JPH0768385B2 - Resin molded product and method for producing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a resin molded product and a method for producing the same, and more specifically, to excellent wear resistance, stain resistance, and solvent resistance on all or desired parts of the surface. TECHNICAL FIELD The present invention relates to a resin molded article having properties such as water repellency, water repellency and non-adhesiveness, and a method for producing the same.

(Prior Art and Problems Thereof) Conventional resin moldings are roughly classified into moldings made of a thermoplastic resin and moldings made of a thermosetting resin.

The thermoplastic resin molded product is obtained by making the thermoplastic resin fluid by heating to shape it into an arbitrary shape, and then fixing the shape by cooling it. It is possible to easily manufacture molded products, and they are currently produced in large quantities.

Therefore, the thermoplastic resin moldings are very easy to manufacture and are inexpensive, and the moldings are easily softened by reheating, so that they can be easily processed after molding. It has many advantages such as being easy to receive and easy to print and adhere.

Due to such numerous advantages, for example, polyethylene, polypropylene, polystyrene, AS, ABS, polyester, polyamide, polyurethane and the like are widely used in general applications.

The drawbacks of the thermoplastic resin moldings as described above are the inside out of the above advantages, and since they are thermoplastic resins, they are inferior in various physical properties such as abrasion resistance, stain resistance, non-adhesiveness and solvent resistance. Is well known.

Therefore, in addition to general applications, in industrial applications where various severe performances are required, their use is significantly limited, and special and expensive engineering plastics are used, but the above-mentioned drawbacks are still insufficient. Is something that cannot be solved.

As a method for solving the above problems, there is known a method of forming a surface layer of a silicone-based compound by applying a silicone-based paint to the surface of the obtained molded article after molding with a thermoplastic resin, There is a problem that the surface thus formed is easily worn and the surface layer is easily peeled off. Further, for the purpose of solving the drawbacks of these surface coating methods, a method of mixing a silicone compound with a raw material for molding before molding a resin is conceivable, but a low molecular weight silicone has a large slip property. It acts as a wax in the molding machine and cannot be sufficiently kneaded with the resin, and a molded product in which the silicone compound is uniformly distributed cannot be obtained. If a reactive compound is used as the silicone compound, the reactive silicone reacts at the temperature during molding, and similarly good molding cannot be performed. Further, since the silicone compound cannot exist only on the surface, the cost becomes very high.

Further, in order to solve such a problem, a method of molding by dispersing fine particles of a high molecular weight silicone compound in a resin can be considered, but in this case, since the silicone fine particles are present in the resin as dots, Although the effect of non-stickiness comes out,
Other properties such as stain resistance and water repellency are less likely to appear, and the use of a large amount reduces the original properties of the resin and is very expensive.

Therefore, an object of the present invention is to provide a technique capable of easily imparting various excellent properties to the surface of a molded product without deteriorating the original properties of the resin.

(Means for Solving Problems) The above object is achieved by the present invention described below.

That is, the present invention is characterized in that a low molecular weight reactive silicon compound is permeated into a desired portion of the surface of a thermoplastic resin molded article, and the permeated compound is made to have a high molecular weight inside the surface of the molded article. It is a method for producing a molded product.

(Function) By impregnating a desired portion of a resin molded article with a reactive silicon compound and then increasing the molecular weight of the silicon compound, excellent properties can be imparted to the entire surface of the molded article or a desired portion.

(Preferred Embodiment) The resin used in the molded article of the present invention includes both thermosetting resins and thermoplastic resins, but thermoplastic resins are preferred, and examples thereof include polyolefin resins such as polyethylene and polypropylene. , Polystyrene resin, polyvinyl chloride resin, AS, ABS resin, vinyl acetate resin, polycarbonate resin, acetyl cellulose resin, polyester resin, polyamide resin, polyurethane resin and the like.

In the present invention, first, an arbitrary molded product is molded from the above resin. As a method used for such molding, any conventionally known method for molding a thermoplastic resin can be used. For example,
Injection molding, extrusion molding, vacuum molding, blow molding, foam molding,
Any molding method such as slush molding or casting, or a conventional molding method using a thermosetting resin such as compression molding or transfer molding may be used.

