Background technology
Release liners is according to different separate paper, peeling paper, Ge Laxin paper, candy wrapper, the greaseproof papers of can be described as again of road processing technology thereafter and purposes, or the like, be widely used in base stock, lining paper or the packing of various self adhesive materials.At present, it is raw material that most release liners manufacturer adopts common release body paper or raw release paper, after polyethylene or polypropylene drench film or plastic-coated, through silicone coated or directly with the silicone oil coating, realizes anti-adhesion effects and stripping performance again.This series products, after filtering film or plastic-coated, its biodegradability step-down, the difficulty that is recycled of paper causes certain harm to environment.High-grade release body paper is on the basis that common release body paper is produced, and through process optimizations such as moistening coatings, makes it have a kind of new product that smoothness height, grease resistance can wait advantage well.Lattice Racine paper structure is tight, its grease resistance height, and to have relatively high expectations (the fiber wire-dividing broom purification is good) of paper fiber, fiber is in conjunction with tight when sheet forming, and the porosity of page is low, and film-formation result is good when moistening coating.High-grade release body paper and Ge Laxin paper price are more expensive, and the source of goods is in short supply, can not satisfy the needs of production and economic benefit.The release liners that is used for back glue bag for postal service express delivery is higher a kind of of release liners quality requirement, it requires minimum peeling force, higher smoothness and good aging properties, and market demand is bigger, therefore improve existing release liners production technology, a kind of competitive technical scheme is provided, and is that realistic meaning is arranged very much.
Summary of the invention
The present invention is used to overcome the defective of prior art and provides a kind of and reduce cost, enhance productivity and performance meets the release liners that is used for back glue bag for postal service express delivery and the preparation method of instructions for use fully.
The alleged problem of the present invention is solved by following technical scheme:
A kind of release liners that is used for back glue bag for postal service express delivery, its special feature is: it reaches the priming coat, the silicon layer that are coated in its appearance successively by light weight coated paper and constitutes, described bottom coating is formed by the preparation of raw material of following parts by mass: water 450, solid content is 50% carboxylic styrene butadiene latex 60~120, carboxymethyl cellulose 1~2, kaolin 10~15, solid content are 7% polyvinyl alcohol 1~15, polycarboxylic acid salt's dispersant 0.4~0.6, silicone based defoamer 0.3~0.4.
The above-mentioned release liners that is used for back glue bag for postal service express delivery, described bottom coating is formed by the preparation of raw material of following parts by mass: solid content is 50% carboxylic styrene butadiene latex 80, carboxymethyl cellulose 1, kaolin 15, solid content is 7% polyvinyl alcohol 10, polycarboxylic acid salt's dispersant 0.5, silicone based defoamer 0.3, water 450.
A kind ofly prepare the above-mentioned method that is used for the release liners of back glue bag for postal service express delivery, it carries out as follows:
A. choose raw material paper: getting light weight coated paper is raw material paper;
B. painting bottom coating: according to proportioning preparation bottom coating, painting bottom coating on coating machine, the gap is adjusted into 7mm between dispense tip air knife and the applicator roll, the priming coat coating weight be 0.7 gram/square metre;
C. drying and shaping: the paper of linging layered material is advanced oven for drying, oven temperature is 160~190 ℃, crimping and drying thoroughly are not as the criterion drying time with the paper of rolling place, can realize by adjusting speed of a motor vehicle speed, then form primary coat paper through the drying cylinder typing, the drying cylinder heating steam pressure is 0.1Mpa, and steam pressure is in case determine that temperature is also fixing thereupon;
D. be coated with silicone oil: with above-mentioned primary coat paper coating silicone oil, the silicone oil coating weight be 0.8 gram/square metre;
E. be heating and curing: the paper of silicone oil coating is entered baking oven for heating curing, and guarantee that the temperature on paper surface is not less than 150 ℃, the back that is heating and curing gives the paper humidification to moisture 6~8%, promptly makes release liners after the rolling.
