KR20160046682A - Composition for resin products containing oil and lubrication products using this - Google Patents

Abstract

The present invention relates to a composition for oil-containing resin products, and to a lubricating product using the same. More specifically, the present invention relate to a composition for oil-containing products, which comprises: a mixed resin in which low-density polyethylene (LDPE) and ultra-high-molecular-weight polyethylene (UHWPE) are mixed at the weight ratio of 6-7:4-3; 30-90 parts by weight of oil with respect to the mixed resin; 0.06-0.6 parts by weight of a crosslinking agent; and 0.1-0.8 parts by weight of an antioxidant. The present invention further relates to a lubricating product using the same. According to the present invention, the composition can offer products with outstanding flexural rigidity and hardness and ensures less weight loss while being used. Further, the composition can also extend the service life of the products.

Description

TECHNICAL FIELD [0001] The present invention relates to a composition for an oil-containing resin product and a lubricating product using the composition.

The present invention relates to a composition for an oil-containing resin product and a lubricating product using the composition. More particularly, the present invention relates to a composition for an oil-containing resin product having excellent bending strength and hardness and low weight loss during use.

In general, the conveying means including the LM guide, the ball screw, the ball spline, and the linear bush guide or convey the conveyed material by the rolling motion of the rolling element. At this time, A lubricating material having a high viscosity (for example, grease) is applied for smooth transfer, or the lubricating material having a low viscosity is continuously supplied.

If a lubricant having a high viscosity is used, the lubricant is overflowed to the area and the loss is generated. When the lubricant is old, deformation due to aging occurs. Therefore, the lubricant needs to be replaced at an arbitrary interval.

When lubricating material having a low viscosity is continuously fed, that is, a lubricating oil is supplied at a position adjacent to the rolling surface of the conveying means and the lubricating oil is continuously supplied by an operator periodically or by using an automatic lubricating machine. However, And periodic cleaning of the lubricant tank.

In recent years, products having self-lubricating properties have been developed. In Korean Patent Laid-Open No. 10-2004-0015015, ultrahigh molecular weight compounds having an intrinsic viscosity [?] Of 10 to 40 dl / g Molecular weight polyethylene (component (a-2)) having an intrinsic viscosity [?] Of 0.1 to 5 dl / g, wherein the ultra high molecular weight polyethylene component: low molecular weight polyethylene Component is a polyethylene resin composition which has a mixing ratio of 35-90: 10-65 and is added with a crosslinking agent (peroxidizing agent), an antioxidant, an oil, etc. as an additive and has excellent wear resistance, balance between appearance and formability used in gaskets have.

However, the prior art described above is an invention relating to a resin composition focused only on the moldability and abrasion resistance of a polyethylene resin, and it has a self-lubricating property but is used in applications such as gaskets and lubrication seals that require separate lubricant supply or the like There is a problem that sufficient lubrication effect can not be achieved, and there is no consideration of the performance of such a product.

Accordingly, the present invention relates to a process for producing a polyolefin resin which comprises an oil while containing a polyethylene resin and includes a low molecular weight polyethylene (hereinafter referred to as LDPE), ultra high molecular weight polyethylene (hereinafter referred to as UHWPE), an oil and a crosslinking agent, To provide a composition of a mixed resin having good mechanical properties and elongated oil which serves as a lubricant and has a long life, and to provide a molded article made of the resin composition with excellent lubrication and sealing effect.

In order to achieve the above object, the present invention is characterized in that a mixed resin in which LDPE: UHWPE is mixed in a weight ratio of 6-7: 4-3, and a mixture of 30 to 90 parts by weight of oil, 0.06 to 0.6 And 0.1 to 0.8 parts by weight of an antioxidant.

The UHWPE is used for improving heat resistance and absorbency and LDPE is used for improving workability and flexibility. The weight ratio of UHWPE is 6-7: 4-3. When the UHWPE is out of the above range, It is difficult to anticipate the adjustment of the elution amount of the oil and the mutual complement of the mechanical properties.

When the oil is mixed with a resin and then applied to a product, the oil is eluted to the outside of the product by heat and pressure and applied to a lubricating part of a linear motion system to perform lubrication. When the content is less than 30 parts by weight, It is difficult to expect lubrication due to a shortage of the content. When the amount exceeds 90 parts by weight, the mechanical properties are deteriorated and the workability is lowered, which makes it difficult to produce lubricating products such as gaskets and lubricating seals.

The crosslinking agent contains 0.06 to 0.6 part by weight of a crosslinking agent based on 100 parts by weight of the mixed resin. When the content is less than 0.06 parts by weight, the mechanical properties are deteriorated. When the content is more than 0.6 parts by weight, excess gelation occurs due to networking between main chains due to excessive reaction, resulting in excessive increase in hardness and appearance damage have.

