JP2002069145A - Polyacetal copolymer - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a polyacetal copolymer excellent in adhesion and fusion to metals and other resins. SOLUTION: (A) 100 parts by weight of trioxane, (B)
Copolymerizable with 0.005 to 5 parts by weight of one or more compounds selected from compound (b-1) and lactone (b-2) having a carboxyl group and an alcoholic hydroxyl group in one molecule and trioxane (C) A polyacetal copolymer obtained by copolymerizing 0 to 20 parts by weight of a cyclic ether compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyacetal copolymer having excellent adhesion to metals and other resins and excellent fusibility.

[0002]

2. Description of the Related Art Polyacetal resins have excellent properties in mechanical properties, thermal properties, electrical properties, slidability, moldability, and the like. Widely used for parts, precision machine parts, etc. However, with the expansion of the fields where polyacetal resins are used, the usage forms have changed drastically, and there is a tendency to become more sophisticated, complex, and specialized. And, in accordance with such a change of the use form, there is a tendency that various advanced characteristics are required.

[0003] For example, with the improvement of molding technology and the progress of molding machines, it has been actively performed to integrally integrate a molded article made of polyacetal resin and a hard part such as metal by insert molding or outsert molding. ing. In addition, a component made of a polyacetal resin and a component made of another resin are compositely integrated at the time of molding by a two-color molding method. Furthermore, a hard part such as a metal is press-fitted into a molded article made of a polyacetal resin once formed by post-processing, or a molded article made of a polyacetal resin and a molded article made of another resin are thermally welded. . As described above, in the case of a composite molded article composed of a polyacetal resin and a hard member such as a metal or another resin, sufficient bonding strength or fusion strength at the joint surface is required.

However, polyacetal resins have high crystallinity, poor surface activity, and low affinity with metals and other resins. Therefore, a composite molded product simply formed by these molding methods or processing methods cannot be used. However, there is a problem that a sufficient bonding strength and fusion strength cannot be obtained at the joint surface.

[0005] In order to solve such problems, for example, a method of designing the shape of a molded product, a method of roughening the surface of a composite metal part or the like, or a method of applying an adhesive layer such as a primer. Further, a method of blending an additive for imparting activity and affinity to the polyacetal resin has been carried out, and a certain improvement effect is recognized. However, all of these methods are inferior in productivity, and have not yet fundamentally solved the adhesive strength and the fusion strength at the joint surface of the composite molded article.

In view of the problems of the prior art described above, the present inventor has proposed that the polymer skeleton of the polyacetal resin be modified by modifying the polymer skeleton itself in order to improve the adhesion and the fusion property between the polyacetal resin and other materials. It was speculated that giving these properties to themselves would be an important key to solving the problem.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polyacetal resin material which solves the above-mentioned problems and has improved adhesion or fusion with metals and other resin materials.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, obtained by copolymerizing a compound having a specific functional group, a polyacetal copolymer having a special functional group introduced therein. The inventors have found that the above-mentioned problems can be solved, and have completed the present invention.

That is, the present invention relates to (A) 100 parts by weight of trioxane, (B) one or more compounds selected from a compound (b-1) having a carboxyl group and an alcoholic hydroxyl group in one molecule and a lactone (b-2). It is a polyacetal copolymer obtained by copolymerizing 0.005 to 5 parts by weight of two or more compounds and 0 to 20 parts by weight of a cyclic ether compound copolymerizable with (C) trioxane.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The polyacetal copolymer of the present invention comprises (A) trioxane, (B) a compound (b-1) having a carboxyl group and an alcoholic hydroxyl group in one molecule, and a lactone (b-2).
And a copolymer obtained by adding a cyclic ether compound copolymerizable with (C) trioxane as an essential component, and further adding the compound.

The trioxane (A) used in the present invention 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 obtained by a method such as distillation. It is used after purification. The trioxane used for the polymerization is in a liquid state, and its temperature is preferably 65 to 135 ° C.

