JPH07109402A - Flexible polyacetal resin composition - Google Patents

Abstract

PURPOSE:To obtain a resin composition excellent in flexibility, toughness, impact resistance, and moldability by mixing a polyacetal resin with a specific multi- phase interpolymer, an ester, and a poly(alkylene glycol) in a given proportion. CONSTITUTION:A polyacetal resin in an amount of 35-94.7wt.% is mixed with 5-50wt.% multi-phase interpolymer having a multilayer structure consisting of at least one alternation of a soft phase comprising 10-100wt.% (meth)acrylic ester units and a rigid phase from the central phase to the outermost phase, 0.2-10wt.% ester, and 0.1-5wt.% poly(alkylene glycol) to produce the objective composition. Examples of the ester include 2-ethylhexyl stearate and 2-ethylhexyl oleate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel polyacetal resin composition, and more particularly to a polyacetal resin which is excellent in flexibility and toughness, and has excellent impact resistance, surface peeling and moldability. It relates to a composition.

[0002]

2. Description of the Related Art Polyacetal resin has excellent mechanical strength, fatigue resistance, chemical resistance, electrical characteristics, etc., and is therefore widely used as an engineering resin for gears, bearings, other mechanical parts, automobiles, home appliances parts, etc. It is used, and there are many applications that make the most of its characteristics.

However, in order to increase the functionality and use of polyacetal resins, it is not always sufficient to use the compositions having the characteristics inherent in polyacetal resins for the further required applications, and especially the flexibility, toughness, and impact. Use is restricted to applications that require sex. Also,
In recent years, there has been an increasing demand for polyacetal resins having flexibility in automobile parts and the like.

Originally, the polyacetal resin is characterized by a high rigidity (flexural modulus), and in the studies so far, many attempts have been made to maintain the rigidity and further improve the impact characteristics, thereby improving flexibility. There was a concern that the rigidity would be reduced in order to improve the impact resistance, not the purpose of holding it. On the other hand, various attempts have been made to improve impact resistance. For example, it is generally known to add a modifier such as rubber to a polyacetal resin, and for example, a method of adding polyurethane (Japanese Patent Publication No. 3-755).
74, Japanese Patent Publication No. 4-39496, Japanese Patent Publication No. 5-
No. 12390), a method of adding a polyorganosiloxane rubber component and a polyalkylacrylate rubber component (JP-A-5-98131), and a method of adding a vinyl copolymer and the like are also known. However, in these methods, there is no description that the flexibility, toughness and impact resistance are improved by adding an ester compound, and there is no study aiming at the flexibility. Further, the degree of softness is not sufficient, the improvement of impact properties is still insufficient, and there are many defects such as molding peeling. As a method of blending the multiphase interpolymer, a method of adding an acrylic multiphase interpolymer having a two-phase structure (JP-A-59-136343), -20
A method of adding a rubber elastic graft copolymer having a glass transition temperature of ℃ or lower (Japanese Patent Publication No. 48-34830) and a method of adding a rubber elastic graft copolymer having butadiene (Japanese Patent Laid-Open No. 61-120849). ), A method of adding a weathering (light) agent and a core-shell polymer (JP-A-5-179104), a method of adding a multiphase interpolymer and a methacrylic acid ester-based polymer (JP-A-2-294352), and A method of adding a multiphase interpolymer having a multiphase structure of two or more phases composed of repeating soft phase and hard phase from the central phase to the outermost phase (JP-A-2-283752, JP-A-3-2054).
42, JP 5-175514, and JP 5-
179104) is also disclosed, but in these publications, addition of an ester compound results in flexibility,
There is no description of improving toughness and impact resistance, and there is no study aiming at flexibility.

[0005]

The object of the present invention is to provide a polyacetal resin composition which overcomes the drawbacks of the prior art and has excellent flexibility, toughness, impact resistance and moldability without mold peeling. That is.

[0006]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that a polyacetal resin obtained by adding a multiphase interpolymer having a specific composition, an ester compound and a polyalkylene glycol to the polyacetal resin. It has been found that the composition has extremely excellent flexibility, toughness, impact resistance and moldability without molding peeling, and has completed the present invention.

That is, according to the present invention, A: polyacetal resin 3
5 to 94.7% by weight, B: a structure in which two or more phases are formed by repeating a soft phase and a hard phase from the central phase to the outermost phase, and the total of the acrylic acid ester or the methacrylic acid ester is the soft phase in the soft phase. 1 for all monomers that make up
5 to 50% by weight of a multi-phase interpolymer containing 0 to 100% by weight, C: 0.2 to 10% by weight of an ester compound, and
D: 0.1 to 5% by weight of polyalkylene glycol,
A polyacetal resin composition in which the total amount of A, B, C, and D is 100% by weight.

