JPS62129307A - Production of molded resin article - Google Patents

Abstract

PURPOSE:To obtain a molded article in which only a required part is crosslinked to provide properties equal to those of thermosetting resins, by permeating and reacting a polyisocyanate with a desired part of a molded thermosetting resin article having groups reactive with isocyanate groups. CONSTITUTION:A polyisocyanate compound, e.g. 2,4-tolylene diisocyanate, etc., is permeated into a desired part of a molded thermosetting resin article, e.g. polyurethane based resin or cellulosic resin, etc., having groups reactive with isocyanate groups, e.g. -OH, -COOH, -NH2 or urethane bonds, etc., or a molded thermosetting resin article, e.g. polyethylene or ABS based resin, etc., containing a compound, e.g. ethylene glycol or polyurethane based resin, etc., containing >=2 groups reactive with the isocyanate groups, and reacted with the above- mentioned reactive groups.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for manufacturing a resin molded article, and more particularly, to a method for manufacturing a resin molded article that allows only desired portions to have a crosslinked structure.

(Prior Art and Problems) Conventional resin molded products can be roughly classified into molded products made of thermoplastic resin and molded products made of thermosetting resin.

Thermoplastic resin molded products are obtained by heating the thermoplastic resin to make it fluid, shaping it into an arbitrary shape, and then cooling it to fix the shape. Molded products can be easily manufactured and are currently produced in large quantities. Therefore, thermoplastic resin molded products are very easy to manufacture and inexpensive, and since they are easily softened by reheating, they are easy to process after molding, and their surfaces are free from solvents. It has many advantages, such as easy printing and adhesion because it is easily affected. Due to these numerous advantages, e.g. polyethylene, polypropylene, polystyrene,
AS, ABS, polyester, polyamide, polyurethane, etc. are widely used in general applications.

The disadvantages of thermoplastic resin moldings as described above are the opposite of the above advantages, and because they are thermoplastic resins, they have poor heat resistance, solvent resistance, abrasion resistance, chemical resistance, compression resistance, etc. It is well known that various physical properties are inferior. Therefore, apart from general uses, its use is severely limited in industrial uses that require various strict properties such as those mentioned above, and special and expensive polyamides, polyimides, polyesters,
Although engineering plastics such as polycarbonate have been used, the above-mentioned drawbacks cannot be fully solved.

On the other hand, thermosetting resin molded products exhibit plasticity before or during molding, but the resin develops a three-dimensional crosslinked structure due to heating during molding, and thereafter becomes an insoluble and infusible molded product. Therefore, it has solved many of the drawbacks of the above-mentioned thermoplastic resin molded products, and is widely used in industrial fields where various physical properties such as heat resistance, chemical resistance, and compression resistance are required.

Many such thermosetting resins are known, such as phenol resin, melamine resin, and epoxy resin, but the disadvantages of molded products made of such thermosetting resins are that
First of all, the molding method is limited to press molding method, compression molding method, etc., and even during molding, curing is too fast,
There are many process problems such as being too slow, and compared to thermoplastic resin molded products, moldability is significantly inferior. Regarding molded products, since the entire molded product is insoluble and infusible, there are drawbacks in that it is almost impossible to process the molded product after molding, and it is difficult to print or adhere to the surface.

Therefore, a molded product that is easy to mold like a thermoplastic resin and exhibits the excellent performance of both thermoplastic resin molded products and thermosetting resin molded products as described above is ideal and desired. .

(Means for Solving the Problems) As a result of intensive research in order to solve the above-mentioned problems of the prior art and to satisfy the above-mentioned demands, the inventors of the present invention have found that during molding, a thermoplastic resin is used, and then the The present invention was completed by developing a method that can crosslink only desired parts of a molded article so that it has properties equivalent to those of a thermosetting resin.

That is, the present invention provides polyisocyanate in a desired portion of a thermoplastic resin molded article having a group capable of reacting with an isocyanate group, or a thermoplastic resin molded article containing a compound containing two or more groups capable of reacting with an isocyanate group. This is a method for producing a resin molded article, which is characterized by permeating a compound and reacting a polyisocyanate compound with the above-mentioned reactive group.

