KR20140024884A - Nonwoven abrasive article containing elastomer bound agglomerates of shaped abrasive grain - Google Patents

Abstract

The nonwoven abrasive article formed from the nonwoven web and the aggregate includes formed ceramic abrasive particles bonded to each other by a second binder and a first flexible binder that bind the aggregate to the nonwoven fiber web.

Description

Nonwoven Abrasive Article Containing Elastomer Bound Agglomerates of Shaped Abrasive Grain

Nonwoven abrasive articles generally include a nonwoven web (eg, a lofty open fibrous web), abrasive particles, and a binder material (usually " bonding fibers " with each other and securing the abrasive particles to the nonwoven web). Binder ". Examples of nonwoven abrasive articles include nonwoven abrasive hand pads, such as those sold by 3M Company, St. Paul, Minn., USA, for example, under the trade name "SCOTCH-BRITE".

Other examples of nonwoven abrasive articles include convolute abrasive wheels and unitized abrasive wheels. Nonwoven abrasive wheels typically have abrasive particles distributed through the layers of nonwoven webs bonded to each other using a binder that binds the layers of the nonwoven web to each other and further binds the abrasive particles to the nonwoven web. The united abrasive wheel has individual disks of nonwoven webs arranged in parallel to form a cylinder with a hollow axial core. Alternatively, the convoluted abrasive wheel has a nonwoven web that is attached to and spirally wound around the core member.

The amount of cut and the resulting roughness of the nonwoven abrasive article is important in performance properties while using the nonwoven abrasive article on the work piece. For some applications, it may be highly desirable to reduce the resulting surface roughness (roughness) on the workpiece while maintaining or even increasing the amount of cut of the nonwoven abrasive article during use. Surprisingly, it has been found that the nonwoven abrasive article according to the present invention exhibits a significant improvement in surface roughness upon evaluation according to the disclosed test method as compared to alternative nonwoven abrasive articles as shown in the Examples.

In particular, it has been found that the resulting surface roughness of the processed pieces is significantly improved by using a flexible binder, such as a polyurethane binder, in preparing the aggregates of the ceramic abrasive particles formed. This result is quite surprising because it was previously believed that the binder for making aggregates was not a significant contributor to the resulting roughness of nonwoven abrasive articles. Previously, the resulting surface roughness had contributed to the type of binder class (urethane to phenol) that holds the nonwoven layers together in the abrasive wheel when using the same abrasive particle size and amount in each wheel. In addition, it has been surprisingly found that the combined flexible aggregates of abrasive particles formed produce finer roughness than nonwoven abrasive articles made using the same non-aggregated abrasive particles. Previously, agglomeration of formed abrasive particles only increased the life of the abrasive article and the resulting roughness was considered to be the same as non-aggregated abrasive particles having the same size.

Thus, in one aspect, the invention relates to a nonwoven abrasive article comprising a nonwoven web, an aggregate comprising formed ceramic abrasive particles bonded to each other by a first flexible binder, and a second binder that binds the aggregate to the nonwoven fiber web. Belong.

