JPH0881581A - Polymer meshed structure and its production - Google Patents

Abstract

PURPOSE: To obtain a meshed structure with dense and uniform cells and improved in high-temperature heat resistance and modulus of elasticity by using a crystalline thermoplastic and a low-molecular material as the constituents. CONSTITUTION: A crystalline thermoplastic having a melting point of 100-300 deg.C and a number-average molecular weight of 5,000 to 700,000, if necessary, together with 10-90wt.% other plastic is mixed with a low-molecular material of a number-average molecular weight of below 20,000, comprising, e.g. a softening agent, a plasticizer, a tackifier, an oligomer or a lubricant by stirring at a rate as high as at least 300rpm at 100-350 deg.C for 5-120min. The content of the crystalline thermoplastic should be 5-30wt.% based on the total of the crystalline thermoplastic and the low-molecular material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention has a structure in which a low molecular weight material is held between three-dimensional continuous network skeletons made of crystalline thermoplastics and the low molecular weight material is enclosed in continuous cells of a microcell. The present invention relates to a polymer network structure which is used as a cushioning material or the like itself, or for the purpose of utilizing exudation of a low molecular weight material, and a method for producing the same.

[0002]

2. Description of the Related Art In recent years,
As disclosed in JP-A-5-239256 and the like, a polymer blend material of a polymer organic material having a three-dimensional continuous network skeleton structure and a low molecular weight material is known.

This polymer blend material is a mixed system composed of a high molecular weight organic material and a low molecular weight organic material, and by forming a small amount of the high molecular weight organic material into a three-dimensional network skeleton structure, It is a polymer network structure that maintains the characteristics and compensates for the shortcomings of low molecular weight organic materials with high molecular weight organic materials, and that various characteristics are remarkably improved by the synergistic effect of blending low molecular weight organic materials and high molecular weight organic materials. .

Therefore, although it can be applied to a wide range of applications, there is a demand for a polymer network structure having heat resistance at high temperatures and a high elastic modulus in order to allow the development of a wider range of applications.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a polymer reticulated structure having high heat resistance and elastic modulus and capable of being widely used, and a method for producing the same.

[0006]

Means and Actions for Solving the Problems The present inventors have
As a result of intensive studies to achieve the above object, a crystalline thermoplastic, preferably an olefin thermoplastic such as crystalline polyethylene or polypropylene, and a low molecular weight material are added to the crystalline thermoplastic in an amount of 5 to 30. A polymer network structure in which a low molecular weight material is encapsulated in a three-dimensional continuous network structure (open cells of microcells) composed of the crystalline thermoplastic is obtained by mixing so as to have a content of wt%. What is obtained is that the polymer network has a very dense cell structure, is uniform, has good heat resistance at high temperatures, and has a high elastic modulus. A wide range of materials can be enclosed with good retention,
The present invention has been accomplished by finding a polymer network structure having excellent properties such as rich elasticity and a wide range of applications.

Therefore, the present invention is (1) obtained by mixing a crystalline thermoplastic with a low-molecular material, and the low-molecular material is retained between the three-dimensional continuous network skeletons of the above-mentioned crystalline thermoplastic. (2) The polymer network structure according to the above (1), wherein the crystalline thermoplastic is selected from olefin-based thermoplastics, and (3) The crystalline thermoplastic and the low molecular weight material are mixed and used so that the content of the crystalline thermoplastic is 5 to 30% by weight.
Alternatively, a method for producing the polymer network structure according to (2) is provided.

The present invention will be described in more detail below. In the polymer network structure of the present invention, a three-dimensional continuous network skeleton having an internal communication space is composed of a crystalline thermoplastic and a low molecular weight compound is present between the skeletons. The material is retained.

The crystalline thermoplastic has a melting point of 100 to 300 ° C. and a number average molecular weight of 5000.
~ 700,000, preferably 80,000 to 500,000
Those in the range of are desirable.

Specific examples of the crystalline thermoplastic include polyethylene (PE) and polypropylene (P
P), ethylene vinyl acetate copolymer (EVA), polybutylene (PB), acrylonitrile resin, polyvinyl chloride resin, polyvinylidene chloride resin, nylon (6, 6-
6, 6-2, 12), polyethylene terephthalate (P
ET), polybutylene terephthalate (PBT), polycarbonate (PC), polyoxymethylene (PO)
M), polyphenylene sulfide (PPS), fluororesin (PTFE, etc.), polyether ether ketone (P
Examples thereof include synthetic resins such as EEK), and fibrin-based resins such as ethyl cellulose, cellulose acetate, cellulose nitrate, and cellulose propionate. These can be used alone or in admixture of two or more. You can Of these, polyethylene, polybutylene, polypropylene, nylon, polyethylene terephthalate and polybutylene terephthalate are preferable, and crystalline polyolefin plastics such as polyethylene, polybutylene and polypropylene are most preferable.

