SE436039B - squeegee - Google Patents

Description

In connection with the present invention, various studies have been made with respect to the development of rubber scrapers which meet the above-mentioned requirements, and as a result, it has been found that a rubber scraper with improved scraping ability and durability can be used. obtained by using among the above-mentioned rubber compositions only compositions of a certain composition, which compositions develop a remarkable orientation anisotropy, and by extruding or rolling the composition to further improve the orientation anisotropy and form, heat and vulcanize the composition so as to obtain scraper surface, which is perpendicular to the orientation direction.

According to the invention there is provided a rubber scraper which is prepared by heating a volcano at 110 DEG-180 DEG C. a mixture of (a) at least one diene rubber, (b) methacrylic acid, the weight ratio of component (a) to component (b) being 83/17. to 65/35, (c) a divalent metal compound selected from oxides, hydroxides and carbonates of zinc, magnesium or calcium and present in an amount of 50-110 parts by weight per 100 parts by weight of component (b), and ( d) an organic peroxide, present in an amount of 0.3-4.5 parts by weight per 100 parts by weight of the sum of components (a) and (b), and optionally a secondary arylamine, present in an amount of 0.1- 3.0 parts by weight per 100 parts by weight of the sum of components (a) and (b), (e) which rubber scraper has a scraping surface perpendicular to an orientation direction created by extrusion and / or rolling of the mixture. The invention will be described in more detail below. The component (a) used in the invention consists of at least one diene rubber. Diengummina includes natural rubber; homopolymers of conjugated dienes such as 1,3-butadiene, isoprene, chloroprene and the like; and copolymers of the conjugated dienes with acrylonitrile or alkenyl aromatic hydrocarbon compounds such as styrene and the like. Among these, it is preferred to use 1,3-butadiene homopolymer (ie butadiene rubber, hereinafter abbreviated BR), butadiene styrene copolymer (styrene-butadiene rubber, hereinafter abbreviated SBR) and natural rubber (hereinafter abbreviated NR). In these diene rubbers, the cis-1,4 configuration preferably constitutes at least 30% by weight.

The diene rubbers may be used individually or in admixture as component (a) and they may additionally contain a suitable amount of a non-diene rubber, such as isoprene-isobutylene copolymer or the like.

Methacrylic acid (hereinafter abbreviated as MAA) is used as component (b). The weight ratio between component (a) and component (b) should be in the range 83/17 to 65/35. When component (b) is less than 17% by weight, the function of the scraping surface perpendicular to the orientation direction of the rubber composition or the orientation anisotropy does not significantly contribute to the modulus of elasticity in bending to prevent skew, resistance to plastic deformation to prevent flattening and tear strength. similar, while the wear resistance is poor. Furthermore, when component * (b) exceeds 35% by weight, the orientation anisotropy to the above properties becomes noticeable, while the wear resistance is considerably reduced.

The divalent metal compound used as component (c) is selected from oxides, hydroxides and carbonates of zinc, magnesium or calcium. It is preferred to use zinc oxide, in particular activated zinc oxide. Component (c) should be used in sufficient quantity to neutralize all the carboxyl groups in component (b). The amount of the component (c) may be varied according to the kind of component (b), the kind of metal or the shape of the metal compound, but is usually 50-110 parts by weight per 100 parts by weight of the component (b). . When component (c) is mixed in too large an amount, the elongation at break decreases and chipping or chipping tends to occur.

The organic peroxide used as component (d) is a dialkyl peroxide including dicumyl peroxide (hereinafter abbreviated as DCPO), 1,1-bis (t-butyl peroxy) -3,3,5-trimethylcyclohexane (hereinafter abbreviated as P-3M). ), di-t-butyl peroxide, 2,5-dimethyl-2,5-di-t-butyl peroxyhexane, α, α '-bis-t-butyl peroxy-p-diisopropylbenzene and the like. Among them, it is preferred to use DCPO and P-3H. Component (d) 1nr is used in an amount of 0.3-4.5 parts by weight per 100 parts by weight of the sum of components (a) and (b). When the amount of component (d) is less than 0.3 parts by weight, the modulus of elasticity of the rubber composition is too low, while when the amount exceeds 4.5 parts by weight, the modulus of elasticity becomes too high and chipping tends to occur.

