JPS6049084B2 - Method for manufacturing crosslinked polyolefin resin molded products with improved properties - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a crosslinked polyplane resin molded article with improved properties, and in particular, a method for producing a crosslinked polyplane resin molded article with improved properties, in particular a method for producing a crosslinked polyplane resin molded article, in which a small amount of an incompatible resin is distributed in the form of fibers in a material mainly composed of a polyolefin material. The present invention relates to a method for obtaining a crosslinked polyolefin resin molded article with improved characteristics, which is firmly fixed to a polyolefin matrix by crosslinking treatment after molding.

Conventionally, methods for improving the physical properties of polyolefin resin molded articles, ie, methods for producing polyolefin resin molded articles with improved physical properties, include the following. In other words, (a)
There are chemical methods using crosslinking, grafting, copolymerization, blending, etc., and physical methods using composites with different materials such as inorganic materials and metal materials. For example, (a) the method of improving physical properties by crosslinking can be expected to have the great advantage of improving heat resistance. However, for polypropylene and the like with poor crosslinking efficiency, a crosslinking aid is required. 2 Crystallinity decreases.

3. In the case of a ship's bridge that has been irradiated with radiation, the wall thickness is limited.

4) Chemical crosslinking has the disadvantage that crosslinking cannot be carried out at the same time as molding. In addition, the method by (mouth) compounding,
1 Generally heavier.

Considering the adhesion between the two interfaces, if fibers or the like are used, pretreatment and the like are required, which increases the number of steps.

Therefore, there is an inadequacy in that the cost increases. When the inventor conducted intensive research into a method for manufacturing crosslinked polyolefin resin molded products with improved properties, he added a high melting point resin with poor compatibility to polyolefin and extruded it under special conditions to create a blended high melting point resin. We focused on the fact that a unique molded product having a structure similar to FRTP, in which the polyolefin becomes fibrous and the polyolefin exhibits a matrix phase, can be obtained.

However, it has been found that even in this case, the adhesion at the interface between the fibrous high melting point resin and the polyolefin matrix is low, resulting in poor product properties. Therefore, as a result of further research into the microstructure of crosslinked polyolefins, their physical properties, and the crosslinking reaction of polyolefins, the inventors developed a special extrusion molded product consisting of a blend composition of polyolefin and a certain type of incompatible resin. We have found that the adhesion between different types of polymers can be improved by crosslinking.

That is, compared to polyolefins that are generally easily crosslinked, polyamides with a high modulus of elasticity that are heat resistant and have excellent fiber-forming properties have a solubility parameter value of 9.
By mixing zero or more incompatible polymers, extrusion molding, and then crosslinking, a composite material with improved physical properties can be obtained by crosslinking occurring at the interface between the polyolefin matrix and polyamide and crosslinking the polyamide. This discovery led to the completion of the present invention.

According to the present invention, by improving the adhesion at the interface between different polymers as described above, the resulting molded product has properties that have significantly improved mechanical strength such as Young's modulus and heat resistance such as high temperature creep resistance. An improved crosslinked polyolefin resin molded article can be obtained. That is, to explain the method of the present invention in more detail, one or two types of thermoplastic resins other than polyolefins, which have a high melting point with a solubility parameter value of 9.0 or more and have fiber moldability, are used for polyolefins. The above is mixed in 5 to 3 parts by weight, preferably 5 to 3 parts by weight, and then extrusion molded and crosslinked by radiation, irradiation, etc. to obtain a polyolefin obtained by a conventional crosslinking method for polyolefin alone. Compared to cross-linked polyolefin molded products, polyolefin resin molded products can be obtained that have superior mechanical properties such as Young's modulus and tensile strength, and superior heat resistance such as high-temperature creep resistance.

The polyolefin in the present invention refers to high density, medium density,
Low density polyethylene, polypropylene, polybutene-1
, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, etc., preferably high density, medium density,
Low-density polyethylene, polyethylene pyrene, and those that can be crosslinked by radiation, crosslinking agents, etc. are all used.

