JPS59191751A - Polyacetal composition - Google Patents

Abstract

PURPOSE:To provide a polyacetal compsn. having excellent impact properties, consisting of an elastomer, an acetal block copolymer and a polyacetal. CONSTITUTION:A compsn. consists of a polyacetal, an elastomer having a number-average MW of 10,000-500,000 and a second-order transition temp. of -120-+40 deg.C and an acetal block copolymer having a number-average MW of 10,000-500,000, composed of an acetal polymer component and an elastomer component and having a structure wherein an elastomer having a second-order transition temp. of -120-+40 deg.C is inserted into the main chain of the linear polymer. An example of the elastomer or the elastomer component are polystyrene elastomer wherein the hard segment is composed of polystyrene.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel polyacetal composition, and particularly to a polyacetal composition having unprecedentedly excellent impact properties.

Of polysecure? # Many attempts have been made to improve impactability. For example, Tokko Showa 4 (&-/10.
In Publication No. 23, the addition of a so-called ionomer is
In Special Publication Shoda S-ko4ko No. 31, ethylene-
The addition of acrylic acid copolymer was published in Japanese Patent Publication No. 50-33093.
The publication proposes the addition of an aliphatic polyether.

Polyacetal, which is a crystalline polymer, and the non-quality polymers proposed in these publications do not easily mix or dissolve, and it is extremely difficult to create a uniform composition of the two. For this reason, the compositions proposed in these publications do not sufficiently improve impact properties, and the appearance of molded products is also poor.

To improve non-uniform mixing and dissolution
Kota publication describes the reaction of a trioxane copolymer containing free amide 7 groups with an isocyanate group-containing polyether. This method requires reducing the nitro groups in the polymer to amino groups, and the polymer has the defect of violently decomposing during the reduction operation.

Also, Tokukai Akira! ;'I-/! In 2Dg publication, it is proposed to add an elastomer and a segmented polyester or polyurethane, which are processing aids, to polyoxymethylene. By adopting this method,
Although the impact value is improved, the appearance of the molded article is still poor. This is due to the fact that uniform mixing and dissolution of the elastomer and polyoxymethylene is insufficient even when segmented polyester and polyurethane are used as processing aids. Furthermore, the strength and rigidity of molded articles based on this composition are greatly reduced due to the addition of segmented polyester and polyurethane. The decrease in strength and rigidity becomes obvious in all comparative examples. Polyacetal is widely used as an engineering plastic due to its well-balanced physical properties. Attempts to improve impact properties even at the expense of strength and rigidity, such as the composition of the present invention, cannot necessarily be said to be an advantageous direction.

As a result of extensive studies on methods for improving the impact properties of polyacetal, the present inventors found that a polyacetal composition containing a certain A-specific elastomer and an acetal block copolymer has outstanding impact properties. This discovery led to the completion of the present invention.

Moreover, this composition maintains high strength and stiffness, and this composition can be appropriately called a highly balanced composition.

That is, the present invention provides an elastomer having a second-order transition temperature of -/20°C to 100°C and a number average molecular weight of between 70.000 and SOθ000, and a linear polymer in the main chain. −／
It has a structure in which an elastomer having a second-order transition temperature of 10°C to +4IO°C is inserted, and the number average molecular weight is /4θθO
The present invention relates to a polyacetal composition having excellent impact properties, which is composed of polyacetal and an acetal block copolymer composed of an acetal polymer component and an elastomer component, which is between soo and ooo.

The polyacetal composition of the present invention has an Izod impact value (
It has a value of r-qokg (with a notch) and has excellent impact properties that have never existed before.

Demand for polyacetal as an engineering plastic has been increasing in recent years, and improving the impact properties of polyacetal has great industrial significance.

Next, the polyacetal composition of the present invention will be explained in detail.

The polyacetal used as the base material in the present invention includes polyacetal homopolymers and polyacetal copolymers.

Polyacecool homopolymer is oxymethylene unit +
It is a polymer consisting of repeating CH2O+, and is obtained by homopolymerizing formaldehyde and trioxane.

A polyacetal copolymer is an oxyalkylene unit n 0 (RO: selected from hydrogen, an alkyl group, and an allyl group, each of which may be the same or different. m = λ) in a chain consisting of oxymethylene units. It is a polymer having a structure in which ~t) are randomly inserted.

The insertion rate of oxyalkylene units in the polyacetal copolymer is θθt with respect to 100 moles of oxymethylene units.
NSO mole, more preferably 0IN20 mole.

