CN105408402A - Cavity-containing polypropylene film - Google Patents

Abstract

The purpose of the present invention is to provide a cavity-containing polypropylene film (for use in an in-mold label or the like) that has high rigidity and a low shrinkage rate compared to PET at high temperatures. Provided is a cavity-containing polypropylene film that is a cavity-containing film configured using a polypropylene resin as a main constituent thereof and that is characterized by: having a shrinkage rate of 9.0% or less at 155 DEG C in the MD direction and the TD direction; and by having an apparent specific gravity of 0.90 or less. In a preferred embodiment, the cavity-containing polypropylene film is a multilayer film that has three or more layers and that comprises: a substrate layer (A) that contains cavities and that is configured using a polypropylene resin as a main constituent thereof; a heat-sealable resin adhesive layer (B) that has a lower melting point than the melting point of the resin of the substrate layer; and a printed layer (C).

Description

Containing hole polypropylene film

Technical field

The present invention relates to containing hole polypropylene film.More specifically, relate to the various fields going for requiring the dimensional stability under high temperature, high rigidity, and thermotolerance, mechanical characteristics excellence containing hole polypropylene film.In addition, the present invention relates to thermotolerance, mechanical characteristics excellent, be applicable to in-mold labels purposes containing hole polypropylene film.

Background technology

Generally speaking, wrapping material can consider the character such as disguise, barrier, aesthetic property according to the object/purposes of the kind of content etc., thus select suitable starting material/formation.

As the key property of wrapping material, disguise can be enumerated.As the concealed method of imparting packaging film, can enumerate: (1) prints; (2) mix, add pigment, tinting material etc.; (3) form space etc. by interpolation whipping agent, from cost, quality stability aspect, usual use (2) interpolation mineral dye, (3) be interstitial method by interpolation whipping agent.

Wherein, as space mechanism of production, representational method has: [1] by add mineral filler and in stretching process with the stripping of resin, produce the method in space thus; [2] add microcapsule and utilize heat and produce gas, producing the method in space thus; [3] add solvent-soluble substances, after masking, impregnated in solvent and soluble substance, thus interstitial method etc. are removed in melting.Wherein, the most universal in practicality is in resin, add the inorganic particles such as calcium carbonate as whipping agent, utilizes the method (for example, referring to patent documentation 1,2,3,4) of the splitting produced when stretching.

In addition, as the key property of wrapping material, importantly add the thermotolerance in man-hour.Such as, as giving the method for stopping property, have by dry lamination make sealing film fit in base material film method, encapsulant resin is layered in method etc. on substrate layer by extruding lamination.

But so-called heat-sealing heat resin and the mode sealed, therefore, if the poor heat resistance of film substrate, then can produce gauffer, skew because of thermal contraction when sealing, it is bad to produce so-called processing.Have and be laminated with in the stacked oriented film (patent documentation 5) of the foamed substrate layer of upper layer at the one side of foaming layer or two sides, although be reduced to less than 8% by making the percent thermal shrinkage at 150 DEG C, the gauffer produced because of thermal contraction when observing heat-sealing, skew improve, but not yet reach sufficient level.

In addition, in outward appearance, there is shortcoming containing hole film easily occurs to stretch uneven sometimes.And, if consider processibility, then require to improve rigidity further.

But, when with the outside attachment labels of the resin container as representative examples such as polypropylene container or polyethylene container, preferably use owing to having following multiple advantage with the in-mold labels method attached at container exterior while of container shaping: can integral adhesive and be not easy to peel off; Excellence in the designabilitys such as big area label display can realized; In addition, utilize label to improve the rigidity of container itself, the thin-walled property etc. of container can be realized thus.

In the past, as in-mold labels base material, use and have paper, synthetic paper, plastics film etc. (such as with reference to patent documentation 6, patent documentation 7, patent documentation 8 etc.)。

When plastics film, in order to implement printing, lamination process or bond processing etc., extensively implement same plastic film to be fitted each other or will the various raw-material plastic film of label formats be met and form in-mold labels.As this plastics film, from the view point of the cementability with container, mostly use the polypropylene film that its fusing point is lower.

But the shrinking percentage of existing polypropylene film at 155 DEG C is tens %, compared with PET etc., thermotolerance is low, and rigidity is also low, therefore easily produces cause by shrinking curling during printing, become the reason of bad generation, containing hole polypropylene film not separately for in-mold labels purposes.

In addition, also known mostly exist following problem in existing in-mold labels polypropylene film: shrink by producing to extend or produce to the tension force under the heating of film applying when these processing, specifically printing, therefore after being processed into label there is curling (for example, referring to patent documentation 9) in label.In in-molded, the position skew etc. time in-molded can cause the critical defect of products formed, therefore must reduce the curling of label.