The crosslinking agent may be selected from the group consisting of dicumyl peroxide, dibenzoyl peroxide, cyclohexanone peroxide, t-butyl peroxyisopropyl carbonate, t-butyl peroxylaurate, t- Butyl diperoxyphthalate, t-dibutylperoxymaleic acid, t-butylcumylperoxide, t-butyl hydroperoxide, 1,3-bis (t-butylperoxyisopropyl) benzene, methyl ethyl ketone peroxide, (2,4-dichlorobenzoyl) peroxide, 1,1-di (t-butylperoxy) -3,3,5-trimethylcyclohexane, 2,5- (T-butylperoxy) hexane, di-t-butylperoxide, and n-butyl-4,4- And any one selected.

If the content of the antioxidant is less than 0.1, it is difficult to achieve the structural protection of the resin from heat or pressure generated during mixing and processing. If the content of the antioxidant is more than 0.8 part by weight, the transition phenomenon during use in a gasket, And the mechanical properties may be lowered.

Such antioxidants include pentaerythritol tetrakis (3,5-ditert-butyl-4-hydroxyhydrocinnamate) and tris 2 (3,5-ditert- , And 4-di-tert-butylphenyl phosphite] is preferable.

INDUSTRIAL APPLICABILITY As described above, the composition for oil-containing resin products according to the present invention and the lubricating products using the same have mechanical properties that can serve as conventional gaskets or lubricating seals, The maintenance cost and time required for the conventional lubrication can be saved.

In addition, the above-mentioned resin composition and the lubricating product using the same provide not only the oil to be retained in the chain structure for a longer time by crosslinking by the crosslinking agent but also the oil flow rate is adjusted by controlling the amount of the crosslinking material, .

In addition, the antioxidant has the effect that the properties of the product are maintained unchanged for a long time.

1 is a drawing showing the result of oil leaching test by resin;
2 is a drawing showing the result of oil leaching test according to the content of DCP of an LDPE / UHWPE mixed resin
3 is a view showing a structure of a lubricating seal according to the present invention;
4 is a view showing the oil leaching test result of the lubricating seal according to the embodiment of the present invention
5 is a view showing an apparatus for testing reciprocating friction wear of a lubricating seal according to the present invention
6 is a view showing a result of reciprocating friction wear test of the lubricating seal according to the present invention
Fig. 7 is a view showing a wear trace according to the reciprocating friction wear test of the lubricating seal according to the present invention
8 is a graph showing the amount of wear and tear on the reciprocating friction wear test of the lubricating seal according to the present invention

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, the terminology used in the present invention, the characteristics of the resin, and an experimental method will be described.

LDPE (Low Density Polyethylene) is a synthetic resin produced by polymerizing ethylene. It is a transparent solid (density 0.91 ~ 0.94) at room temperature. It has low crystallization and excellent workability, flexibility and transparency. It is used as raw material for lap and the like.

Linear low-density polyethylene (LLDPE) is linear and contains a small branch like LDPE and is low density. It has a molecular weight distribution narrower than that of LDPE and has excellent physical properties such as excellent electrical insulation and withstanding voltage characteristics, excellent mechanical properties, good chemical resistance, easy processing, relatively low cost, good dielectric properties, Good water resistance and moisture resistance.

HDPE (High Density Polyethylene) is a synthetic resin produced by polymerization of ethylene. Its properties are semitransparent solid (density is 0.94 or more) and has excellent strength but poor flexibility workability. It is mainly used as raw materials for disposable shopping bags, containers, .

UHPE or Ultra High Molecular Weight Polyethylene (UHWPE) has a molecular weight of 100 to 800 million, which is one digit larger than that of general-purpose PE (10 to 300 thousand). It has exceptional performance compared to general-purpose PE and is positioned as an engineering plastic with polyacetal, nylon, and fluorine resin.

Polyolefin elastomer (POE) is a resin that gives elasticity by using butene or octane, which is long chain of olefin series, and is used for improving properties of various resins by copolymerization or blending. Is used.

The elution characteristics were obtained by exposing the prepared specimen to an oven at 50 ° C for 2 days, wiping off the eluted oil, and measuring the weight loss rate of the specimen for 30 days (wt%).

The tensile strength and the bending strength were measured in accordance with a known tensile strength and bending strength test method, and the strength (kg / cm 2) of the sample at breakage was measured.

Hardness was measured with a plastic composition Rockwell Shore A durometer.

