JPS59102936A - Composite polymer material for ultra-low temperature use - Google Patents

Abstract

PURPOSE:To provide a composite polymer material having extremely excellent mechanical properties e.g. elasticity, strength, dimensional accuracy, etc. within an ultra-low temperature range, by compounding a polymer with a flaky powder having particular shape at a specific weight ratio. CONSTITUTION:A composite polymer material having excellent mechanical properties at an extremely low temperature, i.e. at <=-100 deg.C, is prepared by compounding (A) 20-50wt% of flaky powder (e.g. mica) having a weight-average aspect ratio of >=15 and a weight-average flake diameter of <=35mum and (B) 80-50wt% of a polymer (preferably having a flexural strain at break of >=1% measured in liquid nitrogen, e.g., polyethylene, nylon 6, polycarbonate resin, etc.).

Description

[Detailed description of the invention] The present invention relates to A-grade agglomerates for ultra-low temperature applications.

More specifically, it contains a flake powder with a specific shape and a specific A content fraction, and has mechanical properties such as elasticity, strength, and dimensional accuracy that are extremely easily peeled off at ultra-low temperatures, particularly in the temperature range of -10σ℃ or lower. The present invention relates to a polymer composite material for ultra-low temperature use.

In recent years, ultra-low-temperature fluids such as liquefied natural scum and liquefied nitrogen gas have been widely used in various industrial fields, and 9% nickel steel and aluminum alloys are used for storage and import equipment for these ultra-low-temperature fluids. The remaining pA'N materials are used.

However, these metal materials are expensive, and their molding requires extremely advanced precision processing technology. - Sword plastics are lightweight polymeric materials that can be used for injection molding, compression molding, etc., but due to the fragility of plastics, they cannot be used when cooled from room temperature to the low temperature range of use. In addition to causing SG due to changes in shape and dimensions, when used in combination with metal, cranks are likely to occur at the combination site due to internal stress due to the difference in shrinkage rate between metal and plastic. Furthermore, when using ultra-low temperature materials made of these plastics as paints,
Use when cooling to low UK l or room temperature and use low temperature #+
Cracks are likely to occur in the coating film when performing thermal cycles at bJ.

As a result of intensive research to develop a polymer material that can be used in the ultra-low temperature range of -1oo'c or lower, the present inventors have discovered that flake-like powder having a specific shape can be made into a polymer material with a specific weight fraction. The present invention was based on the discovery that a polymer composite material having extremely excellent mechanical properties in the ultra-low temperature range of -100° C. or lower can be obtained by blending it with the above. That is, in the present invention, the average aspect ratio of 1ffit is 15 or more, and N = 20 to 50% by weight of flaky powder with an average flake diameter of 35 μm or less and a high molecular weight polymer of 8
The present invention is an ultra-low temperature polymer composite material containing 0 to 50% by weight and having excellent mechanical properties in the ultra-low temperature region below -100''C.

There are no particular restrictions on the type of polymer used in the present invention, and examples include aliphatic polyolefin resins such as polyethylene and polypropylene, and nylon 6.66.6.
Can melt polyamide resins such as 10.12, polybutylene terephthalate, polyethylene terephthalate, thermal iJ copper pourable polyester resins, polycarbonate resins, polysulfone resins, polyphenylene oxide resins, polyacetal resins, soft polyurethane/resins, epoxy resins, etc. However, these resins used in the present invention are processed by the three-point bending method in liquid nitrogen! It is preferable that the bending strain at break determined by 1111 is 1% or more.

The bending fracture strain measured by the three-point bending method is y = 1 straight according to the following equation ('').

Bending strain at break (chi) -6dδ/z2xlO (J tl
) In formula (1), t is the span, d is the specimen thickness, and δ
is the key point where the test piece breaks during three-point bending. Furthermore, there is no particular restriction on the degree of polymerization of the resin of TorL et al., but it is desirable that the degree of polymerization be lower in order to achieve a bending failure of 1% or more in liquid nitrogen.

The flaky powder used in the present invention includes, for example, mica powder such as muscovite (muscovite) and phlogopite (70 gobite), glass flakes, talc, clay, and metal flakes such as aluminum. However, mica powder is particularly preferably used in the polymer composite material of the present invention.The flaky powder of the present invention has an average diameter of 3.
5 μm or more, preferably 30 μm or less, more preferably 20 μIn or more F), and the mouse average aspect ratio is 15 or more, preferably 20 or more, and more preferably 30 or more. Average flake diameter is 35μm
The strength of the composite material using flakes larger than 11 decreases in the low temperature region, and the average aspect ratio of
Composite materials using flakes of less than 5% cannot be used because the strength of the workmanship is low and the dimensional change is large when cooled to an ultra-low temperature.