The composition of the present invention will be described in detail below. The polyacetal resin used in the composition of the present invention is a substantially repeating oxymethylene unit produced from a cyclic oligomer such as a formaldehyde monomer or its trimer (trioxane) or tetramer (tetraoxane). An oxymethylene homopolymer consisting of the above, and an oxy group having 2 to 8 carbon atoms produced from the above-mentioned raw material and a cyclic ether such as ethylene oxide, propylene oxide, epichlorohydrin, 1,3-dioxolane, glycol formal, or diglycol formal. It is an oxymethylene copolymer containing 0.1 to 20% by weight of an alkylene unit. Also included are oxymethylene copolymers having branched molecular chains and block copolymers containing 50% by weight or more of oxymethylene repeating units and less than 50% by weight of different polymer units. A preferred polyacetal resin is an oxymethylene copolymer having an introduced amount of ethylene oxide used in the production of 1 to 4% by weight and excellent in thermal stability. In addition, melt index (ASTM D1238-57T E,
Hereinafter, abbreviated as MI) is preferably 5 to 50 g / min, 7 to 3
5 g / min is more preferred.

The multiphase interpolymer which can be used in the present invention has a multiphase structure of two or more phases consisting of a repeating soft phase and a hard phase from the central phase to the outermost phase. 10 to 100 based on all monomers (excluding cross-linking monomers other than butadiene and grafting monomers) that constitute the soft phase of methacrylic acid ester
It is a multi-phase interpolymer containing wt%.

For example, a multi-phase interpolymer having a two-phase structure, an elastomer phase which is a soft phase in a first phase which is a central phase, and a hard phase which is a second phase which is an outermost phase is used in the present invention. be able to. Further, it may be a multiphase interpolymer having an epoxy group or a hydroxyl group in the outermost phase. The glass transition temperature (hereinafter abbreviated as Tg) of the polymer constituting the soft phase is preferably less than 25 ° C, and 0 ° C.
Less than is more preferred. On the other hand, the Tg of the polymer constituting the hard phase is preferably 25 ° C. or higher, more preferably 50 ° C. or higher.

In the case of a three-phase structure, for example, the first phase (central phase) and the third phase (outermost phase) are hard phases, the second phase (central phase) is an elastomer phase, and the soft phase is The Tg of the constituting polymer is preferably less than 25 ° C, more preferably less than 0 ° C. The Tg of the polymer constituting the hard phase is
It is preferably 25 ° C or higher, more preferably 50 ° C or higher. Further, in order to improve the interfacial adhesion between the polyacetal resin and the multiphase interpolymer, the outermost phase of these multiphase interpolymers may have a functional group such as an epoxy group, a hydroxyl group, or a carboxyl group.

The soft phase and hard phase of the multiphase interpolymer are specifically composed of the following homopolymers of vinyl monomers or copolymers of two or more kinds of monomers. Examples of usable monomers include aromatic vinyl monomers such as styrene, p-methylstyrene and α-methylstyrene; halogenated vinyl monomers such as vinyl chloride and vinylidene chloride; nitrile monomers such as acrylonitrile and methacrylonitrile; Methyl acrylate, butyl methacrylate, methacrylic acid hydroxyester, methacrylic acid 2-
Methacrylic acid esters such as ethylhexyl; methyl acrylate, ethyl acrylate, n-butyl acrylate,
2-ethylhexyl acrylate, dodecyl acrylate,
Acrylic esters such as hydroxyethyl acrylate; Vinyl esters such as vinyl acetate and vinyl propylene; Unsaturated amides such as acrylamide and methacrylamide; Vinyl alkyl ethers such as vinyl ethyl ether, vinyl ethyl ether, vinyl butyl ether, butadiene, isoprene And the like, such as conjugated dienes.

The soft phase of the multi-phase interpolymer is preferably a polymer or copolymer formed of one or more selected from acrylic acid esters, methacrylic acid esters, and conjugated dienes, and specifically preferably , Methyl methacrylate, 2-ethylhexyl acrylate, and butadiene.

Further, the total amount of acrylic acid ester or methacrylic acid ester monomer contained in the soft phase means that all monomers constituting the soft phase (crosslinking monomers other than butadiene, grafting, and grafting) are included in order to enhance the synergistic effect with the ester compound. 10 to 100% by weight relative to (excluding monomers) is required. More preferably, the acrylic acid ester or methacrylic acid ester has a Tg of the monomer.
Is less than 0 [deg.] C., and a multiphase interpolymer containing 10 to 100% by weight with respect to all monomers constituting the soft phase (excluding crosslinking monomers other than butadiene and graft monomers) is preferable. Furthermore, the preferable range of all monomers (excluding the crosslinking monomer other than butadiene and the grafting monomer) constituting the soft phase of acrylic acid ester or methacrylic acid ester is 30 to 90% by weight, more preferably 50 to 80% by weight. Most preferred.

