JP3455420B2 - Olefin resin composition for calendering and its application - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an olefin resin composition for calender molding (hereinafter, simply referred to as an olefin resin composition) and its application, more specifically, high production without sticking to a calender roll. Olefin resin composition capable of forming a sheet with excellent properties, a calender molding color sheet having excellent printability and surface smoothness obtained therefrom (hereinafter, simply referred to as a color sheet),
The present invention also relates to a surface-coated sheet obtained by processing this color sheet, which has excellent printability and adhesiveness to other base materials.

[0002]

2. Description of the Related Art In recent years, demand for sheets and films made of olefin resin such as polyethylene resin is increasing in various fields due to environmental problems. Conventional olefin resin sheets have been conventionally formed by extrusion, but extrusion sheets are inferior to calender molding in terms of thickness accuracy and productivity, so there is an increasing demand for molding olefin resins by calendering. ing. When attempting to calender an olefinic resin, the olefinic resin strongly adheres to the calender roll, and the release of the sheet from the roll is not stable.Therefore, the method of adding metal soap or amide lubricant has been used so far. It was

[0003]

However, when it is attempted to coat the sheet thus obtained with a primer in advance for printing or laminating another substrate, these lubricant components are not used. However, since it has a high transferability to the sheet surface, such as being condensed on a cooling roll and transferred to the sheet surface, there is a drawback in that the adhesion of the primer is hindered and a high quality coating film cannot be obtained. In addition, olefinic resins with poor transparency are often colored, but the processability decreases as the amount of colorant added increases.Therefore, high concentration of the colorant is suitable for applications where light-shielding properties and color development are required. It was difficult to obtain the added thin sheet by calendering.

Therefore, an object of the present invention is to improve the surface property of the sheet by facilitating the peeling of the sheet from the calender roll during the calendering process using the olefin resin composition, and the adhesion of the primer to the sheet surface. It is intended to provide an olefin-based resin composition which improves the above-mentioned properties and gives a surface-coated sheet excellent in printability and adhesiveness to other substrates.

[0005]

As a result of research, the inventors of the present invention have found that the melt measured at 190 ° C. under a load of 2.16 kg.
Linear low density poly with an index of 0.1-10.0
For 100 parts by weight of ethylene or high-density polyethylene
And, inorganic fillers 1-50 parts by weight, mono- or polyhydric alcohols fatty ester lubricant 0.3 to 10 parts by weight, oxide
1 to 30 parts by weight of titanium and 0.01 to 1.0 of antioxidant
It has been found that an olefin resin composition for calender molding composed of parts by weight can achieve the above object.

A color sheet can be easily obtained from the olefin resin composition by calendar molding.
The critical surface tension γ _{c on} one or both sides of this color sheet
Of 34 to 54 dyn / cm as the corona discharge treated surface, and by further applying a primer coating to this surface or both surfaces, a thickness of 0.1
A surface coating sheet for printing and adhesion having a primer coating film of -10 μm is obtained.

In the olefin resin composition of the present invention, the lower the melt index of the olefin resin is, the more the peelability from the calender roll is improved. However, if the melt index is too low, the surface smoothness of the sheet deteriorates. The inorganic filler improves the blocking property and dimensional stability of the printing sheet. The fatty acid ester of a monohydric or polyhydric alcohol prevents deterioration of printability due to addition of a lubricant and deterioration of peelability from a calender roll due to addition of a colorant necessary for light-shielding property, color development property and the like. After the corona discharge treatment is applied to the olefin resin sheet, the primer to be coated also acts as an anchor material when the adhesive processing is performed using another substrate and an adhesive.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
In the present invention, the olefin resin is polyethylene
Resin is used.

[0009] the polyethylene resin, high density polyethylene (HDPE), linear low density polyethylene (LLDPE) is
Used, these are obtained by polymerizing gaseous ethylene C ₂ H ₂ , and by changing the polymerization catalyst and the polymerization conditions, for example, density, melt index, crystallinity,
Properties such as branching degree and crosslinking degree, molecular weight and molecular weight distribution can be controlled in a wide range. Further, various modified products can be obtained by graft polymerization, chlorination, addition of additives and the like.

Generally, a high molecular weight polymer having a molecular weight of 6,000 or more and having a density in the range of about 0.900 to about 0.940 g / cc is referred to as low density polyethylene and has a density of about 0.9.
Those with densities of 41 to about 0.965 g / cc, or higher, are called high density polyethylene. Low density polyethylene is usually polymerized at high temperature and high pressure, while high density polyethylene is polymerized at relatively low temperature and low pressure. Linear low density polyethylene includes ethylene with C ₄ to C ₁₀ α-
An long-chain copolymer having a small amount of a branched chain or a crosslinked structure, which is obtained by copolymerizing with an olefin, for example, one or more copolymerizable monomers selected from butene-1, octene and the like, The branched chains present are short chains compared to non-linear polyethylene. Linear low density polyethylene has a density in the range of about 0.916 to about 0.940 g / cc,
It is produced by a low pressure gas phase method and a liquid phase method using a transition metal catalyst.

