Environment-friendly paper and preparation method
Technical field
The present invention relates to environment-friendly paper and the relevant preparation method of a kind of being called as " stone paper ".
Background technology
For solving the problem that paper raw material consumes timber resources in a large number, with inorganic mineral powder particulate and TPO macromolecular material is the common composite environmental-friendly material paper of forming (being commonly called as environmental protection (stone) paper) of main raw material, is the focus of constantly researching and developing at present.Mainly be based on calcium carbonate and polyolefin resin in the production process of this paper, not only can solve the raw material problem, the more important thing is that these two kinds of raw materials are pollution-free, be easy to get, need not disafforestation, pollution-free in manufacture process, reach the purpose of protecting environment.
In the disclosed at present patent, the main component of most environmental protection (stone) paper all is that to adopt crystal type be light, the heavy or the ultra-fine CaCO of calcite type
3Carry out surperficial coupling processing, after mixing with polyolefin resin again, extrude, carry out curtain coating at last, prolong formers such as pressure and be processed into corresponding environmental protection (stone) paper through screw extruder.Reported by PP, HDPE or LDPE and the common composite of forming of heavy, precipitated calcium carbonate, talcum powder or clay as the Chinese patent literature of publication number CN1090554C; CN1202166C has reported that by polyolefin and calcium carbonate superfine powder be the manufacture method of filler; CN1651649A, CN1378909A and CN101462387A have reported equally by inorganic mineral powders such as polyolefin and heavy, precipitated calcium carbonates to be preparation method of main raw material etc.
The common ground of the environmental protection of above-mentioned bibliographical information (stone) paper is all to adopt common calcite type CaCO
3Be raw material.Calcite type CaCO
3Profile is cube or spindle shape, has to comprise as certain lattice defect such as hole, impurity, granular boundary structure be imperfect.Calcite type CaCO
3These natural defects that exist can directly influence its dispersiveness and compatibility in polymeric matrix, also can influence the forming process and the application performance of paper at last, cause the finished product sheetage, quantitatively, thickness is all bigger, tend to plastic sheeting more, no paper texture, serious also easily cause coarse, the shedding of paper surface, hindered its production and application.
Summary of the invention
At above-mentioned situation, the present invention will provide a kind of novel environment-friendly paper, and the environmental protection that promptly is commonly called as (stone) paper is to overcome the problems referred to above that exist in the present similar technology.On this basis, the present invention also will provide the related manufacturing processes of this environment-friendly paper.
The present invention contains the environment-friendly paper of calcium carbonate fibre composition, and the weight of its each composition consists of:
Calcium carbonate fiber 65~85%,
Thermoplastic starch 3~10%,
Polyolefin resin 10~20%,
Auxiliary element 2~5%.
In above-mentioned group, said calcium carbonate fiber is that a kind of average diameter is the whiskers fibrous material of 0.5~1 μ m and length 〉=20/1, and wherein preferred length is the calcium carbonate fiber of (20~30)/1; Said thermoplastic starch, be at present starch materials of handling through miniaturization and plasticization and modification that report arranged and/or use more, at least a in cornstarch, tapioca, farina, starch from sweet potato or wheaten starch that miniaturization and plasticization and modification are handled that was once provided in the patent documentation of publication number CN1778833A as the applicant can be provided.Said polyolefin resin can be in 5~30 the polyolefine materials such as LDPE, HDPE, mHDPE or PP any for melt index (MI).Said auxiliary element, generally can be multiple adjunct ingredient commonly used in plastic processing, wherein comprise surfactant and lubricant at least, surfactant wherein can be selected at least a as in sulfonated castor oil, sodium alkyl benzene sulfonate, polyphosphate, poly dimethyl silane, the polyoxyethylene alkylphenol ether; Lubricant can be selected at least a as in Tissuemat E, microcrystalline wax, mineral oil, white oil, stearic calcium salt or the magnesium salts.The content of said surfactant and lubricant respectively all 〉=1%.