Examples of oxyalkylene units include oxyethylene units, oxypropylene units, oxytrimethylene units,
There are oxytetramethylene units, oxybutylene units, oxyphenylethylene units, etc.

Among these oxyethylene units, oxyethylene unit F (CT(2/)20→ and oxytetraethylene unit +(CH2')a O+) are particularly preferred from the viewpoint of improving the physical properties of the polyacetal composition.

A polyacetal copolymer is obtained by copolymerizing or reacting formaldehyde, trioxane, polyoxymethylene with a cyclic ether or a cyclic formal.

After polymerization and reaction, the polyacecool homopolymer and polyacetal co-9-polymer are added as a base material after the polymer terminals are converted into stable groups.

In the present invention, an elastomer and an acetal block copolymer composed of an acetal component and an elastomer component are added to the polyacecool base material. Further, the elastomer to be added and the elastomer component in the acetal block copolymer may have the same structure or may have completely different structures.

The elastomer or elastomer component that can be used in the present invention has a second-order transition temperature (glass transition temperature, Tg) of -72[theta]C to 100[deg.]C.

Here, the elastomer/elastomer component is a thermoplastic polymer that is a combination of an amorphous segment with a low secondary transition temperature (soft segment) and a segment that creates a thermoreversible crosslinked/bonded structure (hard segment). It is a polymer.

The number average molecular weight of the elastomer or elastomer component is set between 10,000 and SOO,θoo. If the number average molecular weight is too low, the impact properties will not be improved sufficiently, and if it is too high, it will be difficult to mix and dissolve uniformly with the base material polyacetal.

The first elastomer or elastomer component of the present invention
An example of this is a polystyrene-based elastomer, in which polystyrene is used as a hard segment. Soft segments to be combined with polystyrene include diene types such as polybutadiene and polyisoprene, and hydrogenated diene types such as hydrogenated polybutadiene and hydrogenated polyisoprene. Among these polystyrene-based elastomers, polystyrene-polybutadiene block fluoromers and polystyrene-hydrogenated polybutadiene block copolymers are particularly preferred.

A second example of an elastomer or elastomer component is
It is a polyester elastomer, and has a hard segment of polyester such as polyethylene terephthalate, polybutylene terephthalate, modified polyethylene terephthalate, and polyethylene/butylene terephthalate. Soft segments to be combined with polyesters include polyethers such as polypropylene glycol, polytetramethylene glycol, and the like. Among these polyester elastomers, polybutylene terephthalate-polytetramethylene glycol block copolymer and polyethylene-butylene terephthalate-polytetramethylene glycol block copolymer are particularly preferred.

A third example of an elastomer or elastomer component is
It is a polyamide-based elastomer, and uses polyamides such as nylon 6, nylon 1--As, nylon t-io, etc. as 8-do segments.

Soft segments F to be combined with polyamides include polyethers such as polypropylene glycol and polytetramethylene glycol, and polyesters such as polyethylene adipate and polybutylene succinate. Among these polyamide elastomers, especially nylon 6
- Polypropylene glycol block copolymers, nylon 6-polytetramethylene glycol block copolymers are preferred.

A second example of an elastomer or elastomer component is
It is a polyurethane elastomer with urethane as the hard segment.

Here, the urethane is obtained by reacting a diisocyanate such as lI, q'-diphenylmethane diisocyanate, ge, da'-dicyclohexylmethane diisocyanate, and a glycol such as ethylene glyfur or tetramethylene glycol.

Soft segments to be combined with urethane include polyester diols such as polyethylene adipate and polybutylene adipate, and polyether diols such as polypropylene glycol and polytetramethylene glycol.

Among these polyurethane elastomers, p,
Polyurethanes synthesized from lI-diphenylmethane diisocyanate, tetramethylene glycol and polytetramethylene glycol are preferred.

Next, the acetal block co-/3-polymer used in the present invention is a linear polymer with a concentration of -72θ°C to +l in the main chain.
It is a polymer into which an elastomer having a second-order transition temperature of lo DEG C. is inserted, and is an A-B-A type triplic copolymer of an acetal polymer component (A) and an elastomer component (B).

The acetal polymer component includes an acetal homopolymer component and an acetal copolymer component.

The acetal homopolymer component is a polymer component consisting of repeating oxymethylene units + CH2O+.