In the olefin resin of the present invention, it is preferable to use one or more of the above-mentioned polyethylene resins and to set the melt index (according to JIS K 7210) in the range of 0.1 to 10.0, preferably 0.4 to 5.0. . If the melt index is less than 0.1, the bank rotation will not be stable and the flow marks will result in poor sheet smoothness.If the melt index is more than 10.0, peeling from the roll will be poor and adhesion will occur, and air bubbles will be generated on the surface of the sheet due to poor bubble removal in the bank. It will be easier.
If the surface smoothness is poor due to flow marks or air marks,
It may cause uneven coating during subsequent primer coating or printing.

As the inorganic filler, talc, calcium carbonate, barium sulfate, calcium sulfate, aluminum silicate, clay, kaolin, bentonite, potassium silicate, calcium silicate, magnesium silicate, silica,
Examples include diatomaceous earth, calcium oxide, magnesium oxide, aluminum oxide, aluminum hydroxide, magnesium hydroxide and the like, which are used alone or in combination of two or more kinds. Of these, talc and calcium carbonate are preferred. This inorganic filler is an olefin resin
1 to 50 parts by weight, preferably 3 to 100 parts by weight
It is added in the range of 20 parts by weight. If the added amount is less than 1 part by weight, the rolled sheet will be blocked and 50
If it exceeds the weight part, the pinhole and the smoothness of the sheet are deteriorated and the appearance is deteriorated.

Examples of fatty acid ester type lubricants of monohydric or polyhydric alcohols include stearic acid-n-butyl stearate, hydrogenated methyl rosinate, di-n-butyl sebacate, dioctyl sebacate, distearyl adipate and glycerin lactostear. Glycerin fatty acid ester such as phthalate, pentaerythritol tetrastearate such as pentaerythritol stearate, pentaerythritol adipate, dipentaerythritol hexastearate, dipentaerythritol mixed ester of adipic acid and stearic acid, sorbitan Fatty acid (C
₈ -C ₂₂₎ esters, ethanediol montanic acid ester, 1,3-butanediol montanic acid ester, diethylene glycol stearic acid ester, polyethylene glycol fatty acid (C _{8 ~C 18)} esters, propylene glycol fatty acid (C _{8 ~C 22)} Esters and the like can be mentioned, and these can be used alone or in combination of two or more kinds.

The fatty acid ester lubricant of monohydric or polyhydric alcohol is added in an amount of 0.3 to 10.0 parts by weight, preferably 0.5 to 3.0 parts by weight, based on 100 parts by weight of the olefin resin. If the amount added is less than 0.3 parts by weight, peeling from the roll will be poor and sticking will occur, and if it exceeds 10.0 parts by weight, the adhesion of the primer will be impaired. This lubricant does not interfere with primer adhesion due to bleeding or plate-out, and when the sheet peeled from the calender roll is picked up, the lubricant component does not condense on the cooling roll and retransfer to the sheet. It has excellent advantages.

Examples of the colorant include titanium oxide,
It is added in an amount of 1 to 30 parts by weight, preferably 5 to 20 parts by weight, based on 100 parts by weight of the olefin resin. When the amount of the colorant is less than 1 part by weight, the dispersibility is non-uniform and the color becomes uneven, resulting in poor designability after printing. Also, the hiding property is insufficient and the base material is affected when it is attached to another base material. To lose sexuality.
If it exceeds 30 parts by weight, peeling from the calendar roll is poor and sticking occurs. In addition, polyethylene wax or the like may be used as a vehicle to improve the dispersibility of the colorant.

The antioxidants include those generally known as antioxidants for plastic materials,
For example, tris (nonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, distearyl pentaerythritol phosphite, bis (2,4-di-t-butylphenyl) pentaerythritol phosphite, Bis (2,6-di-t-butyl-4
-Methylphenyl) pentaerythritol phosphite, 2,2-methylene-bis (4,6-di-t-butylphenyl) octylphosphite, tetrakis (2,4)
-Di-t-butylphenyl) -4,4'-biphenylene-di-phosphonite and other phosphorus-based antioxidants;
-Di-o-butyl-4-methylphenol, n-octadecyl-3- (3'-5'-di-t-butyl-4'-hydroxyphenyl) propionate, tetrakis [methylene-3 (3,5-di -T-butyl-4-hydroxyphenyl) propionate] methane, tris (3,5-di-t-4-hydroxybenzyl) isocyanate, 4,
4'-butylidene-bis (3-methyl-6-t-butylphenol), triethylene glycol-bis [3-
(3-t-butyl-4-hydroxy-5-methylphenyl) propionate], 3,9-bis {2- [3- (3
-T-butyl-4-hydroxy-5-methylphenyl)
Propionyloxy] -1,1-dimethylethyl}-
Examples include phenolic antioxidants such as 2,4,8,10-tetraoxaspiro [5,5] undecane, which may be used alone or in combination of two or more.