Further, the crystalline thermoplastic resin according to the present invention may be modified depending on the intended use by modifying it with a hydrophilic group such as a hydroxyl group or a lipophilic group such as a nitro group.

In the present invention, plastics other than the above crystalline thermoplastics may be used in combination with the above crystalline thermoplastics. Examples of such plastics include polybutadiene and butadiene-styrene random copolymer. Polyethylene and ethylene-styrene random copolymer obtained by hydrogenating a block copolymer with a polymer, obtained by hydrogenating a block copolymer of polybutadiene and polystyrene, or a block copolymer of polybutadiene and polystyrene Block copolymers of polyethylene and polystyrene, etc., which can be used, and are 10 to 9 relative to the above-mentioned crystalline thermoplastics.
It can be used in an amount of 0% by weight, preferably 20 to 80% by weight.

The three-dimensional continuous network skeleton composed of such a crystalline thermoplastic has a microstructure as shown in FIG. In FIG. 1, 1 is a three-dimensional continuous network skeleton made of the above-mentioned crystalline thermoplastic, 2 is an internal communication space, and the internal communication space 2 holds a low-molecular material described later. Here, in FIG. 1, the average diameter d of the skeleton 1 is preferably 10 μm or less, and the average diameter D of the cells is preferably 100 μm or less.

On the other hand, the low molecular weight material held in the internal communication space may be solid or liquid, and various materials can be used depending on the application. If the low molecular weight material is an organic material, its number average molecular weight is less than 20,000,
It is preferably 10,000 or less, more preferably 5000 or less. The low molecular weight material is not particularly limited, but the following can be exemplified. Softening agent: A softening agent for various rubbers such as mineral oil type, vegetable oil type, synthetic type, or resin. As mineral oils, process oils such as aromatics, naphthenes and paraffins. Vegetable oils include castor oil, cottonseed oil, linseed oil, rapeseed oil, soybean oil, palm oil, coconut oil, peanut oil, wood wax,
Pine oil, olive oil, etc. Plasticizer: phthalic acid ester, phthalic acid mixed base ester,
Various ester-based plasticizers such as aliphatic dibasic acid esters, glycol esters, fatty acid esters, phosphoric acid esters, and stearic acid esters, epoxy plasticizers, other plasticizers for plastics, or phthalate-based and adipate-based plasticizers,
Sebacate-based, phosphate-based, polyether-based, polyester-based plasticizers for NBR. Tackifier: various tackifiers such as coumarone resin, coumarone-indene resin, phenol terpine resin, petroleum hydrocarbon, rosin derivative, etc. Oligomer: Crown ether, fluorinated oligomer, polybutene, xylene resin, chlorinated rubber, polyethylene wax, petroleum resin, rosin ester rubber, polyalkylene glycol diacrylate, liquid rubber (polybutadiene, styrene-butadiene rubber, butadiene-acrylonitrile rubber, polychloroprene Etc.), silicone-based oligomers, various oligomers such as poly-α-olefins. Lubricants: Hydrocarbon lubricants such as paraffin and wax, fatty acid lubricants such as higher fatty acids and oxyfatty acids, fatty acid amide lubricants such as fatty acid amides and alkylenebis fatty acid amides, fatty acid lower alcohol esters, fatty acid polyhydric alcohol esters, fatty alcohols , Alcoholic lubricants such as polyhydric alcohol, polyglycol, polyglycerol,
Various lubricants such as metal soaps and mixed lubricants.

In addition, latex, emulsion, liquid crystal, bituminous composition, clay, natural starch, sugar, inorganic silicone oil, phosphazene and the like can be used. In addition, animal oil such as cow oil, pig oil, horse oil, bird oil,
Dairy products such as fish oil, honey, fruit juice, chocolate, yogurt, hydrocarbons, halogenated hydrocarbons, alcohols, phenols, ethers, acetals, ketone fatty acids, esters, nitrogen compounds, sulfur compounds Organic solvents such as type, or various medicinal components, soil conditioners,
Fertilizers, petroleum, water, aqueous solutions and the like can also be used.

Further, in the present invention, in addition to the above-mentioned materials, the following fillers may be blended, if necessary. That is, clay, diatomaceous earth, carbon black, silica, talc, barium sulfate, calcium carbonate, magnesium carbonate, metal oxides, mica, graphite, scale-like inorganic fillers such as aluminum hydroxide, various metal powders, wood chips, glass powders , Ceramic powder, granular or powdered solid filler such as granular or powdered polymer, other various natural or artificial short fibers, long fibers (for example, straw, hair, glass fiber, metal fiber, other various polymer fibers, etc.) Etc. can be blended.

The polymer network structure of the present invention is one in which a low molecular weight material is held between the three-dimensional continuous network skeletons (inside the internal communication space) made of crystalline thermoplastic as described above. However, in this case, it is desirable to form the three-dimensional continuous network skeleton with as little crystalline thermoplastic as possible.

