JPH0347859A - Polyoxymethylene resin composition excellent in adhesion - Google Patents

Abstract

PURPOSE:To obtain a polyoxymethylene resin composition readily bondable with cyanoacrylate-based adhesives by blending a polyoxymethylene resin with one or more compounds selected from isocyanate compounds, (substituted) melamines, dicyandiamide, etc., in a specific amount. CONSTITUTION:A resin composition obtained by blending (A) >=90wt.% to <100wt.% polyoxymethylene resin with (B) 0.1-5wt.%, preferably 0.5-3wt.% isocyanate compound (e.g. hexyl isocyanate), (C) 0.01-3wt.%, preferably 0.05-1.5wt.% one or more compounds selected from melamine, substituted melamines, dicyandiamide, boric acid esters of glycerol monofatty acid esters, and, as necessary, (D) <=2wt.%, preferably 0.05-1.5wt.% calcium salt of a fatty acid and melt kneading the resultant blend at the melting point of the polyoxymethylene resin or above.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a polyoxymethylene resin composition that is easily adhered with a cyanoacrylate adhesive.

[Conventional technology]

Polyoxymethylene resin is an engineering resin with well-balanced mechanical properties and excellent chemical resistance.
It is widely used in OA equipment to fit various mechanical parts.

However, polyoxymethylene resin has a major drawback in that it is difficult to bond due to its excellent chemical resistance.

Conventionally, methods for modifying polyoxymethylene resin include blocking the ends of the polyoxymethylene resin with an isocyanate compound and introducing a polar group to the ends of the polyoxymethylene resin (Japanese Patent Publication No. 5026592), or A method for producing a modified polyoxymethylene resin by coupling a methylene resin and a different type of polymer with an isocyanate compound is known (Japanese Patent Publication No. 5609/1989).

However, these methods hardly improve the adhesiveness of the cyanoacrylate adhesive, which is the object of the present invention.

[Problem to be solved by the invention]

An object of the present invention is to make it possible to bond polyoxymethylene resins with cyanoacrylate adhesives, which conventionally could not be bonded at all with cyanoacrylate adhesives.

[Means to solve the problem]

That is, one invention according to the present application includes (1) a polyoxymethylene resin of 90% to less than 100%, (2) an isocyanate compound of 0.1 to 5% by weight, and (3) melamine, substituted melamine, dicyandiamide, and glycerin. 1 selected from boric acid esters of monofatty acid esters
Another invention is a polyoxymethylene resin composition obtained by melt-kneading 0.01 to 3% by weight of at least one compound at a temperature equal to or higher than the melting point of the polyoxymethylene resin. ), (3) and (4) a polyoxymethylene resin composition obtained by melt-kneading 2% by weight or less of fatty acid calcium at a temperature equal to or higher than the melting point of the polyoxymethylene resin.

Furthermore, this application provides embodiments of the above two inventions (
1) Substituted melamine is henzoguanamine, guanamine, 2
．． (2) The polyoxymethylene resin composition according to claims 1 to 2, which is 4-diamino-6-methyltriazine; (2) Claim 1, wherein the fatty acid calcium is a fatty acid calcium having 12 to 22 carbon atoms; - The polyoxymethylene resin composition according to item 2, (3) the fatty acid of the borate ester of glycerin monofatty acid ester has 12 to 22 carbon atoms.
(4) The composition according to claims 1 to 2, wherein the polyoxymethylene resin temperature during melt-kneading is 210 to 230°C. A polyoxymethylene resin composition, (5) a polyoxymethylene resin composition according to claims 1 to 2 which is cooled with water after melt-kneading, (6) a polyoxymethylene resin composition which is cooled with water at 80°C or higher after melt-kneading. and (7) the polyoxymethylene resin composition according to claims 1 to 2, which is immersed in water at 80°C or higher after melt-kneading and cooling. A methylene resin composition is provided.

The polyoxymethylene resin used in the composition of the present invention is essentially an oxymethylene resin produced from a cyclic oligomer such as formaldehyde monomer or its trimer (trioxane) or tetramer (tetraoxane). An oxymethylene homopolymer consisting of oxymethylene units and oxyamethylene units having 2 to 8 carbon atoms produced from the above raw materials and a cyclic ether such as ethylene oxide, propylene oxide, epichlorohydrin, 1,3-dioxolane, glycol formal, diglycol formal, etc. It is an oxymethylene copolymer containing 0.1 to 20 weight percent alkylene units. It also includes oxymethylene copolymers with branched molecular chains.

Next, the isocyanate compound used in the present invention is a compound containing one or more isocyanate groups or isothiocyanate groups in the molecule.