The acetal copolymer component is an oxyalkylene unit (Ro' hydrogen,
They are selected from alkyl groups and allyl groups, and may be the same or different. It is a polymer component having a structure in which mr ==-~6) is randomly inserted.

-/4'- The insertion rate of oxyalkylene units in the a7talf polymer component is O per 100 moles of oxymethylene units.
OS~70 mol, more preferably 07~30 mol.

Examples of oxyalkylene units include oxyethylene units, oxypropylene units, oxytrimethylene units,
There are oxytetramethylene units, oxybutylene units, oxyphenylethylene units, etc.

Elastomer components to be inserted into the backbone of the linear polymer include the polymers described above.

Further, the acetal block copolymer of the present invention can be treated with formaldehyde, formaldehyde, It can be obtained by polymerizing trioxane, copolymerizing formaldehyde or trioxane with a cyclic ether or cyclic formal, or reacting polyoxymethylene with a cyclic ether or cyclic formal.

Here, the telekirik elastomer functions as a molecular weight regulator during polymerization and reaction, and at the same time controls the molecular weight of the polymer, it is also inserted into the polymer as a blocking makpmer.

Like the base material polyacetal, the acetal block copolymer is also added after polymerization and reaction, converting the polymer terminal into a stable group.

The number average molecular weight of the acetal block copolymer is /Qθ
Set between oo N5oo and ooo.

The content of the elastomer component in the acetal block copolymer is set between as-so weight percent.

In the present invention, the elastomer is added in an amount of θ/ to yo parts by weight based on 100 parts by weight of polyacetal. If the amount of elastomer added is too low, the impact properties will not be improved sufficiently, and if it is too high, strength and rigidity will decrease.

Further, the amount of the acetal block copolymer added is determined in balance with the amount of the elastomer added, but is usually in the range of 0/-1IO parts by weight.

It is also possible to further add and use a conventionally known compound as a stabilizer for polyacetal to the composition of the present invention. The first of the known stabilizers are thermal stabilizers, such as amide compounds, polyamides, amidine compounds, melamine, polyvinylpyrrolidone, carboxylic acid metal salts, and the like.

A second type of known stabilizer is an antioxidant, such as a hindered phenol compound.

A third type of known stabilizer is a light stabilizer, such as a benzotriazole compound or a hydroxybenzophenone compound.

These stabilizers usually contain 003 to 10 parts by weight, more preferably θotr to 700 parts by weight of polyacetal.
3 parts by weight is added.

In order to produce the polyacetal composition of the present invention, it is necessary to mix each component with each other in powder or granular form and then homogenize using a melting device such as an extruder.

The present invention will be specifically explained below using Examples.

Note that the terms used in the examples have the following meanings.

-l KuMI: /q□℃, 2. /Akg Melting index under standard load (ASTM D l: t3g left?T) Addition amount (phr): Addition amount Fll per 100 parts by weight of polyacetal -A-t-butylphenol) Antioxidant p,o-B: Pentaerythritol-tetrakis[3-(3,A;-di-t-butyl-t-hydroxyphenol]propionate) Izod impact value (notched): After adding a stabilizer, a composition consisting of polyacetal, elastomer, and acetal mellock copolymer was uniformly mixed and dissolved using an extruder.

Next, a flat plate is formed, and a test piece is cut from this flat plate and measured according to ASTM I) 2&&. The larger the Izot impact value, the better the impact properties.

Tensile strength: Cut a test piece from a flat plate, ASTM D 63
Measured according to g, the one with higher tensile strength is -/g-.

Examples / (]) Synthesis of polymer /-/ Polyacetal anhydrous formaldehyde was introduced into cyclohexane containing diptyltin dilaurate as a polymerization catalyst, and jA''
Polymerization was carried out at c. After separating the polymer from cyclohexane, the terminals of the polymer were acetylated with acetic anhydride to stabilize the polymer. The MI of this polymer is /left (9710 minutes).

/−λ Elastomer terephthalic acid, ethylene glycol, tetramethylene glycol and polytetramethylene glycol (Mn 1
Polyethylene-butylene tele-7thalet-polytetramethylene-11 Kohlbrochoff polymer (hereinafter abbreviated as PET-PTG) was synthesized using 2rO) as a starting material, and the number average molecular weight of this elastomer was λ, tX/0'
It is.

/ -,? Acetal block copolymer PET-PTG synthesized from anhydrous formaldehyde as a telechelic elastomer at /-λ.