The hard phase of the multiphase interpolymer is preferably a polymer containing acrylic acid ester or methacrylic acid ester, aromatic vinyl or vinyl halide as a main component, and further, methyl acrylate or meta. Polymers containing methyl acrylate, styrene and vinyl chloride as main components are preferred. A preferable composition of the polymer constituting the hard phase and the soft phase in the multiphase interpolymer is, for example, a polymer in which the hard phase has methyl methacrylate as a main component, and the soft phase is 2-ethylhexyl acrylate, methacrylic acid. It is a copolymer containing methyl acid and butadiene as main components or a copolymer containing 2-ethylhexyl acrylate, methyl methacrylate, styrene and butadiene as main components.

More preferably, the hard phase comprises 80% by weight or more of methyl methacrylate (based on all monomers constituting the hard phase excluding the crosslinking agent and the grafting agent),
The soft phase is 40 to 60% by weight of 2-ethylhexyl acrylate based on all the soft phase monomers, and methyl methacrylate is 1
It is a multiphase interpolymer composed of 0 to 30% by weight and 10 to 50% by weight of butadiene.

The proportion of methyl methacrylate in the hard phase is 80
This is because if it is less than wt%, sufficient flexibility cannot be obtained. Next, the proportion of 2-ethylhexyl acrylate in the soft phase is 4 in order to increase the affinity with the ester compound.
This is because 0 to 60% by weight is suitable. On the other hand, if the proportion of butadiene is less than 10% by weight, sufficient toughness and impact properties cannot be obtained, and if it exceeds 50% by weight, the weather resistance is remarkably reduced. Further, the proportion of methyl acrylate in the soft phase is preferably 10 to 30% by weight in order to enhance the affinity with methyl acrylate in the hard phase. When it exceeds 30% by weight, 2-ethylhexyl acrylate in the soft phase and This is because, in terms of balance with butadiene, sufficient effects on softness, toughness and impact characteristics do not appear.

The ratio of the hard phase and the soft phase in the multiphase interpolymer is not particularly limited, but preferably the hard phase 10
The range of 50 to 50% by weight and the soft phase of 90 to 50% by weight are preferable.
More preferably, the hard phase is 20 to 40% by weight and the soft phase is 80.
-60% by weight is preferred. The multiphase interpolymer of the present application may be one in which an epoxy group or a hydroxyl group is introduced into the outermost phase, and it is usually carried out by copolymerizing a monomer constituting the outermost phase and a vinyl monomer having an epoxy group or a hydroxyl group.

The vinyl monomer having an epoxy group is, for example,

[0020]

[Chemical 1]

There is a glycidyl ester of an α, β-unsaturated acid represented by (R is a hydrogen atom or a lower alkyl group). Specific examples thereof include glycidyl acrylate and glycidyl methacrylate, and glycidyl methacrylate is more preferable. Examples of the vinyl monomer having a hydroxyl group include hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxyisopropyl acrylate, hydroxyisopropyl methacrylate, hydroxybutyl acrylate, and methacrylic acid. Examples thereof include hydroxybutyl acrylate, and hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, and hydroxypropyl methacrylate are more preferable.

Further, the amount of the vinyl monomer having an epoxy group or a hydroxyl group which is copolymerized with the monomer forming the outermost phase is preferably 0.5 to 10% by weight based on the total monomers forming the multiphase interpolymer. The most preferable addition amount is 1 to 3% by weight from the viewpoint of flexibility and impact properties. The multiphase interpolymer in the present invention is disclosed in Japanese Patent Publication No.
It can be produced by the conventional emulsion polymerization technique described in JP-A No. 5-27576 and JP-B No. 59-136343.