As described above, the present invention creates a crosslinked structure by forming a large number of urethane bonds or urea bonds in the thermoplastic resin only in desired portions of the thermoplastic resin molding.

The reactive thermoplastic resin that can be used in the present invention is a thermoplastic resin having active hydrogen in its structure, such as a group capable of reacting with an isocyanate group, such as a hydroxyl group, a carboxyl group, an amino group, a urethane bond, a urea bond, etc. Any resin can be used, and examples of thermoplastic resins having such groups as they are include polyurethane resins, polyamide resins, polyester resins, acrylic resins, cellulose resins, etc. .

In such a thermoplastic resin, a large number of reactive groups can be introduced into the resin as necessary by copolymerizing a comonomer having a group capable of reacting with an isocyanate group during its production.

Furthermore, even in the case of thermoplastic resins that generally do not have reactive groups, such as polyresins such as polyethylene and polypropylene, polycarbonate resins, acetyl cellulose resins, etc., seven compounds that have reactive groups are used during their production. By copolymerizing Zimmer, a reactive thermoplastic resin can be obtained.

Furthermore, in the case of a thermoplastic resin having no reactivity as described above, the method of the present invention can be carried out by incorporating therein a compound having two or more groups capable of reacting with isocyanate groups, that is, groups having active hydrogen. It can be implemented.

Such reactive compounds may be reactive thermoplastic resins such as those mentioned above, low molecular weight polyols, polyamines, polycarboxylic acids, etc., polyester polyols, polyether polyols, polyester polycarboxylic acids, etc. It may also be an oligomer such as polyamide polyamine.

Preferred low molecular weight reactive compounds include, for example, ethylene glycol, 1,4-butanediol, 1
, 6-hexanediol, 1,5-naphthylene-di-β
-dihydroxyethyl ether, hydroquinone-β-dihydroxyethyl ether, trimethylolpropane,
Low molecular weight polyol compounds such as glycerin and hexanetriol; For example, ethylenediamine, propylene diamine, butylene diamine, hexamethylene diamine, 3,3'-dichlorbenzidine, 3,3'-dichloro-4,4'-diaminodiphenylmethane, Low molecular weight polyamines such as 2,5-dichlorophenylene-1,4-diamine; low molecular weight amino alcohols such as e.g. amino-ethyl alcohol, 3-amino-chlorhexanol, p-aminophenyl-ethyl alcohol, e.g. oxalic acid. , malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, fumaric acid, maleic acid, methylmaleic acid, methylfumaric acid, itaconic acid, citraconic acid, mesaconic acid, acetylenic acid, malic acid, methylmalic acid, citric acid , isocitric acid, tartaric acid and other low molecular weight aliphatic polycarboxylic acids; For example, phthalic acid, terephthalic acid, isophthalic acid, trimellitic acid, 1,2,3-benzenetricarboxylic acid,
Aromas such as 1,3.5-benzenetricarboxylic acid, pyromellitic acid, benzenehexacarboxylic acid, naphthalenedicarboxylic acid, naphthalenetricarboxylic acid, naphthalenetetracarboxylic acid, diphenyltetracarboxylic acid, diphenyl ethertetracarboxylic acid, azobenzenetetracarboxylic acid, etc. Group polycarboxylic acids; Alternatively, polyester polyols, polyester polycarboxylic acids, polyamide amines and polyamide carboxylic acids composed of the above polyols and polycarboxylic acids, and furthermore, the above polyols and polyamines are used as polymerization initiators. Examples include polyether polyols formed by polymerizing fullylene oxides such as ethylene oxide and propylene oxide.

Furthermore, such reactive compounds are not limited to the above-mentioned low molecular weight compounds, oligomers, etc., but include resins having groups that can react with isocyanate groups.

For example, polymer compounds such as polyurethane resins, polyamide resins, polyester resins, acrylic resins, melamine resins, urea resins, phenol resins, and alkyd resins may be used.