Polymerization was carried out at 75° C. by blowing into toluene containing tetrabutylammonium acetate as a polymerization catalyst. The structure of the resulting polymer after acetylation is as follows, and the number average molecular weight is 4. ．． 2X/04.

(Here, XI is PET-PTG, which is composed of the following soft segments and eight-domain segments.

In addition, a indicates / to //29) 1/q- (2) Composition The following polymers and stabilizers were added to the polyacetal of /-/, and then melt-mixed using a 3Qf1mφ extruder.

! -One Elasto Y-(PET-PTG") 1
0.2 pbr/-3 acetal block copolymer
, t/phr nylon 6-A
O left phrAOA
0.3 phrThe Ml of this composition is /daA(f/
/θ min) and has the following physical property values.

Izotsu impact value 23.4 ('? ・cm/c
m) Tensile strength 6/θ (kg) This composition has both excellent impact properties and strength/rigidity. In addition, the appearance of molded products based on this composition is extremely beautiful.
No 70-mark or the like was observed at all. This fact indicates that the polyacetal, elastomer, and acetal block copolymer are mixed and dissolved extremely homogeneously.

- Yul - 1101 Example (3) Synthesis of polymer, ? -/Polyacetal After mixing qt% of anhydrous trioxane and ethylene oxide flathead in a Nigu with two Σ blades, boron trifluoride dibutyl etherate as a polymerization catalyst was added to initiate polymerization.

After polymerizing for 1S minutes at 7g°C, tributylamine was added to stop the polymerization. A mixture of triethylamine and water was added to this polymer, and the mixture was fed to a 3 omφ extruder equipped with a vent.

The MI of a polymer that has undergone melt hydrolysis in an extruder to remove unstable terminal portions is q,o (y/10 min).

3-2 Elastomer Polypropylene glycol obtained by polycondensing a prepolymer (Mn/3gO) made by reacting adipic acid with an ε-prolactam polymer (nylon A, Mn //?0) Nylon 6-polypropylene glycol block copolymer, the number average molecular weight of this elastomer is lt x 10'.

- Coco 3-37 Setal Block Copolymer Anhydrous formaldehyde is blown into toluene containing a polystyrene-hydrogenated polybutadiene block copolymer (hydroxyl group terminal) as a telechelic elastomer and tetrabutylammonium acetate as a polymerization catalyst at Aθ°C. Polymerization was carried out at The structure of the polymer after acetylation is as follows, and the number average molecular weight is 2×10′.

(Here, X2 is a polystyrene-hydrogenated polybutadiene block polymer, which is composed of the following soft segments and hard segments.

Soft segment +CH2CH2CH “CT(2-
+ (-CFI2- CM+ C, H5, and b indicates 1 to 99) (4) After adding the following polymers and stabilizers to the polyacetal of composition J-/, melt-mix using a jfQmφ extruder. I forced it.

Coarse elastomer 3. Aph
r-co-3 acetal block copolymer 20
phr nylon A-100, A; phr AOB l17.
The physical properties of this 2 phr composition are as follows, and it has excellent impact properties.

MI 9 da (2//θ min)
Izotsu Impact @ t 11? Ckq・cm/
am) Tensile strength t, 30 (ki/cA Example 3 (5) Polymer synthesis A--/Polyoxymethylene sibide p-oxide of polyacetal MIlza,
Boron trifluoride dibutyl etherate was added as a polymerization catalyst to cyclohexane containing ethylene oxide and a polystyrene-hydrogenated polybutadiene block polymer (MnYO x 10', hydroxyl group terminated) as a telechemical elastomer, and the mixture was heated at 5°C for 20 minutes. It was allowed to react for a minute. After terminating the reaction by adding tributylamine, the polymer was separated. A triethylamine-water mixture was then added to the polymer, and the terminal unstable portions were removed in a pen)n'jO■φ extruder. The MI of the polymer after terminal stabilization is
173 (2/lθ min).

S-Co Elastomer' A polyurethane synthesized from l,ll-diphenylmethane diisocyanate, tetramethylene glycol and polytetramethylene glycol. The number average molecular weight of this elastomer is 30 x lO4.

Left-3 Acetal block copolymer formaldehyde, ethylene glycol formal, toluene containing nylon 6-boritetramethylene glycol block copolymer as a telechelic elastomer, and diptyltin dimethoxide as a polymerization catalyst. Boron trifluoride diethyl etherate was added separately to initiate copolymerization. 32”
After reacting for /& minutes at C.C., the polymer was separated from toluene, and then the ends of the polymer were cetylated. The structure of this polymer is as follows, and the number average molecular weight is gOx
It is 104.