응집체 결합제의 제조
실시예에 대한 응집된 결합제 용액을 후술된 바와 같이 구성요소들을 혼합함으로써 제조하였다.
결합제 AR1은 72.3%의 BL16, 26.8%의 K-450S, 및 0.9%의 D-1122이었다.
결합제 AR2는 63.9%의 페놀, 27.7%의 수돗물, 7.8%의 SR511, 및 0.6%의 D-1122이었다.
결합제 AR3은 포괄적으로 아크릴1 내지 아크릴7로부터 선택된 87%의 자유 라디칼-경화 수지, 및 13%의 개시제 S이었다.
결합제 AR4는 61.4%의 BL16, 22.7%의 K4-450S, 15.3%의 PMA, 및 0.6%의 D-1122이었다.
응집체의 제조
응집체 전구체 조성물은 약수저(spatula)를 이용하여 손으로 혼합된 결합제 및 광물(선택적 충전제를 포함하는 연마 입자)을 포함하였다. AR1, AR2, 및 AR4로 제조된 응집체는 고체 함량을 기초로 94 중량%의 광물이었다. AR3로 제조된 응집체는 고체 함량을 기초로 90 중량%의 광물이었다.
방법 1
미세복제된 폴리프로필렌 공구의 15 ㎝ × 86 ㎝ 시트의 캐비티 내로 응집체 전구체 조성물을 밀어 넣기 위하여 스테인리스 스틸 퍼티 나이프를 사용하였다. 공구는 2.2 ㎜의 총 두께, 복수의 정밀하게 성형되고 미세복제된 캐비티(4.0 ㎜ 제곱) 및 1.5 ㎜ 두께의 벽에 의해 분리되는 1.6 ㎜ 깊이를 가졌다. 공구를 일반적으로 후프만(Hoopman) 등의 미국 특허 제6,076,248호의 절차에 따라 해당 마스터 롤로부터 제조하였다.
폴리프로필렌 공구의 충전된 시트를 강제 공기 오븐 내에서 가열하여 응집체를 경화시켰다. 우레탄 응집체를 127℃(260℉)에서 20분 동안 경화하였다. 페놀 응집체를 91℃(200℉)에서 90분 동안, 그 후에 102℃(215℉)에서 16분 동안 경화하였다. 자유 라디칼 경화 수지를 함유하는 응집체를 138℃(280℉)에서 30분 동안 경화하였다. 경화된 응집체를 초음파 에너지에 의해 공구로부터 제거하였다. 보다 구체적으로, 공구의 후방측을 단일의 에지에 테이퍼링된 초음파 혼의 전방 에지를 가로질러 인장 하에서 잡아당겼다. 혼을 약 130 마이크로미터의 진폭에서 19,100 HZ의 주파수에서 진동시켰다. 혼은 6-4 티타늄으로 구성되었고, 2:1 부스터(Booster) 802 압전 변환기와 결합된 900 와트 184 V 브란손(Branson) 파워 소스를 이용하여 구동시켰다. 생성된 연마 응집체의 예가 도 4에 도시된다.
방법 2
연마 입자 3000 그램을 AR1의 250 그램과 완전히 혼합시켜 깨지기 쉽고 점착성의 응집체 전구체 조성물을 제조하였다. 응집체 전구체 조성물을 상표명 "쿼드로 코밀(QUADRO COMIL)"(캐나다 온타리오 워털루 소재의 쿼드로 엔지니어링 인코포레이티드(Quadro Engineering Incorporated)로부터의 모델(Model) #197)로 입수된 크기 감소 장치(size reduction machine)의 도움으로 연마 응집체 입자로 가공하였다. 크기 감소 장치의 작동의 세부는 쿨러(Culler) 등의 제WO 02/32832 A1호에서 찾을 수 있다. 50 rpm 내지 3500 rpm의 범위에서 구동되는 임펠러를 사용하여 원뿔형 스크린의 1.9 ㎜(75 밀) 원형 개구를 통하여 예비혼합물을 밀어 넣었다. 임계 길이가 획득 시에, 필라멘트 형태의 응집물 전구체 입자는 분리되고 알루미늄 수집 팬으로 중력에 의해 떨어진다. 전구체 입자의 단일- 또는 2-층을 팬 내에 수집하였고, 그 뒤에 결합제 수지를 경화시키기 위하여 15 분 동안 160℃(320℉)로 설정된 오븐 내에 배치하였다. 실온으로 냉각한 후에, 2.4 ㎜(95 밀)의 둥근 홀이 천공된 원뿔형 스크린을 포함하도록 설치된 크기 감소 장치("쿼드로 코밀")를 통하여 1회 연마 응집체 입자를 통과시킴으로써 이의 크기를 감소시켰다. 크기-감소된 입자를 14-메시(1400 미크론) 스크린 상에서 체로 걸렀다. 유나이티즈드 연마 휠을 제조하기 위해 스크린 상에 보유된 이들 입자를 사용하였다. 연마 응집체의 예가 도 5에 도시된다.
방법 3
연마 그레인, 또는 연마 그레인 및 충전제의 응집체를 두께가 1 ㎝ 내지 2 ㎝인 광물의 베드에 AR4의 액적을 도포함으로써 제조하였다. 광물 베드 위의 대략 7 ㎝의 수직 위치에서 지지된 무딘 팁을 갖는(blunt-tipped) 22-게이지(guage) 피하주사 니들(hypodermic needle)을 통하여 용액을 공급함으로써 액적을 형성하였다. 광물 또는 광물/충전제 블렌드의 표면적에 따라 소정 부피의 재료를 습윤시키는, 10초의 도포 시간 내에 광물 베드 내로 수지 액적을 위킹하였다(wicked). 30분 동안 150℃(302℉)에서 응집체를 경화하였고, 그 뒤에 응집체 형성 방법에서 재차 재활용된 비-응집된 광물로부터 체로 걸렀다. 대안으로, AR2를 광물/충전제 베드 상으로 유사한 방식으로 떨어뜨렸고, 91℃(200℉)에서 90분 동안, 그 후에 102℃(215℉)에서 16시간 동안 경화시켰다. 개별 응집체는 0.033 그램 내지 0.076 그램으로 계량되었고, 12 중량% 내지 4 중량%의 수지를 함유하였다. 형성된 연마 응집체의 예가 도 6에 도시된다.
유나티즈드 연마 휠 제조
미국 뉴욕 마세돈 소재의 란도 머신 코포레이션으로부터 상표명 "란도-웨버"로 입수가능한 에어 레이드 섬유 웨브 형성 장치 상에서 부직포 웨브를 형성하였다. 25.4 ㎜ + 12.7 ㎜(1 인치 + 1/2 인치)의 스테이플 길이를 갖는 70 데니어 나일론 크림프 세트 섬유(미국 델라웨어 윌밍턴 소재의 이. 아이. 듀폰 디 네모아 앤드 컴퍼니(E. I. du Pont de Nemours & Company)로부터 입수가능함)로부터 섬유 웨브를 형성하였다. 웨브의 중량은 대략 105 gsm(gram per square meter)이었고, 두께는 대략 10 ㎜(0.4 인치)이었다. 프리본드 수지가 89 gsm의 습윤 부가 중량(wet add-on weight)으로 도포되는 수평 2-롤 코터에 웨브를 이송하였다. 프리본드 수지는 하기 조성물(모두가 구성요소 중량에 대한 백분율): 54.1%의 BL16, 19.9%의 K450S, 26%의 PMA를 가졌다. 프리본드 수지를 4.5분 동안 166℃(330℉)에서 컨벡션 오븐(convection oven)을 통해 코팅된 웨브를 통과시킴으로써 비-점착 상태로 경화시켜 평량이 168 gsm이고 두께가 대략 6 ㎜인 미리 접합된 부직포 웨브를 산출하였다.
유나이티즈드 연마 휠을 다음과 같이 미리 접합된 부직포 웨브로부터 제조하였다. 23-㎝(9-인치)의 정사각형 섹션을 미리 접합된 부직포 웨브로부터 절단하였고, 두 가지의 휠 접착제들 중 하나로 적셨다. 휠 접착제 1(WA1)은 44%의 BL16, 16.4%의 K-450S, 15.8%의 PMA, 7%의 MP-22VF, 6%의 페녹시, 9.9%의 카오린, 및 0.4%의 D-1122이었다. 휠 접착제 2(WA2)는 60.8%의 페녹시, 31.2%의 물, 7.4%의 SR511, 및 0.6%의 D-1122이었다. 적셔지고 미리 접합된 웨브를 그 뒤에 85-쇼어(Shore) A 듀로미터 경도(durometer hardness)의 10-㎝(4-인치) 직경의 고무 롤을 갖는 롤 코터의 닙을 통과시켜 WA1에 대해 14.5 ± 1.03 mL (0.49 ± 0.035 온스 (14 ± 1 g)) 또는 WA2에 대해 17.7 ± 1.03 mL (0.60 ± 0.035 온스(17 ± 1 g))의 원하는 수지 부가 중량이 수득된 때까지 초과 수지를 제거하였다. 전형적으로 69-145 kPa(10-21 psi)의 압력 하에서 0.06 m/s(11 fpm(3.35 mpm))로 닙을 통한 다수회의 통과가 목표 중량에 도달되기 위해 요구되었다. 각각의 휠에 대해, 미리 접합된 웨브의 7개의 섹션을 전술된 방식으로 코팅하였다. 미리 접합된 웨브의 코팅된 섹션을 용매 대부분을 제거하기 위하여 1분 동안 127℃(260℉)로 설정된 강제 공기 오븐 내에 배치하였다. 부직포 연마 재료의 단일의 유나이티즈드 슬래브를 형성하기 위하여, 프리본드의 6개의 섹션을 무작위로 균일하게 분포된 광물 또는 광물 응집체 42 그램으로 각각 덮었다. 6개의 코팅된 섹션을 그 뒤에 적층하였고 프리본드의 일곱 번째 섹션으로 덮었다. 이형 라이너가 유압식 가열 플래튼 프레스 내에 배치되기 전에, 이를 그 뒤에 스택의 상부와 하부에 도포하였다. 34.5 MPa(5,000 psi)의 압력을 플래튼에 인가하였다. 플래튼의 각각의 코너에서 0.635 ㎝(0.25 인치) 두께의 금속 스페이서를 배치시킴으로써 유나이티즈드 슬래브의 규일한 두께가 유지되었다. WA1(우레탄)을 함유하는 스택을 30분 동안 127℃(260℉)로 설정된 프레스 내에 두었다. WA2(페놀)을 함유하는 스택을 5시간 동안 93℃(200℉)로 설정된 프레스 내에 두었다. 프레스가 개방될 때, 웨브의 섹션들은 단일의 유나이티즈드 슬래브로 함께 융합되었다. 슬래브를 그 뒤에 2시간 동안 127℃(260℉)(WA1), 또는 16시간 동안 102℃(215℉)(WA2)로 설정된 강제 공기 오븐 내에 배치하였다. 오븐으로부터 제거한 후에, 슬래브를 실온으로 냉각하였고, 3.2-㎝(1.25-인치)의 중심 홀을 갖는 20-㎝(8.0-인치) 직경의 유나이티즈드 연마 휠을 독일 프랑크푸르트 소재의 도이치 베레이니그테 쉬마치엔 게엠베하 & 컴퍼니(Deutsche Vereinigte Schuhmaschinen GmbH & Co)에 의해 제조된 삼코(SAMCO) SB-25 스윙 빔 프레스(swing beam press)를 사용하여 이로부터 다이 커팅하였다.
유나이티즈드 연마 휠 성능 시험
시험되는 미리 계량된 6.4 ㎜(0.25 인치)-두께의 유나이티즈드 연마 휠을 분당 대략 1065 미터(3500 피트)의 휠 에지에서의 표면 속도를 생성하도록 조절된 기계 구동식 가변 속도 선반의 아버 상에 수직 배향으로 장착하였다. 아버의 높이에서 수평방향으로 보유된 1.59 ㎜(0.0625 인치)-두께, 5.08-㎝ × 27.9-㎝(2-인치 × 7-인치)의 냉각 롤링된 탄소강 또는 T304 스테인리스 스틸 패널의 에지를 20초 동안에 대략 22.2 뉴턴(5 파운드)의 힘으로 휠의 회전 에지 내로 눌러 넣었다. 시험 순서 동안에 패널로부터 제거된 재료의 양은 "절단량(cut)"으로 지칭되고, 시험 순서 이전 그리고 이후에 패널의 중량 간의 차이로서 정해진다. 시험 순서 동안에 휠로부터 제거된 재료의 양은 "마모량"으로 지칭되고, 시험 순서 이전 그리고 이후에 휠의 중량 간의 차이로서 정해진다.
유나이티즈드 연마 휠 거칠기 시험
분당 대략 1065 미터(3500 피트)의 표면 속도를 형성하기 위하여 속도를 조절하고 후방 스탠드 상에 6.4 ㎜-두께의 휠을 배치함으로써 거칠기 샘플을 제조하였다. 대략 22.2 뉴턴(5 파운드)의 압력을 인가하면서, 1.59 ㎜(0.0625 인치)-두께, 5.08-㎝ × 27.94-㎝(2-인치 × 11-인치)의 냉간 롤링된 탄소강 또는 T304 스테인리스 스틸 패널의 면을 연마하였다. 휠에 걸쳐서 패널을 8회 이동시키고, 이동들 간에 대략 6.4 ㎜(0.25 인치)를 스텝핑하며, 패널을 분당 대략 5.04 ㎝(2 인치) 이동시킴으로써 패널의 10.2-㎝(4-인치) 길이를 완성하였다. 거칠기를 페르토미터(Perthometer) PRK 프로필로미터(profilometer)(독일 고팅겐 소재의 파인프뤼프 게엠베하(Feinpruf GmbH))를 사용하여 측정하였다. 각각의 표면에 대해 10개의 측정차를 취하였다.높고 낮은 값을 제외하였고, 나머지 8개의 데이터값을 평균하였다.
수지 모듈러스의 측정
모듈러스 측정을 위한 필름을 14 ㎝(5.5 인치)의 직경과 3 ㎜(0.12 인치) 높이의 측벽을 갖는 원형 스테인리스 스틸 폼 상에 AR1(16 그램)을 배치함으로써 제조하였다. 대부분의 용매를 제거하기 위하여 1 시간 동안 82℃(180℉)로 설정된 강제 공기 오븐에 샘플을 배치하였다. 오븐을 그 뒤에 경화를 완료하기 위하여 2 시간 동안 127℃(260℉)로 설정하였다. 대략 0.69 ㎜(0.027 인치) 두께의 형성된 필름을 스틸 폼으로부터 제거하였다. 22.54 ㎝ × 10.2 ㎝(1 인치 × 4 인치)로 측정되는 시편을 필름으로부터 절단하였고, 미국 미네소타 에덴 프레리 소재의 MTS 시스템즈 코포레이션(Systems Corporation)으로부터 입수가능한 어드밴티지(Advantage)™ 2000N 용량의 공압 샘플 그립이 장착된 MTS 모델 큐테스트 엘리트(Model QTest Elite) 100 인장 시험기를 사용하여 ASTM D882-10 "얇은 플라스틱 시팅의 인장 특성을 위한 표준 시험 방법(Standard Test Method)"에 따라 측정하였다.
실시예 1 내지 3 및 비교예 A 내지 L
표 1에 보고된 구성요소를 사용하여 유나이티즈드 연마 휠 제조 및 응집체의 제조에 대한 부분에서 전술된 절차에 따라 우레탄-결합된 유나이티즈드 연마 휠을 제조하였다. 유나이티즈드 연마 휠 성능 시험 및 유나이티즈드 연마 휠 거칠기 시험에 따라 유나이티즈드 연마 휠을 시험하였다. 결과가 표 2에 보고되어 있다. 비교예 G 내지 L의 경우, 절단량과 마모량 데이터가 수집되지 않았고, 이는 더 작은 연마 입자 크기가 매우 작은 절단량에서 야기되기 때문이다. 비교예 G 내지 L은 수득된 비교 거칠기를 나타내기 위해 제시된다.
결과는, 가요성 결합제(우레탄)와의 응집 시에 유사한(우레탄 결합된) 부직포 연마 휠, 성형된 세라믹 연마 그레인이 동일한 구성에서 비 응집된 동일한 성형된 세라믹 연마 그레인에 대해 더 미세한 거칠기를 형성하는 것을 보여준다. 게다가, 세라믹 또는 산화알루미늄이든지 유사한 입자 크기의 표준 분쇄된 그레인이 동일한 우레탄 결합제와의 응집 시에 더 조대한 거칠기를 생성한다. 시험되는 모든 연마 입자는 강성의 결합제(페놀)와 응집 시에 이의 비 응집된 제어에 대해 더 조대한 거칠기를 생성하였다. 최종적으로, 더 미세한 거칠기에 추가로, 성형된 세라믹 연마 입자는 응집된 연마 입자로부터 예상되는 성능 향상(절단량 및 마모량)이 여전히 제공되는 응집체로 형성되었다.
[표 1]

