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We can't argue with free money, and we guess you can't either.
Our hunger for a little extra spending is what drives us to sign up for cash back cards; well, that and the endless offers we get in the mail for $100 sign-up bonuses and extra rewards for using our credit cards at grocery stores and gas stations.
There are a lot of similarities with credit cards in the cash back category, but there are some distinct differences as well. It can be pretty annoying to have to sort through all the fine print to figure out which cards are better than others.
Thankfully, we've sorted through all that fine print to help you know which card is best. And it's from all that research that we've created our Best Cash Back Credit Card of 2017 award. Here are the contenders:
- BankAmericard Cash Rewards
- Capital One Quicksilver
- Citi Double Cash
- American Express Blue Cash Preferred
- Discover it
- Chase Freedom Unlimited
To come up with the cash-back champ, we examined six different credit cards according to seven important categories. Here's a chart of each card and category:
|BankAmericard Cash Rewards
|Capital One Quicksilver
|Citi Double Cash
|AmEx Blue Cash Preferred
|Discover It
|Chase Freedom Unlimited
|Intro cash offer
|$100 after $500 spend
|$100 after $500 spend
|$100 after $1,000 spend, plus up to $200 on 5% of travel buys
|Match on 1st-year cash back
|$150 after $500 spend
|Intro APR
|0% for 12 months
|0% for 9 months
|0% for 18 months
|0% for 12 months
|0% for 12 months
|0% for 15 months
|General cash back rate
|2% (1% plus 1% on paid balances)
|Bonus categories?
|2% grocery/wholesale clubs, 3% gas
|3% groceries, 2% gas
|5% in rotating categories, changes every 4 mths.
|Limit on cash back?
|Yes, $2,500 in all 3 categories combined
|Yes, $6,000 on groceries
|Yes, $1,500 per quarter
|Permanent APR
|13.24%-23.24% (Penalty APR up to 29.99%)
|13.24%-23.24% (no)
|13.24%-23.24% (Penalty APR up to 29.99%)
|13.24%-23.24%(Penalty APR up to 29.49%)
|11.24%-23.24% (no)
|13.24%-23.24% (no)
|Best perk
|10% deposit bonus
|Visa Signature enrollment
|Citi Price Rewind
|Free FICO score
|Chase Ultimate Rewards redemption
Here's a quick explanation of each category:
- Intro cash offer – Amount of free cash you get for signing up and the amount you have to spend to get it
- Intro APR – If and how long they offer 0% APR
- General cash back rate – How much you get for everyday purchases not included in bonus categories
- Bonus categories – Purchases like gas and groceries that get you more cash back than the general rate
- Limit on cash back – Max amounts you can get back on general/bonus purchases
- Non-intro APR – Interest rate after promo period.
- Best perk – Something awesome that's not part of the intro offer or cash-back rates
We'll pick a winner from each category and assign it points. Since there are six cards, the winner of the category will get 6 points, second place will get 5, third will get 4 and so on.
We'll double the points for the cash back/bonus rate category since it's the most important. The winner will be the card with the most points.
During this article we're going to talk about how much cash back you can get over the course of the year. Our estimates are based on the Bureau of Labor Statistics' 2015 numbers for the income of an average American household. Here's what we're saying the average American spends per year on their card:
- About $25,000 overall
- About $4,000 on groceries
- About $2,000 on gas
- About $1,400 on travel*
*This is according to financial site Value Penguin, who estimates Americans spend 2% of their yearly budget on travel.
Those numbers will come in handy later when we talk about bonus percentages for gas and groceries.
Now, for the first category in our contest…introductory cash back!
Intro Cash Offer Winner: Discover it
This category included some straight-up cash along with a few non-traditional offers. Sorting out which card was best took a little math, but we've found our winner. Here's the list:
- Discover it: $600 (bonus categories incl.)
- Chase Freedom Unlimited: $150
- Blue Cash Preferred: $170
- BofA Cash Rewards/ Quicksilver: $100
- Citi Double Cash: $0
The Discover it was our top choice, but it may not be yours if you're looking for a quick bonus. The Discover's intro offer is all about one year down the road when they double any cash back you've racked up during the year. So, while you won't get $100 or $150 in a few months, you will get, according to average spending habits, about $600 at the end of the year.
Also, remember that any bonus purchases you make (more on that in a few sections) will get 5% and then be matched, making them 10% purchases the first year.
The Chase Freedom Unlimited was the clear choice for second even though its intro offer is lower than the AmEx. Why did it get ranked higher than the AmEx? Great question.
The Unlimited's cash back is a straight-up $150 offer; spend $1,000 and you'll get the money. The AmEx's intro offer is $100, plus 5% cash back on travel purchases in the first three months. The average American spends around $1,400 per year on travel. If you spend all that money during the intro period on the AmEx, you'd get $70.
There's a good chance you won't spend your entire travel budget during the first three months, which is why we ranked the Unlimited above the AmEx, while ranking the AmEx above the BankAmericard Cash Rewards and Quicksilver cards and their $100 intro offer.
Intro APR Winner: Citi Double Cash
This category had a couple of great cards that were above 12 months of 0% interest, a logjam in the middle ground and one card at the bottom. Here are the results:
- Citi Double Cash: 18 months
- Chase Freedom Unlimited: 15 months
- BofA Cash Rewards/ AmEx Blue Cash/ Discover: 12 months
- Capital One Quicksilver: 9 months
The Citi Double Cash is the clear winner here, finishing three months ahead of the Freedom, a full half-year ahead of the Bank of America, AmEx and Discover cards, and it doubled up the intro-APR offer of the Quicksilver.
Our guess is that the Double Cash is offering such a long intro-APR period to make up for the fact that cardmembers don't get the up-front cash bonuses the other cards offer.
General Cash Back Rate + Bonuses Winner (2 years): Citi Double Cash
This category is where things get tricky because certain types of purchases will get more cash back than others. So, to make this as simple as possible, we've used the Bureau of Labor Statistics numbers to figure out how much cash back you can get in two years, including bonuses.
We're using two years to offset the Discover it's promotional cash-matching in the first year. Here are the results:
- Citi Double Cash: $1,000
- Discover it: $900
- Quicksilver/ Freedom Unlimited: $750
- AmEx Blue Cash: $700
- BofA Cash Rewards: $660
The big winner here is Citi's Double Cash card, with a straightforward $1,000 in cash back after two years. The key here is that you pay off your balances in full because you only get cash-back matches on balances you pay off.
In second is Discover's card, due to its hefty first-year doubling. We tallied up the bonus categories, added them to the 1% purchases and got $300 per year, but the first year is double because of the promotion.
Quicksilver and Freedom Unlimited are tied for third, while AmEx and the BofA card finished in fourth and fifth, respectively.
The big lesson here is not to be fooled by rotating categories. Cards with one cash-back percentage took three of the top four spots. While 1.5% may not be as exciting as 5% bonus categories, it certainly pays out a lot more….and you don't have to keep track of which categories are giving you bonuses.
Another tip: Judge a card by its four-year value. For example, the Discover it is great the first two years because of their first-year matching program. After two years, you'll get $150 more in cash back than the Quicksilver and Freedom Unlimited. However, after five years, you'll get $1,800 back while the other two cards will get you $1,875.
The same principle applies to travel rewards cards. Capital One's Venture card gets you more miles over time (annual fees included) than the Chase Sapphire Preferred and the Chase Sapphire Reserve.
Limit on Cash Back Winner: Capital One/Citi/Chase
Some of the cards in the competition place limits on how much you can earn in certain categories. Some don't. Here are the final standings on cash-back limits:
- Quicksilver/ Double Cash/ Freedom Unlimited: None
- AmEx Blue Cash: $6,000 on groceries
- Discover it: $6,000 combined from four different bonus categories
- BofA Cash Rewards: $2,500
This category is not as important as the others, simply because the average American household doesn't spend enough money in any of these categories to max out their cash rewards. That being said, if you have a huge family and spend tons of money (or you're super wealthy and spend freely), the unlimited cash-back rewards from the Capital One, Citi and Chase cards are a great perk.
Related: 4 Types of Credit Cards Responsible Consumers Use for Big Rewards
Permanent APR Winner: Discover it
This category would seem like it's tough to judge; after all, all but one of the cards has an APR range of 13.24%-23.24% (based on your credit history, income, etc.).
However, some of these cards have a penalty APR that kicks in when you pay late, and that's what separates the best from the worst:
- Discover it: 11.24%–23.24% (no penalty)
- Freedom Unlimited/ Quicksilver: 13.24%–23.24% (no penalty)
- AmEx Blue Cash Preferred: 13.24%–23.24% (Penalty APR up to 29.49%)
- BofA Cash Rewards/Citi Double Cash: 13.24%–23.24% (Penalty APR up to 29.99%)
The Discover card wins out here because it's best APR is two percent better than the Freedom Unlimited and Quicksilver; none of the three have penalty APR's either.
AmEx finishes ahead of the bottom two cards because their penalty is 0.05% lower, and there's a chance they'll remove the penalty after six months. The other two cards don't mention a set time to review the account and change the penalty APR.
To give you an idea of how much APR matters, we'll need to frame it in the context of the average debt a person with a credit card balance has: $16,000 over about four cards. Per card balance: $4,000.
Over the course of a year, a difference in APR of 2% will cost you $80 a year on a $4,000 balance. So, you can see why the Discover it's best APR (11.24%) can save you a nice chunk of change compared to the rest (13.24%).
And if your penalty APR kicks in and you pay 29.99% a year instead of 13.24%, you could end up paying as much as $640 extra, which nearly cancels out your entire cash rewards from the Bank of America card.
Best Perk Winner: Citi Double Cash
Perks are those benefits you get from a card that aren't part of the intro offers. We narrowed down this category even further by not allowing perks available on more than one card.
For example, both the AmEx Blue Cash and the Citi Quicksilver have travel and shopping protection, so those perks cancelled each other out:
- Citi Double Cash: Price Rewind
- BofA Cash Rewards: 10% cash-back bonus
- Capital One Quicksilver: Visa Signature program
- Chase Freedom Unlimited: Chase Ultimate Rewards
- Discover it: Free FICO score
- AmEx Blue Cash Preferred: None
After reading this post from the New York Times, we decided to put the Citi card first because of Citi's Price Rewind program. Basically, if you buy something with your card and the price drops within 60 days of your purchase, you can get reimbursed for the price difference. The Times article pointed out that the average saving on Price Rewind is about $80 on products purchased for $1,000 or more.