By using a rubber composition consisting of components (a) - (d) above, a high performance rubber scraper can be made. In order to further improve the flatness during vulcanization and the internal homogeneity, whereby the difference in properties between the surface part and the inner part of the thick, shaped product is eliminated, addition of the component (s) is required.

The secondary arylamine used as component (e) includes N-isopropyl-N'-phenyl-p-phenylenediamine, phenyl-d-naphthylamine, phenyl-β-naphthylamine, N, N'-di-2-naphthyl-p- phenylenediamine, diphenyl-p-phenylenediamine, p-isopropyl diphenylamine, p- (p-toluenesulfonamido) -diphenylamine, diphenylamine and the like. It is preferred to use N-isopropyl-N'-phenyl-p-phenylenediamine (hereinafter abbreviated as 81NA).

Component (e) is used in an amount of 0.1-3.0 parts by weight per 100 parts by weight of the sum of components (a) and (b).

When the amount of the component (e) is less than 0.1 parts by weight, the effect of the additive is very small, while when the amount of the component (e) is more than 3.0 parts by weight, the hardness of the obtained rubber composition decreases considerably. If it is intended to impart heat resistance to the rubber scraper according to the invention, a reaction product of amine and ketone, such as 1,2-dihydro-2,2,4-trimethylquinoline polymer (hereinafter abbreviated as RD) and the like, are added to the rubber composition, as described above. In this case, the practical amount of additive of the reaction product amounts to 0.1-3.0 parts by weight per 100 parts by weight of the sum of components (a) and (b).

The rubber composition of the invention may further include fillers, such as carbon black, silica and the like, which are used in normal rubber compositions.

Furthermore, in order to improve the fatigue strength of the rubber composition, carboxylic acids including saturated fatty acids such as stearic acid, etc .; unsaturated fatty acids, such as oleic acid, etc .; alicyclic carboxylic acids, such as naphthenic acid, etc .; and aryl carboxylic acids such as benzoic acid, etc .; or metal salts thereof. The metal contained in these metal salts is not limited to any particular metal, but zinc, calcium, magnesium and the like are preferably used.

According to the invention, the hardness of the rubber composition having the composition described above is 80-98 °, measured as Shore A hardness. When the hardness is less than 800, skew of the scraper occurs during use and consequently the scraping ability decreases, while when the hardness exceeds 980 the scraper becomes more brittle and consequently chipping often occurs, which impairs the wear resistance.

In the rubber scraper according to the invention, the scraper surface is perpendicular to an orientation direction of the rubber composition, which is produced by means of a sheet extruder, such as a rolling machine, calender machine, spraying machine or the like. The mixture of the above-mentioned components is thus formed into a sheet-like rubber composition by means of the sheet-spraying machine, during which the rubber composition is given an orientation direction. It is generally known that when an ordinary rubber composition is formed by means of a sheet machine of the above-mentioned type, hardly any orientation occurs.

It is therefore surprising that the rubber composition according to the invention has an orientation direction. The thus oriented rubber composition is heated and vulcanized to produce a rubber scraper having a plane which is perpendicular to the orientation direction of the rubber composition and which forms a scraping surface. In this case, the vulcanization of the rubber composition is usually carried out at 110-180 ° C. When the vulcanization temperature is lower than 110 ° C a long vulcanization time is required, while when the vulcanization temperature is higher than 180 ° C the resulting rubber scraper becomes more brittle.

The invention will now be described with reference to the accompanying drawings. Figs. 1a and 1b show schematic perspective views of rubber scrapers, the direction of orientation of which is indicated by means of arrows, Fig. 1a showing a rubber scraper according to the invention with a scraping surface which is perpendicular to the orientation direction (hereinafter referred to as a type scraper), and Fig. 1b shows a conventionally used rubber scraper with a scraper surface which is parallel to the orientation direction (hereinafter referred to as B-type scraper).

Fig. 2 is a perspective view of an oriented rubber sheet for a scraper, from which sheet different test pieces have been cut out, the test pieces A, C and E being Q-type scrapers and the test pieces B, D and F being B-type scrapers. Fig. 3 is a schematic perspective view of an apparatus for measuring the abrasion loss of the rubber scraper. Figures 4 and 5 are diagrams showing the relationship between the weight ratio of components (b) / (a) and the wear loss. Fig. 6 is a diagram showing the relationship between the wear loss and the separation.