These antioxidants are olefin resin
0.01 to 1.0 parts by weight, preferably 0.1 to 100 parts by weight
From 0.5 parts by weight is added. If it is less than 0.01 part by weight, the physical properties will deteriorate due to oxidative deterioration during processing or over time, and if it exceeds 1.0 part by weight, it will be yellowed and the colorability will be poor and the primer adhesion will be poor.

The olefin resin composition of the present invention is further kneaded with an antistatic agent, an ultraviolet absorber, etc., if necessary, and then uniformly kneaded by a kneading machine commonly used such as a Banbury mixer or an extruder. The material is directly fed to a calender or pelletized by a pelletizer and then fed to a calender to calender a film or sheet having a thickness of 0.05 mm to 2 mm. Matting with an embossing roll is more preferable in order to further reduce blocking of the sheet.

The obtained film or sheet is subjected to corona discharge treatment on one side or both sides thereof in order to impart printability and adhesiveness to another substrate, and then coated with a primer on one side or both sides thereof, A surface coated sheet for printing and adhesion is used. In this corona discharge treatment, discharge is performed between a needle-shaped electrode or a counter electrode with a knife edge, and a sheet is inserted between the electrodes for processing. The critical surface tension γ _c due to corona discharge treatment is preferably 34 to 54 dyn / cm, and when it is less than 34 dyn / cm, the adhesion of the primer is low, and when it exceeds 54 dyn / cm, blocking between sheets occurs and printability is increased. descend. The critical surface tension is measured by a method described in JIS K 6768 using a mixed solution of formamide and ethylene glycol monoethyl ether.

The primer is a resin-based coating agent, and also functions as an anchor agent for improving the ink adhesiveness at the time of printing or an adhesive agent for improving the adhesiveness with other base materials such as plywood. . Examples of the primer include polyurethane resin, vinyl acetate resin, styrene resin, (meth) acrylic resin, ethylene resin, vinyl chloride resin, vinylidene chloride resin, polyester resin, polyvinyl alcohol resin, and epoxy resin. Resins and the like that are generally used for plastics are mentioned, and they may be used alone or in combination of two or more. Of these, polyurethane resins are particularly preferable. Further, an inorganic powder such as silica or an organic powder such as polyethylene may be added to the primer as a surface modifier for improving the blocking property of the sheet. Further, in order to increase the adhesion to the sheet, the isocyanate resin or the like may be a two-pack type of a prepolymer and a curing agent.

[0021] These primers are uniformly dissolved or mixed in an organic solvent, and this is applied by a commonly known coating means such as gravure coating, gravure reverse coating, silk coating, bar coating, spraying or dipping. The dried layer is coated and dried by controlling the coating amount so that the thickness is in the range of 0.1 to 10 μm, preferably 0.5 to 3 μm. When the thickness of the dry layer is less than 0.1 μm, the ink adhesion is not sufficient and the adhesion with other substrates cannot be obtained, and when it exceeds 10 μm, the physical properties of the sheet and the cost increase due to the solvent.

The olefin-based resin composition of the present invention can be used for building materials such as wood cutting materials and for tagging by printing the front side and adhering the back side to plywood by applying a primer coating after corona discharge treatment on both sides of the sheet. It is effective for use as a sheet.

[0023]