Specifically, (A) monoisocyanate compounds such as hexyl isocyanate, octyl isocyanate, octadecyl isocyanate, cyclohexyl isocyanate, phenyl isocyanate, tolyl isocyanate, benzyl isocyanate, naphthyl isocyanate, or (
B) to B) toxicrange isosocyanate, cyclohexylange isocyanate, dischicrohexyl methane dizousisiananate, isofolong isocyanate, phenylange isocyanate, tolphenic yisocyanet, xylange isocyanate, naphthalange isocyanate, diphenylmetanine dizzy. Jimethyl Zhenyl Methanir Methane Zicocyanate, Dimethyl Zhenilange isocyanate, etc. , or (C) a triisocyanate compound such as triphenylmethane triisocyanate or benzene triisocyanate, or an isothiocyanate compound corresponding to the above isocyanate compound, or a dimerized product of the above diisocyanate compound, 3
Multimerized products such as quantified products, or water-added isocyanate compounds of the above-mentioned aromatic isocyanate compounds, or alkyl groups, allyl groups, aryl groups of the above-mentioned isocyanate compounds,
Products substituted with substituents containing a petero atom, or isomers of the above isocyanate compounds, or reaction products of the above isocyanate compounds with alcohols or carboxylic acids with a molecular weight of 3000 or less (those with residual isocyanate groups) ) etc. are also included. Two or more types of these isocyanate compounds can also be used in combination. These specific examples of isocyanate compounds are not intended to equally limit the isocyanate compounds used in the present invention.

Further, the amount of the isocyanate compound used in the present invention needs to be 0.1 to 5% by weight. 0.1
This is because if the amount is less than 5% by weight, the effect of the addition of isocyanate on adhesive properties will not appear, and if it is more than 5% by weight, the moldability of the polyoxymethylene resin will be significantly reduced. Furthermore, the most preferable range for maximizing the effects of the present invention is 0.5 to 3% by weight.

Next, the boric acid ester of melamine, substituted melamine, dicyandiamide, and glycerin monofatty M ester used in the present invention (3) will be described in detail.

Commercial products of melamine and dicyandiamide can be used as they are.

Although it is a substituted melamine, specific compounds include benzoguanamine, guanamine, 2,4-diamino-6-methyltriazine, N-butylmelamine, N-phenylmelamine, N-methylolmelamine, 2,4-diamino-
Examples include 6-methyltriazine, 2,4-diamino-6-hensyloxytriazine, and 2,4-dioxy-6-aminotriazine. Among these, particularly preferred are 1, benzoguanamine, guanamine, and 2,4-diamino-6-methyltriazine.

Specific examples of boric acid esters of glycerin monofatty acid esters include (a) caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, undecylic acid, lauric acid, tridecylic acid, myristic acid, pentadecylic acid,
Saturated fatty acids such as balmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, heptacanoic acid, montanic acid, or (b) isocrotonic acid, undecylic acid, oleic acid, elaidic acid, It is obtained by heating and dehydrating a monoester consisting of unsaturated fatty acids such as cetoleic acid, erucic acid, brassic acid, sorbic acid, linoleic acid, lylunic acid, and arachidonic acid and glycerin with boric acid. Its main component is (however, m
=1 + 2 or a mixture thereof R; fatty acid residue).

The most preferable condition for maximizing the effect is that the fatty acid used in the boric acid ester of the glycerin monofatty acid ester used in the present invention has 12 to 22 carbon atoms.

If it is smaller than 12, the rate of volatilization during melt-kneading is high;
If it is larger, the boric acid content will be lower.

The amount of one or more compounds selected from melamine, substituted melamine, dicyandiamide, and boric acid ester of glycerin monofatty acid ester used in the present invention is 0.
．． It is necessary that the amount is 0.01 to 3% by weight. If it is less than 0.01% or more than 3% by weight, the adhesiveness will decrease.

More preferably, it is 0.105 to 1.5% by weight.

Next, fatty acid calcium (4) used in the present invention will be described in detail. Specifically, the calcium salt of the saturated fatty acid (a) or the unsaturated fatty acid (b) used in the boric acid ester of glycerin monofatty acid ester can be used as is. It is also possible to use two or more types of fatty acid calcium in combination.

In the present invention, fatty acid calcium may not be added, or may be added up to 2% by weight.

If it exceeds 2% by weight, it is not preferable because adhesiveness decreases. A more preferable blending ratio from the viewpoint of adhesiveness is 0.
05 to 1.5% by weight.