In second is the Bank of America card. We put it there because you get a 10% redemption bonus when you deposit your cash rewards in a Bank of America account. Based on yearly averages, that bonus will put an extra $66 in your pocket.
Capital One customers get enrollment into the Visa Signature program, which gives nice perks at more than 900 luxury hotels around the world.
The last three in this group have pretty uninspiring benefits: the Freedom Unlimited's link to the Chase Ultimate Rewards program, free FICO score access with Discover and nothing much to speak of from AmEx.
See Also: Good Credit Scores and How to Get There
The Best Cash Back Credit Card of 2017: Citi Double Cash
The race for the best cash back card was really close to the final category. In fact, the Discover it was leading the Citi Double Cash by one point after five rounds. However, it was that perks category that pushed the Citi card into the lead for good on the home stretch. Here are the final point totals…the double-value category is in bold and italics:
- Citi Double Cash: 33 [1, 6, 12, 6, 2, 6]
- Discover it: 30 [6, 4, 10, 2, 6, 2]
- Freedom Unlimited: 27 [5, 5, 8, 6, 5, 3]
- Quicksilver: 27 [3, 1, 8, 6, 5, 4]
- AmEx: 19 [4, 4, 4, 3, 3, 1]
- Bank of America: 17 [3, 4, 2, 1, 2, 5]
Overall, we think the Citi Double Cash card is a solid choice. As we talked about a few sections ago, the cards without rotating categories tend to provide the consumer with much better cash-back returns. This card is no exception, as we predict it can put about $500 in your pocket every year for as long as you own the card.
Both the Freedom Unlimited and Quicksilver finished with 27 points, but we decided to put the Unlimited in third because it offers $50 more in its intro cash bonus offer.
The American Express Blue Cash Preferred finished in fifth. The card fared pretty well in the first two categories, but its low cash-back earnings over the course of two years ended its chance at victory, as did its poor perks.
Bank of America finished last in this competition; it's not the first time one of the bank's credit cards occupied the basement in our rankings. The BankAmericard Travel Rewards was one of the worst cards in our Best Travel Rewards Card of 2017 competition.
If you want to learn more about rewards credit cards, feel free to check out the travel rewards competition we just mentioned, as well as our Best Hotel Rewards Card of 2017 and Best Airline Rewards Card of 2017.
We've also got a great collection of credit card reviews, where we lay out each card's offer, terms/conditions, reviews and more.
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Freezing Egg Whites and Yolks
Extra egg whites and yolks can be frozen for use in another recipe. Freeze egg whites in ice cube trays and then transfer to resealable plastic freezer bags. When freezing egg yolks, be sure to mix them with either sugar or salt before freezing (depending on whether you plan to use them in a sweet or savory recipe); otherwise, they will be pasty and hard to mix later on. For four egg yolks, mix in 1-1/2 tsp. sugar or corn syrup or 1/8 tsp. salt before freezing.
© 2017 RDA Enthusiast Brands, LLC

subset: commoncrawl


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I love Mitchell and Webb's sitcom "Peep Show", so I've been thrilled to indulge in their sketch comedy show "That Mitchell and Webb Look", which began its run on BBC America just last month. You can, and should, check it out at 9:20 PM tonight.
Here's a taste, a very brilliant and appropriate short sketch which features Robert Webb as somebody who really, really wants something particular for Christmas.
More pleasurable to my comedy nerd heart is Numberwang, a running sketch about a confusing game show. The following clip, I believe, was the first and all of the following versions use it as a template. But yet I find it surprising every single time.
The best part about the sketch: everybody in it seems to believe there's some logic in the game. So often a sketch is done like this where one person has to be the straight man to point out the absurdities of what's happening. This one they let everybody be nuts and the absurdities hit even harder, because everyone inside it believes they make complete sense.
By the way, one of the great things about the BBC's short seasons is that talented folks like these can switch up and do an entirely different series for a time, in this case going from "Peep Show" to "That Mitchell and Webb Look" and back again. It keeps funny people from feeling stuck inside a premise which may not fit all their comedic ideas. It'd be kind of nice to see an American cable channel take a similar philosophy, alternating seasons of two different shows for some talented comic. It would be fun to see what the creators and cast behind "Reno 911!" or "It's Always Sunny in Philadelphia" could do with a sketch show.


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Three weeks ago I tried an at-home face peel for the first time, as I had a couple of photoshoots coming up and the harsh winter weather had left my skin looking dull and dry. I used Sanctuary Spa's 30 Day Youth Revolution Glycolic Peel-Off Mask and Serum System (longest product name, like, ever) and was so impressed with the results I've started using the mask on a weekly basis.
The peel contains Glycolic acid, which apparently stimulates cell renewal and helps to reveal younger, radiant looking skin. I can't vouch for the reduction of fine lines and wrinkles (I'm still in my early twenties and have nothing to reduce*) but I can recommend this product on the feel-good factor alone. I look forward to my weekly applications as it leaves my skin feeling revived and gives a fresh, healthy glow.
Best of all, though, is the actual peeling off process. It's strangely fulfilling and it reminds me of the scene in Three Men and a Little Lady, when Ted Danson pulls off his wedding disguise. Once the peel is removed you then apply a pea-sized amount of the accompanying anti wrinkle serum, which you can also use on a daily basis for more intense results.
Find Sanctuary Spa's 30 Day Youth Revolution, £22.50, at Boots


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We're available 24/7 to discuss treatment options.
Christina Shannon, ND, FABNO
October 01, 2013
Last month, I had the pleasure of talking alongside two colleagues of mine from CTCA, Dennis Citrin, MD, medical oncologist and Katherine Puckett, PhD, MS, MSW, LCSW, National Director of Mind-Body Medicine.
We came together to share information with a group of writers, reporters and journalists who are interested in telling the truth about breast cancer.
The message we, as experts and as people who care about life, wanted this group to take away from this meeting is the importance of knowledge and information in changing the course of breast cancer.
The discussion focused on the conventional advances in breast cancer treatment, breast-conserving surgeries, less toxic targeted therapies, the benefit of an integrated approach to breast cancer treatment, and the impact of mind-body medicine.
Dr. Citrin began the discussion by sharing a retrospective study that was conducted at CTCA. The study identified that 11 percent of the women diagnosed with breast cancer had delayed treatment for six months or longer with some delaying for several years before seeking medical attention. The study showed that the longer a woman delayed treatment, the more likely the disease is to spread to other parts of the body, making it more challenging to effectively treat the disease.
Dr. Citrin's message to women is very clear. Take control of your own health. If you feel something isn't right, have that conversation with your doctor. The earlier we are able to diagnose and begin treatment, the greater the potential for a favorable outcome.
I see many women with breast cancer come to the clinic who have been treating for years but actually know very little about the course of the disease or its treatments. Working side by side with Dr. Citrin, I witness him daily take the time to explain to women what their diagnosis means, what their options are for treatment, and why he would recommend one treatment over another. If questions arise during the consultation, they are welcomed and answered. Women leave feeling empowered and confident that they have the knowledge from which to base their current and future decisions.
Dr. Puckett spoke about fear and stress as it relates to a breast cancer diagnosis. Dr. Puckett and her team of licensed therapists work with women to overcome and manage both real and perceived fear. Unmanaged fear can lead to stress, and stress left unchecked is unhealthy. Together, fear and stress can affect a woman's relationships, her happiness and her decisions about treatment.
The limited research on women delaying treatment and diagnosis has pointed to depression, lack of coping skills, and fear of treatments as some of the driving factors in delay. Dr. Puckett and her team try to help reduce delays in treatment by addressing these concerns with patients.
In naturopathic medicine, my goal is to help educate women. I discuss with them the use of scientifically-based natural therapies in an integrated approach to care. The reality is women are using complementary and alternative treatments, many times on their own, without the guidance of a trained medical professional and often without divulging these treatments to their medical oncologist.
Research shows that about 50 percent of patients diagnosed with cancer are not telling their medical oncologist about these treatments. They will often come to the clinic overwhelmed with all the information provided to them or that they have obtained on the Internet. I work to create a safe, caring environment in which all women are respected. This helps lead to an open discussion about all treatment options and therapies and how to best integrate them.
As we provide more women with information on conventional treatments and integrative medicine, we can move women away from fear. Empowering more women with knowledge and providing them with the power to take control, we can help reduce delays in diagnosis and treatment for thousands of women.
Fill out all of the form below and we will connect you to someone to assist you.
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According to a report from Radar Online, Halle Berry and Gabriel Aubry have broken up.
The site reported that the unmarried pair – parents to 2-year-old daughter Nahla – have "spent months" working out the terms of their split.
A source told the site that a third party may have been involved.
"Gabriel is a really nice, decent guy and he would never cheat on her, but I suspect that he had become attracted to someone and that he felt he needed to break it off with Halle before anything developed any further," the source told Radar.
The source reportedly added that Gabriel, a successful model, is only asking for the home the two own in his native Canada.
Halle, who was previously married to David Justice and Eric Benet, told Harper's Bazaar last year that the couple's matrimony-free relationship just "works."
"No. I'm done," she told the mag of getting married again. "I happened to find a person who feels done too, and he's never been married before. So it works."


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I had no idea. Seriously.
Gilbert Gottfried doesn't really talk like that?
|by Anonymous
|reply 7
I knew it.
Y iz U so ignunt?
|by Anonymous
|reply 1
|by Anonymous
|reply 2
I remember listening to him on the radio once. This (insane) woman who worked in show biz had young daughters who she allowed to prank Gottfried on the phone. It turned into a regular thing with them calling Gottfried and him making really shocking sexual remarks to them at least once a week. These girls were like 11 and 13 years old.
Their mother thought it was hilarious.
|by Anonymous
|reply 3
Is he our brother?
|by Anonymous
|reply 4
Gottfried is Mr. Inappropriate. He used to be a regular on the Howard Stern show and has been fired from high-profile gigs for making spectacularly tasteless jokes about recent horrific disasters (most recently by AFLAC after he tweeted zingers about that hilarious nuclear meltdown/tsunami in Japan.)
|by Anonymous
|reply 5
Golly, R5. Thanks for that important bit of information.