The papermaking material of the above-mentioned environment-friendly paper of the present invention, can adopt following manner to prepare:
Earlier with said calcium carbonate fibrous material processed to moisture≤1%, then with add said surfactant and thermoplastic starch, lubricant successively, vistanex fully mixes, that is: said each constituents that adds successively adds one by one with interval mode, after the composition that adds before treating is fully mixed, add a kind of composition down again.After each composition evenly mixes, under 100 ℃~160 ℃ and 10~30Mpa pressure condition, cool off behind the melting mixing, pulverize, obtain the paper grade (stock) pellet through response type screw extruder mixing die face cutting of extruding under 90 ℃~180 ℃ temperature conditions again, or extrude through the T of screw extruder pattern head and to make corresponding paper grade (stock) raw material.
Test shows, among the above-mentioned preparation method, the moisture of control calcium carbonate fibrous material can help guaranteeing and improving the dispersive property of each raw material, also helps follow-up technological operation, and the quality that guarantees and improve the aspects such as flatness, the uniformity of paper.Dehydration can be carried out under heating condition by general fashion, for example can preferably dewater under 100 ℃~120 ℃ heating condition.This heating condition can also satisfy the needs of surfactant activation powder simultaneously.
For avoiding the superfine little powder material of granularity uneven phenomenon to occur mixing because of easily reuniting, when the calcium carbonate fiber after the dehydration mixes with surfactant, generally with adopt currently reported and/or use be mixed into good as mixing of materials equipment commonly used such as spiral ribbon mixer, rotary drum mixer, high-speed mixer, pneumatic mixers, wherein can preferably adopt high-speed mixer, stir with 300~900 rev/mins, to realize better full and uniform mixing, improve its surface-activity and with the uniformity of the blending reaction of chemical assistant.
To fully mixing the mixing of material, generally can in material mixing facilities such as banbury commonly used, mill, kneader, carry out, wherein be preferably banbury.Well-mixed material is continued melting mixing under High Temperature High Pressure, make resinous principle and the abundant melting mixing of thermoplastic starch (getting final product in for example mixing generally speaking 5~20 minutes) in the material.Then with after the material cooling and pulverizing, again by spiro rod reaction type extrusion equipment, preferably because of production capacity with excellent mixing shear effect and high efficiency continuously and the twin-screw response type extrusion equipment that in modifying plastics and machine-shaping, more generally adopts at present, by its reverse meshing part the mixing and shearing of the efficient plasticizing of component materials is uniformly dispersed, starch component is wherein effectively plastified.For example, a kind of optimal way when adopting twin-screw response type extrusion equipment, can be chosen in 100~300 rev/mins of engine speeds, 8~30 rev/mins of feeding machine rotating speeds, each is distinguished extrusion temperature and is controlled at respectively: 90 ℃~130 ℃ in one to three district, 140 ℃~180 ℃ in four to six districts, 180 ℃~150 ℃ in seven to nine districts, ten to 150 ℃~125 ℃ of No.12 Districts, vacuum 0.02~0.08Mpa, and head pressure remains 0.5~10Mpa.
When above-mentioned employing twin-screw response type extrusion equipment, the big extruder of screw slenderness ratio is used in special recommendation, for example can select the twin-screw response type extruder of draw ratio 〉=52: 1.
When extruding die face cutting and obtain the papermaking of paper grade (stock) pellet with above-mentioned screw extruder, can adopt paper film apparatus for blow moulding to carry out, ZM-55 for example, ZM-60, individual layer co-extrusion rotating head paper film machines such as ZM-65, or ZM-1000, ZM-1200, three-layer co-extruded rotating head paper such as ZM-1500 film unit, can be chosen in 400~600 rev/mins of engine speeds, 165 ℃~180 ℃ materials that will be heated to molten state are blow molded into the paper film by the inflation of paper film machine die head, regulate paper film blow-up ratio 2.5~3.5, draw ratio 4~8, on demand through vertical/horizontal biaxial tension, can be prepared into the plane extension paper and the cooling forming of institute's required thickness again.
With above-mentioned when double screw extruder T pattern head is extruded the corresponding paper grade (stock) raw material papermaking of making of obtaining, this raw material can be delivered to calendering formation equipment, for example SY4S-Φ 230 * 630, SY4S-Φ 300 * 950, SY4S-Φ 360 * 1120 four-roll calendaring units, can select 150 ℃~170 ℃ of roller temperature, roller speed 42~65/mmin
-1Stretch and cooling forming through two-way expanding in length and breadth, obtain the plane extension paper of institute's required thickness.