The following examples are provided to illustrate the invention and are not intended to limit it.

EXAMPLE 1 This example shows that the rubber composition of the invention with the blending recipe shown in Table 1 has an orientation anisotropy compared to a conventional rubber composition. 10 15 20 25 7909776 ~ 2 7 TABLE 1 I: Component Mixture recipe É (a) BR BR / MAA = 77/23 (b) MAA (c) ZnO ZnO / MAA = 95/100 (d) DCPO DCPO / BR + MAA = 0.77 / 100 Vulking conditions 150 ° C x 30 min The rubber composition with the mixing recipe according to table 1 was sprayed through the spraying machine to give the composition an orientation direction and then vulcanized under the specified vulcanization conditions. Thereafter, the linear thermal expansion coefficient (k) of the samples was measured parallel and perpendicular to the orientation direction of the sample.

In this case, the coefficient of linear expansion in a direction parallel to the orientation direction was found to be k = 1.72 x 10 ° K straight to the orientation direction, k = 4.72 x 10-4 degrees -1 in the direction while in a direction wind degrees _1, which clearly indicates the enormous anisotropy of the present rubber composition.

EXAMPLE 2 In this example, orientation experiments were performed by changing the weight ratio of components (b) / (a).

In a kneader, thoroughly and uniformly given quantities (as shown in Table 2) were mixed BR containing 98% cis-1,4 configuration (from Japan Synthetic Rubber Co. Ltd., under the tradename BR01) and NR as component (a) (weight ratio BR / NR was constant 70/30), activated zinc oxide (hereinafter abbreviated as ZnO) as component (C), 810NA as component (e) and in addition other additives consisting of RD, stearic acid (hereinafter fÖrkOrt & d St-Syra) G fl lkimrök HAF-LS. The resulting mixture was added and mixed with a given amount of MAA as component (b) on several occasions. To this mixed mass was added a given amount of P-3M as component (d) by means of rollers, and then the resulting mixture was oriented in the usual manner to obtain an oriented, unvulcanized sheet having a thickness of 2 mm.

Thereafter, this sheet was heated and vulcanized in a platform at 150 ° C for 30 minutes to form an oriented, vulcanized sheet.

Two dumbbell-shaped specimens A and B according to JIS No. 3 (see Fig. 2) were cut from the vulcanized sheet described above.

The stress per unit area at 50% elongation (Modso) of each specimen was determined using an Instron tester at a drawing speed of 200 mm / min, obtaining the results in Table 2.

Table 2 shows that the ratio of Modso for specimen A (ie MODASO in a direction parallel to the orientation direction) and Mod50 for specimen B (ie ModB50 in a direction perpendicular to the orientation direction) increases as the weight ratio of components (b) / (a) increases .

The orientation anisotropy becomes particularly noticeable when the weight ratio of components (b) / (a) exceeds 17/83.

A property required of the rubber scraper is that it must have a high modulus of elasticity during bending so that the scraper does not become skewed during use. If one considers that the modulus of elasticity when bending is largely proportional to the Modso a-type scraper, it is very advantageous to prevent skew. shows the fact that ModA50 greater than Modßso that 7909776-2 .c f mouucm al CMMM flfl umucw fl no muse mømMuw> mm mc al nwcm mncmw SMe .uOOmG AWV 300 As mšuwuüw al omšox> etc. fi uw f m f tra mw al MH fifl m w f LMA nd xßmumw flfi> .N .Hav Gwucwdomåøx> m HmHwUuMH> oo al Hmm microns al mwux fl b of mmwu m .NH> ß .UWQWE G0 H w fl lhä S00 .Nhämlßm _QM mü flfl ß flfiflfl u. Hwmvüšwß fl w fiflfl u. whßmv flfi hw flfl ä EOW .H .E24 ~ ~ n ~ s H0 H HH H ßø H mc HW Ho H omm @ oz \ om «woz n ° .æm w_w ~ oH ~ m.mH M>«. m _ mwos WMW ß ^ Nau \ @xv Omøoz H. ~ @ o.om m.->. @ HM «mw w anus Q ° H \ mo QcH \ ° _H ooH \ oH o ° H \ HH W, ooH \ ~ .H <<: + mz + mm \ «zoHæ_ ^ n. + Hm. \ ^ wV o ° H \ o_ ~ ° oH \ ~ _N ° oH \ ~. ~ ø @ H \ HN M ooH \ w. ~ W«, q | mmCHG ooH \ m> ° oH \ m> øoH \ m> ° oH \ m> QoH \ m> 4 _ m >> \ m ~ mw \> H ßm \ ~ H Hm \ @ ° oH \ ° mz + mm \ <« s ^ mV \ ^ nv ww vw if mm m ~ Hc H @ wH @ m N .HAHMÉB 7909776-2 10 15 20 25 30 35 10 EXAMPLE 3 From the same vulcanized sheet as described in Example 2, two strip-shaped specimens C and D are cut out with a size of 5 x 100 x 2 mm, as shown in Fig. 2. The creep quantity of each specimen was determined at room temperature at a load of 10 kg / cm 2 by means of a creep sampler, the results in Table 3 being obtained.