[표 2]

실시예 4 내지 6 및 비교예 M 내지 R
표 3에 보고된 성분들을 사용하여 유나이티즈드 연마 휠 제조 및 응집체의 제조에 대한 부분에서 전술된 절차에 따라 페놀-결합된 유나이티즈드 연마 휠을 제조하였다. 유나이티즈드 연마 휠 성능 시험 및 유나이티즈드 연마 휠 거칠기 시험에 따라 유나이티즈드 연마 휠을 시험하였다. 결과가 표 4에 보고되어 있다.
결과는 거칠기 데이터의 트렌드(비 응집된/우레탄 응집된/페놀 응집된)가 또한 페놀 제2 결합제와 결합된 비 유사 휠에 대해 보유되는 것을 나타낸다. 우레탄 응집체는 제어에 비해 더 미세한 거칠기를 제공하고, 페놀 응집체는 더 조대한 거칠기를 제공한다.
[표 3]

[표 4]

실시예 7a, 7b, 및 7c 및 비교예 S 내지 Y
AR1의 모듈러스를 상기 수지 모듈러스의 측정에 대해 부분에서의 절차에 따라 측정하였다. 표 5에 보고된 성분들을 사용하여 유나이티즈드 연마 휠 제조 및 응집체의 제조에 대한 부분에서 전술된 절차에 따라 다양한 자유 라디칼 경화 수지에 의해 결합된 응집체를 함유하는 우레탄 결합된 유나이티즈드 휠을 제조하였다. 유나이티즈드 연마 휠 거칠기 시험에 따라 유나이티즈드 연마 휠을 시험하였다. 결과가 표 6에 보고되어 있다.
결과는 응집체 결합제 수지를 '가요성' 또는 '강성'으로 형성하는 목적으로 ASTM D882에 따라 측정 시에 모듈러스 값이 206.84 MPa(30,000 psi) 미만으로 감소될 때 전이가 발생되는 것을 입증하는 데이터를 나타낸다.
[표 5]

[표 6]

실시예 8 및 9 및 실시예 Z 및 AA
정밀 성형된 그레인의 응집체에 의해 형성되는 거칠기에 대한 충전제의 효과를 입증하기 위하여 실시예 8 및 9 및 실시예 Z 및 AA를 제조하였다. 표 7에 보고된 성분들을 사용하여 유나이티즈드 연마 휠 제조 및 응집체의 제조에 대한 부분에서 전술된 절차에 따라 우레탄 결합된 유나이티즈드 연마 휠을 제조하였다. 유나이티즈드 연마 휠 성능 시험 및 유나이티즈드 연마 휠 거칠기 시험에 따라 유나이티즈드 연마 휠을 시험하였다. 결과가 표 8에 보고되어 있다.
결과는 형성된 세라믹 연마 입자의 가요성 결합제 응집체 내에 충전제(형성된 세라믹 연마 입자 이외의 입자)의 첨가가 더 미세한 거칠기를 형성하는 것을 나타낸다.
[표 7]

[표 8]

실시예 10 및 11
뜻밖의 향상된 거칠기 결과가 응집체 제조 방법과는 독립적인 것을 입증하기 위하여 실시예 10 및 11을 제조하였다. 표 9에 보고된 변수들을 사용하여 유나이티즈드 연마 휠 제조 및 응집체의 제조에 대한 부분에서 전술된 절차에 따라 우레탄 접합된 유나이티즈드 연마 휠을 제조하였다. 유나이티즈드 연마 휠 성능 시험 및 유나이티즈드 연마 휠 거칠기 시험에 따라 유나이티즈드 연마 휠을 시험하였다. 결과가 표 10에 보고되어 있다.
결과는 가요성 수지와 성형된 세라믹 연마 입자를 응집시킴으로써 제공되는 놀라운 거칠기 향상이 응집체의 형상과 독립적이라는 것을 보여준다. 실시예 1 내지 7 및 비교예 A 내지 Y는 몰딩된 정사각형이었다. 실시예 10 및 11은 무작위 형상이었다.
[표 9]

[표 10]