The above-mentioned preparation method who is used for the release liners of back glue bag for postal service express delivery, coating speed is 200~350 meters/minute in the described painting bottom coating step; Coating speed is 200~300 meters/minute in the coating silicone oil step, and Silicon coating machine coating speed and rolling speed speed ratio are 1/1.
Product of the present invention adopts light weight coated paper for making the raw material of release liners, and provide the release liners preparation method who meets material characteristic, its main feature is as follows: 1. the release liners of this method preparation, and peeling force that it is lower and good resistance to ag(e)ing meet the requirement of back glue bag for postal service express delivery to release liners fully; The bottom coating viscosity that provides of the present invention low, be fit to produce continuously, rate of drying is fast, production efficiency has improved nearly 82%.And primer viscosity is low, helps the air knife coating, can reduce the primer coating weight, and cost reduces nearly 50%; And the seepage-proof oil effect is better, and coating evenly.Used in addition primer, perishable being absorbed in soil can not work the mischief to environment; The coating silicon oil dosage by common 1.2 grams/square metre reduce to 0.8 gram/square metre and don't influence properties of product, can further reduce production costs.Based on above-mentioned advantage, the present invention can adapt to environmental requirement, few, the competitive technical scheme of raw materials consumption for release liners provides a kind of.
The specific embodiment
The present invention chooses the raw material paper of light weight coated paper for the preparation release liners, and light weight coated paper is that the tow sides at body paper add skim coating, passes through press polish again, can improve physical performance of paper and printability.Two surface smoothnesses of light weight coated paper are good, generally all more than 400S, and supply abundance, stable performance, price are lower, help continuous production, its higher smoothness can guarantee continuity, planarization and the uniformity of silicone oil rete, reduces the consumption of silicone oil and guarantees the good anti-adhesion performance of paper.But light weight coated paper also has some inherent shortcomings, and is bigger as difficulty of processing, requires also higher to processing technology.At present release liners manufacturing enterprise generally adopts poly-vinyl alcohol solution to do the precoated shet primer, and is slow because of its rate of drying, causes the false phenomenon of doing easily, have that speed of production is slow, viscosity is high, crawling, can not be with shortcomings such as air knife coatings.The present invention is according to the characteristics of selected raw material paper, adjusted the proportioning of bottom coating, adopt components preparation bottom coatings such as carboxylic styrene butadiene latex, carboxymethyl cellulose, polyvinyl alcohol, kaolin, it has, and viscosity is low, cost is low, be easy to coating, perishable absorption in soil, can not be to advantages such as environment work the mischief.Coating process adopts the air knife coating.
Polycarboxylic acid salt's dispersant can adopt polycarboxylic acid's ammonia dipersant, as the TH-904 dispersant, it is a kind of anionic polymer, can be adsorbed on various molecules surface and produce electrostatic repulsion to make it to disperse, avoid sedimentation, return slightly, consumption in the present invention is 0.4~0.6.Silicone based defoamer can adopt water-based polyethers copolymerization amino-modified silicone, and addition in the present invention is 0.3~0.4.
Owing to select light weight coated paper for use, increased coating, be further to reduce the release liners cost, keep the release liners grammes per square metre, the content of paper fiber reduces, and the toughness of paper reduces, and becomes fragile, easily broken, is difficult for processing, and the technological parameter of original release liners processing also needs to improve.The present invention adjusts and improves the relevant parameter of painting bottom coating, drying and shaping among the preparation method, step such as be heating and curing, test shows, adopt this method can realize that light weight coated paper manufactures the batch process of release liners, its product meets the requirements fully, reaches the purpose that reduces the release liners peel strength, reduces production costs, enhances productivity.