In addition, high melting point thermoplastic resins with a solubility parameter of 9.0 or higher include nylon 6, nylon 66
, nylon 10, polyamide resin of nylon 1, polyimide and its derivative resin, thermoplastic polyester resin such as polyethylene 7-ethylene terephthalate, polybutylene terephthalate, fiber moldable resin such as polycarbonate resin, polysulfone resin, etc. are particularly preferred. These are polyamide resin and polycarbonate resin.

O In the present invention, the blending amount of the high melting point thermoplastic resin with a solubility parameter of 9.0 or more is
The reason for limiting the amount to 5 to 5 parts by weight is that below 5 parts by weight, there is not much difference in mechanical strength and heat resistance compared to the case without additives, and if the part by weight is 5 or more, the mechanical strength and heat resistance are This is because although the strength and heat resistance are good, the elongation is significantly reduced.

Next, the method of mixing the polyolefin and these high melting point thermoplastic resins is usually in the form of pellets or powder.
It is preferable to use a resin that has been uniformly blended in advance using a device that has a common blending function (such as a mold blender or a pump blender).

The extrusion process for obtaining molded products in the process of the present invention is carried out in an extruder equipped with a screw zone at a temperature higher than the melting point of the resin, which has a higher melting point than the polyolefin. It is absolutely necessary to dissolve the thermoplastic resin.

Furthermore, the temperature of the die head is 40° higher than the melting point of the high melting point material.
It is sufficient as long as it is below a high temperature of °C. The temperature is preferably between the melting point of the high melting point thermoplastic resin and 60°C lower than it. The reason for this is that fiber formability is better when extruded at a temperature lower than the melting point of the high melting point thermoplastic resin, and when extruded at a temperature 40°C or more higher than the melting point of the high melting point material, the resin tends to deteriorate significantly. This is because there is. Further, the extruder used here is preferably one with a large L/D value or a device with high kneading effect such as a twin-screw extruder, since it is necessary to uniformly distribute each blended component in the molded body.

The shape of the extruded molded product is film, sheet [
For example, a molded product such as a rod, a vibrator, a wire coating, or various molded products by injection may be used, as long as the equipment used has a kneading function similar to that of an extruder.

Further, the above film or sheet may be further stretched before use, and biaxial stretching is particularly preferred since the direction of the fibers changes randomly. The extracted film/sheet may also be crosslinked and then stretched. A blowing agent may also be used to form a foam. Next, methods for crosslinking the above-mentioned molded article include, for example, a method using radiation, and a chemical crosslinking method using organic peroxides, azide compounds, etc.

When irradiating with radiation, the irradiation amount is 50 Mrad or less, preferably in the range of 0.5 to 20 Mrad, and outside this range, the treatment effect is small as shown in the Examples below.

In the case of a chemical crosslinking method, with a commonly used crosslinking agent, the screw zone reaches a temperature higher than the decomposition temperature of the crosslinking agent during extrusion, so it is difficult to extrude as is.

However, if a radical promoter such as hydroquinone or hydrazyl is added in advance and extruded, organic peroxides and azide compounds can also be used. In addition, a method using so-called silane crosslinking using a silane compound such as vinyltrimethoxysilane and an organic peroxide, and a method in which the crosslinking agent is dissolved in a solvent after molding and the polymer is impregnated with the crosslinking agent, followed by heat treatment. There is no problem with the method of application. Usually, the gel content of the molded article obtained in this way is 20 to 80%. During crosslinking, a crosslinking aid may be used to further increase the crosslinking efficiency. On the other hand, antioxidants, ultraviolet absorbers, flame retardants, inorganic fillers 5, etc. can also be added. The method for producing a crosslinked polyolefin resin molded article with improved properties according to the present invention can improve mechanical and thermal properties, and can also improve mechanical and thermal properties using existing equipment. The industrial value is very large because it can be achieved by

EXAMPLES The present invention will be explained in more detail below with reference to Examples.

Note that the term "parts" hereinafter means "parts by weight." Example 1 and Comparative Examples 1 and 2 Low density polyethylene (Mll.
MlO2l, the value of the solubility parameter is 12.
5) Dry blend the W part with a V-type blender for 3 minutes, and then blend this into a diameter of 4 cyrf0rL under the following conditions.
It was extruded into a sheet with a width of 15" and a thickness of 0.3" using a φ extruder.