The above-mentioned reactive compounds may be mixed into the thermoplastic resin before molding the thermoplastic resin to obtain a molded product, or after the thermoplastic resin molded product is obtained. However, in the case of compounds that require time or are difficult to penetrate, it is preferable to incorporate them into the thermoplastic resin before molding. Of course, such a reactive compound is not limited to a non-reactive thermoplastic resin, but may also be included in a reactive thermoplastic resin.

In addition, the proportion of such reactive compounds included in the non-reactive thermoplastic resin is as follows:
The reactive group concentration ranges from about 0.0001 mol to 1 mol, and if the concentration is less than 0.0001 mol, the crosslinking density due to the polyisocyanate compound will be low and the object of the present invention cannot be fully achieved. On the other hand, an amount exceeding 1 mole is not preferable because it is uneconomical and may conversely impair the physical properties of the molded product.

The polyisocyanate compound used in the present invention is a compound having two or more isocyanate groups, and any polyisocyanate compound used in conventional technology related to polyurethane resins can be used. For example, 2.4-)lylene diisocyanate, 2.6-tolylene diisocyanate and mixtures of both, 4,4-diphenylmethane diisocyanate, m-phenylene diisocyanate, 4,4-)
Aromatic diisocyanates such as '-biphenyl diisocyanate, aliphatic diisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate and octamethylene diisocyanate, or aromatic aliphatics such as xylene diisocyanate, and triisocyanates such as 4, 4', 4'' -triphenylmethane triisocyanate, 2,4.4'-biphenyltriisocyanate, 2,4.4'-diphenylmethane triisocyanate, etc.Other usable isocyanates include these di- or triisocyanates and diols or triols. There are addition products or isocyanate polymers, etc., which are reacted with a compound having two or more hydroxyl groups in the molecule thereof, and which have two or more isocyanate groups in the reaction product.

The above polyisocyanate compounds can be used alone or as a mixture, and the method for infiltrating a desired part of a thermoplastic resin molding with such a polyisocyanate compound is as follows: (1) Using these polyisocyanate compounds (2) Method of dissolving it in an appropriate organic solvent and using it as a solution.

(3) Any method such as heating to gasify and use as a gas may be used.

Particularly preferred polyisocyanate compounds in such a method are relatively low molecular weight polyisocyanate compounds.

The concentration of such a polyisocyanate compound infiltrated into a thermoplastic resin molded product is preferably about 0.1 to 70 parts by weight per 100 parts by weight of the molded product, and if it is less than 0.1 part by weight, the desired crosslinking density can be achieved. Moreover, if the amount exceeds 70 parts by weight, the crosslinking density will be too high, and unreacted polyisocyanate compounds will remain in the molded product, which is undesirable. The amount of penetration of such polyisocyanate compounds is
It can be arbitrarily changed depending on the desired crosslinking density, the reactive groups present in the thermoplastic resin, or the reactive compounds included.

The method of the present invention is carried out using the above-mentioned materials, and an arbitrary molded article is first formed from a thermoplastic resin. As the method used for such molding, any conventionally known method for molding thermoplastic resins can be used. For example, injection molding,
Any molding method such as extrusion molding, vacuum molding, blow molding, foam molding, slush molding, casting, etc. may be used, and also molding methods using conventional thermosetting resins such as compression molding, transfer molding, etc. may be used. Of course, thermoplastic resins used in such arbitrary molding include thermoplastic resins having groups that can react with isocyanate groups, non-reactive thermoplastic resins mixed with compounds having such reactive groups, and the above-mentioned thermoplastic resins. These include thermoplastic resins containing reactive resins such as.