According to this test method, LDPE, LLDPE, HDPE and POE were mixed with oil at a ratio of 100: 80 in order to find a resin suitable for the composition for oil-containing resin product of the present invention and a lubricating product using the same, (Dicumyl Peroxide) is mixed with 1 parts per hundred (100 parts per hundred) resin of the resin and 0.12Phr of an antioxidant, and the mixture is subjected to migration test at 50 ° C in an oven.

As shown in FIG. 1, the higher the molecular weight of the resin, the more stable the migration of the HDPE and the oil mixed material is. However, HDPE hardness is hard due to its high density and it is difficult to seal.

The higher the density, the more stable the oil elution and the lower the moldability. Therefore, in order to facilitate moldability and sealing function of the resin product, LDPE having excellent moldability and highly dense resin are mixed, In order to select the resin to be mixed, the dissolution characteristics are as follows.

(Example 1)

80 parts by weight of oil, 0.1 part by weight of dicumyl peroxide, 0.15 part by weight of antioxidant Anox 20 (Chemtura Corporation) and 0.15 part by weight of Alkanox 240 (Chemtura Corporation) were added to 100 parts by weight of LDPE and UHWPE 7: 3 by weight And these were premixed and then mixed at 150. The composition thus prepared was injected in the form of a linear motion system gasket or a lubricating seal, and physical properties thereof are shown in Table 1.

(Example 2)

80 parts by weight of oil, 0.1 part by weight of dicumyl peroxide, 0.15 part by weight of antioxidant Anox 20 (Chemtura Corporation) and 0.15 part by weight of Alkanox 240 (Chemtura Corporation) were added to 100 parts by weight of LDPE and LLDPE 7: 3 by weight And these were premixed and then mixed at 150. The composition thus prepared was injected in the form of a linear motion system gasket or a lubricating seal, and physical properties thereof are shown in Table 1.

(Example 3)

80 parts by weight of oil, 0.1 part by weight of dicumyl peroxide, 0.15 part by weight of antioxidant Anox 20 (Chemtura Corporation) and 0.15 part by weight of Alkanox 240 (Chemtura Corporation) were added to 100 parts by weight of LDPE and HDPE 7: And these were premixed and then mixed at 150. The composition thus prepared was injected in the form of a linear motion system gasket or a lubricating seal, and physical properties thereof are shown in Table 1.

(Example 4)

80 parts by weight of oil, 0.1 part by weight of dicumyl peroxide, 0.15 part by weight of antioxidant Anox 20 (Chemtura Corporation) and 0.15 part by weight of Alkanox 240 (Chemtura Corporation) were added to 100 parts by weight of LDPE and POE 7: And these were premixed and then mixed at 150. The composition thus prepared was injected in the form of a linear motion system gasket or a lubricating seal, and physical properties thereof are shown in Table 1.

(Comparative Example 1)

80 parts by weight of oil, 0.1 part by weight of dicumyl peroxide, 0.15 part by weight of antioxidant Anox 20 (Chemtura Corporation) and 0.15 part by weight of Alkanox 240 (Chemtura Corporation) were added to 100 parts by weight of LDPE and UHWPE 3: And these were premixed and then mixed at 150. The composition thus prepared was injected in the form of a linear motion system gasket or a lubricating seal, and physical properties thereof are shown in Table 1.

Example 1 Example 2 Example 3 Example 4 Comparative Example 1 The amount of oil (wt%) eluted for 30 days 2.75 5.80 4.58 3.84 3.12 Tensile strength (kgf / cm2) 46 49 35 34 50 Flexural Strength (kgf / cm2) 55 47 41.8 45 57 Hardness 80 84 85 82 95

As shown in Table 1, it was confirmed that the amount of oil eluted in Example 1 was more stable than that in Examples 2, 3 and 4 and Comparative Example 1, and the mechanical properties were suitable for use as a gasket or a lubricating seal .

Therefore, in order to investigate the effect of mixing the LDPE and the UHWPE in addition to the mixing ratio and the elution characteristics according to the addition amount of the crosslinking agent, the mixing ratio of LDPE and UHWPE was adjusted to 6: 4 by weight , And the eluted oil was measured at intervals of 2 days by varying the DCP (crosslinking agent) content to 0.5 to 1.3 Phr (parts by weight).

As a result, as shown in FIG. 2, in the case of the resin of the LDPE / UHWPE mixed series, the tendency of the oil elution amount in the early stage is not known as the DCP content is increased, but the increase in the oil elution amount is decreased.

It can be seen that DCP maintains the oil content through crosslinking and the amount of elution is stabilized. However, when DCP is added excessively (usually more than 1Phr), excessive crosslinking causes the resin to be destroyed and broken, which can be seen from many references. In this experiment, too, I can not capture it well and I can see that there is a lot of early oil leaching.