[Examples] Specific embodiments of the present invention will be described below in Examples (Experiment N).
1 to 3) and comparative examples (Experiment Nos. 4 to 17). Polyethylene resin shown in Table 1 and Table 2 (all manufactured by Asahi Kasei Kogyo Co., Ltd.
E, high density polyethylene HDPE, melt index
MI), an inorganic filler, talc MS (manufactured by Nippon Talc, trade name), a fatty acid ester lubricant, No. 7329 (manufactured by Akishima Chemical Co., trade name, pentaerythritol adipic acid and stearic acid Mixed ester lubricant), colorant, titanium oxide (made by Ishihara Sangyo Co., Ltd.), antioxidant, AO-60
(Asahi Denka Kogyo Co., Ltd., trade name) PEP-24G (same as above) was blended in the ratio shown in each table, and after uniformly kneading using a twin-screw extruder, each of these compositions was mixed with reverse L 4-roll calendering machine with roll temperature 190 ℃, thickness 0.1mm, width
The sheet was formed into a sheet of 1,000 mm, and both surfaces of the obtained sheet were subjected to corona discharge treatment to measure the critical surface tension γ _c , and the results are also shown in each table. A primer [urethane resin: silica = 10: 5 (weight ratio)] diluted with a mixed solvent of methyl ethyl ketone, ethyl acetate, toluene, and isopropyl alcohol (3: 1: 1: 2) was dried on this corona discharge treated surface. After coating by gravure coating so that the layer thickness becomes the value shown in each table, gravure printing is applied to the front surface and modified ethylene / vinyl acetate copolymer emulsion adhesive / BA-10 (Central Chemical Industrial product, trade name) was applied and adhered to plywood. The following evaluations in the above manufacturing process were performed based on the following criteria, and the results are also shown in each table.

[Roll peelability] -Sheet peeling from the calender roll is stable ...
………… ○ ・ Peeling is not stable due to adhesion to the calendar roll …………
………… ×

[Sheet surface property] -Smooth without flow marks or surface defects such as skin marks ...
………… ○ ・ There are flow marks and skin-like surface irregularities, resulting in poor smoothness ………… ×

[Air mark] -Ballet escape between the calender rolls is good and smooth.- ○ -Air bubble escape between the calender rolls is bad and there is a crater-like dent on the surface. ………………
…………………………………………… ×

[Pinhole] ・ There is no pinhole …………………… ○ ・ There is a pinhole …………………… ×

[Thermal stability] ・ Physical property deterioration and color change after processing are small ... ○ ・ Physical property deterioration and color tone change after processing are large ... ×

Colorability: The sheet has no color unevenness and has good design after printing. It has a proper concealing property and is not affected by the base when laminated with plywood ... ○ ・ The sheet has uneven color and the design after printing is poor. Or when it is bonded to plywood, the design is poor due to the effect of the base material.
…… ×

[Primer Adhesion: A cellophane tape adhesion test is performed after applying a primer to a sheet] -The primer layer does not come to the cellophane tape side ...
… ○ ・ The primer layer is attached to the cellophane tape side ……
… ×

[Printability in Gravure Printing] [Blocking] -There is no blocking between sheets and smooth feeding from the original sheet is possible.- ○ Blocking occurs between sheets, and feeding from the original sheet is possible. Unstable ... × [Design] ・ No bleeding of ink after printing, good color development, good ink quality with no ink loss or uneven density …………………………
…… ○ ・ Printing problems such as printing bleeding after printing, ink bleeding, uneven density, etc. cannot be expressed, and printing problems occur. ×

[Adhesiveness to other base materials] -After bonding to plywood, the base material is destroyed when peeled off at the interface ...
……………… ○ ・ After being bonded to plywood, it peels without breaking the base material when peeling at the interface… ×

[0033]

[Table 1]

[0034]

[Table 2]

[0035]

The olefin resin composition of the present invention facilitates the peeling of the sheet from the calender roll during calendering to improve the surface properties of the sheet, and does not undergo oxidative deterioration due to heat, resulting in deterioration of physical properties, There is no change in color tone and color unevenness of the sheet, which enhances productivity and improves the adhesion of the primer to the sheet surface, there is no blocking between sheets, there is no ink bleeding, good color development, and excellent printability. It has excellent effects such as providing a surface-coated sheet with excellent adhesiveness to other base materials.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References Japanese Patent Laid-Open No. 9-300560 (JP, A) Japanese Patent Laid-Open No. 10-52896 (JP, A) Special Table 6-503382 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) C08L 23/00-23/36 C08K 3/00-13/08 B32B 27/00-27/42

Claims (4)

(57) [Claims] 1. Measured at 190 ° C. under a load of 2.16 kg.
Linear with a melt index of 0.1 to 10.0
1 to 50 parts by weight of inorganic filler, 0.3 to 10 parts by weight of fatty acid ester lubricant of monohydric or polyhydric alcohol, 1 to 30 parts by weight of titanium oxide and oxidation to 100 parts by weight of low density polyethylene or high density polyethylene Inhibitor 0.01
The olefin resin composition for calendering is characterized by comprising: 2. A calender molding color sheet obtained from the olefin resin composition according to claim 1. 3. The calender molded color sheet according to claim 2, wherein one or both surfaces of the calender molded color sheet have a critical surface tension of γc 34 to 54 dyn / cm. 4. A surface-coated sheet having a primer coating film having a thickness of 0.1 to 10 μm on one or both sides of the calendered color sheet according to claim 3.