You insufferable, humorless, misplaced cunt.
|by Anonymous
|reply 6
Breaking: The Blue Man Group aren't really blue.
|by Anonymous
|reply 7


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Three Liverpool players have been named in the England squad for the forthcoming FIFA World Cup qualifiers with Moldova and Ukraine.
Steven Gerrard, Glen Johnson and Andy Carroll are among the 24 men selected by coach Roy Hodgson.
England travels to Moldova on Friday, September 7, before playing host to Ukraine on Tuesday, September 11.
Thumbnail photo via Facebook/Hillsborough 1989 – Don't Ever Forget
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text:
Westfield Super White Ash Kitchen Doors
Westfield Super White Ash
- FREE Delivery over £250
- Dispatch by 2nd October
- Available in Made to Measure and Standard Sizes
- Made in UK
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- 6 year guarantee
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You can also get a quote over the phone, where our Customer Account Managers will be able to answer any questions you may have.
The Westfield style in Super White Ash
The Westfield door in the textured Super White Ash colour is one of the more traditional, country combinations the Trends collection has to offer.
The Westfield kitchen doors, with their customisable sizes and the possibility to accessorise them however you want, offer a perfect solution to getting the dream kitchen you always desired. This subtle, elegant kitchen, manages to bring traditional elements to your house, at the same time allowing you to keep it modern. The tasteful patterns on the door, finished off with a simple cathedral arch, are faint enough not to overwhelm, yet visible enough not to be plain. If you decide to buy these doors, you can manipulate the vibe it gives off by accessorising it. Wooden handles will give it more of a "country house" feel, steel ones will make it seem more modern.
The Super White Ash is perfect if you want your kitchen to be warm and welcoming. The bright colour along with the woodgrain pattern give it a very country, cosy feel. When looking at it you can almost smell the delicious aroma of an apple pie coming from the oven! This kitchen is definitely for you, if you value tradition and if you want a safe feel to it. Whether its cooking dinner for your family or friends, or baking cookies or cakes, the time spent in a kitchen like that will be relaxing and soothing.
The Super White Ash from the Trends colour range allows you to create a kitchen that will bring warmth and love to your household.
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Made to measure sizes in 7 Days
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|Publication number
|Publication type
|Application number
|Publication date
|Aug 3, 1993
|Filing date
|Nov 8, 1991
|Priority date
|Sep 29, 1987
|Fee status
|Also published as
|Publication number
|Nagaraj S. Dixit, Amjad Farooq, Rhyta S. Rounds, Makarand Shevade
|Original Assignee
|Colgate-Palmolive Company
|Export Citation
|BiBTeX, EndNote, RefMan
|Patent Citations (6), Referenced by (19), Classifications (20), Legal Events (4)
|External Links: USPTO, USPTO Assignment, Espacenet
This application is a Continuation-in-Part of U.S. Ser. No. 07/353,712 filed May 18, 1989, now U.S. Pat. No. 5,064,553, and is also a continuation in part of U.S. Ser. No. 570,454 filed Aug. 21, 1990, now U.S. Pat. No. 5,089,161, which in turn is a continuation in part of U.S. Ser. No. 323,134 filed Jul. 10, 1990, now U.S. Pat. No. 4,970,016, which in turn is a continuation application of U.S. Ser. No. 07/114,911 filed Oct. 30, 1987, abandoned.
The present invention relates generally to an automatic dishwasher detergent composition in the form of an aqueous linear viscoelastic liquid.
Liquid automatic dishwasher detergent compositions, both aqueous and nonaqueous, have recently received much attention, and the aqueous products have achieved commercial popularity.
The acceptance and popularity of the liquid formulations as compared to the more conventional powder products stems from the convenience and performance of the liquid products. However, even the best of the currently available liquid formulations still suffer from two major problems, product phase instability and bottle residue, and to some extent cup leakage from the dispense cup of the automatic dishwashing machine.
Representative of the relevant patent art in this area, mention is made of Rek U.S. Pat. No. 4,556,504; Bush, et al. U.S. Pat. No. 4,226,736; Ulrich U.S. Pat. No. 4,431,559; Sabatelli U.S. Pat. No. 4,147,650; Paucot U.S. Pat. No. 4,079,015; Leikhem U.S. Pat. No. 4,116,849; Milora U.S. Pat. No. 4,521,332; Jones U.S. Pat. No. 4,597,889; Heile U.S. Pat. No. 4,512,908; Laitem U.S. Pat. No. 4,753,748; Sabatelli U.S. Pat. No. 3,579,455; Hynam U.S. Pat. No. 3,684,722: other patents relating to thickened detergent compositions include U.S. Pat. No. 3,985,668; U.K. Patent Applications GB 2,116,199A and GB 240,450A; U.S. Pat. No. 4,511,487; Drapier, et al. U.S. Pat. No. 4,752,409; Drapier, et al. U.S. Pat. No. 4,801,395; Drapier, et al. U.S. Pat. No. 4,801,395. Commonly assigned co-pending patents include, for example, Ser. No. 07/204,476 filed, Jun. 9, 1988, abandoned; Ser. No. 06/924,385, filed Oct. 29, 1986 now U.S. Pat. No. 4,857,226; Ser. No. 07/323,138, filed Mar. 13, 1989, now U.S. Pat. No. 4,968,445; Ser. No. 07/087,836, filed Aug. 21, 1987, now U.S. Pat. No. 4,836,946; Ser. No. 07/328,716, filed Mar. 27, 1989, abandoned; Ser. No. 07/323,137, filed Mar. 13, 1989, now U.S. Pat. No. 4,968,446 ; Ser. No. 07/323,134, filed Mar. 13, 1989, now U.S. Pat. No. 4,970,016.
FIGS. 1-13 are rheograms, plotting elastic modules G' and viscous modulus G" as a function of applied strain, for the compositions of Example 1, Formulations A, C, D, G, J, H, I and K, Example 2, A and B, Example 3, L and M and Comparative Example 1, respectively and
FIGS. 14-30 are rheograms as functions of frequency and applied strain for the compositions of Example V.
According to the present invention there is provided a novel aqueous liquid automatic dishwasher detergent composition. The composition is characterized by its linear viscoelastic behavior, substantially indefinite stability against phase separation or settling of dissolved or suspended particles, low levels of bottle residue, relatively high bulk density, and substantial absence of unbound or free water. This unique combination of properties is achieved by virtue of the incorporation into the aqueous mixture of dishwashing detergent surfactant, alkali metal detergent builder salt(s) and chlorine bleach compound, a small but effective amount of high molecular weight cross-linked polyacrylic acid type thickening agent, a physical stabilizing amount of a long chain fatty acid or salt thereof, and a source of potassium ions to provide a potassium/sodium weight ratio in the range of from about 1:1 to about 45:1, such that substantially all of the detergent builder salts and other normally solid detergent additives present in the composition are present dissolved in the aqueous phase. The compositions are further characterized by a bulk density of at least about 1.32 g/cc, such that the density of the polymeric phase and the density of the aqueous (continuous) phase are approximately the same.
The compositions of this invention are aqueous liquids containing various cleansing active ingredients, detergent adjuvants, structuring and thickening agents and stabilizing components, although some ingredients may serve more than one of these functions.
The advantageous characteristics of the compositions of this invention, including physical stability, low bottle residue, high cleaning performance, e.g. low spotting and filming, dirt residue removal, and so on, and superior aesthetics, are believed to be attributed to several interrelated factors such as low solids, i.e. undissolved particulate content, product density and linear viscoelastic rheology. These factors are, in turn, dependent on several critical compositional components of the formulations, namely, (1) the inclusion of a thickening effective amount of polymeric thickening agent having high water absorption capacity, exemplified by high molecular weight cross-linked polyacrylic acid, (2) inclusion of a physical stabilizing amount of a long chain fatty acid or salt thereof, (3) potassium ion to sodium ion weight ratio K/Na in the range of from about 1:1 to 45:1, especially from 1:1 to 3:1, and (4) a product bulk density of at least about 1.32 g/cc, such that the bulk density and liquid phase density are about the same.
The polymeric thickening agents contribute to the linear viscoelastic rheology of the invention compositions. As used herein, "linear viscoelastic" or "linear viscoelasticity" means that the elastic (storage) moduli (G') and the viscous (loss) moduli (G") are both substantially independent of strain, at least in an applied strain range of from 0-50%, and preferably over an applied strain range of from 0-80%. More specifically, a composition is considered to be linear viscoelastic for purposes of this invention, if over the strain range of 0-50% the elastic moduli G' has a minimum value of 100 dynes/sq.cm., preferably at least 250 dynes/sq.cm., and varies less than about 500 dynes/sq.cm, preferably less than 300 dynes/sq.cm., especially preferably less than 100 dynes/sq.cm. Preferably, the minimum value of G' and maximum variation of G' applies over the strain range of 0 to 80%. Typically, the variation in loss moduli G" will be less than that of G'. As a further characteristic of the preferred linear viscoelastic compositions the ratio of G"/G (tanδ) is less than 1, preferably less than 0.8, but more than 0.05, preferably more than 0.2, at least over the strain range of 0 to 50%, and preferably over the strain range of 0 to 80%. It should be noted in this regard that % strain is shear strain�100.
By way of further explanation, the elastic (storage) modulus G' is a measure of the energy stored and retrieved when a strain is applied to the composition while viscous (loss) modulus G" is a measure to the amount of energy dissipated as heat when strain is applied. Therefore, a value of tanδ,
0.05<tan δ<1,
0.2<tan δ<0.8
means that the compositions will retain sufficient energy when a stress or strain is applied, at least over the extent expected to be encountered for products of this type, for example, when poured from or shaken in the bottle, or stored in the dishwasher detergent dispenser cup of an automatic dishwashing machine, to return to its previous condition when the stress or strain is removed. The compositions with tan values in these ranges, therefore, will also have a high cohesive property, namely, when a shear or strain is applied to a portion of the composition to cause it to flow, the surrounding portions will follow. As a result of this cohesiveness of the subject linear viscoelastic compositions, the compositions will readily flow uniformly and homogeneously from a bottle when the bottle is tilted, thereby contributing to the physical (phase) stability of the formulation and the low bottle residue (low product loss in the bottle) which characterizes the invention compositions. The linear viscoelastic property also contributes to improved physical stability against phase separation of any undissolved suspended particles by providing a resistance to movement of the particles due to the strain exerted by a particle on the surrounding fluid medium.