(Here, X3 is a polyurethane elastomer component.

C is /~#, 49. d represents /~/A. Again here (
(6) The following weights are added to the polyacetal of -/ in the composition. After combining and adding a stabilizer, they were melt-mixed using an A, ymφ extruder.

Elastomer of S-2 Acetal block copolymer of left-3 3θOphr26
One melamine 0! ;phrAO-BO
2phr The physical properties of this composition are as follows, with good strength and
Impact characteristics are greatly improved while maintaining rigidity.

M Is Le (9710 minutes) Izot impact value 31.3 (kg ・tm/c
m) Tensile strength sto (kq/cl)
Comparative Example/(Method of Japanese Unexamined Patent Application Publication No. 1999-1991) ethylene-vinyl acetate copolymer was added as an elastomer to the polyacecool synthesized in Example 3-/, and dimethyl terephthalate and isophthalic acid were used as processing aids. Dimethyl, tetramethylene glycol and polyethylene glycol (
Segmented polyester synthesized from Mn /θoo), melamine and AO-A are added as stabilizers in the following amounts, and! The mixture was melt-mixed using an rO■φ extruder.

EVA copolymer IIOphr segmented polyester 4IOphr melamine
0.3 phrA O-B
The physical properties of this composition are as follows.

M I 9.2 <9710 minutes) Izod impact value 9A (kg・tM/equipment) Tensile strength
! ; , 20 (kg/cr!) Although the impact properties have been improved, the strength and rigidity have decreased, and this composition has unbalanced physical property values.

In addition, melamine θ5p)lr is added to the 3-/polyacetal.
The physical properties of the composition containing 0.2 phr of XAOB are as follows.

MI ql (fly θ min) Izot impact value j' g (kg・cm/cm) Tensile strength A IIOCkq/ct/1) Comparative example (when no acetal block copolymer is added) Example / of /-/ The elastomer obtained in Example/-2 and the following stabilizer were added to the polyacecool obtained as an elastomer, and the mixture was melt-mixed in a j;QtEIRφ extruder.

L-Co Elas) Ma (PET-PTG) /
0.2 phr nylon 6-6 0! rphr AO-A 0.3phr The physical properties of this composition are as follows.

M I /4<7 (9710 minutes)
Izotsu impact value AJ (kg・tyn/c
m) Tensile strength A/0 (kg/crI)
The impact properties of this composition are poor. This is caused by the polyacetal and elastomer not being uniformly mixed and dissolved. The appearance of molded articles based on this composition is poor, with many 70-marks being observed. This fact also indicates non-uniform mixing and dissolution.

In addition, nylon 6-A O,
! The physical properties of the composition containing 3 phr and AO-A O are as follows.

M ■ /j:/ (9710 minutes) lim value M3 (kg・cm/cm
) Tensile strength 5o (kq/ctl) Example II-9 Polyacetal homopolymer (MI/U θf/10 min) 2
9- Elastomers, acetal block copolymers and nylon A-/00! as shown in Table 1. ;phr.

AO-A O,? phr was added and mixed and dissolved using an A&■φ extruder. Further, the physical property values of these compositions are also shown in Table 1. In all Examples, compositions with excellent impact properties were obtained.

Examples 70 to 13 Polyacecool copolymer (a polymer containing 11 moles of oxytetramethylene units per mole of oxymethylene units/θO and having an MI qO of 9710 minutes) was added with an elastomer and an acetal block copolymer as shown in Table 1. , nylon 6 θ3 phr, and AO-BθQ phr were added and uniformly mixed and dissolved in a 30 φ twin screw extruder.

The obtained physical property values are also shown in Table 1.

In all Examples, compositions with excellent impact properties were obtained.

(Leaving space below) 30- Procedural amendment (voluntary) July 25, 1980 Director-General of the Patent Office Kazuo Wakasugi 1, Indication of the case 1982 Patent Application No. 64872 2, Name of the invention Polyacetal composition 3, Relationship with the case of the person making the amendment Patent applicant: 1-2-6 Dojimahama, Kita-ku, Osaka-shi, Osaka (OO3) Teru Miyazaki, President and Representative Director of Asahi Kasei Industries, Ltd. 4; Agent: 3-7 Yotsuya, Shinjuku-ku, Tokyo In addition, the statement in the statement of contents of the amendment to be made for New Building 5B6 shall be amended as follows.