본 개시 내용에 대한 다른 수정 및 변형은 첨부하는 특허청구의 범위에 보다 구체적으로 개시된 본 개시 내용의 정신 및 범위로부터 일탈함 없이 본 기술 분야의 통상의 기량을 가진 자에 의해 실시될 수 있다. 위의 다양한 실시예의 태양들은 전체적으로 또는 부분적으로 상호 교환될 수 있거나 또는 다양한 실시예의 다른 태양과 결합될 수 있다. 특허증을 위한 상기 출원에서 열거한 모든 참고 문헌, 특허 또는 특허 출원들은 그 전체 내용을 일관된 방식으로 언급함으로써 본 명세서에 인용한다. 인용된 참고 문헌 부분들과 본 출원 사이에 불일치나 모순이 있는 경우, 앞의 설명의 정보가 지배하여야 한다. 본 기술 분야의 통상의 기량을 가진 자가 청구 범위의 개시 내용을 실시할 수 있도록 제공한 앞의 설명은 청구 범위 및 그 등가물에 의해 한정되는 본 개시 내용의 범위를 한정하는 것으로 해석되어서는 안 된다.Repeat use of reference characters in the present specification and drawings is intended to represent the same or similar features or elements of the present disclosure.
≪ 1 >
1 is a perspective view of an exemplary nonwoven abrasive article in accordance with the present invention.
<FIG. 2>
2 is a schematic perspective view of an exemplary convoluted abrasive wheel in accordance with an aspect of the present invention.
3,
3 is a schematic perspective view of an exemplary united abrasive wheel in accordance with another aspect of the present invention.
<Fig. 4>
4 is a micrograph of one embodiment of an abrasive aggregate made from the abrasive particles formed.
5,
5 is a micrograph of another embodiment of an abrasive aggregate made from the abrasive particles formed.
6,
6 is a micrograph of another embodiment of an abrasive aggregate made from the abrasive particles formed.
Justice
As used herein, variations of the words "include", "have", and "include" are legally equivalent and without limitation. Thus, in addition to the listed elements, actions, steps, or limitations, additional non-listed elements, actions, steps, or limitations may be presented.
As used herein, the term "curing" refers to the material by drying (ie evaporating the solvent), polymerizing (eg, providing a sufficient degree of chain extension of the curable polyurethane prepolymer), or cooling the molten material. It means to solidify.
As used herein, the term "flexible binder" means that the cured binder material has a modulus of elasticity such that the cured binder material can be bent to a sufficient degree without breaking, unlike phenolic binders, which can be broken. . In various embodiments of the present invention, the modulus of elasticity may be less than 193.05 MPa (28,000 psi), or less than 172.37 MPa or 158.58 MPa (less than 25,000 psi or 23,000 psi) when tested by ASTM D882. Examples of suitable flexible binders include those of polyurethanes, polyureas, polyisoprene, polybutadiene, polychloroprene, butyl rubber, styrene-butadiene copolymers, and nitrile rubbers.
As used herein, “formed ceramic abrasive particles” means abrasive particles having a shape that is at least partially replicated. A non-limiting method for producing the formed abrasive particles includes molding precursor ceramic abrasive particles in a mold having a predetermined shape to produce shaped ceramic abrasive particles, and forming the precursor ceramic abrasive particles through an orifice having a predetermined shape. Extruding, printing the precursor ceramic abrasive particles through an opening in a printing screen having a predetermined shape, or embossing the precursor ceramic abrasive particles in a predetermined shape or pattern. Non-limiting examples of ceramic abrasive particles formed include US RE 35,570, 5,201,916, and 5,984,998, US Patent Publications 2009/0169816, 2009/0165394, 2010/0151195, 2010/2010. Ceramic abrasive particles shaped as triangle plates, or Saint-Gobain Abrasives, as disclosed in 0151201, 2010/0146867, 2010/0151196 and 2010/0319269. Elongated ceramic rods / filaments having a generally circular cross-section, manufactured by US Patent No. 5,372,620, are included.
As used herein, the term "mineral" means abrasive particles or a mixture of abrasive particles and a filler.
DETAILED DESCRIPTION OF THE INVENTION [
Various exemplary abrasive articles in accordance with the present invention, including lofty open nonwoven abrasive articles (eg, webs and sheets), unitized abrasive wheels, and convolute abrasive wheels, are, for example, nonwoven fabrics. It can be prepared via a method comprising the step of coating a curable composition, typically in slurry form, on a web. The curable composition includes at least one of a curable polyurethane prepolymer, an effective amount of an amine curing agent, a cationic surfactant, an anionic surfactant, a fluorinated nonionic surfactant, or a silicone-based nonionic surfactant, and an amphoteric aminosilane. do. In forming a convoluted or united abrasive wheel, the nonwoven web is typically pressed (ie, densified) against the nonwoven web used in the lofty open nonwoven fibrous article.
Nonwoven web
Nonwoven webs suitable for use in the abrasive articles described above are well known in the abrasive art. Typically, nonwoven webs include entangled fiber webs. The fibers may comprise continuous fibers, staple fibers, or a combination thereof. For example, the nonwoven web can include staple fibers that are at least about 20 millimeters (mm), at least about 30 mm, or at least about 40 mm, and less than about 110 mm, less than about 85 mm, or less than about 65 mm in length. However, shorter fibers and longer fibers (eg continuous filaments) may also be useful. The fibers may have a fineness of at least about 1.7 decitex (ie, grams / 10000 meters), at least about 6 dtex, or at least about 17 dtex, and less than about 560 dtex, less than about 280 dtex, or less than about 120 dtex, or Fibers having smaller and / or larger linear densities may also be useful, although they may have a linear density. Mixtures of fibers having different line densities can be useful, for example, in providing abrasive articles in which particularly desirable surface roughness will be obtained in use. If spunbond nonwovens are used, the filaments may have a substantially larger diameter (eg, up to 2 mm or more in diameter).
Nonwoven webs may be, for example, conventional air laid, carded, stitch bonded, spun bonded, wet laid, and / or melt blown ( melt blown). For example, airlaid fiber webs can be made using equipment such as those available under the trade name “RANDO WEBBER”, available from Rando Machine Company, Macedon, NY. have.
Nonwoven webs are typically selected to be suitably compatible with adhesive binders and abrasive particles and also to be treated in combination with other components of the article, and are typically treated with processing conditions such as those used during application and curing of the curable composition. Temperature, for example). The fibers can be selected to affect the properties of the abrasive article (eg, flexibility, elasticity, durability or lifespan, wear and roughness properties). Examples of fibers that may be suitable include natural fibers, synthetic fibers and mixtures of natural fibers and / or synthetic fibers. Examples of synthetic fibers include polyester (e.g. polyethylene terephthalate), nylon (e.g. hexamethylene adipamide, polycaprolactam), polypropylene, acrylonitrile (i.e. acrylic), rayon, cellulose acetate , Polyvinylidene chloride-vinyl chloride copolymers, and those made from vinyl chloride-acrylonitrile copolymers. Examples of suitable natural fibers include cotton, wool, jute, and hemp. The fibers may be of virgin material or may be of recycled or waste material, for example recycled from garment altars, carpet making, fiber making, or textile processing. The fibers can be homogeneous or composite such as bicomponent fibers (eg, co-spun sheath-core fibers). The fibers may be stretched and crimped, but may also be continuous filaments as formed by the extrusion method. Combinations of fibers can also be used.
Prior to impregnation with the curable composition, the nonwoven fiber web typically has a unit suitable weight (ie, a basis weight) of at least about 50 grams per square meter, at least about 100 gsm, or at least about 200 gsm, and And / or less than about 400 gsm, less than about 350 gsm, or less than about 300 gsm (eg, measured prior to any coating with the curable composition or optional pre-bond resin), but more Larger and smaller basis weights can also be used. Additionally, prior to impregnation with the curable composition, the fiber web typically has a thickness of at least about 5 mm, at least about 6 mm, or at least about 10 mm, and / or less than about 200 mm, less than about 75 mm, or about 30 Although less than mm, larger and smaller thicknesses may also be useful.
Further details regarding nonwoven abrasive articles, abrasive wheels and methods of making the same are described, for example, in US Pat. No. 2,958,593 (Hoover et al.); 5,591,239 (Larson et al.); 6,017,831 (Beardsley et al.); And US Patent Application Publication No. 2006/0041065 A1 (Barber, Jr.).
Often, it is useful to apply the prebond resin to the nonwoven web prior to coating with the curable composition. Prebond resins are provided, for example, to help maintain the integrity of the nonwoven web during handling, and may also assist in bonding the urethane binder to the nonwoven web. Examples of prebond resins include phenolic resins, urethane resins, hide glue, acrylic resins, urea-formaldehyde resins, melamine-formaldehyde resins, epoxy resins and combinations thereof. The amount of prebond resin used in this way is typically adjusted to the minimum amount by joining the fibers to each other at their cross contact points. If the nonwoven web comprises thermally bondable fibers, thermal bonding of the nonwoven web may also help maintain web integrity during processing.