The shape of the molded product made of such a thermoplastic resin is not limited at all, and examples thereof include ball joints by injection molding, various bushes, various dust covers, various shock absorbers, brake stoppers, O-rings,
Lubricating rings, leaf spring spacers, door lock strikers, various gears, packings, sealing materials, plate materials, pickers, KP holders, urethane balls, various casters, thrust washers, tuner parts,
Tap water taps, shoe soles for various sports shoes, lifts, heel tops, ski grips, sprocket for snowmobiles, caterpillars, soles for military shoes and safety shoes, golf balls, belts, gaskets. ,
Plugs, sockets, etc., various conveyor belts made by extrusion molding, water containers, brewing containers, flexible containers, motor oil / boiling sachets, powder sheet transport sheets, various kappa, clothing , Film extruded products such as various tapes, inflation compounds and various tubes, tube extruded products such as various hoses, underground cables, submarine cables, power / communication cables, lead wires, computer wiring, automobile wiring, Examples thereof include coated extruded compounds such as various enameled wires, and belt extruded products of various belts.

In the present invention, the reactive silicon compound is permeated on the surface of the molded article as described above.

Examples of the reactive silicon compound used in the present invention include alkyl silicates such as methyl silicate, ethyl silicate, propyl silicate, and butyl silicate, various silane coupling agents, hydrogen-modified silicone, vinyl-modified silicone, hydroxy-modified silicone, amino. Reactive silicones such as modified silicones, carboxy-modified silicones, chlor-modified silicones, epoxy-modified silicones, methacryloxy-modified silicones and mercapto-modified silicones can be mentioned. Many of these reactive silicon compounds are known, and any commercially available reactive silicon compound can be used in the present invention, but a preferable one in the present invention is one having a molecular weight of 2,000 or less. If the molecular weight exceeds 2,000, it will take time for the resin to penetrate into the molded article.

The above-mentioned reactive silicon compounds may be used alone or in a mixture, and may be used in combination with an organic or inorganic crosslinking agent such as polyamine, polyol or polyisocyanate, and a catalyst may be used if necessary.

The portion where the reactive silicon compound is permeated may be the entire surface of the molded product or a part of the surface. For example, in the case where the molded product is a hollow molded product such as a hose, the reactive silicon compound may be permeated throughout, or only the surface layer thereof may be permeated, or only the inner surface layer thereof. It may be permeated into the hose or into only one part of the hose instead of the entire length of the hose. Can only penetrate.

The method of infiltrating may be as it is when the reactive silicon compound as described above is liquid, but is preferably a solution of an appropriate organic solvent, and a method of immersing a part or all of the molded product in this solution, Method of applying the liquid of the above to the molded product,
Any method such as using pressure to promote permeation may be used.
In particular, when permeating, it is possible to promote the permeation of the reactive silicon compound by heating the solution of the reactive silicon compound to a temperature that does not damage the molded product, for example, a temperature of about 50 to 200 ° C. I can.

The solvent used for permeation of the reactive silicon compound varies depending on the thermoplastic resin used for molding, and a solvent that partially dissolves or swells the thermoplastic resin used for molding is preferable. For example, in the case of polyamide resin, methanol or a mixed solvent of methanol and other solvent, in the case of polyurethane resin, methyl ethyl ketone or a mixed solvent of methyl ethyl ketone and other solvent, in the case of polyester elastomer, tetrahydrofuran or tetrahydrofuran and other In the case of a mixture with the above solvent and an olefin elastomer, an aromatic solvent seems to be suitable.

As described above, the reactive silicon compound permeates the desired part of the molded product, but the reaction with the reactive silicon compounds, the resin or the cross-linking agent proceeds by taking a long time even at room temperature, so heating is an essential condition. is not. However, in general, a molded product impregnated with a reactive silicon compound is treated with 50 to 200
It is preferable to heat the molded product at a suitable temperature which does not deform the molded product to a temperature of about several minutes to several hours to react the reactive silicon compound to increase the molecular weight.

