is characterized in that it is uniformly and very finely dispersed in the polyacetal resin, and in addition to the improvement in impact resistance, the weld property of the composition is also improved. There are features. The core-shell polymer in the present invention utilizes a continuous multi-stage emulsion polymerization method in which the polymer of the previous stage is sequentially coated with the polymer of the subsequent stage, that is, a so-called seed emulsion polymerization method. After the core rubbery polymer is formed, it is obtained by forming a shell made of a glassy polymer so as to cover its surface by polymerization in a later stage. Examples of the monomer constituting the rubbery polymer serving as the core include a conjugated diene, an alkyl acrylate having an alkyl group having 2 to 8 carbon atoms, and a mixture thereof. Such conjugated dienes include, for example, butadiene, isoprene,
Chloroprene and the like can be mentioned, but butadiene is particularly preferably used. The alkyl group has 2 to 8 carbon atoms
Examples of the alkyl acrylate include ethyl acrylate, propyl acrylate, butyl acrylate, cyclohexyl acrylate, and 2-ethylhexyl acrylate, and butyl acrylate is particularly preferably used.

In the first-stage polymerization for forming such a rubbery polymer (the polymerization in the previous stage), a monomer copolymerizable with a conjugated diene and an alkyl acrylate as described above, for example, styrene, vinyl toluene, α- Aromatic vinyl such as methylstyrene, aromatic vinylidene, vinyl cyanide such as acrylonitrile and methacrylonitrile, and vinyl methacrylate, alkyl methacrylate such as methyl methacrylate and butyl methacrylate, and the like can also be copolymerized.

When the first-stage polymerization does not contain a conjugated diene as a monomer component, or when it contains 20% by weight or less of the total amount of the first-stage monomer even if it contains a conjugated diene, the crosslinking monomer and the graft It is preferable to use a small amount of the activated monomer, whereby high impact resistance can be achieved.

Examples of the crosslinkable monomer include aromatic divinyl monomers such as divinylbenzene, ethylene glycol diacrylate, ethylene glycol dimethacrylate, butylene glycol diacrylate, hexanediol diacrylate, hexanediol dimethacrylate, oligoethylene glycol diacrylate, and oligoethylene glycol diacrylate. Ethylene glycol dimethacrylate, trimethylolpropane diacrylate, trimethylolpropane dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate and the like alkane polyol polyacrylate or alkane polyol polymethacrylate, etc.
Particularly, butylene glycol diacrylate and hexanediol diacrylate are preferably used.

Examples of the grafting monomer include allyl acrylate, allyl methacrylate, diallyl maleate, diallyl fumarate, and allyl unsaturated carboxylate such as diallyl itaconate. Particularly, allyl methacrylate is preferably used.

On the other hand, as a monomer constituting the glassy polymer forming the shell phase by coating the core made of the rubbery polymer as described above, a monomer copolymerizable with methyl methacrylate is used. For example, ethyl acrylate, butyl Alkyl acrylates such as acrylates,
Ethyl methacrylate, alkyl methacrylate such as butyl methacrylate, styrene, vinyl toluene, α-
Aromatic vinyl such as methylstyrene, aromatic vinylidene,
Examples thereof include vinyl cyanide such as acrylonitrile and methacrylonitrile, and vinyl polymerizable monomers such as vinylidene cyanide. Particularly preferably, ethyl acrylate, styrene, acrylonitrile and the like are used.

The core-shell polymer used in the present invention is preferably a core-shell polymer in which substantially no anion is detected, and specifically, emulsion polymerization using a nonionic surfactant and a polymerization initiator in which a generated radical is neutral. The core-shell polymer obtained by the above is preferred. The anion content of the core-shell polymer is such that it cannot be detected by a conventional anion qualitative test. For example, as a measurement method, 5 g of a sample (core-shell polymer) is weighed in a 50 ml Erlenmeyer flask,
Then, the mixture was stirred with a magnetic stirrer for 3 hours, and then the filtrate filtered with a No. 5C filter paper was divided into two parts. Sulfate ion qualitative test). In addition, the same treatment is performed, and a 0.1 N silver nitrate aqueous solution is added in place of the 1% barium chloride aqueous solution, and the occurrence of turbidity is compared and observed (qualitative test of halogen ions), or other methods such as metal salts of carboxylic acids are used. As for the anion, a measurement method used as a similar ordinary qualitative test can be mentioned.

In the present invention, the compounding amount of the impact modifier (B) is 3 to 50 parts by weight, preferably 5 to 40 parts by weight, based on 100 parts by weight of the branched polyacetal copolymer (A). If less than 3 parts by weight, the effect of improving impact resistance is poor,
If it exceeds 50 parts by weight, the mechanical properties, heat resistance, chemical resistance and the like inherent in the polyacetal resin are greatly reduced, which is not preferable.