Below provide several specific embodiments:
Table 1 bottom coating proportioning:
Component |
Embodiment 1 |
Embodiment 2 |
Embodiment 3 |
Embodiment 4 |
Embodiment 5 |
Carboxylic styrene butadiene latex 50% (solid content percentage composition) |
60 |
70 |
80 |
100 |
120 |
Carboxymethyl cellulose |
2 |
2 |
1 |
1.5 |
1.5 |
Kaolin |
15 |
13 |
15 |
10 |
12 |
Polyvinyl alcohol 7% (solid content percentage composition) |
15 |
13 |
10 |
5 |
1 |
Polycarboxylic acid salt's dispersant |
0.4 |
0.5 |
0.5 |
0.6 |
0.6 |
Silicone based defoamer |
0.3 |
0.4 |
0.3 |
0.35 |
0.4 |
Water |
450 |
450 |
450 |
450 |
450 |
Primer preparation steps following (is example with embodiment 3):
1. accurate weighing 400 kg of water add in the agitator tank, stir 900r/min;
2. add 15 kilograms of kaolin, add 0.5 kilogram of dispersant, continue to stir 15 minutes;
3. accurately 80 kilograms of styrene-butadiene latexes of weighing add agitator tank, stir 20 minutes;
4. accurate 50 kilograms of hot water of weighing (70~90 ℃ get final product) add 1 kilogram of carboxymethyl cellulose, manually be stirred to complete molten till, add continuation stirring 15 minutes to the back to the styrene-butadiene latex mixing time;
5. add 0.3 kilogram of defoamer;
6. add 10 kilograms of 7% polyvinyl alcohol, stir and got final product discharging in 10 minutes.
Release liners preparation method of the present invention is as follows:
A. choose raw material paper: getting light weight coated paper is raw material paper;
B. painting bottom coating: according to said ratio preparation bottom coating, the primer viscosity is lower, and viscosity is about 10.8 seconds, and the gap is adjusted into 7mm between dispense tip air knife and the applicator roll, the priming coat coating weight be 0.7 gram/square metre; Rolling tension force is looked the different size difference and is selected different tension force for use, and principle is to guarantee that paper can flatten when coating; 200~350 meters/minute of coating speeds;
C. drying and shaping: the paper of linging layered material is put into oven for drying, form primary coat paper through the drying cylinder typing then, the drying cylinder heating steam pressure is increased to 0.1Mpa to increase the typing degree;
D. be coated with silicone oil: with above-mentioned primary coat paper coating silicone oil, the silicone oil coating weight be 0.8 gram/square metre, the release liners peeling force can reach 0.40N/cm, and silicon oil dosage has reduced by 33%, adjust paper and unreel and rolling tension force, rolling speed speed ratio is 1/1, and promptly stretching with zero guarantees continuous paper; 200~300 meters/minute of coating speeds;
E. be heating and curing: the paper of silicone oil coating is entered baking oven for heating curing; for increasing toughness, give the paper humidification before being heating and curing, promptly make release liners after being heating and curing to moisture 6~8%; being heating and curing needs the open cold blower fan that release liners is lowered the temperature when shutting down, prevent aging the becoming fragile of paper and disconnected paper.
The release liners that adopts the technology of the present invention to make, show after tested: the priming coat coating weight 0.7 the gram/square metre the time, the seepage-proof oil performance reaches more than 5 grades, and prior art reaches same seepage-proof oil effect, adopt regular convention formula, common primary coat paper should apply at least 1.5 grams/square metre more than just can reach this kind effect.Because the smoothness height on light weight coated paper surface is coated with less priming coat and just can reaches good barrier properties, and, because of the priming coat fast drying,, be coated with the also corresponding minimizing of silicon amount, and curing rate is accelerated also so the speed of a motor vehicle is fast.The present invention be coated with the silicon amount be 0.8 the gram/square metre the time, its peel strength is 0.40N/cm.
Table 2: the present invention and the contrast of prior art part index number
Can find that from above contrast the index that the present invention considers obviously is better than prior art.