JPH0676537B2 - Polyoxymethylene resin composition with excellent adhesiveness - Google Patents

Description

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

[Conventional technology]

Polyoxymethylene resin is an engineering resin with well-balanced mechanical properties and excellent chemical resistance.
Widely used in various mechanical parts and office automation equipment.

However, the polyoxymethylene resin has a great drawback that its adhesion is difficult due to its excellent chemical resistance.

Conventionally, as a method for modifying a polyoxymethylene resin, a method in which the end of the polyoxymethylene resin is blocked with an isocyanate compound and a polar group is introduced into the end of the polyoxymethylene resin (Japanese Patent Publication No. 50-26592) or There is known a method (Japanese Patent Publication No. 49-5609) for producing a modified polyoxymethylene resin by coupling a polyoxymethylene resin and a different polymer with an isocyanate compound.

However, in these methods, the adhesiveness by the cyanoacrylate-based adhesive, which is to be improved in the present invention, is hardly improved.

[Problems to be Solved by the Invention]

An object of the present invention is to make it possible to bond a polyoxymethylene resin that could not be bonded at all with a cyanoacrylate-based adhesive, with a cyanoacrylate-based adhesive.

[Means for Solving the Problems]

That is, one invention according to the present application is (1) polyoxymethylene resin 90% by weight or more and less than 100%, (2) isocyanate compound 0.1 to 5% by weight and (3) melamine, substituted melamine, dicyandiamide and glycerin monofatty acid. A polyoxymethylene resin composition obtained by melt-kneading 0.01 to 3% by weight of one or more compounds selected from boric acid esters of esters at a temperature not lower than the melting point of the polyoxymethylene resin, and another invention. Is the above (1),
In addition to (2) and (3), (4) fatty acid calcium 2
A polyoxymethylene resin composition obtained by melt-kneading not more than wt% at a temperature not lower than the melting point of the polyoxymethylene resin. Furthermore, the present application provides the polyoxymethylene according to claims 1 and 2, wherein (1) the substituted melamine is benzoguanamine, guanamine, or 2,4-diamino-6-methyltriazine. A resin composition, (2) the fatty acid calcium is a fatty acid calcium having 12 to 22 carbon atoms, and the polyoxymethylene resin composition according to claim 1 or 2, (3) a boric acid ester of glycerin monofatty acid ester. The composition according to claim 1 or 2, wherein the fatty acid is a fatty acid having 12 to 22 carbon atoms, and (4) the resin temperature of the polyoxymethylene during melt kneading is 21.
The polyoxymethylene resin composition according to any one of claims 1 to 2 having a temperature of 0 to 230 ° C, and (5) water-cooled after melt-kneading.
The polyoxymethylene resin composition according to claim 1, (6) the polyoxymethylene resin composition according to claim 1 or 2, which is cooled with water at 80 ° C. or higher after melt-kneading, and (7) melt-kneading cooling A polyoxymethylene resin composition according to claim 1 or 2, which is subsequently immersed in water at 80 ° C. or higher.

The polyoxymethylene resin used in the composition of the present invention means substantially oxymethylene produced from a cyclic oligomer such as formaldehyde monomer or its trimer (trioxane) or tetramer (tetraoxane). Oxymethylene having 2 to 8 carbon atoms, which is produced from an oxymethylene homopolymer consisting of units and 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 alkylene units. It also includes an oxymethylene copolymer having a branched molecular chain.

Next, the isocyanate compound used in the present invention is a compound containing at least one isocyanate group or isothiocyanate group in the molecule.