A means for further improving the structuring of the gel formulations of the instant invention in order to obtain improved viscosity as well as G' and G" values is to form an aqueous polymeric solution of a crosslinked anionic polymer such as a crosslinked polyacrylic acid thickening agent at about 75� C. to about 80� C. with mixing and subsequently with mixing neutralizing the anionic groups such as the carboxylic acid groups by the addition of an excess basic material such as caustic soda to form an alkali metal neutralized crosslinked polyacrylic acid polymer having a molecular weight of about 60,000 to about 10,000,000. To the aqueous solution of the alkali metal neutralized crosslinked polyacrylic acid containing excess caustic soda is added with mixing a fatty acid or a metal salt of a fatty acid. In the case of the fatty acid the fatty acid reacts "in situ" with the excess caustic soda to form an alkali metal salt of the fatty acid. The alkali metal crosslinked neutralized polyacrylic acid polymer in combination with the metal salt of the fatty acid provides improved G' and G" values as well as improved viscosification of the aqueous polymeric solution having a pH of about 7 to 14 as compared to the use of the alkali metal neutralized crosslinked polyacrylic acid alone as a viscosification agent. It is theorized that the improvement in viscosification results from an increase in solid content and from the association of the alkali metal salt of the fatty acid and the alkali metal neutralized crosslinked polyacrylic acid polymer in the water, wherein the anionic groups of the fatty acid and the anionic groups of the polyacrylic acid are repulsive to each other thereby causing an uncoiling of the polymeric chain of the alkali metal neutralized crosslinked polyacrylic acid which provides a further building of the polymeric structure within the water. To the solution of the alkali metal neutralized crosslinked polyacrylic acid polymer, water and metal salt of the fatty acid can be added detergent builder salts, silicates, surfacants, foam depressants and bleachants without significantly damaging the polymeric structure to form a gel like automatic dishwashing composition. Other commercial and industrial compositions can be formed for a variety of applications such as toothpastes, creams or a toothpaste gels, cosmetics, fabric cleaners, shampoos, floor cleaners, cleaning paste, tile cleaners, thickened bleach compositions, ointments, oven cleaners, pharmaceutical suspensions, concentrated coal slurries, oil drilling muds, cleaning prestoppers and aqueous based paints. These compositions can be formulated by adding the appropriate chemicals to the aqueous polymeric solution of alkali metal neutralized polyacrylic acid polymer, caustic soda and a metal salt of a fatty acid to form the desired composition. The polymeric aqueous solution of water, caustic soda, alkali metal neutralized polyacrylic acid polymer and the metal salt of the fatty acid has a complex viscosity at room temperature at 10 radians/second of about 2 to about 800 dyne seconds/sq.cm., more preferably about 20 to about 700 dyne seconds/sq.cm. The polymeric solution comprises about 0.02 to about 2.0 weight %, more preferably 0.04 to 1.0 weight % of a metal salt of a fatty acid, about 0.1 to about 4.0 weight %, more preferably 0.2 to about 3.0 weight % of an alkali metal neutralized anionic polymer such as a metal neutralized crosslinked polyacrylic polymer and water, wherein the aqueous polymeric solution has a G' value of at least about 80 dynes/sq. cm at a frequency of 10 radians/second, a G" value of at least about 10 dynes/sq. cm at a frequency of 10 radians/second, a ratio of G"/G' is less than 1 and G' is substantial constant over a frequency range of 0.01 to 50.0 radians/second.
If the polymeric solution has a G' value of at least about 80 dynes/sq. cm. at a frequency of 10 radians/second and the G" valve is at least about 10 dynes/sq. cm at a frequency of 10 radians/second, wherein G' is substantially constant over a frequency range of 0.01 to 50 radians/second and a ratio of G"/G' is less than 1 and a yield stress of at least about 2, more preferably about 2 to about 1200 dynes/sq. cm., the polymeric solution will be a gel which can function as a suspension medium for a plurality of solid particles, immiscible liquid droplets or gaseous bubbles. The solid particles, liquid droplets or gaseous bubbles can be inorganic, organic or polymeric. The solid material, liquid droplets or gaseous bubbles which are not soluble in the water phase, should not decompose in an aqueous solution or react with the anionic groups of the anionic polymer or the carboxylate groups of the fatty acid. The concentration of the solid particles, liquid droplets or gaseous bubbles in the suspension medium is about 0.1 to about 70 weight percent, more preferably about 1 to about 50 weight %.
The estimated minimum yield stress of the gel suspension medium which is necessary to suspend each of the solid spherical particles, liquid droplets or gasous bubbles such that the particles, droplets or bubbles remain suspended for at least seven days in the gel suspension medium is expressed by the equation: ##EQU1## wherein R equals the radius of each of the solid particles, liquid droplets and/or gaseous bubbles; g equals the gravitational constant; Δ P equals the difference between the density of the gel suspension medium and the density of each of the solid particles, liquid droplets or gaseous bubbles and A equals the surface area of each of the solid particles, liquid droplets or the gaseous bubbles.
Additionally, by way of explanation, it is necessary to clearly emphasis that in order to minimize the rate and amount of sedimenation of solid particles that are insoluble in the suspension medium that the suspension medium should exhibit frequency independent moduli. For materials that exhibit frequency independence of the viscoelastic moduli (G'), these materials tend to exhibit a critical property known as the yield stress which prevents the sedimentaion of insoluble particles from the suspension medium. It is also critical in the understanding of the data as presented in Example V of this invention that by linear viscoelastic gel it is meant that G' is substantially constant over a strain range of about 0 to about 50 percent. The minimum estimated yield stress for the gel necessary to suspend each of the spherical particles in the gel such that each particles will not precepitate from the gel is expressed by the formula: ##EQU2## wherein R equals the radius of each of the solid particle, A equals the surface area of each of the solid particle, g equals the gravitational constant and Δ P equals the difference in density between the gel and the density of each of the solid particle.
Illustrative of alkali metal neutralized anionic polymers contemplated within the scope of the instant invention beside polyacrylic acid polymers such as the Carbopols are: sulfonated polymers containing a sulfonate functionality as defined in U.S. Pat. Nos. 3,642,728; 4,608,425; 4,619,773; 4,626,285; 4,637,882; 4,640,945; 4,647,603; 4,710,555; 5,730,028; 4,963,032; 4,970,260 and 4,975,482, wherein these aforementioned patents are all hereby incorporated by reference, as well as polymers and monomers containing a carboxylic acid functionally as defined in U.S. Pat. Nos. 4,612,332; 4,673,716; 4,694,046; 4,694,058; 4,709,759; 4,734,205, 4,780,517; 4,960,821 and 5,036,136, wherein these aforementioned patents are all hereby incorporated by reference, as well as copolymers containing a maleic anhydride functionality such as Gantrez provided that these is a sufficient association between the alkali metal neutralized salts of these polymers in the aforementioned patents and the metal salt of a fatty acid to create a viscoelastic gel having the G' and G" properties as defined herein.
The thickened aqueous polymeric solutions are made by neutralizing at room temperature with mixing an aqueous solution of the Carbopol resin with caustic soda such that to the resultant aqueous solution of the alkali metal neutralized Carbopol is added at room temperature with mixing an aqueous dispersion of aluminum oxide to form the thickened aqueous polymeric solution. A further enhancement of thickening can be achieved by the further addition of about 0.02 to 1.0 weight percent of a fatty acid or a metal salt of a fatty acid.
Also contributing to the physical stability and low bottle residue of the invention compositions is the high potassium to sodium ion ratios in the range of 1:1 to 45:1, preferably 1:1 to 4:1, especially preferably from 1.05:1 to 3:1, for example 1.1:1, 1.2:1, 1.5:1, 2:1, or 2.5:1. At these ratios the solubility of the solid salt components, such as detergent builder salts, bleach, alkali metal silicates, and the like, is substantially increased since the presence of the potassium (K+) ions requires less water of hydration than the sodium (Na+) ions, such that more water is available to dissolve these salt compounds. Therefore, all or nearly all of the normally solid components are present dissolved in the aqueous phase. Since there is none or only a very low percentage, i.e. less than 5%, preferably less than 3% by weight, of suspended solids present in the formulation there is no or only reduced tendency for undissolved particles to settle out of the compositions causing, for example, formation of hard masses of particles, which could result in high bottle residues (i.e. loss of product). Furthermore, any undissolved solids tend to be present in extremely small particle sizes, usually colloidal or sub-colloidal, such as 1 micron or less, thereby further reducing the tendency for the undissolved particles to settle.
A still further attribute of the invention compositions contributing to the overall product stability and low bottle residue is the high water absorption capacity of the cross-linked polyacrylic acid type thickening agent. As a result of this high water absorption capacity virtually all of the aqueous vehicle component is held tightly bound to the polymer matrix. Therefore, there is no or substantially no free water present in the invention compositions. This absence of free water (as well as the cohesiveness of the composition) is manifested by the observation that when the composition is poured from a bottle onto a piece of water absorbent filter paper virtually no water is absorbed onto the filter paper and, furthermore, the mass of the linear viscoelastic material poured onto the filter paper will retain its shape and structure until it is again subjected to a stress or strain. As a result of the absence of unbound or free water, there is virtually no phase separatin between the aqueous phase and the polymeric matrix or dissolved solid particles. This characteristic is manifested by the fact that when the subject compositions are subjected to centrifugation, e.g. at 1000 rpm for 30 minutes, there is no phase separation and the composition remains homogeneous.
However, it has also been discovered that linear viscoelasticity and K/Na ratios in the above-mentioned range do not, by themselves, assure long term physical stability (as determined by phase separation). In order to maximize physical (phase) stability, the density of the composition should be controlled such that the bulk density of the liquid phase is approximately the same as the bulk density of the entire composition, including the polymeric thickening agent. This control and equalization of the densities is achieved, according to the invention, by providing the composition with a bulk density of at least 1.28 g/cc, preferably at least 1.35 g/cc, up to about 1.42 g/cc, preferably up to about 1.40 g/cc. Furthermore, to achieve these relatively high bulk densities, it is important to minimize the amount of air incorporated into the composition (a density of about 1.42 g/cc is essentially equivalent to zero air content).