In the present invention, in particular, when (B) a thermoplastic polyurethane resin is used as an impact resistance improver, an isocyanate compound or an isothiocyanate compound is used for the purpose of further improving impact resistance, weld properties, and the like. Is preferable. The isocyanate compound or isothiocyanate compound preferably combined and used in the present invention is a compound containing two or more isocyanate groups or isothiocyanate groups in the molecule, and specifically, for example, toluene diisocyanate, toluene diisothiocyanate , Xylene diisocyanate, xylene diisothiocyanate, diphenylmethane diisocyanate, diphenylmethane diisothiocyanate, phenylene diisocyanate, phenylene diisothiocyanate, naphthalene diisocyanate, naphthalene diisothiocyanate, propylene diisocyanate, propylene diisothiocyanate, tetramethylene diisocyanate, tetramethylene diisothiocyanate , Hexamethylene diisocyanate, hexamethylene diisocyanate Thiocyanate, cyclohexylene diisocyanate, cyclohexylene isothiocyanate, dicyclohexylmethane diisocyanate, dicyclohexylmethane diisothiocyanate, isophorone diisocyanate, isophorone diisothiocyanate, and their dimers or trimers thereof. The amount of the isocyanate compound or isothiocyanate compound used here is preferably in the range of 0.01 to 10% by weight based on the component (A) + the component (B).

The resin composition of the present invention preferably contains various stabilizers selected as necessary. Examples of the stabilizer include any one or more of a hindered phenol compound, a nitrogen-containing compound, an alkali or alkaline earth metal hydroxide, an inorganic salt, and a carboxylate. Furthermore, as long as the objects and effects of the present invention are not impaired, if necessary, general additives for thermoplastic resins, for example, coloring agents such as dyes and pigments, lubricants, release agents, antistatic agents, and surfactants Alternatively, one or more kinds of organic polymer materials, inorganic or organic fibrous, powdery, and plate-like fillers can be added.

The composition of the present invention can be easily prepared by a known method generally used as a conventional method for preparing a resin composition. For example, after mixing each component, the mixture is kneaded and extruded with an extruder to prepare pellets, a predetermined amount of the pellets are mixed and subjected to molding to obtain a molded product having a desired composition after molding. Alternatively, any method such as a method of directly charging two or more can be used.

[0040]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples. still,
The evaluation was performed by the following method. [Tensile strength] A dumbbell-shaped test piece was molded using an injection molding machine, and measured according to the ASTM D638 method. [Flexural modulus] A test piece was molded using an injection molding machine, and AS
The measurement was performed according to the TM method. [Izod impact value] A test piece was molded using an injection molding machine, a notch was made according to the ASTM D256 method, and the Izod impact value was measured. Examples 1 to 10 A paddle was prepared by using a continuous mixing reactor having a barrel provided with a jacket through which a heat (cooling) medium passes and having a cross section partially overlapping two circles, and a rotary shaft with paddles. While rotating the two rotating shafts marked with at 150 rpm,
Trioxane (a), monofunctional glycidyl compound (b-
1), the cyclic ether compound (c) was added at the ratio shown in Table 1, and methylal was continuously supplied as a molecular weight regulator, and a dibutyl ether solution of boron trifluoride dibutyl etherate as a catalyst was added to trioxane. A homogeneous mixture mixed so as to be 0.005% by weight in terms of boron fluoride was continuously added and supplied to perform bulk polymerization. The reaction product discharged from the polymerization machine was immediately passed through a crusher and added to an aqueous solution containing 0.05% by weight of triethylamine at 60 ° C. to deactivate the catalyst. Further, after separation, washing and drying, a crude polyacetal copolymer was obtained.

Next, the crude polyacetal copolymer 1
4 wt% of a 5 wt% aqueous solution of triethylamine and pentaerythrityl-tetrakis [3-
(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] was added in an amount of 0.3% by weight, and the mixture was melt-kneaded at 210 ° C. with a twin-screw extruder to remove unstable portions. The structure and copolymer composition of the obtained polyacetal copolymer were confirmed by ¹ H-NMR measurement using hexafluoroisopropanol d ₂ as a solvent.

The compound (B) shown in Table 1 was added to 100 parts by weight of the branched polyacetal copolymer (A) obtained by the above method.
(C), and pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-4-) as a stabilizer.
[Hydroxyphenyl) propionate] and 0.15 part by weight of melamine were added and melt-kneaded at 210 ° C. by a twin-screw extruder to obtain a pelleted branched polyacetal resin composition. Table 1 shows the evaluation results evaluated by the above-described method. Comparative Examples 1 to 5 When a polyacetal copolymer prepared without using a monofunctional glycidyl compound (b-1) and having no branched structure is used as a base resin, and a branched polyacetal copolymer (A)
In the case where Compounds (B) and (C) were not blended, a pellet-shaped composition was prepared and evaluated in the same manner as in the Examples. Table 1 shows the results.