Abrasive particles
Useful abrasive particles for incorporation into the agglomerates of the present invention are formed ceramic abrasive particles, and in particular shaped ceramic abrasive particles. Molded ceramic abrasive particles are prepared according to the disclosure of US Patent Publication No. 2010/0151196. Molded ceramic abrasive particles are made by molding alumina sol gel, for example, from an equilateral triangle-shaped polypropylene mold cavity of 0.3 mm (0.012 inch) mold depth and 1.37 mm (0.054 inch) side length. After drying and firing, these formed shaped ceramic abrasive particles included a triangular plate that was about 570 micrometers (longest dimension) and could pass through a 30-mesh sieve.
In addition to shaped ceramic abrasive particles, the articles of the present invention may also contain conventional (eg, ground) abrasive particles. Examples of conventional abrasive particles useful for blending with shaped ceramic abrasive particles include any abrasive particles known in the abrasive arts. Exemplary useful abrasive particles may include fused aluminum oxide based materials such as aluminum oxide, ceramic aluminum oxide (one or more metal oxide modifiers and / or seeding agents or nucleating agents). Aluminum oxide, silicon carbide, common solution alumina-zirconia, diamond, ceria, titanium diboride, cubic boron nitride, boron carbide, garnet, flint flint, emery, sol-gel derived abrasive particles and mixtures thereof. The abrasive particles may be, for example, in the form of individual particles, aggregates, composite particles, and mixtures thereof.
Conventional abrasive particles have, for example, an average diameter of at least about 0.1 micrometers, at least about 1 micrometers, or at least about 10 micrometers, and less than about 2000 micrometers, less than about 1300 micrometers, or less than about 1000 micrometers. Larger and smaller abrasive particles may also be used, although they may have. For example, conventional abrasive particles can have an abrasive industry specified nominal rating. Classification standards approved by these abrasive industries include the American National Standards Institute, Inc. (ANSI) standard, the Federation of European Producers of Abrasive Products (FEPA) standard, and the Japanese Industrial Standard. Standard (JIS) standards include those known as. Exemplary ANSI class names (ie, regulatory nominal grades) are ANSI 4, ANSI 6, ANSI 8, ANSI 16, ANSI 24, ANSI 36, ANSI 40, ANSI 50, ANSI 60, ANSI 80, ANSI 100, ANSI 120, ANSI Includes 150, ANSI 180, ANSI 220, ANSI 240, ANSI 280, ANSI 320, ANSI 360, ANSI 400, and ANSI 600. Exemplary FEPA class names include P8, P12, P16, P24, P36, P40, P50, P60, P80, P100, P120, P150, P180, P220, P320, P400, P500, 600, P800, P1000 and P1200 . Exemplary JIS grade names are HS8, JIS12, JIS16, JIS24, JIS36, JIS46, JIS54, JIS60, JIS80, JIS100, JIS 150, JIS 180, JIS220, JIS 240, JIS280, JIS320, JIS360,, JIS400JIS400, JIS600, JIS800, JIS1000, JIS1500, JIS2500, JIS4000, JIS6000, JIS8000, and JIS10000.
Abrasive grain aggregate
Aggregates of the invention comprise a first flexible binder. Examples of suitable flexible binders include those of polyurethanes, polyureas, polyisoprene, polybutadiene, polychloroprene, butyl rubber, styrene-butadiene copolymers, and nitrile rubbers.
Typical flexible binders for the production of aggregates comprising ceramic abrasive particles formed are polyurethane binders. Examples of useful urethane prepolymers include polyisocyanates and blocked versions thereof. Typically, blocked polyisocyanates are substantially non-reactive to isocyanate-reactive compounds (eg, amines, alcohols, thiols, etc.) under ambient conditions (eg, temperatures ranging from about 20 ° C. to about 25 ° C.) Upon application of sufficient thermal energy, the blocking agent is released, thereby generating isocyanate functionality that reacts with the amine curing agent to form covalent bonds.
 Useful polyisocyanates include, for example, aliphatic polyisocyanates (eg, hexamethylene diisocyanate or trimethylhexamethylene diisocyanate); Alicyclic polyisocyanates (eg, hydrogenated xylene diisocyanates or isophorone diisocyanates); Aromatic polyisocyanates (eg tolylene diisocyanate or 4,4'-diphenylmethane diisocyanate); Adducts of any of the above polyisocyanates with polyhydric alcohols (eg, diols, low molecular weight hydroxyl group-containing polyester resins, water, etc.); Adducts of the polyisocyanates (eg, isocyanurate, biuret); And mixtures thereof.
Useful commercially available polyisocyanates are, for example, those available under the trade name "ADIPRENE" from Chemtura Corporation, Middlebury, Connecticut, USA (e.g., "adiprene L 0311", "Adiprene L 100", "adiprene L 167", "adiprene L 213", "adiprene L 315", "adiprene L 680", "adiprene LF 1800A", "adiprene LF 600D", " Adiprene LFP 1950A "," adiprene LFP 2950A "," adiprene LFP 590D "," adiprene LW 520 ", and" adiprene PP 1095 "); Polyisocyanates available under the trade name "MONDUR" from Bayer Corporation, Pittsburgh, Pennsylvania (eg, "Monder 1437", "Monder MP-095", or "Monder 448"); And polyisocyanates (for example, "Airtan APC", available under the trade names "AIRTHANE" and "VERSATHANE" from Air Products and Chemicals, Allentown, Pennsylvania, USA). -504 "," Airtan PST-95A "," Airtan PST-85A "," Airtan PET-91A "," Airtan PET-75D "," Versatan STE-95A "," Versatan STE-P95 "," Versatan STS-55 "," Versatan SME-90A ", and" Versatan MS-90A ").
To extend the pot-life, for example, polyisocyanates such as those mentioned above can be blocked with a blocking agent according to various techniques known in the art. Exemplary blocking agents include ketoxime (eg, 2-butanone oxime); Lactams (eg epsilon-caprolactam); Malonic acid esters (eg, dimethyl malonate and diethyl malonate); Pyrazoles (eg, 3,5-dimethylpyrazole); Alcohols including tertiary alcohols (eg t-butanol or 2,2-dimethylpentanol), phenols (eg alkylated phenols), and mixtures of the described alcohols.
Exemplary useful commercially available blocked polyisocyanates are those sold by Futura Corporation under the trade names "adiprene BL 11", "adiprene BL 16", "adiprene BL 31", and "TRIXENE". (E.g., "Trissen BL 7641", "Trisen BL 7642", "Trisen BL 7772", and "Trisen BL 7774") under the trade names Baseenden Chemicals, Waxenden, Aklington, UK. Blocked polyisocyanates sold by Chemicals, Ltd.).
Typically the amount of urethane prepolymer present in the curable composition is in an amount of 10% to 40% by weight, more typically in an amount of 15% to 30% by weight, and even more typically 20% by weight based on the total weight of the curable composition. Although in amounts of 25% by weight, amounts outside these ranges may also be used.
Suitable amine curing agents include aromatic, alkyl-aromatic, or alkyl multifunctional amines, preferably primary amines. Examples of useful amine curing agents include 4,4'-methylenedianiline; Functional groups from 2.1 to 4.0, including those known under the trade name "CURITHANE 103" available from Dow Chemical Company and "MDA-85" from Bayer Corporation, Pittsburgh, Pennsylvania, USA Polymeric methylene dianiline having; 1,5-diamine-2-methylpentane; Tris (2-aminoethyl) amine; 3-aminomethyl-3,5,5-trimethylcyclohexylamine (ie isophoronediamine), trimethylene glycol di-p-aminobenzoate, bis (o-aminophenylthio) ethane, 4,4 ' Methylenebis (dimethyl anthranilate), bis (4-amino-3-ethylphenyl) methane (eg Nippon Kayaku Company, Ltd., Tokyo, Japan) (KAYAHARD) AA ", and bis (4-amino-3,5-diethylphenyl) methane (eg," Lonzacure "by Lonza, Ltd., Basel, Switzerland) (LONZACURE) under the trade name M-DEA ", and mixtures thereof. If desired, polyol (s) can be added to the curable composition, for example, to modify (eg, delay) the cure rate as needed for the intended use.
The amine curing agent must be present in an amount (ie, an effective amount) effective to cure the blocked polyisocyanate to the extent required by the intended use, for example, with an amine curing agent in the range of 0.8-1.35; For example, a stoichiometric ratio of the curing agent to isocyanate (or blocked isocyanate) in the range of 0.85 to 1.20, or in the range of 0.90 to 0.95, may be present, but stoichiometric ratios outside these ranges may also be used. have.
  Typically, the curable composition will include, but need not be, at least one organic solvent (eg, isopropyl alcohol or methyl ethyl ketone) to facilitate coating the curable composition on the nonwoven fibrous web. Optionally, the curable composition may be mixed with one or more additives and / or may include one or more additives. Exemplary additives include fillers, plasticizers, surfactants, lubricants, colorants (eg, pigments), antibacterial agents, bactericides, grinding aids, and antistatic agents. Typically, the curable composition (including any solvents that may be present) is present in an amount of 1120 gsm to 2080 gsm, more typically 1280 gsm to 1920 gsm, and even more typically 1440 gsm to 1760 gsm on the nonwoven fiber web. Although coated, values outside these ranges can also be used.