(1) rMT 1.8J on page 24, line 17, rMll,
8 (Office/10 minutes)”.

(2) P. 24, page 18 to page 25, line 1, Patent applicant characterized by “as a telekirik elastomer... hydroxyl group terminal)” Procedural amendment written by Toru Hoshino, patent attorney and agent for Asahi Kasei Industries Co., Ltd. ( Voluntary) February 23, 1980 Kazuo Wakasugi, Commissioner of the Japan Patent Office Patent Application No. 64872 (1981) Title of the invention Polyacetal composition 3 Relationship with the party making the amendment P1 Patent applicant (4','J'/ Satoshi 1-2-6-4 Dojimahama, Kita-ku, Osaka-shi, Osaka Prefecture, Agent Address: 5B Katsushin Building, 3-7 Yotsuya, Shinjuku-ku, Tokyo
Explanation Column 8, Contents of the Amendment (as attached) The description in the description of the contents of the amendment is amended as follows.

(1) Amend the claims as shown in the attached sheet.

(2) 2nd line from the bottom of page 8 "Allyl group" is corrected as [aryl group-1.

(3) Page 9, line 12 "oxyethylene unit" Correct it to "oxyalkylene unit."

(4) Page 9, lines 14-15 "Oxytetraethylene unit" Correct it to "oxytetramethylene unit."

(5) Page 13, line 16, "r4,4-diphenylmethane diisocyanate" is corrected to "r4,4'-diphenylmethane diisocyanate."

(6) Page 14, 4th line from the bottom Correct "allyl group" to "aryl group".

(7) Page 24, line 1 "2-1 polyacetal" [Corrected to 3-1 polyacetal-1.

(8) Page 24, line 5 "2-2 elastomer" Correct to "3-2 elastomer."

(9) Page 24, line 6 Correct "2-3 no" to "3-3 no".

01 Page 24, lines 17 to 18, "polyoxymethylene dihydroxide" is corrected to "polyoxymethylene dihydroxide."

01) On page 25, line 11, "4,4-diphenylmethane diisocyanate" is corrected to "r,i,4'-diphenylmethane diisocyanate."

02 Page 26, line 10, correct "r-+-+GHz O++CH2C1 (2CH20-Lee") to "r+CH2O large 4 CH2CH20za".

(13) The item "Polybutylene terephthalate-polytetrabutylene glycol block copolymer" in the acetal block copolymer elastomer component of Example 7 in Table 1 on page 31 was changed to "Polybutylene terephthalate-polytetramethylene glycol block copolymer". correct.

C4) "4,4-diphenylmethane diisocyanate" in the elastomer section and the acetal block copolymer elastomer component section of Example 9 in Table 1 on page 31 is corrected to "4,4'-diphenylmethane diincyanate."

Patent Applicant: Asahi Kasei Kogyo Co., Ltd. Representative Patent Attorney Toru Hoshino-2, Scope of Claims (1) Having a secondary transition temperature of -120°C to +40°C, and a number average molecular weight of 10,000 to 500,000 -1 between the elastomer and the main chain of the linear polymer.
It has a structure in which an elastomer with a secondary transition temperature of 20°C to +40°C is inserted, and the number average molecular weight is 10.00
A polyacetal composition having excellent impact properties comprising polyacetal and an acetal block copolymer composed of an acetal polymer component and an elastomer component, which ranges between 0 to soo to ooo.

(2) The composition according to claim 1, wherein the elastomer component in the elastomer or acetal block copolymer is a polystyrene elastomer.

(3) The composition according to claim 1 or 2, wherein the polystyrene elastomer is a polystyrene-polybutadiene block copolymer or a polystyrene-hydrogenated polyptadiene block copolymer.

(4) Elastomer or acetal block
3- The composition according to claim 1, wherein the elastomer component in the copolymer is a polyester elastomer.

(5) The composition according to claim 1 or 4, wherein the polyester elastomer is a polybutylene terephthalate-polytetramethylene glycol block copolymer or a polyethylene-butylene terephthalate-polytetramethylene glycol block copolymer.

(6) The composition according to claim 1, wherein the elastomer component in the -I-lastomer or acetal block copolymer is a polyamide elastomer.