The polyoxymethylene resin composition of the present invention having excellent adhesive properties is prepared by melting each of the components (1) to (3) and (1) to (4) using a conventional resin melting machine such as a kneader, roll mill, or extruder. It can be adjusted by melt-kneading at a temperature equal to or higher than the melting point of the polyoxymethylene resin, using a known device used for kneading bodies.

As a melt-kneading device, an extruder is most suitable from the viewpoints of blocking oxygen and working environment. Types of this extruder include single-screw, twin-screw, hent type, non-vent type, etc., and the composition of the present invention can be prepared using any of the extruders. The mixing temperature must be higher than the melting point of the polyoxymethylene resin used, and the
It is fully extrudable at temperatures in the range 80-240°C.

The time required for kneading is approximately the same as the time required for extruding the polyoxymethylene resin alone.

Although the mixing conditions for preparing the composition of the present invention have been shown above, the kneading method and conditions are not limited to those mentioned above, and the kneading methods and conditions used for preparing the polyoxymethylene resin composition can be used. Any one can be used.

The composition of the present invention has a resin temperature of 210 to 23°C, in order to obtain a composition with even better adhesion among the above extrusion temperatures.
0°CT: It is preferable to melt and knead.

In addition, water cooling is performed immediately after melt-kneading, or more preferably,
Compositions cooled with water above 80°C or 80°C
A composition obtained by immersing the following melt-kneaded composition at room temperature in water at 80°C or higher shows even better adhesion. When cooling with water at 80°C or higher, it is preferable to cool under these conditions until the lowest temperature of the melt reaches 100°C or lower. As a guideline, the immersion time in water at 80° C. or higher after melt-kneading and cooling is approximately 5 minutes for pellets of 125 mm 3 or less. The soaking time can be adjusted depending on the size of the pellets.

These effects are thought to be due to the fact that unreacted additives with the isocyanate compound and/or low molecular weight compounds that have little interaction with the isocyanate residue after the reaction can be removed to some extent.

As the cyanoacrylate adhesive used in the present invention, a commercially available one (cyanoacrylate instant adhesive) can be used as is. The cyanoacrylate adhesive is a type that forms an adhesive layer by polymerizing cyanoacrylate resin on the adhesive surface.

Incidentally, an antioxidant and/or a light stabilizer, which are usually added to plastics, can be added to the composition of the present invention at the same time.

The present invention is a polyoxymethylene resin that could not be bonded with conventional cyanoacrylate adhesives by simultaneously melt-kneading an isocyanate compound, a specific amine, a boric acid ester, and fatty acid calcium to a polyoxymethylene resin. The present invention provides a polyoxydimethylene resin composition that can be easily bonded with a cyanoacrylate adhesive. The composition of the present invention has excellent adhesion that has not been achieved with conventionally known isocyanate-blocked polyoxymethylene resins or isocyanate-heterogeneous polymer-modified polyoxymethylene resins.

In addition, (1) described in claims 1 and 2 of the present invention.
Even if any one of the three components (3) is missing during melt-kneading, a composition with the highest adhesiveness cannot be obtained.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

The physical properties were measured according to the following method.

3 4 Intrinsic viscosity: Measured at 60'C by dissolving 0.1% by weight of the polymer in a p-chlorophenol solution containing 2% by weight of alpha-pinene.

Melt index; ASTM D1238~51T
(Condition E) Adhesive strength: Take one sample, spread 15 mm3 of cyanoacrylate adhesive (manufactured by Tanabai Chemical, trade name Nizianobond R3300) uniformly on the top surface (one side) of the cylindrical shape, and place another one on top of it. The same sample was placed. (See Figure 1) In this state, it was left in an atmosphere of 23° C. and 50% humidity for 8 hours. This bonded sample was subjected to a tensile test, and the adhesive strength was determined using the following formula.

F: Measured tensile stress Examples 1 to 6 and Comparative Examples 1 to 12 A polyoxymethylene homopolymer powder acetylated at both ends was prepared as described in US Pat. No. 2,998,409 or Japanese Patent Publication No. 3
It was manufactured by a known method described in Japanese Patent No. 3-6099. The intrinsic viscosity of this product was 1.2. Melt index was 9.0 g/10 min. This polyoxymethylene homopolymer powder was dried at 80°C for 3 hours, and was then dried in a vacuum dryer at 60°C for 2 hours to protect it from moisture in the air and the amines, borate esters, and fatty acid calcium shown in Table 1. The obtained isocyanate compounds were blended in a nitrogen atmosphere, melt-kneaded and water-cooled in a twin-screw vented extruder set at 190°C (conditions: screw rotation speed: 100 rpm, discharge 3 kg/hr). At that time, the resin temperature was 200°C, and the cooling water was 20 to 40°C.