Filler materials other than conventional abrasive particles may be blended with shaped ceramic abrasive particles in the aggregates of the present invention. Examples of fillers useful in the present invention include metal carbonates (eg calcium carbonate, calcium magnesium carbonate, sodium carbonate, magnesium carbonate), silica (eg talc, clay, montmorillonite, feldspar, mica, calcium silicate , Calcium metasilicate, metal sulfates (e.g. calcium sulfate, barium sulfate, sodium sulfate, aluminum sodium sulfate, aluminum sulfate), gypsum, vermiculite, sugar, wood floor, aluminum trihydrate, carbon black , Metal oxides (eg calcium oxide, aluminum oxide, tin oxide, titanium dioxide), metal sulfites (eg calcium sulfite), thermoplastic particles (eg polycarbonate, polyetherimide, polyester , Polyethylene, poly (vinylchloride), polysulfone, polystyrene, acrylonitrile-butadiene-styrene block copolymerization , Polypropylene, acetal polymer, polyurethane, nylon particles) and thermosetting particles (eg, phenol bubbles, phenol beads, polyurethane foam particles, etc.) The filler may also be a salt such as halide salts. Examples of halide salts include sodium chloride, potassium cryolite, sodium cryolite, ammonium cryolite, potassium tetrafluoroborate, sodium tetrafluoroborate, silicon fluoride, potassium chloride, magnesium chloride, etc. Examples of metal fillers include tin, lead, bismuth, Cobalt, antimony, cadmium, iron, and titanium Other various fillers include sulfur, organic sulfur compounds, graphite, lithium stearate and metal sulfides.
For best results, the size of the agglomerates can range from 0.8 mm to 5 mm, or 1.4 mm to 4 mm, or 1.8 mm to 3 mm in maximum lateral edge length (usually cylindrical, oval, or other geometric shape) or maximum It has a diameter (usually spherical) and may be spherical, ovoid, cylindrical, pyramid, conical or any multi-sided Platonic solid (tetrahedron, octahedron, etc.). For best results, the ratio of formed abrasive particle size (measured edge length of formed abrasive particles) divided by aggregate size (measuring the maximum diameter or maximum lateral edge length of the aggregate) is 0.0033 to 0.5 (approximately 300 to 2 over the aggregate). Formed abrasive particles) or 0.01 to 0.33 (approximately 100 to 3 formed abrasive particles across aggregates), or 0.05 to 0.25 (approximately 20 to 4 formed abrasive particles across aggregates). For best results, when filler particles (usually ground abrasive particles or diluents) are used, they have an average particle size less than the average particle size of the ceramic abrasive particles formed, or the abrasive particle sizes formed (the maximum diameter of the aggregates). Or by measuring the maximum lateral edge length), the ratio of filler particle size (maximum diameter) is 0.001 to 1.0, or 0.003 to 0.5, or 0.01 to 0.1. Typical aggregates of the invention include up to 30 wt% (wt.%) Of the first flexible binder, up to 20 wt% of the first flexible binder, up to 15 wt% of the first flexible binder, or even up to 10 wt% It may comprise a first flexible binder of. Typical aggregates of the invention comprise at least 50% by weight of formed ceramic abrasive particles. For best results, the ceramic abrasive particle content formed is 50% to 98%, 75% to 96%, or 80% to 94% by weight, and the resin content is 2% to 20%, 4% by weight. % To 10% by weight, or 5% to 8% by weight, and the filler particle content is 0% to 40% by weight, 10% to 35% by weight, or 15% to 30% by weight. The above ranges for various properties may be combined or selected in any manner to specify the properties of the aggregates.
Nonwoven Polishing Web
Nonwoven abrasive webs are prepared by adhering the aggregates of the present invention to nonwoven webs using a curable second binder. Typically, the coating weight for the abrasive aggregates (independent of other components in the curable composition) may depend, for example, on the particular second binder used, the method for applying the abrasive aggregates, and the size of the abrasive aggregates. have. For example, the coating weight of the abrasive aggregates on the nonwoven web (prior to any compression) may be at least 200 grams per square meter, at least 600 g / m, or at least 800 g / m; And / or less than 2000 g / m, less than about 1600 g / m, or less than about 1200 g / m, although larger or smaller coating weights may also be used.
Secondary binders useful for adhering aggregates to nonwoven fibrous webs are known in the art and are selected according to the final product requirements. Typical binders include urethanes, phenols, acrylates, and blends of phenols and acrylates. The precursors for bonding useful urethane binder materials and aggregates to nonwoven webs have been described above.
Phenolic materials are useful binder precursors because of their thermal properties, availability, cost and ease of handling. Resol phenols have a molar ratio of at least one formaldehyde to phenol and typically range from 1.5: 1.0 to 3.0: 1.0. Novolac phenol has a molar ratio of formaldehyde to phenol of less than 1.0: 1.0. Examples of commercially available phenols include the trade names "DUREZ" and "VARCUM" from Occidental Chemicals Corp; "RESINOX" from Monsanto; "AROFENE" from Ashland Chemical Co; And those known as "AROTAP" from Ashland Chemical Company.
Emulsions of crosslinked acrylic resin particles may also have utility in the present invention.
Some binder precursors include phenol mixed with latex. Examples of such latexes include materials containing acrylonitrile butadiene, acrylics, butadiene, butadiene-styrene, and combinations thereof. These latexes are available from a number of different sources and are available from the Rohm and Haas Company under the trade names "RHOPLEX" and "ACRYLSOL", Air Products and Chemicals Inc. "FLEXCRYL" and "VALTAC", available from Air Products & Chemicals Inc, "SYNTHEMUL", "Ticryl" available from Reichold Chemical Co. TYCRYL) "and" TYLAC ", B.F. "HYCAR" and "GOODRITE" available from BF Goodrich, "CHEMIGUM" available from Goodyear Tire and Rubber Co, IC "NEOCRYL", available from (ICI), "BUTAFON", available from BASF, and those available as "RES", available from Union Carbide. .
Nonwoven abrasive supplies
The nonwoven abrasive articles of the present invention may take any of a variety of conventional forms. 1 shows a nonwoven abrasive article 100 that includes a nonwoven web, an aggregate comprising formed ceramic abrasive particles bonded to each other by a first flexible binder, and a second binder that binds the aggregate to the nonwoven fiber web. 4-6 show abrasive aggregates comprising shaped ceramic abrasive particles and a first flexible binder. The shaped ceramic abrasive particles comprise a triangular plate as shown.
Preferred nonwoven abrasive articles are in the form of wheels. Nonwoven abrasive wheels typically have discs or vertical cylinders that have dimensions, for example, the height of the cylinder can be very small (eg, a few millimeters) or can be very large (eg, more than a meter), for example. in the form of a right cylinder, which can be very small (eg, a few centimeters) or very large (eg, a few tens of centimeters). The wheel typically has a central opening for support by a suitable arbor or other mechanical retention means that allows the wheel to rotate during use. Wheel dimensions, shapes, support means, and rotation means are all well known in the art.
The convoluted abrasive wheel, for example, winds a nonwoven web impregnated with a curable composition under tension around a core member (eg, a tubular or rod-shaped core member) such that the impregnated nonwoven layer is compressed, followed by one implementation. It can be provided by curing the curable composition in order to provide a polyurethane binder that bonds the abrasive aggregate to the layered nonwoven web and couples the layers of the layered nonwoven web to each other. An exemplary convoluted abrasive wheel 200 is shown in FIG. 2, wherein the layered nonwoven fiber web 210 coated with a binder that bonds abrasive aggregates to the layered nonwoven fiber web and joins the layers of the layered nonwoven fiber web to each other is a core member. Spirally arranged around and attached to 230. If desired, the convoluted abrasive wheel can be dressed prior to use for removing surface relief, for example using methods known in the abrasive arts.
An exemplary united abrasive wheel is shown in FIG. 3, for example layering an impregnated provided nonwoven web 310 (eg, such as a stack of layered continuous webs or sheets) that compresses nonwoven layers, It can be provided by curing the curable composition (eg, using heat) and die cutting the resulting abrasive article to provide a united abrasive wheel having a hollow axial core 320. When compressing the layers of the impregnated nonwoven web, the layers are typically compacted to form a burn having a density of 1 to 20 times the density of the layers in their non-compressed state. Typically, depending on the urethane prepolymer and the bun size, the bun is then thermoformed typically at elevated temperatures (eg, at 135 ° C.) (eg, for 2 to 20 hours).
Example
The objects and advantages of the present disclosure are further illustrated by the following non-limiting examples. The specific materials recited in these examples and their amounts and other conditions and details should not be construed as unduly limiting the present disclosure. Unless otherwise noted, all parts, percentages, ratios, and the like in the present examples and the rest of the specification are by weight.
The following abbreviations are used throughout the Examples.