As described above, the resin molded product according to the present invention is obtained. The permeation amount of the reactive silicon compound varies depending on the shape, size and application of the molded product and is not specified unconditionally, but the range of 1 to 50% by weight of the reactive silicon compound is generally on the surface of the molded product. Is.

(Example) Next, an Example is given and this invention is demonstrated still more concretely.
In the text, parts and% are based on weight unless otherwise specified.

Example 1 A roller-shaped molded product was obtained by injection molding using the polyether-based thermoplastic polyurethane resin of JISA70. This molded product was immersed in a tetrahydrofuran solution containing 15% of ethyl silicate for 12 hours, then pulled up and dried at 50 ° C. for 2 hours to evaporate and remove tetrahydrofuran.

Next, the above-mentioned molded product is immersed in a 2% ammonia solution for 10 hours and then pulled up, and heated from room temperature to 110 ° C. over 4 hours,
A polymer of silicon dioxide was formed in the surface layer of the molded part by incubating at 12 ° C for 12 hours. When weighed in this state, 5
%, And the silicon dioxide polymer was present in the moldings in an amount of 5% by weight.

When the roller obtained above and the same untreated roller (comparative example) were used as the paper feed roller of the copying machine, the friction coefficient (μ) of the surface changed as follows.

Example 2 The following penetrants A and B were prepared.

Penetrant A Tetramethyldisiloxane of the following formula 30 parts Tetrahydrofuran 30 parts Methyl ethyl ketone 30 parts Penetrant B Terminal silanol polydimethylsiloxane (n =
About 7, molecular weight about 700) 30 parts Tetrahydrofuran 30 parts Methyl ethyl ketone 30 parts Tin octylate (catalyst) 0.5 parts A polyester-based polyurethane elastomer of JISA90 is molded into a tube having an outer diameter of 10 mm and an inner diameter of 4 mm, and the penetrant liquid A is filled in the tube for 5 hours, taken out, and dried at 50 ° C. for 1 hour. Then, the above penetrant liquid B was similarly charged into the tube for 5 hours, taken out, dried at 50 ° C. for 1 hour, and further heated at 100 to 110 ° C.
After heat treatment for 12 hours, the silicone compounds were reacted and polymerized to increase the molecular weight. The hose weight gain was 2%.

After the powdered flour was continuously passed through the tube of the present invention and the same untreated tube (Comparative Example) for 6 hours, the amount of the flour adhering to the tube was measured, and the following results were obtained. was gotten.

The present invention ... 0.5 g / m Comparative example ... 2.0 g / m Example 3 The following penetrants A and B were prepared.

Penetrant A Tetramethyldivinyldisiloxane of the following formula 30 parts Tetrahydrofuran 70 parts Penetrant B Tetramethyldisiloxane of the following formula 30 parts Tetrahydrofuran 70 parts Chloroplatinic acid (catalyst) 0.1 parts Nylon yarn (diameter 0.2 mm) spun from 6-nylon in the above treatment liquid was immersed in the treatment liquid B for 4 hours, taken out, and then dried.
And heat-treated for 12 hours to polymerize the silicone compounds with each other to increase the molecular weight. Nylon fiber weight increase is 1
%Met.

The following results were obtained when a felt-like paper feed roller was prepared from the above treated yarn and untreated nylon yarn (comparative example) and used as a paper feed roller for printed newspaper in a newspaper printing machine.

The present invention: No ink contamination even after 7 days of use.

Comparative example: Contamination is severe after 24 hours of use.

(Effects) According to the present invention as described above, after the reactive silicon compound is permeated into a desired portion of the resin molded product, and then the molecular weight of the silicon compound is increased, the entire surface of the molded product or the desired portion is excellent. It is possible to add the characteristic.

Claims (1)

[Claims] 1. A resin molding characterized in that a low molecular weight reactive silicon compound is permeated into a desired portion of the surface of a thermoplastic resin molding, and the permeated compound is made to have a high molecular weight inside the surface of the molding. Method of manufacturing things.