The CaCO that uses in the above-mentioned environment-friendly paper of the present invention
3Fiber belongs to a kind of aragonitic fiber.Result of the test shows, this aragonitic CaCO that the above-mentioned environment-friendly paper of the present invention adopts
3Fiber, because itself structure is very thin and have a bigger draw ratio, the characteristics of the mechanical property that high strength, high-modulus etc. are excellent, join in the polymer and can play skeleton function, therefore can be toughness reinforcing to matrix strengthening as reinforcing material as fiber, form the polymer-fibre composite, can also adapt to complicated moulding simultaneously, in process, induce macromolecular orientation, improve the rheological property of material and improve process.Thereby can make environmental protection of the present invention (stone) paper have excellent sheet texture, and have quantitatively low, proportion is little, the uniform characteristics of dimensionally stable, make paper have good ink absorption and printing adaptability, can also improve the performance of aspects such as paper whiteness, opacity, smoothness and tensile index simultaneously.By the thermoplastic starch that employing has the thermoplasticity function, strengthened the processing characteristics of system, realized the thermoplasticity processing of environment-friendly paper.In process, carry out hybrid reaction by adopting as common apparatus such as high-speed mixers, and adopt twin-screw to react extrusion equipment, can realize the serialization extruding pelletization, simple to operate, process stabilizing, production efficiency height, reduce the papermaking cost, helped realizing the industrialization production and the popularization of such environmental protection (stone) paper.
The specific embodiment by the following examples is described in further detail foregoing of the present invention again.But this should be interpreted as that the scope of the above-mentioned theme of the present invention only limits to following example.Do not breaking away under the above-mentioned technological thought situation of the present invention, various replacements or change according to ordinary skill knowledge and customary means are made all should comprise within the scope of the invention.
The specific embodiment
Embodiment 1
Raw material (, as follows) in gross weight: average diameter 0.5~1 μ m, the calcium carbonate fiber 65% of length (20~30)/1, thermoplasticity cornstarch 10%, mHDPE 20%, sulfonated castor oil 2%, white oil 3%.Thermoplastic starch wherein obtains (following all herewith) for handling by the method for CN1778833A.
Preparation: the calcium carbonate fiber is carried out preheating, dehydration at 100 ℃~120 ℃, after detecting moisture≤1%, send into LHY-1 type high speed ribbon mixer, add sulfonated castor oil, thermoplasticity cornstarch, white oil and mHDPE successively and carry out the high-speed stirred mixing, the at interval reinforced time is 3~20 minutes, and then in banbury, after continuing mixing 5~20 minutes under 100 ℃~160 ℃ of temperature and the pressure 10~30Mpa condition, blowing also is cooled to 30 ℃~40 ℃ pulverizing.(herewith following)
With said mixture through SHJ-38 type twin-screw response type extruder extruding pelletization (screw slenderness ratio of double screw extruder 〉=52: 1, below herewith).Wherein, 100~600 rev/mins of engine speeds, 8~30 rev/mins of feeding machine rotating speeds, temperature control:: 90 ℃~120 ℃ in one to three district, 140 ℃~180 ℃ in four to six districts, 180 ℃~150 ℃ in seven to nine districts, ten to 150 ℃~125 ℃ of No.12 Districts, vacuum 0.02~0.08Mpa, head pressure remains 0.5~10Mpa.(herewith following).
The gained pellet is delivered to aforesaid ZM-55 individual layer co-extrusion rotating head paper film machine, be blow molded into the paper film 165 ℃~210 ℃ material inflations with fusion, 400~600 rev/mins of engine speeds, blow-up ratio 2.5~3.5, draw ratio 4~8, carry out biaxial tension in length and breadth through the biaxial tension device, at last by sending into cooling unit cooling forming.Can directly batch after the moulding environment-friendly type (stone) paper of 0.05~0.08mm thickness.
Embodiment 2
Raw material: calcium carbonate fiber 70% (with embodiment 1), thermoplastic wood sweet potato starch 10%, PP 15%, mineral oil 2%, sodium alkyl benzene sulfonate 3%.