A specific example of the production of a multi-phase interpolymer having a biphasic structure is as follows. In the water containing an emulsifier such as sodium dioctylsulfosuccinate, the monomer and diisopropylbenzene hydroper which are necessary for forming the soft phase are added. Add a polymerization initiator such as oxide and stir it with the usual 5
Polymerization is carried out at a temperature of 0 to 90 ° C. At this time, in order to impart appropriate elasticity to the soft phase, generally used polyfunctional crosslinking agents such as divinyl compounds other than butadiene, diallyl compounds, diacrylic compounds, and dimethacrylic compounds, such as ethyl diacrylate and n-butyl diacrylate. And the like are preferably copolymerized. The amount of this polyfunctional crosslinking agent added is
0.1 to 5 parts by weight is preferable when the total weight of the polymer constituting the soft phase is 100 parts in total. Further, at this time, it is preferable to add a polyfunctional grafting agent in order to make a chemical bond between the hard phase and the soft phase. As the polyfunctional grafting agent, a polyfunctional monomer having different functionality,
For example, there are allyl esters such as acrylic acid, methacrylic acid, and maleic acid, and it is preferable to use polyfunctional grafting agents such as allyl acrylate and allyl methacrylate. The amount of the polyfunctional grafting agent added is preferably 0.1 to 5 parts by weight when the total weight of the polymer constituting the soft phase is 100 parts in total.

At the time when the polymerization reaction forming the soft phase is completed, next, the monomer forming the soft phase and the vinyl monomer having an epoxy group or a hydroxyl group are additionally added. At this time, a polymerization initiator can be additionally added. The multiphase interpolymer obtained by the emulsion polymerization can be separated from water by using a conventional means such as salting out, freeze-thawing, or spray drying while keeping the particle form.

In the case of an interpolymer having a three-phase structure, first, a monomer forming a central phase (hard phase) and a polyfunctional grafting agent are first polymerized, and then an intermediate phase which is a soft phase is prepared by the above method. Then, the outermost phase, which is the hard phase, may be polymerized in this order. The soft phase or hard phase of the present invention,
It may be a uniform phase composed of the same monomer composition or two or more phases composed of different monomer compositions.

As the multiphase interpolymer, those having a small amount of alkali metals and sulfur compounds contained as impurities are preferably used in view of the thermal stability of the composition. Alkali metal and sulfur compounds here are used as emulsifiers such as lithium dodecylbenzene sulfonate used in the production of multiphase interpolymers, soda, or sulfate ester salts such as potassium, and salting-out agents such as sodium sulfate and sodium chloride. It is due to it. That is, the alkali metal refers to lithium, potassium and sodium.

The content of the alkali metal in the multiphase interpolymer can be quantified by a general method, among which the atomic absorption method or the plasma emission method can be used. In the present invention, the quantification was carried out using the atomic absorption method. That is, it is a method of carbonizing or ashing the multiphase interpolymer, and subjecting the solution obtained by extracting the alkali metal content from the carbonized ash to an atomic absorption.

The content of alkali metal in the present invention is
It is the total of alkali metals (lithium, potassium, sodium) analyzed by the atomic absorption method, and needs to be 100 ppm or less with respect to the multiphase interpolymer. It is preferably 80 ppm or less, more preferably 6
It is 0 ppm or less. Further, the sulfur content in the multiphase interpolymer can be determined by a general method, and among them, the ion chromatography method is preferable. In the present invention, it was quantified using an ion chromatographic method. That is, it is a method in which a multiphase interpolymer is burned by a flask burning method, and a liquid obtained by extracting a sulfur content with an alkaline aqueous solution is subjected to an ion chromatograph.

The content of sulfur in the present invention is calculated by converting the total amount of sulfur compounds analyzed by ion chromatography into the amount of elemental sulfur, and is required to be 200 ppm or less with respect to the multiphase interpolymer. . It is preferably 150 ppm or less, more preferably 100 ppm.
It is below ppm. Further, the particle size of the multiphase interpolymer is preferably 5 μm or less, more preferably 1 μm or less, from the viewpoint of dispersibility when the composition is prepared. The optimum particle size is 0.05
Is 0.5 μm.

The amount of the multiphase interpolymer used in the present invention is 5 to 50% by weight. If it is less than 5% by weight, the flexibility, toughness and impact properties are not sufficiently exerted, and if it exceeds 50% by weight, the moldability and heat stability of the polyacetal resin are remarkably lowered. The preferable addition amount of the multiphase interpolymer that can maximize the effects of the present invention is 10 to 30% by weight.

The ester compound used in the composition of the present invention is an aromatic or aliphatic long chain ester having a total of 5 to 56 carbon atoms. Preferably, the carbon number is 4 to
It is an ester compound of a fatty acid having one or more carboxyl groups at 28 and an aliphatic alcohol having one or more hydroxyl groups at 1 to 28 carbon atoms. Examples of ester compounds include butyl benzoate, octyl benzoate, isostearyl benzoate, dibutyl phthalate, dihexyl phthalate,
Dioctyl phthalate, dilauryl phthalate, or dibutyl succinate, dibutyl adipate, dihexyl adipate, dioleyl adipate, diisodecyl adipate, distearyl adipate, diesters such as benzyl adipate, trioctyl trimellitate, trimellitate trimate. Stearyl, triisodecyl trimellitate, triesters such as 2-ethylhexyl trimellitate, methyl laurate, butyl laurate, isodecyl laurate, stearyl laurate, isopropyl myristate, octyldodecyl myristate, isopropyl palmitate, palmitate 2 -Ethylhexyl,
Phenyl stearate, methyl stearate, butyl stearate, hexyl stearate, stearic acid 2-
Examples include monoesters such as ethylhexyl, decyl stearate, methyl oleate, butyl oleate, octyl oleate, lauryl oleate, and oleyl oleate.