(7) Polyamide elastomer is nylon 6-
7. The composition according to claim 1 or 6, which is a polypropylene glycol block copolymer or a nylon 6-polytetramethylene glycol block copolymer.

(8) The composition according to claim 1, wherein the didistomer component in the elastomer or acetal block copolymer is a polyurethane didistomer.

(9) The polyurethane-based nidistomer is 4.4'-
Claim 1 or 8 is a polyurethane synthesized from diphenylmethane diisocyanate, tetramethylene glycol, and polytetramethylene glycol.
Compositions as described in Section.

The composition according to claim 1, wherein the amount of the elastomer added to 10 parts by weight of α0 polyacetal 1 is in the range of 0.1 to 40 parts by weight.

01) The composition according to claim 1, wherein the amount of the acetal block copolymer added to 100 parts by weight of the polyacetal is in the range of 0.1 to 40 parts by weight.

(121 polyacetal is oxymethylene unit + immediately, 0
The composition according to claim 1, which is a polyacetal homopolymer consisting of repeating + characters.

03) In a polymer in which the polyacetal is composed of repeating oxyethylene units, oxyalkylene units (RO: selected from hydrogen, alkyl groups, and allinyl groups, each of which may be the same or different. m = 2 to 6)
) is inserted into the polyacetal copolymer.

Q4) Claim 1 in which the oxyalkylene unit is an oxyethylene unit ((CHx)tO')
The composition according to item 1 or item 13.

051. The composition according to claim 1 or 13, wherein the oxyalkylene unit is (CH2)40-1- on the oxytetramethylene unit.

Patent applicant: Asahi Kasei Industries, Ltd. Representative Patent Attorney Toru Hoshino -31:

Claims (9)

[Claims] (1) -/ An elastomer having a second-order transition temperature of 20°C to 100°C and a number average molecular weight between 10,000-A; θ00θO, and a main chain of a linear polymer, −／
It has a structure in which an elastomer having a second-order transition temperature of 10°C to +QO°C is inserted, and the number average molecular weight is /Qθ00 to
A polyacetal composition with excellent impact properties consisting of polyacetal and an acetal block copolymer composed of an acetal polymer component and an elastomer component, which is between soo and ooo. (2) The composition according to claim 1, wherein the elastomer component in the elastomer or acetal block copolymer is a polystyrene elastomer. (3) The polystyrene elastomer is polystyrene-
3. The composition according to claim 1 or 2, which is a polybutadiene block copolymer or a polystyrene-hydrogenated polybutadiene block copolymer. (4) The composition according to claim 1, wherein the elastomer component in the elastomer or acetal block copolymer is a polyester elastomer. (5) The composition according to claim 1 or d, wherein the polyester elastomer is a polybutylene terephthalate-polytetramethylene glycol block copolymer or a polyethylene butylene terephthalate-polytetramethylene glycol block copolymer. . (6) The composition according to claim 1, wherein the elastomer component in the elastomer or acetal block copolymer is a polyamide elastomer. (7) The composition according to claim 7 or 6, wherein the polyamide elastomer is a nylon 6-polypropylene glycol block copolymer or a nylon 6-polytetramethylene glycol block copolymer. (8) The composition according to claim 1, wherein the elastomer component in the elastomer or acetal block copolymer is a polyurethane elastomer. (9) The composition according to claim 1 or 13g, wherein the polyurethane elastomer is a polyurethane synthesized from tadiphenylmethane diisocyanate, tetramethylene glycol, and polytetramethylene glycol. 2. The composition according to claim 1, wherein the amount of the elastomer added is in the range θ/-110 parts by weight based on 100 parts by weight of Oi and polyacetal. 2. The composition according to claim 1, wherein the amount of the acetal block copolymer added to 100 parts by weight of the polyacetal is in the range of 0.7 to 0.0 parts by weight. (b) Polyacetal is oxymethylene unit + cHt
The composition according to claim 7, which is a polyacetal homopolymer consisting of repeating O+ atoms. (B) In a polymer in which the polyacetal is composed of repeating oxymethylene units, oxyalkylene is simply 0 (Ro: selected from hydrogen, an alkyl group, and an allyl group, each of which may be the same or different. m = , 2~A
) is inserted into the polyacetal copolymer. 74. The composition according to claim 1 or 73, wherein the oxyalkylene unit is an oxyethylene unit mo(C'H2)20+. (b) The composition according to claim 1 or 73, wherein the oxyalkylene unit is an oxytetramethylene unit f (cT(2)40+).