Here, where A is the amount of the crystalline thermoplastic constituting the three-dimensional continuous network skeleton and B is the amount of the low molecular weight material and other components, the weight fraction of the crystalline thermoplastic [{A / ( A + B) × 100}] is 5 to 30
%, Preferably 7 to 25%.

The polymer network structure of the present invention comprises the above-mentioned predetermined amount of crystalline thermoplastic resin, a low molecular weight material and, if necessary, other components, the crystalline thermoplastic resin having a three-dimensional continuous network structure. Can be obtained by mixing under mixing conditions capable of forming

Specifically, it is recommended to use a high-speed agitator such as a high-shear type agitator and mix at an agitation speed of 300 rpm or more, preferably 500 rpm or more, more preferably 1000 rpm or more. When not stirring at high speed, for example, using a roll or rotor type mixer or a cylinder type mixer and mixing at a low speed, it is difficult to obtain a uniform three-dimensional continuous reticulated skeleton structure of the target crystalline thermoplastic. is there. The mixing temperature is 10
The range of 0 to 350 ° C is desirable, and the mixing time is 5 to 120.
Minutes are good.

The polymer network structure thus obtained has a structure in which the above-mentioned low molecular weight material is held between three-dimensional continuous network skeletons of crystalline thermoplastics having a mesh structure, and is crystalline. Since the thermoplastic three-dimensional continuous network skeleton has high temperature heat resistance and a high elastic modulus, for example, an elastic material such as a cushion material by itself,
Alternatively, properties such as sustained release of the low molecular weight material can be utilized. For this reason, it is possible to provide products in a wide range of industrial fields, particularly household appliances, sports equipment, industrial equipment, precision equipment, transportation equipment, construction, civil engineering, medical care, leisure, and the like. For example, as the vibration-proof / vibration-damping / cushioning material, a sealing member, a packing, a gasket, a fixing member such as a grommet, a support member such as a mount, a holder, and an insulator, and a cushioning member such as a stopper, a cushion, and a bumper can be cited. Furthermore, as shock absorbers, sports equipment such as grabs, mitts, golf clubs, and tennis rackets, insoles for shoes, various toys, audio equipment, electronic and electrical equipment, or beds and chairs, especially for medical applications that keep the same posture for a long time. It is preferably used as a bed, a barber / beauty bed, a theater chair, and a vehicle material that receives vibration.

It can also be used in medical devices such as artificial limbs, artificial hands, robots, electrode materials for measuring electrocardiograms, electrode materials for low-frequency therapeutic devices, and the like. Furthermore, it can be used as an ultra-low hardness rubber for OA equipment, seismic isolation rubber, anti-vibration rubber, and even racing tires. In addition, it can be used as a low hardness plastic for various molding materials. Furthermore,
Since it is possible to control the release of the low molecular weight material to the outside, it is also used for various sustained release materials that utilize the release characteristics of fragrances, medical agents, functional materials and the like. In particular, paper (including thin-leaf materials other than paper) feed rubber rolls, for example, copiers, printers, and other OA equipment and automated teller machines (ATM),
It is suitable for various feeding rolls such as money changers, counters, vending machines, and cash dispensers (CDs).

[0023]

The polymer network structure of the present invention has a structure in which a low molecular weight material is held between three-dimensional continuous network skeletons made of crystalline thermoplastics and the low molecular weight material is enclosed in a porous material. It can be used for a wide variety of purposes, such as having a cushioning material or the like, or utilizing exudation of a low molecular weight material.

The manufacturing method of the present invention can easily and surely manufacture such a structure.

[0025]

EXAMPLES The present invention will now be specifically described with reference to examples, but the present invention is not limited to the following examples.

[Example] Polypropylene (melting point 169 ° C), polyethylene (melting point 125 ° C) as a crystalline thermoplastic, diheptyl phthalate (DHP), diisodecyl adipate (DID) as a low molecular weight material
Using A), these were stirred by a high shear mixer under the mixing ratio and stirring conditions shown in Table 1 to obtain a polymer network structure.

The average diameter d of the skeleton and the average diameter D of the cells of the obtained polymer network structure were determined. The results are also shown in Table 1.

[0028]

[Table 1]

[Brief description of drawings]

FIG. 1 is a schematic diagram showing the structure of a three-dimensional continuous network skeleton according to the present invention.

[Explanation of symbols]

 1 Three-dimensional continuous mesh structure 2 Internal communication space

Claims (3)

[Claims] 1. A low molecular weight material obtained by mixing a crystalline thermoplastic with a low molecular weight material, wherein the low molecular weight material is held between three-dimensional continuous network skeletons of the crystalline thermoplastics. Polymer network structure. 2. The polymer network structure according to claim 1, wherein the crystalline thermoplastic is selected from olefinic thermoplastics. 3. A crystalline thermoplastic and a low molecular weight material, wherein the content of the crystalline thermoplastic is 5 to 3.
The method for producing a polymer network structure according to claim 1, wherein the polymer network structure is used in a proportion of 0% by weight and mixed.