Specifically, (A) hexyl isocyanate, octyl isocyanate, octadecyl isocyanate, cyclohexyl isocyanate, phenyl isocyanate, tolyl isocyanate, benzyl isocyanate, naphthyl isocyanate and other monoisocyanate compounds, or (B) hexamethylene diisocyanate, cyclohexylene diisocyanate. , Dicyclohexylmethane diisocyanate, isophorone diisocyanate, phenylene diisocyanate, toluene diisocyanate, xylene diisocyanate, naphthalene diisocyanate, diphenyl methane diisocyanate, dimethyl diphenyl methane diisocyanate, dimethyl diphenylene diisocyanate and the like, or (C) triphenyl methane 2 weight products of polyisocyanate, triisocyanate compound benzene triisocyanate and the like, or isothiocyanate compounds corresponding to the above isocyanate compounds, or said diisocyanate compound,
A polymer such as a trimer, a water-added isocyanate compound of the above aromatic isocyanate compound, or a substitution product of the above isocyanate compound with a substituent containing an alkyl group, an allyl group, an aryl group, a hetero atom, or the like. It also includes an isomer of an isocyanate compound, or a reaction product of the above-mentioned isocyanate compound with an alcohol having a molecular weight of 3,000 or less and a compound having a carboxylic acid (one in which an isocyanate group remains). These isocyanate compounds may be used in combination of two or more kinds. The specific examples of these isocyanate compounds do not limit the isocyanate compounds used in the present invention.

Further, the amount of the isocyanate compound used in the present invention must be 0.1 to 5% by weight. 0.1% by weight
This is because if it is less than 5% by weight, the effect of addition of isocyanate does not appear on the adhesiveness, and if it is more than 5% by weight, the moldability of the polyoxymethylene resin is significantly reduced. further,
The most preferable range in which the effect of the present invention can be maximized is
It is 0.5 to 3% by weight.

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

As melamine and dicyandiamide, commercially available products can be used as they are.

Specific examples of the substituted melamine include benzoguanamine, guanamine, 2,4-diamino-6-methyltriazine, N-butylmelamine, N-phenylmelamine, N-methylolmelamine and 2,4-diamino. -6-
Butyltriazine, 2,4-diamino-6-benzyloxytriazine, 2,4-dioxy-6-aminotriazine and the like. Among them, benzoguanamine, guanamine and 2,4-diamino-6-methyltriazine are particularly preferable.

Specific examples of the boric acid ester of glycerin monofatty acid ester include (a) caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, undecyl acid, lauric acid, tridecyl acid, myristic acid, pentadecyl acid,
Palmitic acid, heptadecyl acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, heptacosanoic acid, saturated fatty acids such as montanic acid or (b) isocrotonic acid, undecylenic acid, oleic acid, elaidic acid, It is obtained by heating monoesters of unsaturated fatty acids such as cetoleic acid, erucic acid, brassic acid, sorbic acid, linoleic acid, linolenic acid, and arachidonic acid and glycerin with boric acid to remove water. 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 glycerin monofatty acid ester used in the present invention has 12 to 22 carbon atoms.

This is because if it is less than 12, the rate of volatilization during melt-kneading is high, and if it is more than 22, the content of boric acid is low.

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 to be 01 to 3% by weight. If it is less than 0.01 or more than 3% by weight, the adhesiveness is lowered. More preferably, it is 0.05 to 1.5% by weight.

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

In the present invention, fatty acid calcium does not have to be added, and may be blended with an upper limit of 2% by weight.
If it exceeds 2% by weight, the adhesiveness is lowered, which is not preferable. A more preferable compounding ratio in terms of adhesiveness is 0.05
~ 1.5% by weight.

The polyoxymethylene resin composition having excellent adhesiveness of the present invention contains the components (1) to (3) and (1) to (4) as a conventional resin melt such as a kneader, a roll mill or an 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 apparatus used for kneading.

An extruder is most suitable as a melt-kneading device from the viewpoint of blocking oxygen and working environment. The type of the extruder includes uniaxial type, biaxial type, vented type, non-vented type and the like, and the composition of the present invention can be adjusted by any extruder. The mixing temperature must be above the melting point of the polyoxymethylene resin used, and is usually used.
It can be sufficiently extruded at a temperature in the range of 180 to 240 ° C. The time required for kneading is approximately the same as the time required for extruding the polyoxymethylene resin alone, and is sufficient.