Among these ester compounds, ester compounds of fatty acid alcohol having 6 to 22 carbon atoms are preferable. For example, the general formula:

[0033]

[Chemical 2]

An ester compound represented by the formula (wherein R1 is an aliphatic alkyl group having 8 to 22 carbon atoms and R2 is an aliphatic alkyl group having 6 to 22 carbon atoms and having two or more branches) is preferable. Examples of R1 include pelargonic acid, capric acid, undecyl acid, lauric acid, tridecyl acid, myristic acid, pentadecylic acid, palmitic acid, heptadecyl acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, cetrain acid, erucic acid. , Oleic acid, linoleic acid, linolenic acid and the like. Among them, the preferred one is
Palmitic acid, stearic acid, oleic acid and the like.

Examples of R2 include iso-hexyl, sec-hexyl, tetr-hexyl and iso-
Heptyl, sec-heptyl, tetr-heptyl, i
so-octyl, sec-octyl, tetr-octyl, 2-ethylhexyl, iso-nonyl, sec-nonyl, tetr-nonyl, 2,5-dimethylpentyl,
3,4,7-trimethylpentyl, iso-decyl, s
There are ec-decyl, tetr-decyl, iso-stearyl, sec-stearyl, tetr-stearyl and the like. Among them, 2-ethylhexyl and i are preferable.
so-decyl, sec-decyl, tetr-decyl, i
Examples are so-stearyl, sec-stearyl, tetr-stearyl and the like.

More preferred specific ester compounds are
It is preferable that the multiphase interpolymer has an alcohol component that constitutes acrylic acid or methacrylic acid ester used in the soft phase. Furthermore, among the acrylic acid or methacrylic acid used, the Tg of the monomer is 0 ° C.
Ester compounds having the same alcohol component as those less than are preferable. For example, 2 in the soft phase of multiphase interpolymers.
-A preferred ester compound when using ethylhexyl acrylate is 2-ethylhexyl laurate,
2-ethylhexyl palmitate, 2-ethylhexyl stearate, 2-ethylhexyl oleate, 2-ethylhexyl behenate and the like. When butyl acrylate is used for the soft phase, preferred ester compounds are butyl laurate, butyl palmitate, butyl stearate, butyl oleate, butyl behenate and the like.

The amount of the ester compound used in the present invention is 0.2 to 10% by weight. When the addition amount is less than 0.2% by weight, sufficient effects on flexibility, toughness and impact resistance do not appear, and when it exceeds 10% by weight, moldability and thermal stability are remarkably reduced. The preferable addition amount for maximizing the effect of the present invention is 0.5 to 5% by weight, and further 1 to 3%.
Weight percent is more preferred. Furthermore, the ester compounds may be used alone or in combination of two or more.

The polyalkylene glycol used in the composition of the present invention has the general formula:

[0039]

[Chemical 3]

(R1: selected from hydrogen, an alkyl group, a substituted alkyl group, an aryl group and a substituted aryl group, which may be the same or different. M = 2 to 6, n = 10.
It is 10,000. ) Is a compound represented by. Examples of the polyalkylene glycol include polyethylene glycol, polypropylene glycol, polybutylene glycol, polyepichlorohydrin, polystyrene glycol, polyoxetane, poly3,3-bis (chloromethyl) oisetane, polytetrahydrofuran, poly-2-
Examples include methyltetrahydrofuran and polyoxepane.
Among these polyalkylene glycols, polyethylene glycol and polypropylene glycol are preferable, and polyethylene glycol is more preferable, in order to enhance the affinity with the polyacetal resin.

Number of moles of alkylene glycol added (n)
Is required to be in the range of 10 to 10,000,
From the viewpoint of impact resistance, the range of n = 50 to 2000 is preferable.
The addition amount of the polyalkylene glycol used in the present invention is 0.1 to 5% by weight. If the amount added is less than 0.1% by weight, sufficient effects on flexibility, toughness and impact resistance will not be exhibited, and if it exceeds 5% by weight, thermal stability will be significantly reduced.
The preferred amount of addition that can maximize the effect of the present invention,
It is 0.5 to 3% by weight, more preferably 1 to 2% by weight.