As a result, a crosslinking agent (Trigonox 101) was mixed with 0.25Phr, paraffin oil 80Phr, and antioxidant 0.12Phr based on the weight of the mixed resin as shown in FIG. 3 by mixing LDPE and UHWPE in a ratio of 6: 4 As shown in FIG. 4, the lubricating seal was injected between the case and the thick plate as a result of inserting a lubricating seal between the case and the thick plate. As a result, it was found that the lubricating seal maintained a gentle curve over time, The resin with the resin composition can keep the lubrication effect for a long time because the oil leaching amount is kept constant even after the lapse of time.

On the other hand, a resin composition obtained by mixing 0.25Phr of a crosslinking agent (Trigonox 101) based on the weight of the mixed resin, 80Phr of paraffin oil and 0.12Phr of an antioxidant was added to a mixed resin obtained by mixing the LDPE and UHWPE in a ratio of 6: 4 As a result of carrying out a reciprocating friction wear test at a reciprocating frequency of 3.17 Hz under a load of 300 g, a reciprocating stroke of 4 mm and a reciprocating frequency of 3.17 Hz as shown in Fig. 5 using a commercially available lubricating seal, As shown in Table 2, the seal is predicted to have a high degree of hardness and a low possibility of damage to the product during use. Compared to the lubricating seal of the comparative example, the friction coefficient is estimated to be low, It is understood that the sliding resistance is small and the safety of the motion is increased.

division The lubrication seal Commercially available lubrication seals One 42 35 2 42 38 3 40 38 Average 41 37

In Table 2, three inventive and known lubricating seals were randomly selected and tested and their average values were examined.

On the other hand, the lubricating seal sold in the above-mentioned market is obtained by polymerizing a monomer and a polymer of a thermosetting resin together and containing 20 to 50 wt% of a lubricating oil. The thermosetting resin uses a diallyphthalate series and the base resin is an olefin series.

As shown in FIGS. 7 and 8, in the case of a wear trace, it can be seen that the size of a wear trace of the lubricant seal of the present invention is significantly smaller than that of a commercially available lubricant seal. The durability against abrasion at the time of LM rail contact is superior to that of commercially available lubrication seals in terms of the lubricating seal of the present invention, considering the size of the abrasion marks and the occurrence of plastic flow in the material. .

Based on the above experimental results, the resin was prepared by mixing LDPE and UHWPE in a ratio of 6-7: 4-3, adding 30 to 90 parts by weight of oil, 0.06 to 0.6 part by weight of a crosslinking agent and 0.1 to 0.8 parts by weight of an antioxidant Is preferably used.

The present invention is not limited to the above-described embodiments, and various modifications and changes may be made thereto by those skilled in the art to which the present invention belongs. Accordingly, the spirit of the present invention should not be construed as being limited to the embodiments described, and all of the equivalents or equivalents of the claims, as well as the following claims, belong to the scope of the present invention .

Claims (4)

Low-density polyethylene (LDPE): ultra-high density polyethylene (UHWPE) in a weight ratio of 6-7: 4-3,
Based on 100 parts by weight of the mixed resin, 30 to 90 parts by weight of oil,
0.06 to 0.6 parts by weight of a crosslinking agent and
And 0.1 to 0.8 parts by weight of an antioxidant. The method of claim 1, wherein the cross-linking agent is selected from the group consisting of dicumyl peroxide, dibenzoyl peroxide, cyclohexanone peroxide, t-butyl peroxyisopropyl carbonate, t-butyl peroxylaurate, Butyl diperoxyphthalate, t-dibutylperoxymaleic acid, t-butylcumylperoxide, t-butyl hydroperoxide, 1,3-bis (t-butylperoxyisopropyl) benzene, methyl ethyl ketone Di- (2,4-dichlorobenzoyl) peroxide, 1,1-di (t-butylperoxy) -3,3,5-trimethylcyclohexane, 2,5-dimethyl- Butylperoxy) hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, di- ) ≪ / RTI > valerate. ≪ RTI ID = 0.0 > 11. < / RTI > The antioxidant according to claim 1, wherein the antioxidant is pentaerythritol tetrakis (3,5-ditert-butyl-4-hydroxy- hydroxyhydrocinnamate], and tris (2,4-di-tert-butylphenyl) phosphite]. (UHWPE) in a weight ratio of 6-7: 4-3, and a mixture of 30-90 parts by weight of oil, 0.06-0.6 parts by weight of a crosslinking agent, And 0.1 to 0.8 parts by weight of an antioxidant.

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