TABLE 3 Experiment No. j 3b 3c 3d 3e (b) / (a) MAA / BR + NO 9/91 13/87 17/83 23/77 AEG 4.73 2.98 2.16 1.76 Ae (%) D Ae 5.38 3.20 2.95 2.91 Cl D Ae / Ae 0.88 0.83 0.73 0.60 It appears from the results in Table 3 that the ratio of As for the specimen C (ie Asc in a direction parallel to the orientation direction) and Ae for the bridge body D (ie AeD in a direction perpendicular to the orientation direction) rapidly decreases when the weight ratio of components (b) / (a) exceeds 17/83 and consequently the orientation anisotropy becomes noticeable.

The resistance to plastic deformation is estimated by the creep quantity (As =), which is obtained a -e les by reducing the creep quantity after 24 h (a24) by the creep quantity after lh (a1), and this value is relevant with respect to the flattening phenomenon of the rubber scraper after use. . Since flattening is increasingly prevented the smaller the value of the creep quantity, it is realized that the d-type scraper is advantageous for preventing flattening.

EXAMPLE 4 From the vulcanized sheet described in Example 2, two parallel-sided, strip-shaped specimens E and F with a size of 10 x 100 x 2 mm are cut out, as shown in Fig. 2.

In each specimen, a 2 mm notch was made at the center of a ll edge. The breaking strength (Gb) of each specimen was determined using an Instron tester at a drawing speed of 200 mm / min, and using this value, the tear strength (T) was calculated according to the following equation: where d is the thickness of the specimen (ie 2 mm ). The measured results are given in Table 4.

TABLE 4 Experiment No. 4b 4c 4d 4e (b) / (a) MAA / BR + NO. 9/91 13/87 17/83 23/77 TE 46.1 43.7 77.9 122 T (kg / cm) FT 43.6 40.5 36.7 37.6 TE / TF 1.06 1.06 2.12 3.24 The results in Table 4 show that the ratio between the tear strength TE of the specimen E (measured in a direction parallel to orientation direction) and the tear strength TF of the specimen F (measured in a direction perpendicular to the orientation direction) increases with increasing weight ratio between the components (b) / (a) and the increase in the ratio TE / TF becomes particularly noticeable when the weight ratio between the components (b ) / (a) exceeds 17/83.

The tear strength is relevant with regard to the resistance to chipping, ie the higher the tear strength, the greater the resistance to chipping. The fact that TE is larger than TF therefore shows that the a-type scraper has a higher resistance to chipping than the B-type scraper.