The 16-molecule pellet material used for ultra-low I crystal applications is required to have excellent strong ejection properties at the low operating temperatures and to have small dimensional changes when cooled from room temperature to the lower operating temperatures. , such polymeric composites are different from the morphology of the dental molecule composite oleracea, which is recommended from room temperature to 411i. For example, the composite material of the present invention has a particle size of flake powder at room temperature.
The thicker the wire, the higher the bending strength.
In the ultra-low temperature range below, conversely, the smaller the particle size, the greater the bending strength.
It is preferable that the 1-shaped piece is a Tomiai piece with a breaking strain of 1 or more.

In addition, in the present invention, p, % average flake diameter is measured by plotting the lees that have been wet-classified using a standard sieve with a diameter of 1/2 in each ridge on a Rosin-Ran plate ler diagram. The opening ZSO of the sieve through which 50 weight percent of the applied powder passes is determined by Φ7, and is the value determined by the following equation (2).

2 ('j' - t5o - (2) 1 + hold the average flake diameter.
27, Ni29B, P94) KLS611 >ii
Sold bundle II (one degree tie from average flake thickness L)
(7'L = 11α determined by formula 81.

α=t/l (81 α is the average aspect ratio of 41 feet, and is -1 (the average flake diameter of the tanner, which is calculated using the 2F formula.
The mixing ratio of flake powder in the composite material is 20 to 50.
iLDi% is 18 in the middle. Mixing ratio of flake powder is 2
In the region where 0% sparse amount is not dropped, the frequency of moldings of the material to be joined is low, and the dimensional change due to cooling is too small, so it cannot be used. - 10,000, In the area where the mixing ratio of flaky powder is more than 50%, the viscosity that toughens during molding increases and the molding process reaches a peak of 511 tons. 1. The strength of the composite material hz shape also increases. It is not recommended to use it because it will decrease.

In the composite material of the present invention, the silane has an amino group,
41) A silane compound such as an epoxy group or a vinyl group that has affinity for A11 with a fat matrix, and X is an alkoxyl group or a silane compound. / U / Even if the coupling agent is attached to the surface of the flake-like powder in advance, the flake-like powder may be
It may be added directly when kneading with fat. *There is no name for the type of silane coupling agent used in this article, but there are amino groups, epoxy groups,
Silane coupling agents containing vinyl groups often produce good young fruits.

The addition rate of the silane coupling agent is generally 0.1 to 3% of the amount of M in the flaky powder, preferably 0.3 to 2%.
mjt%. By completely improving the menstrual adhesive strength between the flakes and the matrix resin using a silane coating agent, it is possible to further improve the strength of the composite material molded product in the low temperature range, and the strength of the composite material when cooled to the operating temperature can be improved. Changes in shape and dimensions of the molded product can also be reduced.

Akira's arrow material VC must be glass fiber,
Reinforcing materials such as carbon fibers and organic fibers, and fillers such as calcium carbonate, barium sulfate, wollastotite, glass peas, and silica powder can be used in combination. In addition, there is no problem in adding known additives such as colorants, lubricants, stabilizers, plasticizers, and antistatic agents.

The composite material according to the present invention is processed and used as follows. For composite materials with thermo-OT plastic resin as a matrix, after melting and mixing the flake powder and resin using an extruder, Ni-Goo, roll, etc. to create a composite, it can be processed by injection molding, extrusion molding, compression molding, It can be used by forming into any shape such as structural parts, wall parts, electrical parts, sheets, rods, pipes, etc. by calender molding etc. - For the material with thermosetting resin purple matrix, after mixing flakes with uncured resin liquid, it is suitable for compression molding, injection molding, transfer molding, spray-up, hand lay-up, etc. By molding and curing using the same method, it can be used as tK structural parts, machine parts, *machine parts, etc. An uncured resin liquid mixed with flakes prepared in the same manner as the reed may also be used as a paint or lining material.

Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited in any way by the Examples V of the inventors and coworkers.

Examples 1-6 Comparison 1! /! I ~ 5 Phlogopite powder with different flake shapes, polybunalene terephthalate resin (Iu to P B 'l') with a limiting viscosity of 13, 9 dt/y
A series of experiments were carried out using γ-aminopropyltriethoxylan as a raw material. Mica powder, γ-aminopropyltriethoxysilane and P B
The Hund's proboscis mixed in a Ti Henschel mixer was fed to a single-screw extruder and mixed at 250'C to obtain a compound. The compound was fed to an injection molding machine and injection molded at 250″G to form a 100XI0
A square plate test piece of 0×2 tar was obtained. The gate is 0.
It is a 75m thick film gate. A test piece with a width of 10 mm was cut out from the test piece in the flow force direction (MD) of the molten resin,
The bending strength was measured by the three-point bending method at room temperature and in liquid nitrogen (19f)C). The bending strain at break of the PBT resin used in this experiment measured in liquid nitrogen was 4.2%.

