JPS6047099B2 - Heat-resistant and wear-resistant laminate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a laminate having excellent wear resistance, heat resistance, and mechanical strength.

Conventionally, cotton cloth-based phenolic resin laminates have been widely used in sliding parts of cams, gears, bearings, vane motors, etc. of mechanical parts such as mechanical products, automobile parts, and electrical parts.

However, this has limitations in wear resistance and heat resistance, and is unsatisfactory for use under harsh conditions and long life as mechanical parts have become more precise and multifunctional in recent years. Therefore, as a product with improved heat resistance, there is a cotton cloth-based polyimide resin laminate in which phenol resin is replaced with polyimide resin.

Heat resistance has improved by using polyimide resin, but the base material is cotton. Ambu 2, , 1011 Nogu V The use of carbon cloth as a base material, which maintains sufficient heat resistance and has excellent abrasion resistance, is attracting attention, but it is not currently used. The reason for this is that the mechanical strength of carbon cloth is very strong, so a laminate made by laminating a plurality of carbon cloths is not easy to drill, such as making holes, and is too warped to be of practical use. Furthermore, the cost of carbon cloth is extremely high. In order to solve these problems all at once, the present inventors have developed a resin that is heat resistant,
We have discovered a new composite board that uses polyimide or its epoxy modified resin with excellent abrasion resistance, a cotton cloth core as the base material, and a carbon cloth layer on one or both surfaces of the core.

That is, pre-preg is prepared by impregnating and drying polyimide resin or its epoxy-modified resin using plain-woven cotton cloth as a base material, and drying the pre-preg using carbon cloth as a base material and impregnating and drying polyimide resin or its epoxy-modified resin on one or both surfaces of the pre-preg. This is a base composite laminate made by laminating prepregs. The surface of this laminate, which comes in contact with and slides on various parts during mounting, is made of carbon cloth impregnated with polyimide resin, so it has excellent heat resistance and
Excellent wear resistance and mechanical strength.

Next, since the core material is a cotton cloth with excellent machinability, it can be easily drilled and cut. The thickness of the laminate is approximately 1
If the thickness is less than Tnm, punching can be easily performed at room temperature. What is more important is that this laminate has very little warpage, which is an important factor in practical use. When using only a carbon cloth base material and forming the prepreg by heating and pressurizing it, the carbon cloth is too hard, and the internal strain received during molding remains, resulting in large warpage. On the other hand, in the case of only a cotton cloth base material, since the cotton cloth is soft, no internal strain occurs as in the case of carbon cloth, but since the impregnated resin is polyimide, a high molding temperature of 150° C. or higher is usually required. For this reason, cotton fabric begins to undergo thermal deformation when the temperature exceeds about 120°C, and large warpage occurs during high-temperature molding. Therefore, since the laminate of the present invention uses carbon cloth which has excellent heat resistance and hardness for the surface layer, thermal deformation of the cotton cloth of the core material is properly suppressed and no deformation occurs. It was also found that since the carbon cloth on the surface is only in the surface layer, the above-mentioned internal distortion does not occur, and the resulting composite base material laminate exhibits almost no warping. The cotton cloth with a specific density used in the present invention has a thread thickness of 15 to 7 yards in both the warp and width (1st thread refers to the thread thickness when 1 bond cotton is made into a thread length of 840 yards). Thickness) is used, and the number of threads used is woven at a density of 40 to 100 warp yarns and 40 to 95 weft yarns per inch.

If it is used for less than 1 hour, the thread becomes weak and the weave is likely to collapse.