As described above, the kneading conditions for adjusting the composition of the present invention are shown, but the kneading method and conditions are not limited to the above, and known methods and conditions used for adjusting the polyoxymethylene resin composition can be used. Any one can be used from the inside.

The composition of the present invention is preferably melt-kneaded at a resin temperature of 210 to 230 ° C. in order to obtain a composition having more excellent adhesiveness among the above-mentioned extrusion temperatures.

Further, it may be water-cooled immediately after melt-kneading, or more preferably,
A composition cooled with water at 80 ° C. or higher, or a composition obtained by immersing a melt-kneaded composition at room temperature of 80 ° C. or lower in water at 80 ° C. or higher exhibits further excellent adhesiveness. When cooling with water at 80 ° C. or higher, it is preferable to cool under this condition until the temperature of the lowest melt reaches 100 ° C. or lower. After melt-kneading and cooling, the time for immersion in water at 80 ° C or higher is about 5 minutes for pellets of 125 mm ³ or less. The immersion time can be adjusted depending on the size of the pellet.

It is considered that these effects are due to the fact that the unreacted additive with the isocyanate compound and / or the low molecular weight compound having a small 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 it is. The cyanoacrylate adhesive is of a type in which a cyanoacrylate monomer is polymerized on the adhesive surface to form an adhesive layer.

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 relates to a polyoxymethylene resin which has heretofore been unable to be adhered with a cyanoacrylate adhesive by simultaneously melt-kneading an isocyanate compound, a specific amine, boric acid ester and calcium fatty acid into the polyoxymethylene resin. It is intended to provide a polyoxymethylene resin composition which can be easily adhered with a cyanoacrylate adhesive. The adhesiveness of the composition of the present invention has excellent adhesiveness which has not been obtained by the conventionally known isocyanate-capped polyoxymethylene resin or isocyanate-different polymer-modified polyoxymethylene resin.

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

〔Example〕

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

The physical properties were measured according to the following.

Intrinsic viscosity; 0.1% by weight of the polymer was dissolved in a p-chlorophenol solution containing 2% by weight of alfapinene, and the viscosity was measured at 60 ° C.

Melt index; ASTM D1238-57T (E condition) Adhesive strength; Take one sample and spread 15mm ³ of cyanoacrylate adhesive (Taoka Chemical Co., Ltd., trade name: Cyanobond RS300) evenly on the top surface (one surface) of the cylinder. One more on it
Another same sample of the book was placed. (See FIG. 1) In this state, it was left for 8 hours in an atmosphere of 23 ° C. and a humidity of 50%. A tensile test was conducted on the adhered sample, and the adhesive strength was determined by the following formula.

F: Measured Tensile Stress Examples 1 to 6 and Comparative Examples 1 to 12 Polyoxymethylene homopolymer powders having both ends acetylated were produced by a known method described in US Pat. No. 2,998,409. The inherent viscosity of this product was 1.2. The melt index was 9.0 g / 10 minutes. This polyoxymethylene homopolymer powder was dried at 80 ° C for 3 hours and then dried in a vacuum dryer at 60 ° C for 2 hours, protected from amines, boric acid esters and fatty acid calcium shown in Table 1 and moisture in the air. The isocyanate compound was blended in a nitrogen atmosphere, and melt-kneaded in a twin-screw vent extruder (condition: screw rotation speed; 100 rpm, discharge 3 kg / hr) set at 190 ° C. and water-mixed. At that time, the resin temperature was 200 ° C and the cooling water was 20-40 ° C.

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

The extruded resin is cut with a cutter, and the resulting pellets are dried again at 80 ° C for 2 hours or more, and the diameter is measured with a 3 ounce molding machine.
A cylindrical sample having a length of 10 mm and a length of 50 mm was molded (mold temperature 80 ° C., cooling time 20 seconds).