EXAMPLE 5 A mixture having a mixing recipe according to Table 5 was mixed and oriented in the manner described in Example 2 to produce two simulated rubber scrapers, which corresponded to the U- and B-type scrapers in Fig. 2 (a size of 30 x 55 x 60 mm and a scraping surface of 30 x 60 mm). An abrasion test was performed on these two scrapers under conditions, which corresponded to actual operating conditions, using an apparatus according to Fig. 3 for measuring abrasion loss. First, the rubber scraper 7 is attached to a fixing member 5, which was connected to a rear body 1 of an electric car by means of a coupling member 2 and a movable pin 3, by means of fixing screws 6 in such a way that the scraper surface of the rubber scraper 7 was inclined at an angle of 30 to the ground and a load of 0.17 kg / cm 2 was applied by applying an adjustable weight 4 to the fixing means 5. Thereafter, the electric car was driven on a concrete road - at a speed of 2 km / h a distance of 0 16 km in the direction of the arrow 8. In the direction of the abrasion loss (AV) of the rubber scraper 7 was determined as the worn thickness when the scraper surface was driven a distance of 1 km, the results in Table 5 and Figs. 4 and 5 being obtained.

In Table 5, Ava is the wear loss for the u-type scraper and AVB is the wear loss for the 6-type scraper. The results in Table 5 and Fig. 4 show that the ratio of the abrasion loss AVQ / AVB decreases as the weight ratio of the components (b) / (a) increases, and the orientation anisotropy to the abrasion resistance becomes particularly noticeable when the weight ratio of the components (b) ) / (a) exceeds 17/83. This fact shows that the a-type scraper is superior to the ß-type scraper in abrasion resistance.

Furthermore, it can be seen from Fig. 5, which shows the relationship between the weight ratio of the components (b) / (a) and the abrasion loss Avg for the Q-type scraper, that the abrasion resistance force is considerably deteriorated when the weight ratio (b) / (a) is less than 17 / 83 or exceeds 35/65. It follows that the weight ratio of components (b) / (a) should be limited to the range 17/83 to 35/65. The level of abrasion resistance shown by the dashed lines in Fig. 5 corresponds to a level capable of developing a durability of about 500 km in practical products. 7909776-2. ^ @ V Gmßcwzomäox> m cm fl mwmë mm fl mnwcw udmumcox nwuwnøums mumm uum Hmm .m .cm. mmm »m .ß.o> m Ummmë cm A mqnmmm: oo muæm | um .om mwuumm fiflfl u Hwuwewumm fl a fl u wumm flfl umuuæ Eow .H .E: <13« m_o mw. ° mw.o oo_H wm ~ ° m> <\ a> < om> .o _ mmm.Q mm fi. o mmw.o mm. ~. m> <_ 23> šv> <w> «. ° æ-.o mmH.o mww_ø« @. ~ W ö> <mm m.mm mm mm mmw ^ «m fl @ Hm; <wHo @ m .cv wa ooH \ m_ ° QoH \ mo ° cH \ mQ ° oH \ @. o _ooH \ w. ° m <oo ~ \ mo QoH \>. ow ° oA \>. H q ° oH \ m_ «WQcH \ wm M k _ lm GMC øo ~ \ m> ° oH \ m> ° oH \ mß o ° H \ m> W ° oH \ m> h <> w \ - ~ ß \ m ~ >> \ m ~ mw \> HW ßw \ mHw mz + mm \ «_ mm um om am W mm ua xwmumm m Å flfl m fi ß 7909776 ° 2 30 35 14 EXAMPLE 6 The rubber composition with the mixing recipe given in Table 6 was used to produce two simulated m and 5-type rubber scrapers in the same manner as described in Example 5. Thereafter, abrasion tests were performed on the two scrapers under the same conditions as in Example 5, obtaining the results in Table 7.

TABLE 6 Component Mixture recipe (a) BR + NR (b) MAA MAA / BR + NR = 25 / 52.5 + 22.5 (c) ZnO ZnO / MAA = 75/100 (d) DCPO DCPO / BR + NR + MAA = 0.72 / 100 Cultivation conditions l65 ° C x 30 min Note. As additional additives, St-acid and HAF-LS were added in an amount of 3 and 20 parts by weight per 100 parts by weight of component (a), respectively. ~ TABLE 7 a-type scraper 6-type scraper HD (0, Shore A hardness) 97 97 Abrasion loss AV a B (mm / km) AV = 0.169 AV = 0.235 As can be seen from the results in Table 7, the ratio for abrasion loss is AVG / AVB 0.72, which is why the A-type scraper is superior to the B-type scraper in abrasion resistance.