Moreover, if it is more than 7 meters, the thread becomes too thick, impregnation into the fiber becomes poor, and the adhesion between the resin and the fresh fiber decreases. Furthermore, if the number of warp and/or weft yarns is less than 40, the weave becomes coarse and the mechanical strength decreases. If the number of warp yarns and/or weft yarns is 95 or more, the weave becomes too dense, impregnating the resin becomes slow, impairing uniform impregnating properties, and reducing workability. The carbon cloth preferably has a thread thickness of 500 to 5000 filaments (single fiber diameter 2 to 10 μm) in both the warp and the width. It is best to weave with a density of 200 to 1500 warp and weft yarns/m. Preferably the number of filaments is 1
000 to 3000 pieces (single fiber diameter 2 to 310μ), density (number of pieces per meter) 400 to 800 pieces/
The one woven with m is good. Thickness of thread: Number of filaments: 50
If it is less than 0, the abrasion resistance and mechanical strength will decrease, and if it is more than 5,000, impregnation with the resin will be poor and the adhesion between the resin and the fiber will be reduced. If the density is 4r or less than 200, the weave becomes rough and the abrasion resistance of the surface decreases. If it is more than 1,500, the impregnation becomes too dense and uniform impregnating properties cannot be obtained, and the adhesion to cotton fabric decreases.

Examples of polyimide resins include pyromellimide resins produced by reacting pyromellitic anhydride and aromatic diamines, and bismaleimide resins produced by reacting bismaleimide with diamines. Preferred is polyamino bismaleimide or an alkylated bismaleimide obtained by reacting bismaleimide with acetone or methyl ethyl ketone.

As the epoxy modified resin for the polyimide resin, the polyimide resin mentioned above is used, and as the epoxy resin to be modified, bisphenol-based epoxy resin obtained by reacting ordinary bisphenols with epichlorohydrin, or reacting halogenated bisphenols with epichlorohydrin are used. halogenated bisphenol-based epoxy resin obtained by
Various commonly used epoxy resins can be used, such as novolak epoxy resins obtained by reacting Novotelak resin and epichlorohydrin, and combinations thereof. The reason for this epoxy modification is that when polyimide resin is used straight, it has very good heat resistance, but because the molding temperature is as high as 200°C or higher, processing workability is poor.

Cotton fabric deteriorates due to oxidation at high temperatures, so it is complicated to prevent oxygen from being trapped during heating and pressure molding.

When modified with epoxy, it can be molded at 200°C or lower, resulting in good moldability. Moreover, since the flow of the resin is large, the impregnating property into the base material is also improved. If you just blend ordinary epoxy, the heat resistance will be so low that there is no point in using polyimide. We have created a novel epoxy-modified reactant by reacting the amino groups of a polyimide resin with the epoxy groups of an epoxy resin, thereby obtaining a product with little loss of heat resistance. Therefore, even when modified with an epoxy resin, there was almost no decrease in heat resistance, and excellent performance in moldability and adhesion due to resin impregnation could be obtained. The blending ratio of polyimide resin and epoxy resin is polyimide resin/epoxy resin =
The weight range of 100 to 30/0 to 7 parts is used.

Preferably polyimide resin/epoxy resin=100-4
A good range is 0/0 to 6 parts, more preferably polyimide resin/epoxy resin = 99.9 to 60/0.4 to 4.
A range of 0 is preferred. If the amount of polyimide resin is 3 parts by weight or more, that is, 70 parts by weight or more of epoxy resin is blended, the poor heat resistance is impaired and various properties at high temperatures, especially mechanical strength, are reduced. In addition to these ingredients ordinary epoxy hardener,
Curing can be accelerated by adding a curing accelerator or the like.
Also, plasticizers such as polyurethane, rubber, and polysulfide,
Small amounts of flame retardants, flame retardant aids, carbon, graphite, class 5 stearic acids, fillers such as molybdenum disulfide, colorants, etc. may be added, and by adding these, new uses as mechanical parts can be achieved. , can be applied to special purposes. The resin composition of the present invention is soluble in N-methylpyrrolidone, dimethylformamide, dioxane, mixtures thereof, and mixtures of two or more thereof with common organic solvents such as methyl ethyl ketone and acetone.