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

Further, Table 2 shows the adhesive strength of Comparative Examples 1 to 12 obtained by the same method as that of the example.

Example 7 A 2.8% ethylene oxide polyoxymethylene copolymer was polymerized by the known method described in US Pat. No. 3,027,352. The polymer had an intrinsic viscosity of 1.1 and a melt index of 10.0 g / 10 minutes. To this polyoxymethylene copolymer dried at 80 ° C. for 3 hours, the additives shown in Table 3 were added according to the method of Example 1, and the resin temperature was set to 230.
It was extruded under the same conditions as in Example 1 using the above-mentioned extruder so that the temperature became 0 ° C., and cooled with water. At this time, the cooling water was 30 to 45 ° C. Then cut it with a cutter and re-apply the pellets to 80
After drying at 0 ° C. for 2 hours or more, the adhesive strength was measured by the same method as in Example 1. The results are shown in Table 3.

Example 8 Polyoxymethylene copolymer used in Example 7 and third
The additives in the table were blended as in Example 1 and the resin temperature 20
Extrusion was carried out at 0 ° C. under the same conditions as in Example 1. At this time, the melt-kneaded resin is passed through cooling water at 80 ° C, and the temperature of the resin is kept at 100 ° C.
The length of the cooling bath was adjusted so that it would be immersed in cooling water until it became. Then cut with a cutter, and the resulting pellets at 80 ℃
After drying for 2 hours or more, the adhesive strength was measured by the same method as in Example 1. The results are shown in Table 3.

Example 9 The room temperature pellet (volume: about 125 mm ³ ) obtained in Example 5 was immersed 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.

Examples 10 and 11 Polyoxymethylene copolymer used in Example 7 and third
Each compound shown in the table was blended in the same manner as in Example 1, melt-kneaded at a resin temperature of 230 ° C., extruded under the same conditions as in Example 1, and further cooled with cooling water of 80 ° C. until reaching 100 ° C. . Then cut with a cutter, and the resulting pellets at 80 ℃
After drying for 2 hours or more, the adhesiveness was measured by the same method as in Example 1.

The results are shown in Table 3.

EFFECTS OF THE INVENTION The composition of the present invention is conventionally adhered to a polyoxymethylene resin with a cyanoacrylate adhesive by melt-kneading an isocyanate compound and a specific amine, borate ester and calcium fatty acid at the same time. The present invention provides a polyoxymethylene resin composition capable of easily adhering a polyoxymethylene resin composition which could not be obtained with a cyanoarylate adhesive. Further, the composition of the present invention has an excellent adhesiveness which has not been obtained by the conventionally known isocyanate-capped polyoxymethylene resin or isocyanate-different polymer-modified polyoxymethylene resin.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a method for measuring the adhesive strength of a cylindrical sample. 1: sample coated with adhesive, 2: adhesive, 3: another sample of the same type placed on top

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location C08L 59/02 LML 8215-4J

Claims (2)

[Claims] 1. A boric acid ester of (1) 90% by weight or more and less than 100% by weight of a polyoxymethylene resin, (2) 0.1 to 5% by weight of an isocyanate compound and (3) melamine, substituted melamine, dicyandiamide and glycerin monofatty acid ester. A polyoxymethylene resin composition obtained by melt-kneading 0.01 to 3% by weight of one or more compounds selected from the above at a temperature not lower than the melting point of the polyoxymethylene resin. 2. A polyoxymethylene resin of 90% by weight or more and less than 100% by weight, and (2) an isocyanate compound of 0.1 to
5% by weight and (3) 0.01 to 3% by weight of one or more compounds selected from melamine, substituted melamine, dicyandiamide and boric acid ester of glycerin monofatty acid ester, and (4) fatty acid calcium 2% by weight or less A polyoxymethylene resin composition obtained by melt-kneading at a temperature equal to or higher than the melting point of the oxymethylene resin.