Next, the compounds used as the component (B) in the present invention include a compound (b-1) having a carboxyl group and an alcoholic hydroxyl group in one molecule and a lactone (b-2).
Is selected from By copolymerizing such a compound (B) with the above-mentioned trioxane (A), a specific functional group can be introduced into the resulting polyacetal copolymer. Can be improved. Here, the compound (b-1) having a carboxyl group and an alcoholic hydroxyl group in one molecule includes an aliphatic hydroxy acid, and glycolic acid, lactic acid, glyceric acid, malic acid, α-oxy-n-butyric acid ,
α-oxy-isobutyric acid, α-oxy-n-caproic acid,
Examples thereof include hydroacrylic acid, β-oxybutyric acid, β-oxyvaleric acid, α-oxyglutaric acid, tartaric acid, and trioxybutyric acid. Preferably glycolic acid, α-oxy-
Isobutyric acid, glyceric acid and malic acid.

Examples of the lactone (b-2) include β-propiolactone, δ-valerolactone, ε-caprolactone, α-oxy-γ-butyrolactone and the like. Preferably, β-propionlactone, δ-valerolactone and ε-caprolactone are used.

The compound (b-1) having a carboxyl group and an alcoholic hydroxyl group in one molecule thereof and a lactone (b
Compound (B) selected from -2) can be used alone or in combination of two or more for copolymerization with trioxane (A). In the present invention, the compound (B) selected from the compound (b-1) having a carboxyl group and an alcoholic hydroxyl group in one molecule and the lactone (b-2) is (A)
It is used in an amount of 0.005 to 5 parts by weight based on 100 parts by weight of trioxane. Preferably, it is used in the range of 0.01 to 1 part by weight. The amount of the component (B) used is
If the amount is less than 0.005 parts by weight, it is difficult to obtain a polyacetal copolymer excellent in adhesion and fusing properties, which are the properties targeted by the present invention. Mechanical properties of the obtained polyacetal copolymer,
In particular, a decrease in toughness and a deterioration in surface characteristics occur, and both are not preferred.

The cyclic ether compound (C) copolymerizable with trioxane used in the present invention includes 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-
Examples thereof include pentanediol formal and 1,6-hexanediol formal, and among them, ethylene oxide, 1,3-dioxolan, diethylene glycol formal, and 1,4-butanediol formal are preferred. The amount of the cyclic ether compound (C) to be used is one or two with respect to 100 parts by weight of trioxane (A) in consideration of the rigidity, chemical resistance, and the like of the obtained polyacetal copolymer.
The total amount is 0 to 20 parts by weight, preferably 0.01 to 15 parts by weight, particularly preferably 0.1 to 10 parts by weight.

In the production of the polyacetal copolymer of the present invention, a component for adjusting the molecular weight can be used in addition to the above components. As a component for adjusting the molecular weight, a chain transfer agent that does not form an unstable terminal, namely, methylal, methoxymethylal, dimethoxymethylal,
Compounds having an alkoxy group such as trimethoxymethylal and oxymethylene di-n-butyl ether are exemplified. In the present invention, it is preferable that the molecular weight be adjusted so that the obtained polyacetal copolymer has an appropriate molecular weight by adjusting the amount of the molecular weight modifier used.

In producing the polyacetal copolymer of the present invention comprising the above-mentioned monomer component and comonomer component, a cationic polymerization catalyst is generally used as a catalyst. Specifically, lead tetrachloride, tin tetrachloride, titanium tetrachloride, aluminum trichloride, zinc chloride, vanadium trichloride, antimony trichloride, phosphorus pentafluoride, antimony pentafluoride, boron trifluoride, trifluoride Boron trifluoride coordination compounds such as boron diethyl etherate, boron trifluoride dibutyl etherate, boron trifluoride dioxanate, boron trifluoride acetic anhydrate, boron trifluoride triethylamine complex compound, perchloric acid, Acetyl perchlorate, t-butyl perchlorate, hydroxyacetic acid, trichloroacetic acid, trifluoroacetic acid, p-
Inorganic and organic acids such as toluenesulfonic acid, triethyloxonium tetrafluoroborate, triphenylmethylhexafluoroantimonate, allyldiazonium hexafluorophosphate, complex salt compounds such as allyldiazonium tetrabroborate, diethyl zinc, triethylaluminum, diethyl One or more kinds of alkyl metal salts such as aluminum chloride, heteropoly acids, isopoly acids and the like can be mentioned. Among them, especially boron trifluoride, boron trifluoride diethyl etherate, boron trifluoride dibutyl etherate, boron trifluoride dioxanate, boron trifluoride acetic unhydrate,
Boron trifluoride coordination compounds such as boron trifluoride triethylamine complex compounds are preferred. These cationic polymerization catalysts can be used as they are, or can be used by diluting them in advance with an organic solvent or the like, and the preparation method is not particularly limited.