The polyacetal resin composition of the present invention is substantially composed of four components of a polyacetal resin, a multiphase interpolymer, an ester compound and a polyalkylene glycol, and is used for automobile parts and the like. In this case, it is preferable to add an ultraviolet absorber or a hindered amine light stabilizer, because butadiene or the like contained in the soft phase of the multiphase interpolymer in the present composition easily lowers the weather resistance.

For example, the ultraviolet absorber is at least one selected from the group consisting of benzotriazole type and anilide oxalate type, and more specifically, 2- (2'-hydroxy-5'-methyl) is used as the benzotriazole type ultraviolet absorber. -Phenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-t-butyl-phenyl) benzotriazole, 2- (2'-hydroxy-3', 5 '
-Di-isoamyl-phenyl) benzotriazole, 2
-[2'-hydroxy-3 ', 5'-bis- (α, α-
Dimethylbenzyl) phenyl] benzotriazole, 2
-(2'-hydroxy-4'-octoxyphenyl) benzotriazole etc. are mentioned. Further, as an oxalic acid anilide type ultraviolet absorber, 2-ethoxy-2'-ethyl oxalic acid bisanilide, 2-ethoxy-5 is used.
Examples thereof include -t-butyl-2'-ethyl oxalic acid bisanilide and 2-ethoxy-3'-dodecyl oxalic acid bisanilide.

Among these ultraviolet absorbers, 2-
[2′-Hydroxy 3 ′, 5′-bis- (α, α-dimethylbenzyl) phenyl] benzotriazole is particularly preferred. The ultraviolet absorbers may be used alone,
You may use it in combination of 2 or more type. For example, as a hindered amine light stabilizer, bis (2,2,6,6
-Tetramethyl-4-piperidyl) -sebacate, bis (2,2,6,6-tetramethyl-4-piperidyl)-
Adipate, 4-benzoyloxy-2,2,6,6-
Preferable examples include tetramethylpiperidine and 4- (phenylcarbamoyloxy) -2,2,6,6-tetramethylpiperidine. The hindered amine light stabilizers may be used alone or in combination of two or more kinds.

It is more preferable to use the ultraviolet absorber and the hindered amine light stabilizer in combination. Further, in order to impart necessary properties according to other uses and purposes, known heat stabilizers, antioxidants, nucleating agents, lubricants, release agents, antistatic agents, glass fibers, carbon fibers, organic Reinforcing agents such as fibers,
Inorganic fillers such as glass fiber, talc and calcium carbonate, pigments and the like can be added within a range that does not impair the object of the present invention.

The polyacetal resin composition of the present invention can be produced by a generally known method. For example, it can be obtained by blending the above-mentioned respective components and further melt-kneading. As the melt kneader, a known device such as a kneader, a roll mill, an extruder or the like which is usually used for kneading a resin melt can be used, but the extruder is most suitable from the viewpoint of blocking oxygen and working environment. Types of this extruder include uniaxial type, biaxial type, vented type, non-vented type, and the like, and the composition of the present invention can be adjusted in any extruder.

[0047]

EXAMPLES The present invention will be further described below with reference to examples, but the scope of the claims of the present invention is not limited to these examples.

[0048]

Examples 1 to 33 The polyacetal resin used in Examples was manufactured by a known method. The polyacetal homopolymer used was Tenac ^R 40 manufactured by Asahi Kasei Kogyo Co., Ltd.
10 (MI = 10 g / 10 min), the polyacetal copolymer is Tenac ^R- C4520 (MI = 10 g)
/ 10 min) was used.

The multiphase interpolymer used in the examples was prepared by adding 5.7 liters of distilled water to a 10 liter beaker equipped with a stirrer and a condenser, 20 g of sodium dioctylsulfosuccinate as an emulsifier, and 1.2 g of Rongalit as a reducing agent. In addition, it dissolves uniformly. As a soft phase (hereinafter, abbreviated as core) as a first phase, a monomer solution shown in the attached table and a uniform solution of 2 g of diisopropylbenzene hydroperoxide (hereinafter abbreviated as PBP) were added, and polymerization was performed at 80 ° C. The reaction was completed in about 40 minutes. The polymerization yield at this point was substantially 100%. Next, as a second phase (outermost phase), a hard phase (hereinafter, abbreviated as shell), a monomer composition shown in a separate table, 0.6 g of PBP, and a uniform solution of 0.2 g of n-octyl mercaptan were added. The reaction at this stage was completed in about 15 minutes. Then raise the temperature to 95 ° C,
Hold for 1 hour. The obtained polymer was added to a 0.5% aqueous solution of aluminum chloride to coagulate the polymer, and the polymer was warmed to 15%.
After washing twice, it was dried to obtain a white floc-like multiphase interpolymer. The average particle size of this product was 0.2 μm. Further, various alkali metals and sulfur contents were within the preferable ranges described above.