The test piece was fixed with bolts to a steel plate with a thickness of 10 mm, and a thermal cycle test of room temperature (24 hours) and liquid nitrogen immersion (24 hours) was repeated 10 times, and the presence or absence of cracks was visually observed. Table 1 shows the implementation t・l”1.2, Comparative Example 1
．． As is clear from 2, when measured at room temperature, the smaller the Funk diameter of mica, the higher the bending strength of the composite material. It is obvious that the small dovetail bending 11 insect suction becomes ＾, and the bending gummushi no taji becomes even worse when the flake diameter of 11 fingers is in the region of 35 μrn or less. Furthermore, as is clear from the results of Example 3 and Comparative Example 3,
When the aspect ratio of mica decreases by 10 degrees, the bending strength at -196° C. decreases, or cracks occur in the molded product during a one-cycle thermal test. Also, mother-in-law example 4.5,
As is clear from comparison with Comparative Reli 1.5, cracks occur in the thermal cycle test in the region where the mica mixing ratio is less than 2% by weight (Comparative Example 1), and when the mica mixing ratio is 5015 (, 1 branch). In the region exceeding 196C (Comparative Example 5), the strength of the track from C to 196C decreases.Also, as is clear from 7L when comparing the results of Example 1 and Example 6, when the silane coupling agent is It is better to use it at -196℃.”
・The bending strength is further increased.

Example 7, Comparative Examples 6 to 8 Pi3T used in Examples 1 to 6 was placed with needles as crow flakes, crow fibers, glass peas, and Tarkui C reinforced fibers in the same manner as in Example 1 to obtain a composite material. (Actual hm Example 7, Comparative Example 6.7.8). The properties of these materials are shown in Table 1.
” gave satisfactory results in both the low temperature bending test and the heat cycle test, but the glass fiber, glass beads and talc reinforced PBT produced cranks in the heat cycle test.

Examples 8-10 Condensed polyethylene, low temperature Tsukuda impact tief'borif.

A composite material was prepared by adding mica powder to a matrix of nylon and nylon 6 in the same manner as in Example 1 (Practical cell 118.9.10). The temperature of the cylinder at this time is 80℃ in the case of heavy density polyethylene, and 2℃ in the case of polypropylene.
The temperature was 30°C, and in the case of nylon 6, it was 240°C. g4I
As shown in Figure 1, satisfactory results were obtained for all composite materials. The bending strain at break measured in a liquid chamber for the resin test pieces used in this example was 2.5% for high-density polyethylene, 3.8% for low-temperature impact-resistant polypropylene, and 3 for nylon 6. .5≠ and it's a big hit.

Example 11 Polystyrene'+J Ah? A matrix was prepared and prepared in the same manner as in the case of 1. Mica powder was added to it, and 7 pieces of 4 pieces of composite material were prepared in the same manner as in the case of 1. The cylinder temperature during kneading and injection molding is 200℃.
'C. The IC resin test piece used in this example was measured in liquid nitrogen, and the ICIr strain was 0.
．． It was 8%.

Table 1 shows liquid I (611
Although the determined bending strength is very low, it is still effective.
(The result was obtained.

Example 12, Comparison 1 Hari 9 Molecule J11 approximately 300. Epoxy this mouse 190, viscous JLi that is suitable for water temperature) l + no 1 (J Voice's bisphenol A / lj njiledel type Eboyan 4MI Jli'
j, and a polyamide curing agent (...-Samide I 40 )
'e5jj (%'> ratio of 9/1 -C?)A
16 I made it. Distribute the fleas described in Journey 1 to the mixed liquid, and add 14 pieces of the cloud (the thickness of the mixed liquid is 10 r).
ii to the first Atsuo guy! A heat cycle test was carried out in the same manner as in Example 1 using an iron plate coated with an epoxy resin containing mica IC. The coating film of Example 12 did not show any cracks even after the heat cycle test, but cracks did occur in the case of Agent 1 of Example 19. F・Book implementation 1+lJ
The bending fracture N)i strain of the epoxy wood trial piece used in the engineering and comparative examples measured in a liquid bath was 3.1%.

Claims (3)

[Claims] (1) -jlK L=l Consists of 20-50 jfi 1-11% of flaky powder with average aspect ratio of 15 or more and weight average flake diameter of 35 μIn or less and 80-50M tri% of sieve molecular polymer -100-c
Ultra-low temperature polymer composite material with excellent mechanical properties in the following ultra-low temperature range. (2) The polymer composite material for ultra-low temperature use according to claim (1), wherein the polymer has a bending strain at break measured in a liquid suspension of 1% or more. (3) The ultra-low temperature polymer composite material according to claim 1 or 2, wherein the flaky powder is mica.