EXAMPLE 7 A rubber composition having the mixing recipe set forth in Table 8 which developed a remarkable orientation anisotropy to the abrasion resistance was used to prepare two simulated α- and B-type rubber scrapers in the manner described in Example 5. For the purpose of operation, a polyurethane rubber scraper was prepared as shown in Table 8.

TABLE 8 Experiment No. 7a 7b 7c (a) BR + NR y Polyurethane, as; MAA / BR + NR prepared ge- 'í = 28.6 / 50.0 + 21.4 by reacting_ Z lypropylene- ß (b) MAA, P ° _ 1 glycol with (c) Zn0 Zn0 / MAA = 10O / 100 i tolylenediiso- (a) DcPo DcPo / BR + NR + MAA ga fi aïfmgâšïâff _ l I lBland- _ l'l4 / 100 f bis-2-chloroanilin- lninqs- s1oNA s1oNA / ßR + NR + MAA; Lin šrecèpt = 0,93 / 100 a É As additional additives, RD, St- - acid and HAF-LS were added in an amount of 1,3, 3 and 20 parts by weight respectively per 100 parts by weight of I « component (a) of G-type ß-type V-vulcanization conditions 160 ° C x 30 min * Hd (° Shore A hardness) 94 96 Abrasion tests were performed with respect to these three scrapers in the same manner as in Example 5, except that the severity of the wear conditions was changed by varying the adjustable weight 4 in the apparatus of Fig. 3, whereby the results of Fig. 6 were obtained.

In Fig. 6, the symbol l1 represents the result of the polyurethane rubber scraper, the symbol (:) represents the result of the B-type scraper and the symbol O represents the result of the a-type scraper. The abrasion loss of the polyurethane scraper expressed as mm / km separation has been plotted on the abscissa in Fig. 6, while the ordinate represents the wear loss of each a- and B-type scraper measured under the same hardness conditions. 7909776-2 10 15 20 25 30 35 16 From the results in Fig. 6 it can be seen that the abrasion resistance was improved in the following order: Polyurethane rubber scraper <B-type scraper <a-type scraper. It further appears that the relative wear loss of these scrapers is due to the severity of the wear conditions.

EXAMPLE 8 Snow plow blades with a size of 30 mm (thickness) x 200 mm (width) X 810 mm (length) were manufactured using the same polyurethane rubber scraper and ß-type scraper as described in Example 7. Thereafter, the abrasion resistance and ability were measured to scrape off snow for each snowplow blade on the Tohoku Highway under actual snowfall conditions, obtaining the result in Table 9.

TABLE 9 a-type scraper Polyurethane rubber scraper Distance traveled (km) 288 405 Loss of wear (mm) 14.3 42.7 Loss of wear per _2 _l road length unit (mm / km) 5.0 X 10 1.05 X 10 Melting and chipping snow scraping properties of heat generation The results in Table 9 show that the loss of wear per unit length of the a-type scraper is about half of the polyurethane rubber scraper, which fully corresponds to the measured result in examples. 7. This means that the result of Example 8 shows that the laboratory result of Example 7 was reproduced in the practical test of Example 8. Based on this fact, it is assumed that the A-type scraper is superior to the B-type scraper in abrasion resistance even at test in practice. Furthermore, the snow-scraping properties of the U-type scraper are superior to the polyurethane rubber scraper. On the basis of these facts, it can be said that the d-type scraper according to the invention develops satisfactory properties, which are required of a rubber scraper, compared to the conventional products.

Claims (1)

7.7909776-2 18 PATENTK RAV Rubber scraper, characterized in that it is prepared by heating and vulcanizing at 110-180 ° C a mixture of (a) at least one diene rubber, (b) methacrylic acid, the weight ratio of the component ( a) and component (b) is 83/17 to 65/35, (c) a divalent metal compound selected from oxides, hydroxides and carbonates of zinc, magnesium or calcium and present in an amount of 50-110 parts by weight per 100 parts by weight of component (b), and (d) an organic peroxide, present in an amount of 0.3-4.5 parts by weight per 100 parts by weight of the sum of components (a) and (b), and optionally (e) a secondary arylamine, present in an amount of 0.1-3.0 parts by weight per 100 parts by weight of the sum of components (a) and (b), said rubber scraper having a scraping surface perpendicular to an orientation direction created by extrusion and / or rolling of the mixture.