In other words, the extrusion temperature is 2500 at the center of the extruder cylinder.
The temperature of the C1 tie head was 210°C. This sheet obtained by extrusion was irradiated with an electron beam of 10 Mrad in air using a 5 MeV linear accelerator. Next, for comparison with this Example 1, as a comparative example 1, the above-mentioned Example 1
A sample was prepared in which no electron beam irradiation was performed.

Further, as Comparative Example 2, a sample was prepared in which the nylon 6 used in Example 1 was not used at all, but the process was otherwise performed in the same manner as in Example 1. Table 1 shows the physical property values of each of these three.

Next, the temperature of the sample obtained in Example 1 was 1100C.
The results of the creep test under one load of 4.4 kg and 1 c are shown in FIG. 1 together with Comparative Examples 1 and 2.

In Example 1, remarkable effects of the present invention were observed.
Example 2 and Comparative Examples 3, 4, 5 Isotactic polybutyrene (MIO.8, M.P.
．． l67C) 1 (1) part, a polycarbonate (trade name Teijin Panlite Kl3OO manufactured by Teijin Ltd., solubility parameter 9.5) nodule, and divinylbenzene 2
The parts were mixed into 3 powders using a V-type blender, and the powder was mixed into powders with a diameter of 4 mm using an extruder with a diameter of 40 WLφ under the following conditions.
．． It was extruded into a 5Tfr1nφ rod.

That is, the extrusion temperature was 250°C at the center of the extruder cylinder and 220°C at the C1 die head. The extruded product thus obtained was irradiated with an electron beam of 5 Mfa in air using a 5 MeV linear accelerator.

Next, for comparison with this Example 2, a comparative example 3 was prepared in which the electron beam irradiation was not performed at all.

For comparison, a sample was prepared as Comparative Example 4, which was extruded under exactly the same extrusion conditions except that the polycarbonate of Example 2 was removed, and was also irradiated with an electron beam of 5 MeV.

-------Furthermore, as Comparative Example 5, a sample was prepared in which the electron beam was irradiated with 60 Mrad instead of the 5 Mrad. Table 2 below shows a comparison of the physical property values of each of these. In Example 2, remarkable effects of the present invention were observed.

Example 3 and Comparative Examples 6 and 7 High density polyethylene (MlO
．． 7.M. P. 100 parts of l28C) and nylon 6 (
Toray Millan CMlO2l, manufactured by Toray Industries, Inc., with a solubility parameter value of 12.5), is blended with a nodule in a V-type blender, and this is mixed into a width using an extruder with a diameter of 4hφ under the following conditions. 150WL1 thickness 0
．． It was extruded into 3 gourd sheets.

In other words, the extrusion temperature is 2500 at the center of the extruder cylinder.
The temperature of the C1 guide head was 210°C. This sheet obtained by extrusion was mixed with 10% by weight of dicumyl peroxide.
After soaking in the allyl methacrylate solution at a temperature of 60°C for 5 hours to fully impregnate the crosslinking agent, the temperature was 200°C.
The two powders were heated in a hot air constant temperature bath to cause crosslinking. Next, in order to compare with this Example 3, a comparative example 6 was prepared in which only the crosslinking treatment with the above-mentioned crosslinking agent was not performed, and a comparative example 7 was prepared in which the above-mentioned nylon 6 was removed and the same was used. A sample was prepared which was extruded and crosslinked under the same extrusion conditions as in Example 3.

Table 3 shows the physical properties of each of these three materials. In this Example 3, remarkable effects of the present invention were observed.

As shown in the Examples above, according to the method of the present invention, crosslinked polyolefin resin molded articles with excellent mechanical strength and heat resistance were obtained.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the results of a creep test on a molded product according to an example of the present invention.

Claims (1)

[Claims] 1 For 100 parts by weight of polyolefin, substances other than polyolefin with a solvity parameter value of 9
．． 1. A method for producing a crosslinked polyolefin resin molded article with improved properties, which comprises adding 5 to 50 parts by weight of a high melting point thermoplastic resin having a molecular weight of 0 or more to obtain an extrusion molded product, and subjecting the product to a crosslinking treatment.