The method for manufacturing the laminate is to apply a resin composition dissolved in a solvent and use a dryer to impregnate the plain weave cotton fabric with a resin amount of 20 to 80% by weight, preferably 40 to 7% by weight. , 0.5 to 3 powders are dried at 130±40° C. to evaporate the solvent and bring the resin composition into a semi-cured state.

Similarly, carbon cloth is impregnated with 30 to 7 weight percent, preferably 40 to 65 weight percent, and dried at 130±40° C. to evaporate the solvent to semi-cure the resin composition. . One or more sheets of the plain-woven cotton fabric impregnated with this resin composition and carbon cloth are laminated so as to form a surface layer on one or both sides, and a laminate is made by heating and pressurizing using a press machine or the like, and then cooling. . The total thickness of the laminate is preferably in the range of 0.2 to 5-5. The heating and pressure molding conditions are a temperature of 120 to 250°C, a pressure of 5 to 200 k9/Cdl, a heating time of 15 to 24 powder, preferably a temperature of 150 to 220°C.
℃, pressure 10 to 120 kg/d1, heating time 60 to 18 ml is preferable.

By manufacturing under conditions within this range, products with extremely excellent performance in various properties can be obtained. Under conditions outside this range, i.e., if the amount of resin impregnated into the plain weave cotton fabric or carbon cloth is small, adhesion will be poor, and when multiple sheets are stacked together, a force deviation phenomenon will occur in the board, and delamination will easily occur. . If the amount of resin impregnated is large, the coated surface becomes uneven, which tends to impair the appearance of the product, and it also takes a long time to evaporate the solvent, reducing productivity. If the drying temperature is low and the drying time is short, the evaporation of the solvent will be insufficient, resulting in stickiness after drying and the adhesion of foreign matter, etc., and the degree of curing of the resin must be reduced and the subsequent compression heating time must be increased.
If the drying temperature is high and the drying time is long, the curing of the resin composition will proceed too much, and if a plurality of sheets are stacked in the pressing process, adhesion will be poor and delamination will likely occur. If the pressing temperature is low or the pressing time is short, the resin will not be completely cured and the solvent will remain, resulting in a reduction in the product's performance such as heat resistance and chemical resistance. The laminate according to the present invention has excellent heat resistance, warpage resistance, dimensional stability, abrasion resistance, mechanical strength, and workability.
It has extremely high practical value as a material for mechanical parts with high precision and under harsh conditions at high temperatures. The main applications to which the present invention is applied are as vane materials of various compressors, cams, gears, bearings, piston rings, etc., which are used as a single laminate plate or by punching and cutting the same, and also in Ae. ．． It is also used for various mechanical and structural parts that are bonded to metals such as steel plates and plastics.

These applications are particularly effective in applications requiring wear, dimensional stability, and mechanical strength at high temperatures. This will be explained in more detail below with reference to Examples. Example 1 The thickness of the thread is 60 x 6 hatate (warp x width) (1st thread is the thread thickness when 1 bond cotton is made into a thread length of 840 yards), and the thread thickness is 1 inch. Number of pieces: vertical x horizontal: 90 x 8
8X. A plain-woven cotton cloth made of the following was impregnated with 45% by weight of a varnish prepared by mixing and dissolving a polyimide resin (Kelimide #601, a product of Rhone-Poulenc) in a solvent of N-methylpyrrolidone to a concentration of 3% by weight.

After drying at 150°C for 2 minutes, two pieces of cotton cloth impregnated with this resin composition, the number of filaments were 3,000 (each diameter was 7μ), and the number of filaments per meter was as long as vertical. A plain weave carbon cloth consisting of 520 fibers was impregnated with 45% by weight of the same polyimide resin varnish 5 as the cotton cloth.

After drying at 150° C. for 3 minutes, a sheet of carbon cloth impregnated with this resin composition was laminated with carbon cloth as the surface layer, and the laminate was bonded under heat and pressure using a press method to produce a laminate.

Breathing conditions are heating temperature 220℃, pressure 30kg/AfL
, one theta crimping time is 4 minutes.