The method for producing the polyacetal copolymer of the present invention is not particularly limited. Generally, the liquefied trioxane (A) has a carboxyl group and an alcoholic hydroxyl group in one molecule. The compound (B) selected from the compound (b-1) and the lactone (b-2), and the cyclic ether compound (C) are polymerized mainly by using a cationic polymerization catalyst to obtain a solid powdery polymer by bulk polymerization. . The polymerization apparatus is not particularly limited, and a known apparatus is used, and any method such as a batch method and a continuous method can be used. The polymerization temperature is preferably maintained at 65 to 135 ° C.

The deactivation of the catalyst after the polymerization is carried out by adding a basic compound or an aqueous solution thereof to the reaction product discharged from the polymerization machine after the polymerization reaction or 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, or hydroxide salts of alkali metals and alkaline earth metals. 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 the polymerization method and the deactivation method, if necessary, washing, separation and recovery of unreacted monomers, drying, etc. are performed by a conventionally known method. Further, if necessary, a stabilizing treatment is carried out by a known method such as decomposition removal of an unstable terminal or sealing of an unstable terminal with a stable substance, and various necessary stabilizers are blended. Examples of the stabilizer used herein include 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. it can.

The polyacetal copolymer obtained as described above preferably has a weight average molecular weight of 10,000 to 500,000, particularly preferably 20,000 to 100,000.

The polyacetal copolymer of the present invention may contain, if necessary, general additives for thermoplastic resins, for example, coloring agents such as dyes and pigments, lubricants, nucleating agents, release agents, antistatic agents, One or two or more surfactants, organic polymer materials, inorganic or organic fibrous, powdery, plate-like fillers, and the like can be added.

[0022]

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 in the examples was performed by the following method. [Preparation of test piece for measuring fusion strength] Specimen for Measurement of Fusion Strength with Metal The polyacetal copolymer prepared in Examples and Comparative Examples described below was pressed at 200 ° C. with a press machine to form a 1 mm thick sheet. Next, this sheet is laminated on an aluminum plate having a thickness of 0.5 mm, fused by a press at 200 ° C. and 50 kg / cm ² for 2 minutes, quenched with cold water, and fused with a thickness of 1 mm. A test piece for measurement was prepared. 2. Test piece for measuring fusion strength with other resin The following resin was selected as a material to be fused and pressed at 200 ° C. with a press machine to form a 1 mm thick sheet. Next, the sheet of the polyacetal copolymer prepared in the above 1 was superimposed on this sheet, fused at 200 ° C. and 50 kg / cm ² for 2 minutes by a press machine, quenched with cold water, and cooled to a thickness of 1 mm. A test piece for measuring the fusion strength was prepared.

Resin D-1: Maleic anhydride-modified polyethylene (manufactured by Mitsui Petrochemical Co., Ltd., trade name "Toughmer MN685")
6)) Resin D-2: Epoxy-modified SBS (trade name “Epofriend A1010” manufactured by Daicel Chemical Industries, Ltd.) [Measurement method of fusion strength] Using the test piece for fusion strength measurement prepared above, The peeling strength was measured according to the method described in 5.7 (peeling strength) of JIS C6481, and the fusion strength was determined.