It has previously been found in connection with other types of thickened aqueous liquid, automatic dishwasher detergent compositions that incorporation of finely divided air bubbles in amounts up to about 8 to 10% by volume can function effectively to stabilize the composition against phase separation, but that to prevent agglomeration of or escape of the air bubbles it was important to incorporate certain surface active ingredients, especially higher fatty acids and the salts thereof, such as stearic acid, behenic acid, palmitic acid, sodium stearate, aluminum stearate, and the like. These surface active agents apparently functioned by forming an interfacial film at the bubble surface while also forming hydrogen bonds or contributing to the electrostatic attraction with the suspended particles, such that the air bubbles and attracted particles formed agglomerates of approximately the same density as the density of the continuous liquid phase.
Therefore, in a preferred embodiment of the present invention, stabilization of air bubbles which may become incorporated into the compositions during normal processing, such as during various mixing steps, is avoided by post-adding the surface active ingredients, including fatty acid or fatty acid salt stabilizer, to the remainder of the composition, under low shear conditions using mixing devices designed to minimize cavitation and vortex formation.
As will be described in greater detail below the surface active ingredients present in the composition will include the main detergent surface active cleaning agent, and will also preferably include anti-foaming agent and higher fatty acid or salt thereof as a physical stabilizer.
Exemplary of the cross-linked polyacrylic acid-type thickening agents are the products sold by B.F. Goodrich under their Carbopol trademark, especially Carbopol 941, which is the most ion-insensitive of this class of polymers, and Carbopol 940 and Carbopol 934. The Carbopol resins, also known as "Carbomer", are hydrophilic high molecular weight, cross-linked acrylic acid polymers having an average equivalent weight of 76, and the general structure illustrated by the following formula: ##STR1## Carbopol 941 has a molecular weight of about 1,250,000; Carbopol 940 a molecular weight of approximately 4,000,000 and Carbopol 934 a molecular weight of approximately 3,000,000. The Carbopol resins are cross-linked with polyalkenyl polyether, e.g. about 1% of a polyallyl ether of sucrose having an average of about 5.8 allyl groups for each molecule of sucrose. Further detailed information on the Carbopol resins is available from B.F. Goodrich, see, for example, the B.F. Goodrich catalog GC-67, Carbopol� Water Soluble Resins.
While most favorable results have been achieved with Carbopol 941 polyacrylic resin, other lightly cross-linked polyacrylic acid-type thickening agents can also be used in the compositions of this invention. As used herein "polyacrylic acid-type" refers to water-soluble homopolymers of acrylic acid or methacrylic acid or water-dispersible or water-soluble salts, esters or amides thereof, or water-soluble copolymers of these acids of their salts, esters or ameides with each other or with one or more other etylenically unsaturated monomers, such as, for example, styrene, maleic acid, maleic anhydride, 2-hydroxyethylacrylate, acrylonitrile, vinyl acetate, ethylene, propylene, and the like.
The homopolymers or copolymers are characterized by their high molecular weight, in the range of from about 500,000 to 10,000,000, preferably 500,000 to 5,000,000, especially from about 1,000,000 to 4,000,000, and by their water solubility, generally at least to an extent of up to about 5% by weight, or more, in water at 25� C.
These thickening agents are used in their lightly cross-linked form wherein the cross-linking may be accomplished by means known in the polymer arts, as by irradiation, or, preferably, by the incorporation into the monomer mixture to be polymerized of known chemical cross-linking monomeric agents, typically polyunsaturated (e.g. diethylenically unsaturated) monomers, such as, for example, divinylbenzene, divinylether of diethylene glycol, N, N'-methylenebisacrylamide, polyalkenylpolyethers (such as described above), and the like. Typically, amounts of cross-linking agent to be incorporated in the final polymer may range from about 0.01 to about 1.5 percent, preferably from about 0.05 to about 1.2 percent, and especially, preferably from about 0.1 to about 0.9 percent, by weight of cross-linking agent to weight of total polymer. Generally, those skilled in the art will recognize that the degree of cross-linking should be sufficient to impart some coiling of the otherwise generally linear polymeric compound while maintaining the cross-linked polymer at least water dispersible and highly water-swellable in an ionic aqueous medium. It is also understood that the water-swelling of the polymer which provides the desired thickening and viscous properties generally depends on one or two mechanisms, namely, conversion of the acid group containing polymers to the corresponding salts, e.g. sodium, generating negative charges along the polymer backbone, thereby causing the coiled molecules to expand and thicken the aqueous solution; or by formation of hydrogen bonds, for example, between the carboxyl groups of the polymer and hydroxyl donor. The former mechanism is especially important in the present invention, and therefore, the preferred polyacrylic acid-type thickening agents will contain free carboxylic acid (COOH) groups along the polymer backbone. Also, it will be understood that the degree of cross-linking should not be so high as to render the cross-linked polymer completely insoluble or non-dispersible in water or inhibit or prevent the uncoiling of the polymer molecules in the presence of the ionic aqueous system.
The amount of the high molecular weight, cross-linked polyacrylic acid or other high molecular weight, hydrophilic cross-linked polyacrylic acid-type thickening agent to impart the desired rheological property of linear viscoelasticity will generally be in the range of from about 0.1 to 2%, preferably from about 0.2 to 1.4%, by weight, based on the weight of the composition, although the amount will depend on the particular cross-linking agent, ionic strength of the composition, hydroxyl donors and the like.
The compositions of this invention must include sufficient amount of potassium ions and sodium ions to provide a weight ratio of K/Na of at least 1:1, preferably from 1:1 to 45:1, especially from about 1:1 to 3:1, more preferably from 1.05:1 to 3:1, such as 1.5:1, or 2:1. When the K/Na ratio is less than 1 there is insufficient solubility of the normally solid ingredients whereas when the K/Na ratio is more than 45, especially when it is greater than about 3, the product becomes too liquid and phase separation begins to occur. When the K/Na ratio is more than 45, especially when it is greater than about 3, the product becomes too liquid and phase separation begins to occur. When the K/Na ratios become much larger than 45, such as in all or mostly potassium formulation, the polymer thickener loses its absorption capacity and begins to salt out of the aqueous phase.
The potassium and sodium ions can be made present in the compositions as the alkali metal cation of the detergent builder salt(s), or alkali metal silicate or alkali metal hydroxide components of the compositions. The alkali metal cation may also be present in the compositions as a component of an ionic detergent, bleach or other ionizable salt compound additive, e.g. alkali metal carbonate. In determining the K/Na weight ratios all of these sources should be taken into consideration.
Specific examples of detergent builder salts include the polyphosphates, such as alkali metal pyrophosphate, alkali metal tripolyphosphate, alkali metal metaphosphate, and the like, for example, sodium or potassium tripolyphosphate (hydrated or anhydrous), tetrasodium or tetrapotassium pyrophosphate, sodium or potassium hexa-metaphosphate, trisodium or tripotassium orthophosphate and the like, sodium or potassium carbonate, sodium or potassium citrate, sodium or potassium nitrilotriacetate, and the like. The phosphate builders, where not precluded due to local regulations, are preferred and mixtures of tetrapotassium pyrophosphate (TKPP) and sodium tripolyphosphate (NaTPP) (especially the hexahydrate) are especially preferred. Typical ratios of NaTPP to TKPP are from about 2:1 to 1:8, especially from about 1:1.1 to 1:6. The total amount of detergent builder salts is preferably from about 5 to 35% by weight, more preferably from about 15 to 35%, especially from about 18 to 30% by weight of the composition.
Other useful low molecular weight noncrosslinked polymers are Acusol™640D provided by Rohm & Haas; Norasol QR1014 from Norsohaas having a GPC molecular weight of 10,000.
The linear viscoelastic compositions of this invention may, and preferably will, contain a small, but stabilizing effective amount of a long chain fatty acid or monovalent or polyvalent salt thereof. Although the manner by which the fatty acid or salt contributes to the rheology and stability of the composition has not been fully elucidated it is hypothesized that it may function as a hydrogen bonding agent or cross-linking agent for the polymeric thickener.
The preferred long chain fatty acids are the higher aliphatic fatty acids having from about 8 to 22 carbon atoms, more preferably from about 10 to 20 carbon atoms, and especially preferably from about 12 to 18 carbon atoms, and especially preferably from about 12 to 18 carbon atoms, inclusive of the carbon atom of the carboxyl group of the fatty acid. The aliphatic radical may be saturated or unsaturated and may be straight or branched. Straight chain saturated fatty acids are preferred. Mixtures of fatty acids may be used, such as those derived from natural sources, such as tallow fatty acid, coco fatty acid, soya fatty acid, mixtures of these acids, etc. Stearic acid and mixed fatty acids, e.g. stearic acid/palmitic acid, are preferred.
When the free acid form of the fatty acid is used directly it will generally associate with the potassium and sodium ions in the aqueous phase to form the corresponding alkali metal fatty acid soap. However, the fatty acid salts may be directly added to the composition as sodium salt or potassium salt, or as a polyvalent metal salt, although the alkali metal salts of the fatty acids are preferred fatty acid salts.
The preferred polyvalent metals are the di- and trivalent metals of Groups IIA, IIB and IIIB, such as magnesium, calcium, aluminum and zinc, although other polyvalent metals, including those of Groups IIIA, IVA, VA, IB, IVB, VB VIB, VIIB and VIII of the Periodic Table of the Elements can also be used. Specific examples of such other polyvalent metals include Ti, Zr, V, Nb, Mn, Fe, Co, Ni, Cd, Sn, Sb, Bi, etc. Generally, the metals may be present in the divalent to pentavalent state. Preferably the metal salts are used in their higher oxidation states. Naturally, for use in automatic dishwashers, as well as any other applications where the invention composition will or may come in contact with articles used for the handling, storage or serving of food products or which otherwise may come into contact with or be consumed by people or animals, the metal salt should be selected by taking into consideration the toxicity of the metal. For this purpose, the alkali metal and calcium and magnesium salts are especially higher preferred as generally safe food additives.
The amount of the fatty acid or fatty acid salt stabilizer to achieve the desired enhancement of physical stability will depend on such factors as the nature of the fatty acid or its salt, the nature and amount of the thickening agent, detergent active compound, inorganic salts, other ingredients, as well as the anticipated storage and shipping conditions.