[0043]

[Table 1]

Component (b-1) BGE: butyl glycidyl ether 2EHGE: 2-ethylhexyl glycidyl ether PGE: phenyl glycidyl ether CGE: cresyl glycidyl ether OPPG: o-phenylphenol glycidyl ether (c) Component DO: 1,3- Dioxolane EO: Ethylene oxide compound (B) TPE: Thermoplastic polyurethane CSP: Core-shell polymer (manufactured by Takeda Pharmaceutical Co., Ltd.)
PO-0135)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshihisa Tajima 973 Miyajima, Fuji-shi, Shizuoka Prefecture F-term in Polyplastics Co., Ltd. AD34 AD35 AD36 AD37 AD38 AD41 AD43 AD44 AD45 AD46 AD47 AD50 AD51 AE01 AE02 AF08

Claims (11)

[Claims] 1. A thermoplastic polyurethane and a core-shell polymer selected from 100 parts by weight of a branched polyacetal copolymer (A) having an oxymethylene group as a main repeating unit and having a branch unit represented by the following general formula (I). A branched polyacetal resin composition comprising 3 to 50 parts by weight of an impact modifier (B). Embedded image (Wherein, m and n each represent an integer of 0 to 5, and m + n
Is 1 to 5. R represents a monovalent organic group having a molecular weight of 40 to 1,000. ) 2. The branched polyacetal resin composition according to claim 1, wherein R in the branch unit represented by the general formula (I) is selected from a monovalent organic group having an aromatic ring. 3. The branched polyacetal copolymer (A) comprises:
It is obtained by copolymerizing 100 parts by weight of trioxane (a), 0.001 to 10 parts by weight of a monofunctional glycidyl compound (b-1) and 0 to 20 parts by weight of a cyclic ether compound (c) copolymerizable with trioxane. The branched polyacetal resin composition according to claim 1 or 2. 4. The monofunctional glycidyl compound (b-1)
The branched polyacetal resin composition according to claim 3, which is a compound selected from the group consisting of a glycidyl ether compound and a glycidyl ester compound having a molecular weight of 100 to 1,000. 5. The monofunctional glycidyl compound (b-1)
The branched polyacetal resin composition according to claim 3, which is selected from glycidyl ether compounds represented by the following general formulas (II), (III) and (IV). Embedded image (Wherein, R ¹ represents an alkyl group having 1 to 12 carbon atoms, a substituted alkyl group, an alkoxy group, an aryl group, a substituted aryl group,
Alternatively, n is an integer of 0 to 5;
Is 2 or more, R ¹ may be the same or different. ) (Wherein, R ² represents an alkylene group having 1 to 30 carbon atoms, a substituted alkylene group, a polyalkylene oxide glycol residue,
R ³ is an alkyl group having 1 to 12 carbon atoms, a substituted alkyl group,
An alkoxy group, an aryl group, a substituted aryl group, or a halogen, n is an integer of 0 to 5, and when n is 2 or more, R ³ may be the same or different. ) (Wherein, R ⁴ is an alkylene group having 1 to 30 carbon atoms, and n is 0)
Represents an integer of from 20 to 20, and R ⁵ represents an alkyl group having 1 to 30 carbon atoms, an alkenyl group or an alkynyl group having 2 to 20 carbon atoms. ) 6. The branched polyacetal copolymer (A) comprises:
100 parts by weight of trioxane (a), 0.001 to 10 parts by weight of cyclic formal compound (b-2) capable of forming a branch, and cyclic ether compound (c) 0 to 20 copolymerizable with trioxane
3. The composition of claim 1, which is obtained by copolymerizing parts by weight.
The branched polyacetal resin composition according to the above. 7. The branched polyacetal copolymer (A) comprises:
Cyclic ether compound (c) copolymerizable with trioxane
The branched polyacetal resin composition according to any one of claims 3 to 6, wherein the branched polyacetal resin composition is obtained by copolymerizing 0.1 to 20 parts by weight with respect to 100 parts by weight of trioxane. 8. The cyclic ether compound (c) copolymerizable with trioxane is ethylene oxide, 1,3-dioxolan, diethylene glycol formal and 1,4-
The branched polyacetal resin composition according to any one of claims 3 to 7, which is selected from butanediol formal. 9. The thermoplastic polyurethane according to claim 1, wherein the soft component is one or more selected from polyalkylene adipates and polyalkylene ethers.
Item 8. The branched polyacetal resin composition according to item 1. 10. The branched polyacetal resin composition according to claim 1, wherein the core-shell polymer is polymerized by a polymerization method in which substantially no anion is detected. 11. The branch according to claim 1, wherein the impact modifier (B) is selected from thermoplastic polyurethanes and further contains an isocyanate compound or an isothiocyanate compound. Polyacetal resin composition.