Specifically, the test piece for measuring the fusion strength was cut into a strip having a width of 10 mm and a length of 100 mm, and the aluminum plate side (or the opposite resin sheet side) was fixed to a jig. Peel off one end of the united sheet side to an appropriate length and fix it to the jig of the tensile tester. 50mm / mi in the direction where the tensile direction is perpendicular to the aluminum plate surface (or the mating resin sheet surface)
Peel the polyacetal copolymer sheet with the strength of n.
Expressed in cm. Examples 1 to 9 A paddle was used by using a continuous mixing reactor comprising a barrel having a jacket through which a heat (cooling) medium passes and having a cross section in which two circles partially overlap with each other, and a rotary shaft with a paddle. While rotating the two rotating shafts marked with at 150 rpm,
(A) Trioxane, (B) Compound (b-1) or lactone (b-2) having a carboxyl group and an alcoholic hydroxyl group in one molecule, and (C) a cyclic ether compound are added at the ratio shown in Table 1, and further added. Bulk polymerization was carried out while continuously supplying methylal as a molecular weight regulator and 0.005 parts by weight of boron trifluoride as a catalyst to a polymerization machine. 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, 5% by weight of triethylamine was added to 100 parts by weight of the crude polyacetal copolymer.
4 parts by weight of the aqueous solution and 0.3 parts by weight of pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] are added, and the mixture is melt-kneaded at 210 ° C. with a twin-screw extruder. The unstable part was removed. The obtained polyacetal copolymer was measured by ¹ H-NMR measurement using hexafluoroisopropanol d ₂ as a solvent.
Its structure and copolymer composition were confirmed.

The polyacetal copolymer obtained by the above method
To 100 parts by weight, 0.03 parts by weight of pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] and 0.15 part by weight of melamine were added as stabilizers, and a twin-screw extruder was used. And melt-kneaded at 210 ° C. to obtain a pellet-like polyacetal copolymer. Table 1 shows the evaluation results evaluated by the above-described method. Comparative Examples 1-2 Compound (b-1) or lactone (b-2) having a carboxyl group and an alcoholic hydroxyl group in one molecule as component (B)
For the polyacetal copolymer prepared without using the same, a pellet-like polyacetal copolymer containing a stabilizer was prepared and evaluated in the same manner as in the Examples. Table 1 shows the results
Shown in Comparative Examples 3-8 Compound (b-1) or lactone (b-2) having a carboxyl group and an alcoholic hydroxyl group in one molecule as component (B)
Was used as a blending component together with a stabilizer, and a pelletized polyacetal copolymer was prepared and evaluated.
Table 1 shows the results.

[0026]

[Table 1]

(B) Component b-1-1: glycolic acid b-1-2: α-oxy-isobutyric acid b-1-3: glyceric acid b-1-4: malic acid b-2-1: β -Propionlactone b-2-2: ε-caprolactone (C) component C-1: 1,3-dioxolane C-2: ethylene oxide

Continued on the front page (72) Inventor Kuniaki Kawaguchi 973 Miyajima, Fuji-shi, Shizuoka Polyplastics Co., Ltd. F-term (reference) 4J032 AA05 AA31 AA33 AA34 AB05 AB07

Claims (5)

[Claims] (A) 100 parts by weight of trioxane, (B)
Copolymerizable with 0.005 to 5 parts by weight of one or more compounds selected from compound (b-1) and lactone (b-2) having a carboxyl group and an alcoholic hydroxyl group in one molecule and trioxane (C) A polyacetal copolymer obtained by copolymerizing 0 to 20 parts by weight of a cyclic ether compound. 2. The polyacetal copolymer according to claim 1, wherein the copolymerization ratio of the cyclic ether compound (C) is 0.01 to 15 parts by weight. 3. The polyacetal copolymer according to claim 1, wherein the compound (b-1) having a carboxyl group and an alcoholic hydroxyl group in one molecule is an aliphatic hydroxy acid. 4. A compound (b-1) having a carboxyl group and an alcoholic hydroxyl group in one molecule comprises glycolic acid, α
The polyacetal copolymer according to any one of claims 1 to 3, which is selected from -oxy-isobutyric acid, glyceric acid, and malic acid. 5. The polyacetal copolymer according to claim 1, wherein the lactone (b-2) is selected from β-propiolactone, δ-valerolactone and ε-caprolactone.