The preparation: with the calcium carbonate fiber 100 ℃~120 ℃ preheatings, dewater to moisture≤1%, send into GH-50 type high speed rotary drum mixer, adding sodium alkyl benzene sulfonate, thermoplastic wood sweet potato starch, mineral oil stirring and PP successively keeps high-speed stirred to mix, and then continuation is mixing in banbury, last blowing, cooling, pulverizing.
Said mixture is delivered to aforesaid SY4S-Φ 230 * 630 four-roll calendaring units after twin-screw response type extruder T pattern head is extruded, select 150 ℃~180 ℃ of roller temperature, roller speed 42~65/mmin
-1Stretch and cooling forming through two-way expanding in length and breadth, can directly batch after the moulding environment-friendly type (stone) paper of 0.05~0.08mm thickness.
Embodiment 3
Raw material: calcium carbonate fiber (with embodiment 1) 85%, thermoplasticity starch from sweet potato 3%, PP 10%, oxidized polyethlene wax 1%, poly dimethyl silane 1%.
The preparation: with the calcium carbonate fiber 100 ℃~120 ℃ preheatings, dewater to moisture≤1%, send in the SHR-30A type high-speed mixer, adding poly dimethyl silane, thermoplasticity starch from sweet potato, oxidized polyethlene wax and PP high-speed stirred successively mixes, and then continuation is mixing in banbury, last blowing, cooling, pulverizing.
Said mixture is pressed embodiment 2 modes, after twin-screw response type extruder T pattern head is extruded, deliver to four-roll calendaring unit calendering formation becomes thickness 0.10~0.12mm with two-way expanding stretch process in length and breadth environment-friendly type (stone) paper.
Embodiment 4
Raw material: calcium carbonate fiber (with embodiment 1) 65%, thermoplasticity wheaten starch 10%, HDPE 20%, calcium stearate 1%, polyoxyethylene alkylphenol ether 4%.
The preparation: with the calcium carbonate fiber 100 ℃~120 ℃ preheatings, dewater to moisture≤1%, send into GHJ-300 type high-speed pneumatic mixer, adding polyoxyethylene alkylphenol ether, thermoplasticity wheaten starch, calcium stearate and HDPE high-speed stirred successively mixes, and then continuation is mixing in banbury, last blowing, cooling and pulverizing.
Through the double screw rod extruder extruding pelletization, resulting material is pressed embodiment 1 mode with said mixture, is processed into environment-friendly type (stone) paper of 0.10~0.12mm thickness through the biaxial tension of paper film blow moulding equipment.
It is as shown in table 1 that the major technique of the major technique detection index contrast of the imperial alliance calcium carbonate of each embodiment environment-friendly type (stone) paper and CN1378909A document/HDPE environmental protection paper (contrast stone paper) detects index.Comparing result shows that the combination property of various embodiments of the present invention environment-friendly type (stone) paper all obviously is better than contrasting stone paper.
The major technique of table 1 environment-friendly paper of the present invention and ordinary calcium carbonate/HDPE stone paper detects the index contrast
Test item |
Embodiment 1 |
Embodiment 2 |
Embodiment 3 |
Embodiment 4 |
Contrast stone paper (CN1378909A document) |
Quantitative (g/m
2)
|
??45 |
??70 |
??86 |
??60 |
??74.6 |
Proportion g/mg
3 |
??0.8 |
??0.8 |
??0.9 |
??0.8 |
??1.2 |
Test item |
Embodiment 1 |
Embodiment 2 |
Embodiment 3 |
Embodiment 4 |
Contrast stone paper (CN1378909A document) |
Brightness (whiteness) % |
??86 |
??93 |
??96 |
??83 |
??81.5 |
Opacity % |
??90 |
??94 |
??95 |
??93 |
??89 |
Glossiness % |
??25 |
??21 |
??20 |
??20 |
??13 |
Smoothness (positive and negative is average) s |
??120 |
??120 |
??118 |
??125 |
??89 |
Ink absorption % |
??12 |
??15 |
??18 |
??13 |
??10 |
Print surface intensity m/s |
??1.5 |
??1.1 |
??1.0 |
??1.3 |
??0.6 |
Tensile index (vertically) Nm/g |
??15 |
??14 |
??11 |
??16 |
??9 |
Folding strength (inferior) |
??>5000 |
??>3000 |
??>3000 |
??>5000 |
??>5000 |