Furthermore, the shape of molded products made of such thermoplastic resin is not limited at all; for example, injection molded pole joints, various bushings, various dust covers, various shock absorbers, brake stoppers, O-rings, etc. , oil supply rings, spacers for leaf springs, door lock striker-1 various gears, packings, sealing materials, plate materials, pickers, KP holders, urethane poles,
Various casters, thrust washers, tuner parts, tap water faucets, sole materials for various sports shoes, various lifts, heel tops, ski grip materials, sprockets for snowmobiles, caterpillars, military boots, safety shoes, etc. shoe sole materials, golf poles, belts, gaskets, plugs, sockets, etc., as well as various extrusion conveyor belts, water containers, brewing containers, flexible containers, motor oil and boiling containers. Bags, sheets for transporting powder and granular materials, various raincoats, clothing, extruded film products such as various tapes, extruded tube products such as inflation products, various tubes, and various hoses, underground cables, and submarine products. Cables, Electric Power Association communication cables, lead wires, computer wiring, automobile wiring,
Examples include coated extrusion products such as various enameled wires, belt extrusion products of various belts, and the like.

Next, a polyisocyanate compound is infiltrated into the molded article as described above. The portion into which the polyisocyanate compound is permeated may be the entire molded product or a portion of the molded product.

For example, if the molded product is a hollow molded product such as a hose, the polyisocyanate compound may be infiltrated throughout the product, only in its surface layer, or only in its inner layer. It is also possible to infiltrate only a part of the hose instead of the entire length, and it can improve the entire molded product or the heat resistance, chemical resistance, and other parts required for thermosetting resin molded products. It can be applied only to the areas where it is needed. Methods for infiltration include immersing a part or all of the polyisocyanate compound in a melt or solution as described above, applying these liquids to the molded product, promoting penetration using pressure, and Any method using compound gas may be used. In particular, when permeating, the permeation of the polyisocyanate compound can be promoted by heating the liquid or gas of the polyisocyanate compound to a temperature that does not harm the molded product, for example, at a temperature of about 50 to 200°C. .

As described above, the polyisocyanate compound penetrates into the desired part of the molded product, but the reaction between the polyisocyanate compound and the reactive group of the thermoplastic resin or the added reactive compound proceeds over a long period of time even at room temperature. Therefore, heating is not an essential condition. However, in general, molded products impregnated with polyisocyanate compounds are
It is preferable to accelerate the reaction by isocyanate groups, that is, the crosslinking reaction, by heating at an appropriate temperature of about 200° C. for several minutes to several hours.

As described above, a resin molded article can be obtained by the method of the present invention.

(Operations and Effects) According to the present invention as described above, a resin molded article having the excellent physical properties of a thermosetting resin in necessary parts can be provided by a general method of molding a thermoplastic resin. Therefore, in the method of the present invention, any molding method can be adopted and a molded product of any shape can be obtained. Furthermore, in the molded product according to the method of the present invention, the part of the molded product to be processed remains in the thermoplastic resin state. In addition, parts that require various high physical properties can be made into a crosslinked structure, so it is almost impossible to carry out various processing after support molding, as with conventional thermosetting resin moldings. The problem has been resolved.

In addition, the molded product produced by the method of the present invention has, for example, a thermosetting crosslinked structure only on the surface portion that comes into contact with chemicals, and leaves the other portions as a thermoplastic resin with thermoformability. Since the part and the thermoplastic resin part are completely integrated, it has sufficient flexibility and flexibility as a molded product.
It has the advantage of being a molded product with excellent physical properties such as processability, adhesion to other articles, and printability. In contrast, such benefits could not be achieved with conventional thermoplastic resin moldings or thermosetting resin moldings.

Next, the present invention will be explained in more detail with reference to Examples. In addition, parts and percentages in the text are based on weight unless otherwise specified.

Example 1 Using a thermoplastic polyurethane resin having a concentration of 0.32 morph 100 g of urethane bonds that react with isocyanate groups, a molded product with a thickness of 3 m and an outer diameter of 100 mm was molded using an injection molding machine.
A disc-shaped packing with an inner diameter of 40 m + w is manufactured.

On the other hand, each of the above-mentioned packings, in which 4,4'-diphenylmethane diisocyanate was heated to 70 DEG C. and melted, weighed 24 g. Next, the entire packing was immersed in the above-mentioned isocyanate melt for 6 minutes, and then pulled out.
When the weight was measured after heating at 80°C for 10 hours,
It was 25g.