Preparation of Aggregate Binder
Agglomerated binder solutions for the examples were prepared by mixing the components as described below.
Binder AR1 was 72.3% BL16, 26.8% K-450S, and 0.9% D-1122.
Binder AR2 was 63.9% phenol, 27.7% tap water, 7.8% SR511, and 0.6% D-1122.
Binder AR3 was 87% free radical-cured resin, and 13% of initiator S, globally selected from acryl1 to acryl7.
Binder AR4 was 61.4% BL16, 22.7% K4-450S, 15.3% PMA, and 0.6% D-1122.
Preparation of Aggregates
The aggregate precursor composition included binders and minerals (abrasive particles comprising optional filler) mixed by hand using a spatula. Aggregates made from AR1, AR2, and AR4 were 94% by weight minerals based on solids content. Aggregates made from AR3 were 90% by weight minerals based on solids content.
Method 1
A stainless steel putty knife was used to push the aggregate precursor composition into a cavity of 15 cm x 86 cm sheet of microreplicated polypropylene tool. The tool had a total thickness of 2.2 mm, a plurality of precisely shaped and microreplicated cavities (4.0 mm squared) and 1.6 mm depth separated by a 1.5 mm thick wall. Tools were generally manufactured from the corresponding master rolls according to the procedures of US Pat. No. 6,076,248 to Hoopman et al.
The filled sheet of polypropylene tool was heated in a forced air oven to cure the aggregates. Urethane aggregates were cured at 127 ° C. (260 ° F.) for 20 minutes. The phenol aggregates were cured at 91 ° C. (200 ° F.) for 90 minutes and then at 102 ° C. (215 ° F.) for 16 minutes. Aggregates containing free radical curable resins were cured at 138 ° C. (280 ° F.) for 30 minutes. Cured aggregates were removed from the tool by ultrasonic energy. More specifically, the back side of the tool was pulled under tension across the front edge of the ultrasonic horn tapered to a single edge. The horn was vibrated at a frequency of 19,100 HZ at an amplitude of about 130 micrometers. The horn consisted of 6-4 titanium and was driven using a 900 Watt 184 V Branson power source coupled with a 2: 1 Booster 802 piezoelectric transducer. An example of the resulting abrasive aggregate is shown in FIG. 4.
Method 2
3000 grams of abrasive particles were thoroughly mixed with 250 grams of AR1 to prepare a fragile and sticky aggregate precursor composition. Aggregate precursor compositions were obtained under the trade name “QUADRO COMIL” (Model # 197 from Quadro Engineering Incorporated, Waterloo, Ontario). with the aid of a machine). Details of the operation of the size reduction device can be found in WO 02/32832 A1 to Cooler et al. The premix was pushed through the 1.9 mm (75 mil) circular opening of the conical screen using an impeller driven in the range of 50 rpm to 3500 rpm. When the critical length is obtained, the aggregate precursor particles in the form of filaments are separated and dropped by gravity into an aluminum collection pan. Single- or two-layers of precursor particles were collected in a pan and then placed in an oven set at 160 ° C. (320 ° F.) for 15 minutes to cure the binder resin. After cooling to room temperature, its size was reduced by passing the abrasive agglomerate particles once through a size reduction device (" comil " quadruple) installed so that a 2.4 mm (95 mil) round hole included a perforated conical screen. Size-reduced particles were sieved on a 14-mesh (1400 micron) screen. These particles retained on the screen were used to produce united abrasive wheels. An example of an abrasive aggregate is shown in FIG. 5.
Method 3
Abrasive grains, or aggregates of abrasive grains and fillers, were prepared by applying droplets of AR4 to a bed of mineral having a thickness of 1 cm to 2 cm. Droplets were formed by feeding the solution through a blunt-tipped 22-gauge hypodermic needle supported at a vertical position of approximately 7 cm above the mineral bed. The resin droplets were wicked into the mineral bed within 10 seconds of application time, which wetted a volume of material depending on the surface area of the mineral or mineral / filler blend. The aggregates were cured at 150 ° C. (302 ° F.) for 30 minutes, and then sieved from non-aggregated minerals recycled again in the aggregate formation method. Alternatively, AR2 was dropped in a similar manner onto the mineral / filler bed and cured for 90 minutes at 91 ° C. (200 ° F.), followed by 16 hours at 102 ° C. (215 ° F.). Individual aggregates weighed from 0.033 grams to 0.076 grams and contained 12% to 4% by weight of resin. An example of the abrasive aggregate formed is shown in FIG. 6.
Unitized abrasive wheel manufacturers
Nonwoven webs were formed on an air laid fiber web forming apparatus available under the trade name "Rando-Weber" from Rando Machine Corporation, Macedon, NY. 70 denier nylon crimp set fiber with staple length of 25.4 mm + 12.7 mm (1 inch + 1/2 inch) (EI du Pont de Nemours & Company, Wilmington, Delaware, USA) Fibrous web). The weight of the web was approximately 105 gsm (gram per square meter) and the thickness was approximately 10 mm (0.4 inch). The web was transferred to a horizontal two-roll coater where the prebond resin was applied at a wet add-on weight of 89 gsm. The prebond resin had the following composition (all percentages of component weight): 54.1% BL16, 19.9% K450S, 26% PMA. The prebond resin is cured non-tacky by passing the coated web through a convection oven at 166 ° C. (330 ° F.) for 4.5 minutes to pre-bonded nonwoven fabric having a basis weight of 168 gsm and a thickness of approximately 6 mm. The web was calculated.
United abrasive wheels were prepared from prebonded nonwoven webs as follows. 23-cm (9-inch) square sections were cut from prebonded nonwoven webs and wetted with one of two wheel adhesives. Wheel Adhesive 1 (WA1) was 44% BL16, 16.4% K-450S, 15.8% PMA, 7% MP-22VF, 6% phenoxy, 9.9% kaolin, and 0.4% D-1122. . Wheel Adhesive 2 (WA2) was 60.8% phenoxy, 31.2% water, 7.4% SR511, and 0.6% D-1122. The wet and prebonded web was then passed through a nip of a roll coater with a 10-cm (4-inch) diameter rubber roll of 85-Shore A durometer hardness to 14.5 ± for WA1. Excess resin was removed until the desired resin addition weight of 1.03 mL (0.49 ± 0.035 oz (14 ± 1 g)) or 17.7 ± 1.03 mL (0.60 ± 0.035 oz (17 ± 1 g)) for WA2 was obtained. Typically multiple passes through the nip at 0.06 m / s (11 fpm (3.35 mpm)) under pressures of 10-21 psi (69-145 kPa) were required to reach the target weight. For each wheel, seven sections of the prebonded web were coated in the manner described above. The coated section of the prebonded web was placed in a forced air oven set at 127 ° C. (260 ° F.) for 1 minute to remove most of the solvent. To form a single united slab of nonwoven abrasive material, six sections of the prebond were each covered with 42 grams of randomly evenly distributed minerals or mineral aggregates. Six coated sections were then laminated and covered with the seventh section of the prebond. Before the release liner was placed in the hydraulic heated platen press, it was then applied to the top and bottom of the stack. A pressure of 34.5 MPa (5,000 psi) was applied to the platen. The uniform thickness of the united slab was maintained by placing a 0.635 cm (0.25 inch) thick metal spacer at each corner of the platen. The stack containing WA1 (urethane) was placed in a press set at 127 ° C. (260 ° F.) for 30 minutes. The stack containing WA 2 (phenol) was placed in a press set at 93 ° C. (200 ° F.) for 5 hours. When the press was open, the sections of the web were fused together into a single united slab. The slab was then placed in a forced air oven set at 127 ° C. (260 ° F.) (WA1) for 2 hours, or 102 ° C. (215 ° F.) (WA2) for 16 hours. After removal from the oven, the slab was cooled to room temperature, and a 20-cm (8.0-inch) diameter united abrasive wheel with a 3.2-cm (1.25-inch) center hole was removed from Deutsche Berreiigtesch, Frankfurt, Germany. Die cutting therefrom using a Samco SB-25 swing beam press manufactured by Deutsche Vereinigte Schuhmaschinen GmbH & Co.
Unitized Abrasive Wheel Performance Test
The pre-weighed 6.4 mm (0.25 inch) -thick united abrasive wheels tested were placed on an arbor of a machine driven variable speed lathe adjusted to produce surface speeds at wheel edges of approximately 1065 meters (3500 feet) per minute. Mounted in a vertical orientation. 1.59 mm (0.0625 inch) -thick, 5.08-cm × 27.9-cm (2-inch × 7-inch) edges held horizontally at the height of the arbor in 20 seconds for the edge of the cold rolled carbon steel or T304 stainless steel panel. Pressed into the rotating edge of the wheel with a force of approximately 22.2 Newtons (5 pounds). The amount of material removed from the panel during the test sequence is referred to as a "cut" and is defined as the difference between the weight of the panel before and after the test sequence. The amount of material removed from the wheel during the test sequence is referred to as the “wear amount” and is defined as the difference between the weight of the wheel before and after the test sequence.
United Grinding Wheel Roughness Test
Roughness samples were made by adjusting the speed to place a surface speed of approximately 1065 meters (3500 feet) per minute and placing a 6.4 mm-thick wheel on the rear stand. 1.59 mm (0.0625 inch) -thick, 5.08-cm × 27.94-cm (2-inch × 11-inch) side of cold rolled carbon steel or T304 stainless steel panel, applying a pressure of approximately 22.2 Newtons (5 pounds) Was polished. The panel was completed eight times, stepped approximately 6.4 mm (0.25 inch) between movements, and moved the panel approximately 5.04 cm (2 inches) per minute to complete the 10.2-cm (4-inch) length of the panel. . Roughness was measured using a Perthometer PRK profilometer (Feinpruf GmbH, Gotingen, Germany). Ten measurement differences were taken for each surface. The high and low values were excluded and the remaining eight data values were averaged.
Measurement of Resin Modulus
Films for modulus measurements were prepared by placing AR1 (16 grams) on a circular stainless steel foam having a diameter of 14 cm (5.5 inches) and a side wall 3 mm (0.12 inches) high. Samples were placed in a forced air oven set at 82 ° C. (180 ° F.) for 1 hour to remove most solvent. The oven was then set to 127 ° C. (260 ° F.) for 2 hours to complete curing. Approximately 0.69 mm (0.027 inch) thick formed film was removed from the steel foam. Specimens measuring 22.54 cm by 10.2 cm (1 inch by 4 inches) were cut from the film and the Pneumatic Sample Grips of the Advantage ™ 2000N capacity available from MTS Systems Corporation, Eden Prairie, Minn. Measurements were made in accordance with ASTM D882-10 “Standard Test Method for Tensile Properties of Thin Plastic Seating” using a fitted MTS Model QTest Elite 100 tensile tester.
Examples 1-3 and Comparative Examples A-L
The components reported in Table 1 were used to prepare urethane-bonded united abrasive wheels according to the procedures described above in the section on united abrasive wheel manufacture and the preparation of aggregates. The united abrasive wheels were tested according to the united abrasive wheel performance test and the united abrasive wheel roughness test. The results are reported in Table 2. For Comparative Examples G-L, the cut and wear data were not collected because smaller abrasive particle sizes result in very small cuts. Comparative Examples G to L are shown to show the comparative roughness obtained.
The result is that similar (urethane bonded) nonwoven abrasive wheels, molded ceramic abrasive grains, upon flocculation with the flexible binder (urethane) form finer roughness for the same molded ceramic abrasive grains that are non-aggregated in the same configuration. Shows. In addition, standard milled grains of similar particle size, whether ceramic or aluminum oxide, produce coarser roughness upon aggregation with the same urethane binder. All abrasive particles tested produced coarser roughness for their non-aggregated control upon coagulation with the rigid binder (phenol). Finally, in addition to finer roughness, the shaped ceramic abrasive particles were formed into agglomerates that still provide the expected performance improvement (amount of cut and abrasion) from the agglomerated abrasive particles.
[Table 1]