The performance of this laminate is shown in Table 1. Example 2 Polyimide resin 7 heel amount used in Example 1 for plain weave cotton fabric with yarn thickness of warp x width 20 x 2 hatte and number of threads per inch of warp x width 60 x 60. 50 parts by weight of epoxy resin (Shell Chemical Co., Ltd. trade name Epicote #828) and 2 parts by weight of diaminodimethylmethane were mixed and dissolved in a solvent of N-methylpyrrolidone to give a concentration of 4% by weight. % impregnation.

After drying at 160°C for 1 minute, one piece of cotton cloth impregnated with this resin composition, the number of filaments was 1000 (vertical x horizontal) (each diameter 8 μ), and the number of filaments inserted per meter was vertical x horizontal. A plain-woven carbon cloth consisting of 600 fibers was impregnated with 5% by weight of a resin consisting of 7 parts by weight of polyimide resin, 3 parts by weight of epoxy, and 2 parts by weight of diaminodimethylmethane, which are the same as the cotton cloth.

1 at 160°C. After drying, two sheets of carbon cloth impregnated with this resin composition were stacked on top of each other with cotton cloth as the middle material and carbon cloth on both surfaces, and the sheets were bonded under heat and pressure using a press method to produce a laminate.

Breathing conditions are heating temperature 200℃, pressure 60k9/Clt
The heating time was 180 minutes. The performance of this laminate is shown in Table 1. Example 3 Thick yarn length x width 30 x 3 hatte, number of threads per inch length x width 72 x 6CJ
50 parts by weight of polyimide resin (trade name: TVF-#5900 from Toshiba Chemical Co., Ltd.), 5 parts by weight of epoxy resin (trade name: Epicoat #1045 from Shell Chemical Co., Ltd.), 2-phenyl-4-methylimidazole, and dimethyl-formamide were added to a plain-woven cotton cloth made of X. It is impregnated with 55% varnish which has been mixed and dissolved with a mixed solvent consisting of 3 parts by weight to give a concentration of 35% by weight.

After drying at 150'C for 2 minutes, 5 cotton cloths impregnated with this resin composition and 1000 filaments (1 diameter 8
μ), 5 parts of polyimide resin (product name: TVF-1 #5900 manufactured by Toshiba Chemical Co., Ltd.), which is the same as cotton cloth, and 5 parts of epoxy resin (Shell Chemical Co., Ltd. Product name Epicote #1
045) Impregnated with 55% varnish mixed and dissolved to a concentration of 35% by weight with a mixed solvent consisting of 5 parts by weight, 2 phenyl, 4 methyl imidazole, and 30 parts by weight of dimethylformamide.

After drying at 150° C. for 3 minutes, one sheet of carbon cloth impregnated with this resin composition was layered as a surface layer of cotton cloth, and four layers were stacked together and heat-pressed using a press method to produce a laminate.

The pressing conditions were a heating temperature of 180° C., a pressure of 50k9/d1, and a heating time of 15 minutes. 2 laminates obtained by pressing
After-baked for 2 hours in the open at 00℃,
The performance of this laminate is shown in Table 1.

Example 4 The thickness of the laminate obtained in Example 1 was 1.677!77! Each of the steel plates and aluminum plates is pasted using adhesive.

After roughening the bonding surfaces of the laminate, copper plate, and aluminum plate by sandblasting, apply approximately 30μ of varnish made of the polyimide resin used in Example 1 to a concentration of 50% with a solvent of N-methylpyrrolidone to the metal surface as an adhesive. Apply fluoride. 150℃3
After drying for a few minutes, the laminates are stacked and bonded together using a press method.

The pressing conditions were a heating temperature of 180°C, a pressure of 5k9/d1, and a compression time of 40 minutes. The adhesive strength of the material pasted with Ae was tested by tensile shearing and was 120k9/Cfi, and the adhesive strength of the material pasted with the steel plate was tested by tensile shearing and was 105k9/d.