In addition, the boric acid ester of glycerin monofatty acid ester has a molar ratio of glycerin monofatty acid ester and boric acid of 1.
A product produced by heating at 1:1 and dehydrating equimolar water was used.

The extruded resin was cut with a cutter, the finished product was dried again at 80°C for more than 2 hours, and a cylindrical sample with a diameter of 10 mm and a length of 50 mm was molded using a 3-ounce molding machine. temperature 80'C1 cooling time 20 seconds).

Table 1 shows the measurement results of the adhesive strength of this sample.

Furthermore, Table 2 shows the adhesive strengths of Comparative Examples 1 to 12 determined in the same manner as in the Examples.

Example 7 A polyoxymethylene copolymer with 2.8% ethylene oxide was polymerized by the known method described in US Pat. No. 3,027,352. This polymer had an intrinsic viscosity of 1.1 and a melt index of 10.0 g/10 minutes.

To this polyoxymethylene copolymer that had been dried at 80°C for 3 hours, each additive was added according to the method of Example 1 according to the formulation shown in Table 3, and the process was carried out using the extruder described above so that the resin temperature was 230°C. It was extruded under the same conditions as in Example 1 and cooled with water. At this time, the temperature of the cooling water was 30 to 45°C. The pellets were then cut with a cutter, the resulting pellets were dried again at 80°C for 2 hours or more, and the adhesive strength was measured in the same manner as in Example 1. The results are shown in Table 3.

Example 8 The polyoxymethylene copolymer used in Example 7 and the additives listed in Table 3 were blended in the same manner as in Example 1, and the resin temperature was 20.
Extrusion was carried out at 0°C under the same conditions as in Example 1.

At this time, the melted and kneaded resin was passed through cooling water at 80°C, and the length of the cooling bath was adjusted so that the resin remained in the cooling water until its temperature reached 100'C. The pellets were then cut with a cutter, the resulting pellets were dried at 80°C for 2 hours or more, and the adhesive strength was measured in the same manner as in Example 1. The results are shown in Table 3.

Example 9 Room temperature pellets obtained in Example 5 (volume approximately 125 mm')
was soaked in 10 times the amount of water at 80°C for about 5 minutes.

Then, the adhesive strength was measured by the method of Example 1 using the pellets dried at 80° C. for 2 hours or more.

The results are shown in Table 3.

Example 10.11 Polyoxymethylene copolymer 7 used in Example 7 and each compound listed in Table 3 were blended in the same manner as in Example 1, and melt-kneaded at a resin temperature of 230°C.
Extrude under the same conditions as above, and further extrude at 100° with cooling water at 80°C.
It was cooled to C. The pellets were then cut with a cutter, the resulting pellets were dried at 80°C for 2 hours or more, and the adhesion was measured in the same manner as in Example 1.

The results are shown in Table 3.

(The following is a blank space) 9 [Effects of the Invention] The composition of the present invention is produced by melt-kneading a polyoxymethylene resin with an isocyanate compound, a specific amine, a boric acid ester, and fatty acid calcium at the same time. The present invention provides a polyoxymethylene resin composition that can be easily bonded with a cyanoacrylate adhesive to a polyoxymethylene resin composition that could not be bonded with an adhesive. Furthermore, the composition of the present invention has excellent adhesive properties that have not been achieved with conventionally known isocyanate-blocked polyoxymethylene resins or isocyanate-different polymer-modified polyoxymethylene resins.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a method of measuring the adhesive strength of a cylindrical sample. 1: Sample with adhesive applied, 2: Adhesive, 3: Another sample of the same type placed on top 4

Claims (1)

[Claims] 1. (1) Polyoxymethylene resin 90% by weight or more10
(2) 0.1 to 5% by weight of an isocyanate compound; and (3) 0.01 to 5% of one or more compounds selected from melamine, substituted melamine, dicyandiamide, and boric acid ester of glycerin monofatty acid ester. A polyoxymethylene resin composition obtained by melt-kneading 3% by weight of polyoxymethylene resin at a temperature higher than the melting point of the polyoxymethylene resin. 2. (1) Polyoxymethylene resin 90% by weight or more 10
less than 0% by weight, and (2) isocyanate compound 0.1~
5% by weight and (3) 0.01 to 3 of one or more compounds selected from melamine, substituted melamine, dicyandiamide, and boric acid ester of glycerin monofatty acid ester
% by weight, and (4) a polyoxymethylene resin composition obtained by melt-kneading 2% by weight or less of fatty acid calcium at a temperature equal to or higher than the melting point of the polyoxymethylene resin.