Generally, however, amounts of the fatty acid or fatty acid salt stabilizing agents in the range of from about 0.02 to 2%, preferably 0.04 to 1%, more preferably from about 0.06 to 0.8%, especially preferably from about 0.08 to 0.4%, provide a long term stability and absence of phase separation upon standing or during transport at both low and elevated temperatures as are required for a commercially acceptable product.
Depending on the amounts, proportions and types of fatty acid physical stabilizers and polyacrylic acid-type thickening agents, the addition of the fatty acid or salt not only increases physical stability but also provides a simultaneous increase in apparent viscosity. Amounts of fatty acid or salt to polymeric thickening agent in the range of from about 0.08-0.4 weight percent fatty acid salt and from about 0.4-1.5 weight percent polymeric thickening agent are usually sufficient to provide these simultaneous benefits and, therefore, the use of these ingredients in these amounts is most preferred.
In order to achieve the desired benefit from the fatty acid or fatty acid salt stabilizer, without stabilization of excess incorporated air bubbles and consequent excessive lowering of the product bulk density, the fatty acid or salt should be post-added to the formulation, preferably together with the other surface active ingredients, including detergent active compound and anti-foaming agent, when present. These surface active ingredients are preferably added as an emulsion in water wherein the emulsified oily or fatty materials are finely and homogeneously dispersed throughout the aqueous phase. To achieve the desired fine emulsification of the fatty acid or fatty acid salt and other surface active ingredients, it is usually necessary to heat the emulsion (or preheat the water) to an elevated temperature near the melting temperature of the fatty acid or its salt. For example, for stearic acid having a melting point of 68� C.-69� C., a temperature in the range of between 50� C. and 70� C. will be used. For lauric acid (m.p.=47� C.) an elevated temperature of about 35� C. to 50� C. can be used. Apparently, at these elevated temperatures the fatty acid or salt and other surface active ingredients can be more readily and uniformly dispersed (emulsified) in the form of fine droplets throughout the composition.
In contrast, as will be shown in the examples which follow, if the fatty acid is simply post-added at ambient temperature, the composition is not linear viscoelastic as defined above and the stability of the composition is clearly inferior.
Foam inhibition is important to increase dishwasher machine efficiency and minimize destabilizing effects which might occur due to the presence of excess foam within the washer during use. Foam may be reduce by suitable selection of the type and/or amount of detergent active material, the main foam-producing component. The degree of foam is also somewhat dependent on the hardness of the wash water in the machine whereby suitable adjustment of the proportions of the builder salts such as NaTPP which has a water softening effect, may aid in providing a degree of foam inhibition. However, it is generally preferred to include a chlorine bleach stable foam depressant or inhibitor. Particularly effective are the alkyl phosphoric acid esters of the formula ##STR2## and especially the alkyl acid phosphate esters of the formula ##STR3## In the above formulas, one or both R groups in each type of ester may represent independently a C12 -C20 alkyl or ethoxylated alkyl group. The ethoxylated derivatives of each type of ester, for example, the condensation products of one mole of ester with from 1 to 10 moles, preferably 2 to 6 moles, more preferably 3 or 4 moles, ethylene oxide can also be used. Some examples of the foregoing are commercially available, such as the products SAP from Hooker and LPKN-158 from Knapsack. Mixtures of the two types, or any other chlorine bleach stable types, or mixtures of mono- and di-esters of the same type, may be employed. Especially preferred is a mixture of mono- and di-C16 -C18 alkyl acid phosphate esters such as monostearyl/distearyl acid phosphates 1.2/1, and the 3 to 4 mole ethylene oxide condensates thereof. When employed, proportions of 0.05 to 1.5 weight percent, preferably 0.1 to 0.5 weight percent, of foam depressant in the composition is typical, the weight ratio of detergent active component (d) to foam depressant (e) generally ranging from about 10:1 to 1:1 and preferably about 5:1 to 1:1. Other defoamers which may be used include, for example, the known silicones, such as available from Dow Chemicals. In addition, it is an advantageous feature of this invention that many of the stabilizing salts, such as the stearate salts, for example, aluminum stearate, when included, are also effective as foam killers.
Although any chlorine bleach compound may be employed in the compositions of this invention, such as dichloro-isocyanurate, dichloro-dimethyl hydantoin, or chlorinated TSP, alkali metal or alkaline earth metal, e.g. potassium, lithium, magnesium and especially sodium, hypochlorite is preferred. The composition should contain sufficient amount of chlorine bleach compound to provide about 0.2 to 4.0% by weight of available chlorine, as determined, for example by acidification of 100 parts of the composition with excess hydrochloric acid. A solution containing about 0.2 to 4.0% by weight of sodium hypochlorite contains or provides roughly the same percentage of available chlorine. About 0.8 to 1.6% by weight of available chlorine is especially preferred. For example, sodium hypochlorite (NaOCL) solution of from about 11 to about 13% available chlorine in amounts of about 3 to 20%, preferably about 7 to 12%, can be advantageously used.
Detergent active material useful herein should be stable in the presence of chlorine bleach, especially hypochlorite bleach, and for this purpose those of the organic anionic, amine oxide, phosphine oxide, sulphoxide or betaine water dispersible surfactant types are preferred, the first mentioned anionics being most preferred. Particularly preferred surfactants herein are the linear or branched alkali metal mono- and/or di-(C8 -C14) alkyl diphenyl oxide mono- and/or di-sulphates, commercially available for example as DOWFAX (registered trademark) 3B-2 and DOWFAX 2A-1. In addition, the surfactant should be compatible with the other ingredients of the composition. Other suitable organic anionic, non-soap surfactants include the primary alkylsulphates, alkylsulphonates, alkylarylsulphonates and sec.-alkylsulphates. Examples include sodium C10 -C18 alkylsulphates such as sodium dodecylsulphate and sodium tallow alcoholsulphate; sodium C10 -C18 alkanesulphonates such as sodium hexadecyl-1-sulphonate and sodium C12 -C18 alkylbenzenesulphonates such as sodium dodecylbenzenesylphonates. The corresponding potassium salts may also be employed.
As other suitable surfactants or detergents, the amine oxide surfactants are typically of the structure R2 R1 NO, in which each R represents a lower alkyl group, for instance, methyl, and R1 represents a long chain alkyl group having from 8 to 22 carbon atoms, for instance a lauryl, myristyl, palmityl or cetyl group. Instead of an amine oxide, a corresponding surfactant phosphine oxide R2 R1 PO or sulphoxide RR1 SO can be employed. Betaine surfactants are typically of the structure R2 R1 N+ R"COO--, in which each R represents a lower alkylene group having from 1 to 5 carbon atoms. Specific examples of these surfactants include lauryl-dimethylamine oxide, myristyl-dimethylamine oxide, myristyl-dimethylamine oxide, the corresponding phosphine oxides and sulphoxides, and the corresponding betaines, including dodecyldimethylammonium acetate, tetradecyldiethylammonium pentanoate, hexadecyldimethylammonium hexanoate and the like. For biodegradability, the alkyl groups in these surfactants should be linear, and such compounds are preferred.
Surfactants of the foregoing type, all well known in the art, are described, for example, in U.S. Pat. Nos. 3,985,668 and 4,271,030. If chlorine bleach is not used than any of the well known low-foaming nonionic surfactants such as alkoxylated fatty alcohols, e.g. mixed ethylene oxide-propylene oxide condensates of C8 -C22 fatty alochols can also be used.
The chlorine bleach stable, water dispersible organic detergent-active material (surfactant) will normally be present in the composition in minor amounts, generally about 1% by weight of the composition in minor amounts, generally about 1% by weight of the composition, although smaller or larger amounts, such as up to about 5%, such as from 0.1 to 5%, preferably form 0.3 or 0.4 to 2% by weight of the composition, may be used.
Alkali metal (e.g. potassium or sodium) silicate, which provides alkalinity and protection of hard surfaces, such as fine china glaze and pattern, is generally employed in an amount ranging from about 5 to 20 weight percent, preferably about 5 to 15 weight percent, more preferably 8 to 12% in the composition. The sodium or potassium silicate is generally added in the form of an aqueous solution, preferably having Na2 O:SiO2 or K2 O:SiO2 ratio of about 1:1.3 to 1:2.8, especially preferably 1:2.0 to 1:2.6. At this point, it should be mentioned that many of the other components of this composition, especially alkali metal hydroxide and bleach, are also often added in the form of a preliminary prepared aqueous dispersion or solution.
In addition to the detergent active surfactant, foam inhibitor, alkali metal silicate corrosion inhibitor, and detergent builder salts, which all contribute to the cleaning performance, it is also known that the effectiveness of the liquid automatic dishwasher detergent compositions is related to the alkalinity, and particularly to moderate to high alkalinity levels. Accordingly, the compositions of this invention will have pH values of at least about 9.5, preferably at least about 11 to as high as 14, generally up to about 13 or more, and, when added to the aqueous wash bath at a typical concentration level of about 10 grams per liter, will provide a pH in the wash bath of at least about 9, preferably at least about 10, such as 10.5, 11, 11.5 or 12 or more.
The alkalinity will be achieved, in part by the alkali metal ions contributed by the alkali metal detergent builder salts, e.g. sodium tripolyphosphate, tetrapotassium pyrophosphate, and alkali metal silicate, however, it is usually necessary to include alkali metal hydroxide, e.g. NaOH or KOH, to achieve the desired high alkalinity. Amounts of alkali metal hydroxide in the range of (on an active basis) of from about 0.5 to 8%, preferably from 1 to 6%, more preferably from about 1.2 to 4%, by weight of the composition will be sufficient to achieve the desired pH level and/or to adjust the K/Na weight ratio.
Other alkali metal salts, such as alkali metal carbonate may also be present in the compositions in minor amounts, for example from 0 to 4%, preferably 0 to 2%, by weight of the composition.
Other conventional ingredients may be included in these compositions in small amounts, generally less than about 3 weight percent, such as perfume, hydrotropic agents such as the sodium benzene, toluene, xylene and cumene sulphonates, preservatives, dyestuffs and pigments and the like, all of course being stable to chlorine bleach compound and high alkalinity. Especially preferred for coloring are the chlorinated phythalocyanines and polysuphides of aluminosilicate which provide, respectively, pleasing green and blue tints. TiO2 may be employed for whitening or neutralizing off-shades.