The ester compounds used in the examples are described in the attached table. The polyalkylene glycol is also described in the attached table. The number of moles of alkylene glycol added was represented by n. The composition was prepared by blending in a weight ratio of the compositions shown in Tables 1 to 3 under a nitrogen atmosphere.
L / D = 32 twin-screw vent extruder set at 00 ° C (conditions: screw rotation speed 100 rpm, vacuum -500
mmHg, discharge rate = 5 kg / hr), and melt-kneaded into pellets. Further, the obtained pellets were dried at 80 ° C. for 3 hours or more.

Flexural modulus: ASTM
Measured according to D-790, tensile elongation: ASTM D-6
38, measured according to Izod impact value (with notch): A
It was measured according to STM D-256. As for the evaluation criteria, the lower the flexural modulus, the better the flexibility, and the higher the tensile elongation, the better the toughness. The higher the Izod impact value, the better the impact resistance. The evaluation results are shown in Tables 1-7.

The abbreviations used in Examples and Comparative Examples are as follows. MMA: Methyl methacrylate 2EHA: 2-Ethylhexyl acrylate BD: Butadiene BA: Butyl acrylate EGA: Ethylene glycol diacrylate ALMA: Allyl methacrylate ST: Styrene In all examples, acrylic ester or soft ester of the multiphase interpolymer was used. The compounding of a multiphase interpolymer containing methacrylic acid ester in an amount of 10 to 100% by weight based on all the monomers constituting the soft phase, and an ester compound having an alcohol component constituting the acrylic acid ester or the methacrylic acid ester. It can be seen that is excellent in flexibility, toughness, and impact resistance. Also, AS
When a test piece for evaluating TM D-638 (tensile property) was molded, no peeling phenomenon was visually observed on the surface of the test piece, and stable moldability was confirmed.

In Examples 1 and 3, both the homopolymer and the copolymer show low elastic modulus, high elongation and Izod. In Examples 2 to 6, it is understood that the added amount of the multiphase interpolymer is 5 to 50% by weight and the flexibility, toughness and impact resistance are excellent. In Examples 7 to 10, it can be seen that an excellent effect is exhibited when the amount of the ester compound added is 0.2 to 10% by weight. In Examples 11 to 15, it can be seen that an excellent effect is exhibited when the amount of polyalkylene glycol added is 0.1 to 5% by weight.

In Examples 16 to 19, the number of added moles of polyethylene glycol is preferably in the range of 10 to 10,000, and more preferably 50 to 2,000.
In Example 20, it can be seen that polypropylene glycol also exhibits an excellent effect. Examples 21 and 22 show that the ratio of the soft phase and the hard phase is preferably 6: 4 to 8: 2 (60 to 80% by weight of the soft phase and 40 to 20% by weight of the hard phase). .

In Examples 23 to 27, it is understood that the ester compound having an alcohol component which constitutes the acrylic ester or the methacrylic ester exhibits a particularly excellent effect. In Examples 28 and 29, the total weight of the acrylic acid ester and the methacrylic acid ester in the soft phase was evaluated as 10 and 100% by weight, but the flexibility, toughness, and impact resistance were excellent.

In Examples 30 and 31, it was demonstrated that the combined use of two kinds of ester compounds is also effective. Example 3
In No. 2, addition of an ester compound having no component constituting an acrylic ester or methacrylic ester is effective, but the effect is smaller than that of an ester compound having the same component.

In Example 33, Additive A to the copolymer:
2- [2'-hydroxy 3 ', 5'-bis (α, α-dimethylbenzyl) phenyl] benzotriazole, additive B: bis (2,2,6,6-tetramethyl-4-piperidyl) -sebacate Was evaluated by using a polyacetal resin having 0.5 parts by weight of each of them and having weather resistance, and was excellent in flexibility, toughness, and impact resistance. The weather resistance was also extremely excellent as compared with Example 4 in which the additives A and B were not added. The results of evaluation of weather resistance are shown in Table 8. Weather resistance evaluation criteria: The test piece for evaluation was prepared by adding 0.5 part by weight of acetylene black when granulating pellets, and coloring it black to form JIS No. 1 dumbbell with a 3 ounce molding machine.