Even when the temperature was increased to 150° C., the decrease was very strong with almost no decrease. Comparative Example 1 The number of filaments is 3000 (vertical x horizontal) (each diameter is 8μ), and the number of filaments driven per meter is 52 vertical x horizontal.
A plain weave carbon cloth consisting of 0 fibers was impregnated with 6% by weight of the varnish prepared by mixing and dissolving the polyimide resin used in Example 1 with N-methylpyrrolidone to a concentration of 45% by weight.

After drying one powder at 120° C., three sheets of carbon cloth impregnated with this resin composition were stacked on top of each other and bonded under heat and pressure using a press method to produce a laminate.

The pressing conditions were a heating temperature of 180° C., a pressure of 60k9/d1, and a heating time of 10 times. The performance of this laminate is shown in Table 1. Comparative Example 2 7 parts of the polyimide resin used in Example 2 and epoxy were applied to a plain-woven cotton cloth with yarn thickness of 20 x 2 in the warp x width and 60 x 60 threads per inch. A resin consisting of 3 parts by weight of resin and 2 parts by weight of diaminodimethylmethane is mixed and dissolved in a solvent of N-methylpyrrolidone to a concentration of 4% by weight, and then 5 parts by weight of varnish is impregnated.

After drying at 130° C. for 5 minutes, pieces of cotton fabric impregnated with this resin composition were layered and heat-pressed using a press method to produce a laminate.

Breathing conditions are heating temperature 180℃, pressure 70k9/Clt
1 heating time 12 minutes. The performance of this laminate is shown in Table 1. Comparative Example 3 The thickness of the thread is 10 x 1 in length x width, and the number of threads per inch is 120 x 120 in length x width. A plain woven cotton cloth made of the following was impregnated with 45% by weight of the varnish prepared by mixing and dissolving the resin used in Example 2 in a solvent of N-methylpyrrolidone to a concentration of 3% by weight.

After drying at 150°C for 35 minutes, the same resin as the cotton cloth was mixed and dissolved in three pieces of cotton cloth impregnated with this resin composition and the carbon cloth used in Example 1 with a solvent of N-methylpyrrolidone to a concentration of 3% by weight. It is impregnated with 45% by weight of the varnish.

After drying at 150° C. for 4 minutes, two sheets of carbon cloth impregnated with this resin composition for 1′ were stacked on top of each other with the carbon cloth as the surface layer, and heat-pressed by a press method to produce a laminate.

The pressing conditions were 170° C., pressure 50 k9/Cliil heating time 9 times. The performance of this laminate is shown in Table 1.
1 Comparative Example 4 Thickness of yarn is 30 x 3 hatate, number of threads per inch is 72 x 6 g x. A plain woven cotton cloth made of
The varnish is impregnated with 45% by weight of a varnish made by mixing and dissolving two resins consisting of parts by weight in a solvent of methyl ethyl ketone to a concentration of 30%.

After drying at 160°C for 1 minute, two cotton cloths impregnated with this resin composition and 3,000 filaments (vertical x horizontal) were prepared.
100 parts by weight of the same epoxy resin as cotton cloth, 2 parts by weight of diaminodimethylmethane
45% by weight of a varnish made by mixing and dissolving a resin consisting of parts by weight with a solvent of methyl ethyl ketone to a concentration of 30% is impregnated.

After drying at 160°C for 2 minutes, one sheet of carbon cloth impregnated with this resin composition was layered with carbon cloth as the surface layer, and a laminate was made by heat-pressing using a press method.

Breathing conditions are 170℃, 70kg/d1 heating time is 18
It's confusing. The performance of this laminate is shown in Table 1. Comparative Example 5 A phenol resin obtained by refluxing 1 mole of phenol and 1.3 moles of a 1% formalin solution under an ammonia catalyst for 1 hour was mixed and dissolved in a methanol solvent on the cotton cloth used in Example 3. It is impregnated with 45% by weight of two varnishes at a concentration of 3% by weight.