Although for the reasons previously discussed excessive air bubbles are not often desirable in the invention compositions, depending on the amounts of dissolved solids and liquid phase densities, incorporation of small amounts of finely divided air bubbles, generally up to about 10% by volume, preferably up to about 4% by volume, more preferably up to about 2% by volume, can be incorporated to adjust the bulk density to approximate liquid phase density. The incorporated air bubbles should be finely divided, such as up to about 100 microns in diameter, preferably from about 20 to about 40 microns in diameter, to assure maximum stability. Although air is the preferred gaseous medium for adjusting densities to improve physical stability of the composition other inert gases can also be used, such as nitrogen, carbon dioxide, helium, oxygen, etc.
The amount of water contained in these compositions should, of course, be neither so high as to produce unduly low viscosity and fluidity, nor so low as to produce unduly high viscosity and low flowability, linear viscoelastic properties in either case being diminished or destroyed by increasing tan 1. Such amount is readily determined by routine experimentation in any particular instance, generally ranging from 30 to 75 weight percent, preferably about 35 to 65 weight percent. The water should also be preferably deionized or softened.
The manner of formulating the invention compositions is also important. As discussed above, the order of mixing the ingredients as well as the manner in which the the mixing is performed will generally have a significant effect on the properties of the composition, and in particular on product density (by incorporation and stabilization of more or less air) and physical stability (e.g. phase separation). Thus, according to the preferred practice of this invention the compositions are prepared by first forming a dispersion of the polyacrylic acid-type thickener in water under moderate to high shear conditions, neutralizing the dissolved polymer to cause gelation, and then introducing, while continuing mixing, the detergent builder salts, alkali metal silicates, chlorine bleach compound and remaining detergent additives, including any previously unused alkali metal hydroxide, if any, other than the surface-active compounds. All of the additional ingredients can be added simultaneously or sequentially. Preferably, the ingredients are added sequentially, although it is not necessary to complete the addition of one ingredient before beginning to add the next ingredient. Furthermore, one or more of these ingredients can be divided into portions and added at different times. These mixing steps should also be performed under moderate to high shear rates to achieve complete and uniform mixing. These mixing steps may be carried out at room temperature, although the polymer thickener neutralization (gelation) is usually exothermic. The composition may be allowed to age, if necessary, to cause dissolved or dispersed air to dissipate out of the composition.
The remaining surface active ingredients, including the anti-foaming agent, organic detergent compound, and fatty acid or fatty acid salt stabilizer is post-added to the previously formed mixture in the form of an aqueous emulsion (using from about 1 to 10%, preferably from about 2 to 4% of the total water added to the composition other than water added as carrier for other ingredients or water of hydration) which is pre-heated to a temperature in the range of from about Tm+5 to Tm-20, preferably from about Tm to TM-10, where Tm is the melting point temperature of the fatty acid or fatty acid salt. For the preferred stearic acid stabilizer the heating temperature is in the range of 50� C. to 70� C. However, if care is taken to avoid excessive air bubble incorporation during the gelatin step or during the mixing of the detergent builder salts and other additives, for example, by operating under vacuum, or using low shearing conditions, or special mixing operatatus, etc., the order of addition of the surface active ingredients should be less important.
In accordance with an especially preferred embodiment, the thickened linear viscoelastic aqueous automatic dishwasher detergent composition of this invention includes, on a weight basis:
(a) 10 to 35%, preferably 15 to 30%, alkali metal polyphosphate detergent builder;
(b) 5 to 15, preferably 8 to 12%, alkali metal silicate;
(c) 1 to 6%, preferably 1.2 to 4%, alkali metal hydroxide;
(d) 0.1 to 3%, preferably 0.5 to 2%, chlorine bleach stable, water-dispersible, low-foaming organic detergent active material, preferably non-soap anionic detergent;
(e) 0.05 to 1.5%, preferably 0.1 to 0.5%, chlorine bleach stable foam depressant;
(f) chlorine bleach compound in an amount to provide about 0.2 to 4%, preferably 0.8 to 1.6%, of available chlorine;
(g) high molecular weight hydrophilic cross-linked polyacrylic acid thickening agent in an amount to provide a linear viscoelasticity to the formulation, preferably from about 0.4 to 1.5%, more preferably from about 0.4 to 1.0%;
(h) a long chain fatty acid or a metal salt of a long chain fatty acid in an amount effective to increase the physical stability of the compositions, preferably from 0.08 to 0.4%, more preferably from 0.1 to 0.3%; and
(i) balance water, preferably from about 30 to 75%, more preferably from about 35 to 65%; and wherein in (a) the alkali metal polyphosphate includes a mixture of from about 5 to 30%, preferably from about 12 to 22% of tetrapotassium pyrophosphate, and from 0 to about 20%, preferably from about 3 to 18% of sodium tripolyphosphate, and wherein in the entire composition the ratio, by weight, of potassium ions to sodium ions is from about 1.05/1 to 3/1, preferably from 1.1/1 to 2.5/1, the compositions having an amount of air incorporated therein such that the bulk density of the composition is from about 1.32 to 1.42 g/cc, preferably from about 1.35 to 1.40 g/cc.
The compositions will be supplied to the consumer in suitable dispenser containers preferably formed of molded plastic, especially polyolefin plastic, and most preferably polyethylene, for which the invention compositions appear to have particularly favorable slip characteristics. In addition to their linear viscoelastic character, the compositions of this invention may also be characterized as pseudoplastic gels (non-thixotropic) which are typically near the borderline between liquid and solid viscoelastic gel, depending, for example, on the amount of the polymeric thickener. The invention compositions can be readily poured from their containers without any shaking or squeezing, although squeezable containers are often convenient and accepted by the consumer for gel-like products.
The liquid aqueous linear viscoelastic automatic dishwasher compositions of this invention are readily employed in known manner for washing dishes, other kitchen utensils and the like in an automatic dishwasher, provided with a suitable detergent dispenser, in an aqueous wash bath containing an effective amount of the composition, generally sufficient to fill or partially fill the automatic dispenser cup of the particular machine being used.
The invention also provides a method for cleaning dishware in an automatic dishwashing machine with an aqueous wash bath containing an effective amount of the liquid linear viscoelastic automatic dishwasher detergent composition as described above. The composition can be readily poured from the polyethylene container with little or no squeezing or shaking into the dispensing cup of the automatic dishwashing machine and will be sufficiently viscous and cohesive to remain securely within the dispensing cup until shear forces are again applied thereto, such as by the water spray from the dishwashing machine.
The invention may be put into practice in various ways and a number of specific embodiments will be described to illustrate the invention with reference to the accompanying examples.
All the amounts and proportions referred to herein are by weight of the composition unless otherwise indicated.
The following formulations A-K were prepared as described below:
__________________________________________________________________________INGREDIENT/FORMULATION A B C D E F G H I J K__________________________________________________________________________DEIONIZED WATER BAL. BAL. BAL. BAL. BAL. BAL. BAL. BAL. BAL. BAL. BAL.CARBOPOL 941 0.9 0.9 0.9 0.9 1 -- 0.9 0.9 -- 1.5 0.9NaOH (50%) 2.4 2.4 2.4 2.4 3.5 3.5 2.4 -- 2.4 2.4 2.4KOH (50%) -- -- -- -- -- -- -- 2.4 -- -- --TKPP 15 15 15 20 20 20 28 28 15 20 15TPP 13 13 12 7.5 7.5 7.5 -- -- 13 7.5 13HEXAHYDRATE, NaNa SILICATE 21 21 21 21 17 17 21 -- 21 21 21(47.5%)(1:2.3)K SILICATE -- -- -- -- -- -- -- 34 -- -- --(29.1%)(1:2.3)LPKN (5%) 3.2 3.2 3.2 3.2 -- -- 3.2 3.2 3.2 3.2 3.2DOWFAX 3B2 1 1 1 1 1 1 1 1 1 1 1FATTY ACID2 0.1 0.1 0.1 0.1 -- -- 0.1 0.1 1 0.1 0.1BLEACH (13.0% 7.5 7.5 7.5 7.5 9.1 9.1 7.5 7.5 7.5 7.5 9CL)AIR3 Vol. %) <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0 <2.0FRAGRANCE -- 0.17 -- -- -- -- -- -- -- -- --K/Na RATIO 1.12 1.12 1.16 1.89 1.95 1.95 4.16 45.15 -- 1.89 --DENSITY (g/cc) 1.37 1.37 1.35 1.37 1.36 -- 1.37 -- -- 1.37 1.37RHEOGRAM FIG. 1 FIG. 2 FIG. 3 FIG. 4 FIG. 6 FIG. 7 FIG. 5 FIG. 8STABILITY 0.0 0.0 0.0 0.0 >10.0 >10.0 0.0 >20.0 >5.0 0.0RESULTSROOM TEMP.8 WEEKS (%)STABILITY 0.0 0.0 0.0 0.0 >10.0 >10.0 0.0 >20.0 >5.0 0.0RESULTS100� F., 6 WEEKS(%)__________________________________________________________________________ 1. Carbopol 940 2. Emersol 132 (Mixture of stearic and palmitic acid 1:1 ratio 3. All the formulations are aerated to a certain degree depending upon th shear condition employed for the preparation, typically the volume of air does not exceed 7-8% by volume, the preferred degree of aeration (2% by volume) resulting in the indicated densities; the air bubbled average between 20 and 60 microns in diameter.
Formulations A, B, C, D, E, G, J, and K are prepared by first forming a uniform dispersion of the Carbopol 941 or 940 thickener in about 97% of the water (balance). The Carbopol is slowly added to deionized water at room temperature using a mixer equipped with a premier blade, with agitation set at a medium shear rate, as recommended by the manufacturer. The dispersion is then neutralized by addition, under mixing, of the caustic soda (50% NaOH or KOH) component to form a thickened product of gel-like consistency.
To the resulting gelled dispersion the silicate, tetrapotassium pyrophosphate (TKPP), sodium tripolyphosphate TP(TPP, Na) and bleach, are added sequentially, in the order stated, with the mixing continued at medium shear.
Separately, an emulsion of the phosphate anti-foaming agent (LPKN), stearic acid/palmitic acid mixture and detergent (Dowfax 3B2) is prepared by adding these ingredients to the remaining 3% of water (balance) and heating the resulting mixture to a temperature in the range of 50� C. to 70� C.
This heated emulsion is then added to the previously prepared gelled dispersion under low shear conditions, such that a vortex is not formed.