The results of measuring the mechanical properties of the packing before and after immersion are shown in Table 1 below.

Lingsui Payu soil Z 90 (JISA) Kita i Dan 1 ro 450 (Kg/c Go) Kita i Danzu u
430 (%) Direct installation permanent f 60 (%) 斫Jshi'y = 52 夾-m-193 (JISA) Kita Idanmu 1 550 (Kglc Go) Kita-go-ko row u
400 (%) Bile wealth permanent 1 25 (%) Fixed number of fish, 1,5 and 1 -- and in accordance with JISK6301.

Kita 1 No. 1
It was found that the compression set of the packing produced by the method of the present invention was significantly improved after testing at 70°C for 22 hours or more, and that the effect of crosslinking was imparted. , Example 2 A hollow hose with an outer diameter of 120 mm, an inner diameter of 110 mm, and a length of 300 mm was manufactured by an injection molding machine using a thermoplastic polyurethane resin having a urethane bond that reacts with isocyanate groups at a concentration of 0.40 mol/long. Next, both ends of this hose are fused and sealed. The weight of this hose was 207 g. Next, as in Example 1, it was immersed in a 4,4' diphenylmethane diisocyanate melt at 70°C for 10 minutes, and then heated to 80°C for 10 minutes.
heated for an hour. The weight after immersion and heating was 221 g.

Next, the fused parts at both ends were cut off and the inner surface of the hose was observed. As a result, it was confirmed that the polyisocyanate compound had not penetrated into the inner surface.

Next, an adhesive was applied to the surface of a stainless steel rod having a diameter of 110 m, and the fused portion was adhered to the inside of a cut-off hose to produce a roll. A roll was manufactured in the same manner except that it was not dipped into the polyisocyanate compound. Table 2 shows the results of a practical test using these rolls as word processor platen rolls.

, 2 = 1 unit 22 units 7. Cracks occurred after 20 million cycles.

Higeoka Watan 11-8 Kg/crs Two dead bodies Shonori J　　No abnormality after 50 million times.

Mugioka Wataru 12, OKg/c layer Obviously, the impact resistance of the dipping roll is improved because the surface is crosslinked.

Furthermore, since the inside was thermoplastic, the adhesive strength was almost the same as that of the unsoaked roll.

Example 3 70 parts of a heat-resistant ABS resin is mixed with 30 parts of a thermoplastic polyurethane resin having a urethane bond concentration of 0.35 morph and 100 g. At this time, the concentration of urethane bonds that react with the isocyanate groups in the kneaded material is 0.105 morph (100 g). Next, a heel top is molded using an injection molding machine. Each heel top weighed 1.5 g. In the same manner as in Example 1, the sample was immersed in a melt of 4,4'-diphenylmethane diisocyanate at 70°C for 5 minutes, then pulled out and heated at 90°C for 12 hours. The heel top after heating is 1
The weight was 1.6g. Table 3 shows the results of the practical durability test compared to the unsoaked heel top.

-3 = One heel taupe 10 days Urium P untested to B5-903 None heel taupe 30, 0 cc/HP-
hr.

-, -Hee-) Iy Tope 6, Occ/HP
-hr.

It was clear that the heel top treated by dipping had good abrasion resistance.

Claims (4)

[Claims] (1) Infiltrating a polyisocyanate compound into a desired part of a thermoplastic resin molded product that has a group that can react with an isocyanate group, or a thermoplastic resin molded product that contains a compound that contains two or more groups that can react with an isocyanate group. A method for producing a resin molded article, which comprises reacting a polyisocyanate compound with the above-mentioned reactive group. (2) The manufacturing method according to claim (1), wherein the thermoplastic resin is a polyurethane resin. (3) The manufacturing method according to claim (1), wherein the thermoplastic resin is a non-reactive thermoplastic resin containing a compound having a group capable of reacting with an isocyanate group. (4) The thermoplastic resin is a mixture of a non-reactive thermoplastic resin and a polyurethane resin.
) The manufacturing method described in section 2.