After drying at 150° C. for 3 minutes, five sheets of cotton cloth impregnated with this resin composition were stacked on top of each other and pressed together using a press method to form a laminate.

Breathing conditions are 165℃, pressure 45kg/d1, heating time 1
It is a costume.

The performance of this laminate is shown in Table 1 (Note) The test method is as follows.

Bending strength: According to JIS-C-6481.

Dimension change: 200 x 200 x 0.57r1! Using a test piece of n, we measured the dimensions before and after treatment at 130°C x 24 hours.
Also, the measurement accuracy is 5/10007077! (microphone
mouth plotter).

Wear resistance: Non-lubricated sliding wear tester (Suzuki type)
Sliding conditions - PV value...830k9-m/d・M
m Sliding time...311r Mating metal...S55C Warped Using a test piece of 500 x 500 x 0.5 wrIn, hang it vertically at the center of one side, and
Place a straightedge in parallel.

Place the straightedge against the surface of the laminate and measure the maximum distance between the straightedge and the surface of the laminate using a metal straightedge up to 17 m. Even if the other sides are measured, the large gap is taken as the maximum warpage of the sample. Punching property: DIN type DIN-53488
According to Plate thickness - 0.57r$t Punching speed - 10C) m! NlSeC punching temperature - normal temperature interlayer adhesion: bending test (according to JIS-C-6481)
Examine the degree of fracture of the test piece after performing
Determine the presence or absence of delamination.

As can be seen from the results in Table 1, the laminate of the present invention has excellent mechanical strength, heat resistance, abrasion resistance, dimensional stability, warpage, and punching workability (Examples 1 to 3) ) or have good adhesion to metals (Example 4).

A polyimide resin laminate made only of carbon cloth, which has excellent fiber strength, has large warpage and poor punching workability (Comparative Example 1). Polyimide resin laminates based on cotton cloth bamboo are not only generally inferior in abrasion resistance, mechanical strength, and heat resistance to the products of the present invention, but also have a large occurrence of warpage because the polyimide resin is cured at high temperatures (Comparative Example 2) ). Furthermore, although the conventionally used soenol resin laminate made of only cotton cloth as a base material does not warp, its heat resistance and abrasion resistance are significantly reduced (Comparative Example 5). If the impregnating resin is not the polyimide resin used in the present invention or its epoxy-modified resin, but only an epoxy resin is used, the temperature will be high. (Comparative Example 4) Alternatively, when a cotton cloth other than the one according to the present invention is used, the compatibility between the resin 7 and the cotton cloth is poor, resulting in low interlayer adhesion and low mechanical strength (Comparative Example 3). As described above, a laminate made of a polyimide resin with excellent heat resistance and simply made of cotton cloth or carbon cloth as a base material is too warped to be of practical use.

Furthermore, if the base material is cotton cloth, the cotton cloth itself is not heat resistant, so the excellent heat resistance of polyimide resin cannot be fully utilized, and if the base material is carbon cloth only, the carbon cloth is too strong, so punching cannot be performed. This creates a major weakness.

The product of the present invention is a new composite laminate made of polyimide resin, with a cotton cloth base material as the core material and a carbon cloth base material as the surface layer, so that the mutual effect of the two is remarkable, and the heat resistance,
It is an extremely high-quality material for mechanical and structural parts that has high wear resistance and high mechanical properties, and has excellent warpage and punching workability.

Claims (1)

[Claims] 1. Use 15-70 count cotton yarn for both the warp and weft.
40-100 warp threads and 40-95 weft threads per inch
One or more sheets of prepreg impregnated with polyimide resin or its epoxy-modified resin and dried are laminated on a plain-woven cotton cloth woven with the density of a book as a base material, and carbon cloth is used as a base material on one or both surfaces of the prepreg. A heat-resistant and wear-resistant laminate made by laminating dry prepregs impregnated with polyimide resin or its epoxy modified resin, heated and pressurized.