The remaining formulations F, H and I are prepared in essentially the same manner as described above except that the heated emulsion of LPKN, stearic acid and Dowfax 3B2 is directly added to the neutralized Carbopol dispersion prior to the addition of the remaining ingredients. As a result, formulations F, H and I, have higher levels of incorporated air and densities below 1.30 g/cc.
The rheograms for the formulations A, C, D, G and J are shown in FIGS. 1-5, respectively, and rheograms for formulations H, I and K are shown in FIGS. 6, 7 and 8 respectively.
These rheograms are obtained with the System 4 Rheometer from Rheometrics equipped with a Fluid Servo with a 100 grams-centimeter torque transducer and a 50 millimeter parallel plate geometry having an 0.8 millimeter gap between plates. All measurements are made at room temperature (25� C.+1� C.) in a humidity chamber after a 5 minute or 10 minute holding period of the sample in the gap. The measurements are made by applying a frequency of 10 radians per second.
All of the composition formulations A, B, C, D, G and J according to the preferred embodiment of the invention which include Carbopol 941 and stearic acid exhibit linear viscoelasticity as seen from the rheograms of FIGS. 1-5. Formulation E which includes Carbopol 941 but not stearic acid showed no phase separation at either room temperature or 100� F. after 3 weeks, but exhibited 10% phase separation after 8 weeks at room temperature and after only 6 weeks at 100� F.
Formulation K, containing Carbopol 940 in place of Carbopol 941, as seen from the rheogram in FIG. 8, exhibits substantial linearity over the strain range of from 2% to 50% (G' at 1% strain-G' at 50% strain 500 dynes/sq.cm.) although tan 1 at a strain above 50%.
This example demonstrates the importance of the order of addition of the surface active component premix to the remainder of the composition on product density and stability.
The following formulations are prepared by methods A and
______________________________________Ingredient______________________________________Water, deionized BalanceCarbopol 941 0.5NaOH (50%) 2.4Na Silicate (47.5%) 21TKPP 15TPP, Na 13Bleach (1%) 7.5LPKN 0.16Stearic Acid 0.1Dowfax 3B2 1______________________________________
The Carbopol 941 is dispersed, under medium shear rate, using a premier blade mixer, in deionized water at ambient temperature. The NaOH is added, under mixing, to neutralize and gel the Carbopol 941 dispersion. To the thickened mixture the following ingredients are added sequentially while the stirring is continued: sodium silicate, TKPP, TPP, and bleach.
Separately, an emulsion is prepared by adding the Dowfax 3B2, stearic acid and LPKN to water while mixing at moderate shear and heating the mixture to about 65� C. to finely disperse the emulsified surface active ingredients in the water phase. This emulsion premix is then slowly added to the Carbopol dispersion while mixing under low shear conditions without forming a vortex. The results are shown below.
Method A is repeated except that the heated emulsion premix is added to the neutralized Carbopol 941 dispersion before the sodium stearate, TKPP, TPP, and bleach. The results are also shown below.
______________________________________ Method A Method B______________________________________Density (g/cc) 1.38 1.30Stability (RT-8 weeks) 0.00% 7.00%Rheogram FIG. 9 FIG. 10______________________________________
From the rheograms of FIGS. 9 and 10 it is seen that both products are linear viscoelastic although the elastic and viscous moduli G' and G" are higher for Method A than for Method B.
From the results it is seen that early addition of the surface active ingredients to the Carbopol gel significantly increases the degree of aeration and lowers the bulk density of the final product. Since the bulk density is lower than the density of the continuous liquid phase, the liquid phase undergoes inverse separation (a clear liquid phase forms on the bottom of the composition). This process of inverse separation appears to be kinetically controlled and will occur faster as the density of the product becomes lower.
This example shows the importance of the temperature at which the premixed surfactant emulsion is prepared.
Two formulations, L and M, having the same composition as in Example 2 except that the amount of stearic acid was increased from 0.1% to 0.2% are prepared as shown in Method A for formulation L and by the following Method C for formulation M.
The procedure of Method A is repeated in all details except that emulsion premix of the surface active ingredients is prepared at room temperature and is not heated before being post-added to the thickened Carbopol dispersion containing silicate, builders and bleach. The rheograms for formulations L and M are shown in FIGS. 11 and 12, respectively. From these rheograms it is seen that formulation L is linear viscoelastic in both G' and G" whereas formulation M is nonlinear viscoelastic particularly for elastic modulus G' (G' at 1% strain-G' at 30% strain>500 dynes/cm2) and also for G" (G" at 1% strain-G" at 30% strain 300 dynes/cm2).
Formulation L remains stable after storage at RT and 100� F. for at least 6 weeks whereas formulation M undergoes phase separation.
The following formulation is prepared without any potassium salts:
______________________________________ Weight %______________________________________Water BalanceCarbopol 941 0.2NaOH (50%) 2.4TPP, Na (50%) 21.0Na Silicate (47.5%) 17.24Bleach (1%) 7.13Stearic Acid 0.1LPKN (5%) 3.2Dowfax 3B2 0.8Soda Ash 5.0Acrysol LMW 45-N 2.0______________________________________
The procedure used is analogous to Method A of Example 2 with the soda ash and Acrysol LMW 45-N (low molecular weight polyacrylate polymer) being added before and after, respectively, the silicate, TPP and bleach, to the thickened Carbopol 941 dispersion, followed by addition to the heated surface active emulsion premix. The rheogram is shown in FIG. 13 and is non-linear with G"/G' (tan δ)>1 over the range of strain of from about 5% to 80%.
Formulations A, B, C, D and K according to this invention and comparative formulations F and a commercial liquid automatic dishwasher detergent product as shown in Table 1 above were subjected to a bottle residue test using a standard polyethylene 28 ounce bottle as used for current commercial liquid dishwasher detergent bottle.
Six bottles are filled with the respective samples and the product is dispensed, with a minimum of force, in 80 gram dosages, with a 2 minute rest period between dosages, until flow stops. At this point, the bottle was vigorously shaken to try to expel additional product.
The amount of product remaining in the bottle is measured as a percentage of the total product originally filled in the bottle. The results are shown below.
______________________________________Bottle ResidueFormulation Residue______________________________________A 8B 10C 6D 5K 7 F* 4Commercial Product 20______________________________________ *The sample separates upon aging
The following formulas (A-K) were prepared according to the following procedure:
______________________________________ A B C D E F______________________________________Carbopol 614 0.5 0.5 0.5 0.5 0.5 1.0NaOH 0.5 0.5 0.5 0.5 0.5 1.0Stearic Acid -- 0.1 0.2 0.3 0.4 .02Water 99.0 98.9 98.8 98.7 98.6 97.98Figure Nos. 14,15 16,17 18,19 20,21 22,23 24,25Brooksfield 730 1730 2245 2770 3685 9050viscosity cpsat RT, #4spindle 20rpms readingtaken after 90seconds______________________________________ G H I J K______________________________________Carbopol 614 1.0 1.0 1.0 1.0 0.5NaOH 1.0 1.0 1.0 1.0 0.5Stearic Acid .06 0.1 0.15 0 0.04Water 97.94 97.9 97.85 98.0 98.96Figure Nos. 26,27 28,29 30,31 32,33 34Brooksfield 10,25 8300 1400viscosity cps 0at RT, #4spindle 20rpms readingafter 90 seconds______________________________________
The Carbopol polymer was added to water at about 75�-80� C. with mixing. To the solution of the Carbopol polymer and water was added with mixing the sodium hydroxide to neutralize the Carbopol polymer. The stearic acid was added with mixing to the solution of water and the neutralized Carbopol polymer to form formulas (A-K). The polymer solutions were tested on the System 4 Rheometer as in Example 1. The Brookfield viscosities were run at room temperature using a #4 spindle at 20 rpms. Rheograms 14-33 depict the G' and G" for formulas A-J wherein for each formula a plot of G' and G" is illustrated. The rheograms (FIGS. 14, 15, 32, 33) for formulas A and J show that these formulas are not linear viscoelastic and the rheograms for formulas B-I (FIGS. 16-31) show that these formulas exhibit linear viscoelastic properties.
|Cited Patent
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|Mar 25, 1993
|Mar 29, 1994
|Colgate Palmolive Co.
|Linear viscoelastic aqueous liquid automatic dishwasher detergent composition
|Oct 22, 1992
|Apr 5, 1994
|Colgate Palmolive Company
|Viscoelastic dentifrice composition
|Aug 27, 1993
|Dec 12, 1995
|Ofosu-Asanta; Kofi
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|The Clorox Company
|Composition and method for developing extensional viscosity in cleaning compositions
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|The Procter & Gamble Company
|Liquid automatic dishwashing compositions providing high pH wash solutions
|Feb 9, 1999
|Feb 27, 2001
|Baker Hughes Incorporated
|Use of alkoxylated surfactants and aluminum chlorohydrate to improve brine-based drilling fluids
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|Mar 10, 2006
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|Baker Hughes Incorporated
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|Composition and process for preparing a phosphonate and phosphate-free automatic dishwashing powder
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|Smith Kim R
|Detergent composition for removing polymerized food soils and method for cleaning polymerized food soils
|Oct 31, 2007
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|U.S. Classification
|510/223, 510/434, 510/370, 510/222, 510/403
|International Classification
|Cooperative Classification
|European Classification
|Jan 15, 1993
Owner name: COLGATE-PALMOLIVE CO., NEW JERSEY
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:DIXIT, NAGARAJ S.;FAROOQ, AMJAD;ROUNDS, RHYTA;AND OTHERS;REEL/FRAME:006393/0801
Effective date: 19921201
|Feb 3, 1997
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I am trying to setup a postgres DB under win using cygwin. I've installed the latest version of cygwin and the postgres binaries. Then i've installed the last version of cygipc (1.1.3 if I am not wrong). The ipc-daemon works fine (at least so is said by ipctest). Since I have the postgres binaries installed I proceed directly to run initdb. The command hangs on creating db Template1 in dir data/base/1. Any clue on what I am missing to configure psql? Oh.. if it means anything.. I am using Windows XP. Thanks for help to anyone! ************************ Antonio Scotti
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Stayed for 2 nights start of december 16. Hotel is a few mins walk from the city centre alongside a mian road not far from the main station. city is nice and alot to do there at day or night. we got the train from...More
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