The weather resistance test was conducted by using an ultraviolet auto fade meter (WEL-SUN-HC-B.EM manufactured by Suga Test Instruments Co., Ltd.).
The mold) was exposed to a black panel temperature of 83 ° C. and a humidity of 50% for 500 hours. Regarding the time of occurrence of cracks, the time until the cracks were visually confirmed on the surface of the test piece was shown. The faster the crack generation time, the poorer the weather resistance. In addition, the color difference was measured using a color difference meter (Handy Color Tester HC-T manufactured by Suga Test Instruments Co., Ltd.) on the light-irradiated surface of the test piece after 500 hours of exposure, and the ΔE value (JISZ-87
30) was calculated. The higher the ΔE value, the poorer the weather resistance.

[0059]

Comparative Examples 1 to 9 Polyacetal resin used in the composition,
The multiphase interpolymer and ester compound are the same as described in the examples. Further, the production of the composition was adjusted by the same operation as described in the examples. The methods for evaluating the flexural modulus, the tensile elongation and the Izod impact value are the same as those described in the examples. The evaluation results are shown in Tables 9 and 10.

Comparative Examples 1 and 2 in which the polyacetal resin is only a homopolymer or a copolymer, and Comparative Examples 3, 4, and 5 in which a combination of polyacetal resin / multiphase interpolymer, polyacetal resin / ester compound, polyacetal resin / polyalkylene glycol is used. Shows that the flexural modulus is absolutely high, the tensile elongation is low, and the Izod impact value is absolutely low. Further, in Example 6, even in the combination of polyacetal resin / multiphase interpolymer / polyalkylene glycol, and in Example 7, the combination of polyacetal resin / multiphase interpolymer / ester compound, the flexural modulus and the tensile elongation were absolutely low. is there. It is understood that the effect of the present invention does not appear even if any of the four raw material components of polyacetal resin / multiphase interpolymer / ester compound / polyalkylene glycol is lacking.

In Comparative Examples 8 and 9, it can be seen that the effect is small when the addition amount of the multiphase interpolymer or the ester compound is small. In Comparative Example 10, the total amount of acrylic acid ester or methacrylic acid ester in the soft phase was 1 with respect to all the monomers constituting the soft phase.
It can be seen that the effect is small even when the content is 0% by weight or less.

[0062]

Comparative Examples 11 to 13 The polyacetal resin, multiphase interpolymer and ester compound used in the composition are the same as those described in Examples. Further, the production of the composition is the same as described in the examples. As a method of evaluating the composition,
For surface peeling during molding, see ASTM D-638.
(Tensile property) When a test piece for evaluation was molded under the same conditions as the test piece used in the examples, the presence or absence of layer delamination was visually confirmed on the surface of the test piece near the gate portion. The presence of surface peeling during molding indicates poor moldability.

Regarding the thermal stability, it was confirmed whether or not a decomposition gas generated in the form of silver was generated on the surface of the test piece when the same was molded as in the surface peeling evaluation. The generation of decomposition gas indicates poor thermal stability. The evaluation results are shown in Table 11.
As a result, in Comparative Example 10, the addition amount of the multiphase interpolymer was 51% by weight, and in Comparative Example 11, the addition amount of the ester compound was 11% by weight. It can be seen that generation occurs, moldability is poor, and thermal stability is further reduced. In Comparative Example 12,
It was evaluated that the amount of polyalkylene glycol added was 6% by weight, but it was found that decomposition gas was generated during molding and the thermal stability was lowered.

[0064]

[Table 1]

[0065]

[Table 2]

[0066]

[Table 3]

[0067]

[Table 4]

[0068]

[Table 5]

[0069]

[Table 6]

[0070]

[Table 7]

[0071]

[Table 8]

[0072]

[Table 9]

[0073]

[Table 10]

[0074]

[Table 11]

[0075]

EFFECTS OF THE INVENTION The composition of the present invention contains a polyacetal resin, a specific multi-phase interpolymer, an ester compound and a polyalkylene glycol, to obtain surprising flexibility, toughness, impact properties and moldability without molding peeling. It is possible for the first time to realize that it is extremely excellent.

Claims (1)

[Claims] 1. A: Polyacetal resin 35 to 94.7.
%, B: has a multi-phase structure of two or more phases composed of repeating soft and hard phases from the central phase to the outermost phase, and the total of the acrylic acid ester or methacrylic acid ester is the soft phase in the soft phase. 10 for all monomers that make up
5 to 50% by weight of a multiphase interpolymer containing 100 to 100% by weight, C: 0.2 to 10% by weight of an ester compound, and D:
A flexible polyacetal resin composition comprising 0.1 to 5% by weight of polyalkylene glycol.