[Table 2]

Examples 4-6 and Comparative Examples M-R
Using the components reported in Table 3, phenol-bonded united abrasive wheels were prepared according to the procedures described above in the section on united abrasive wheel preparation and preparation of aggregates. The united abrasive wheels were tested according to the united abrasive wheel performance test and the united abrasive wheel roughness test. The results are reported in Table 4.
The results indicate that trends in roughness data (non aggregated / urethane aggregated / phenol aggregated) are also retained for non-like wheels combined with phenolic second binders. Urethane aggregates provide finer roughness than control, and phenol aggregates provide coarser roughness.
[Table 3]

[Table 4]

Examples 7a, 7b, and 7c and comparative examples S to Y
The modulus of AR1 was measured following the procedure in part for the measurement of the resin modulus. The components reported in Table 5 were used to prepare urethane bonded united wheels containing aggregates bound by various free radical curable resins according to the procedures described above in the section on preparing united abrasive wheels and preparing aggregates. It was. The united abrasive wheels were tested according to the united abrasive wheel roughness test. The results are reported in Table 6.
The results show data demonstrating that a transition occurs when the modulus value decreases below 206.84 MPa (30,000 psi) as measured according to ASTM D882 for the purpose of forming the aggregate binder resin to be 'flexible' or 'rigid'. .
[Table 5]

TABLE 6

Examples 8 and 9 and Examples Z and AA
Examples 8 and 9 and Examples Z and AA were prepared to demonstrate the effect of fillers on roughness formed by agglomerates of precision molded grains. The components reported in Table 7 were used to prepare urethane bonded united abrasive wheels according to the procedures described above in the section on united abrasive wheel preparation and preparation of aggregates. The united abrasive wheels were tested according to the united abrasive wheel performance test and the united abrasive wheel roughness test. The results are reported in Table 8.
The results indicate that the addition of fillers (particles other than the formed ceramic abrasive particles) into the flexible binder aggregate of the formed ceramic abrasive particles forms finer roughness.
[Table 7]

[Table 8]

Examples 10 and 11
Examples 10 and 11 were prepared to demonstrate that unexpectedly improved roughness results are independent of the aggregate preparation method. The variables reported in Table 9 were used to prepare urethane bonded united abrasive wheels according to the procedures described above in the section on united abrasive wheel manufacture and the preparation of aggregates. The united abrasive wheels were tested according to the united abrasive wheel performance test and the united abrasive wheel roughness test. The results are reported in Table 10.
The results show that the surprising roughness enhancement provided by flocculating the flexible resin with the shaped ceramic abrasive particles is independent of the shape of the aggregate. Examples 1-7 and Comparative Examples A-Y were molded squares. Examples 10 and 11 were random shapes.
TABLE 9

[Table 10]

Other modifications and variations of the present disclosure can be made by those of ordinary skill in the art without departing from the spirit and scope of the disclosure as disclosed in more detail in the appended claims. The aspects of the various embodiments above may be wholly or partly interchanged or combined with other aspects of the various embodiments. All references, patents or patent applications enumerated in the above application for a patent document are hereby incorporated by reference in their entirety in a consistent manner. In case of inconsistency or inconsistency between the cited references and this application, the information in the preceding description shall control. The foregoing description, which is provided to enable those of ordinary skill in the art to practice the disclosure of the claims, should not be construed as limiting the scope of the disclosure, which is defined by the claims and their equivalents.

Claims (11)

As a nonwoven abrasive article,
Nonwoven web,
An aggregate comprising formed ceramic abrasive particles bonded to each other by a first flexible binder, and
A nonwoven abrasive article comprising a second binder that binds the aggregate to the nonwoven fiber web. The nonwoven abrasive article of claim 1, wherein the formed ceramic particles comprise shaped ceramic abrasive particles comprising a triangular plate. The nonwoven abrasive article of claim 1, wherein the first flexible binder comprises polyurethane and the second binder comprises polyurethane. The nonwoven abrasive article of claim 1, wherein the first flexible binder comprises polyurethane and the second binder comprises phenol. 3. The nonwoven abrasive article of claim 1, wherein the elastic modulus of the first flexible binder is less than 18,000 MPa (28,000 psi). The nonwoven abrasive article of claim 1, wherein the elastic modulus of the first flexible binder is less than 158.58 MPa (23,000 psi). 3. The aggregate of claim 1, wherein the aggregate comprises filler particles having an average particle size less than the average particle size of the ceramic abrasive particles formed, wherein the filler particles comprise from 5% to 40% by weight of the total particles in the aggregate. Nonwoven Abrasive Supplies. 3. The nonwoven abrasive article of claim 1, wherein the aggregate generally has a size that includes a maximum diameter when spherical or has a maximum side edge length of 1.8 mm to 3 mm when non-spherical. The nonwoven abrasive article according to claim 1 or 2, wherein the ratio of the formed ceramic abrasive grain size divided by the aggregate size is 0.0033 to 0.5. 3. The method of claim 1, wherein the aggregate comprises filler particles, the ceramic abrasive particles content formed is 75 wt% to 96 wt%, the first flexible binder content is 4 wt% to 10 wt%, and the filler A nonwoven abrasive article having a particle content of 10% to 35% by weight. 3. The nonwoven abrasive article of claim 1 or 2 comprising a convolute abrasive wheel or a unitized abrasive wheel.

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