In order to suppress curling, in printing processing, even exist must high frequency adjust processing conditions or identical polypropylene also to increase its thickness or the width central part product be chosen at when manufacturing polypropylene uses, carry out the restriction such as processing in limited printing condition.In addition, although also there is the thermotolerance by improving stacked oriented film to improve the technology of the curling problem of label, not yet obtain the film (for example, referring to patent documentation 10) with abundant thermotolerance.

Prior art document

Patent documentation

Patent documentation 1: Japanese Laid-Open Patent Publication 55-126056 publication

Patent documentation 2: Japanese Unexamined Patent Publication 2005-22300 publication

Patent documentation 3: Japanese Unexamined Patent Publication 1-4338 publication

Patent documentation 4: Japanese Unexamined Patent Publication 11-5852 publication

Patent documentation 5: Japanese Unexamined Patent Publication 2003-231225 publication

Patent documentation 6: Japanese Laid-Open Patent Publication 58-69015 publication

Patent documentation 7: Japanese Patent Publication 02-7814 publication

Patent documentation 8: Japanese Unexamined Patent Publication 02-84319 publication

Patent documentation 9: Japanese Unexamined Patent Publication 2005-208355 publication

Patent documentation 10: Japanese Unexamined Patent Publication 2003-231255 publication

Summary of the invention

the problem that invention will solve

The present invention completes for background with the problem of above-mentioned prior art.That is, the object of the invention is to, provide excellent heat resistance, the gauffer namely produced because of thermal contraction during such as heat-sealing, skew are few, and excellent appearance, and be high rigidity contain hole film.In addition, other object of the present invention is, provides containing hole polypropylene film, its mould relating to the contraction that can suppress when heating is interior with containing hole polypropylene film, and should be that there is the low-shrinkage of the PET that can match in excellence or beauty at 155 DEG C containing the feature of hole polypropylene film, and high rigidity.

for the scheme of dealing with problems

The present inventor etc. conduct in-depth research to achieve these goals, found that the present invention.

That is, the feature containing hole polypropylene film of the present invention is, its be using acrylic resin formed as main body containing hole film, the MD direction at 155 DEG C and the percent thermal shrinkage in TD direction are less than 9.0%, and apparent specific gravity is less than 0.90.The percent thermal shrinkage in above-mentioned MD direction at 155 DEG C and TD direction is less than 8.0% is preferred.

Of the present invention containing hole polypropylene film for the laminate film of more than 3 layers comprising substrate layer (A), heat sealability resin bonding layer (B) and printed layers (C) be suitable, wherein, substrate layer (A) is formed using acrylic resin as main body and is had the low-melting fusing point of the resin than this substrate layer containing hole, heat sealability resin bonding layer (B).The resin forming aforementioned heat sealability resin bonding layer (B) is be suitable by propylene, the random copolymer of propylene that formed with the alpha-olefin of ethene and/or carbonatoms more than 4.In addition, it is suitable that the resin forming aforementioned printed layers (C) contains the acid modified polyolefin good with the cementability of ink.

In the present invention, aforementioned film contains whipping agent is suitable.

In addition, in the present invention, the total light transmittance of aforementioned film is less than 75% is suitable, and in addition, total light transmittance is less than 40% is suitable.

In the present invention, the Young's modulus in MD direction is more than 1.6GPa, the Young's modulus in TD direction be more than 2.7GPa is suitable.

the effect of invention

Excellent heat resistance containing hole polypropylene film of the present invention, the gauffer namely produced because of thermal contraction during such as heat-sealing, skew lack, and excellent appearance, and be high rigidity.Specifically, can the match in excellence or beauty low-shrinkage of polyethylene terephthalate (PET) film, high rigidity at 155 DEG C, can be shown, and then can filming.

Therefore, not only can heat-sealing temperature be set higher, can heat seal strength be improved, but also the line speed etc. in bag processing can be increased, thus boost productivity.And then, even if also can suppress the deflection of bag when carrying out the pyroprocessing such as boiling.

And then, in a preferred embodiment of the invention, also each physical property can be maintained under exposing more than 155 DEG C environment even if of the present invention to the open air containing hole polypropylene film, therefore, even if also using with under the hot environment cannot imagined containing hole polypropylene film existing in-mold labels, purposes widely can be applied to.

Embodiment

The present invention relates to the dimensional stability under high temperature, mechanical characteristics excellence containing hole polypropylene film, if make the laminate film with specified layer stack structure, be then applicable to in-mold labels and use.Feature containing hole polypropylene film of the present invention is, its be using acrylic resin formed as main body containing hole film, the MD direction at 155 DEG C and the percent thermal shrinkage in TD direction are less than 9.0%, and apparent specific gravity is less than 0.90.

MD direction containing hole polypropylene film of the present invention is (in this specification sheets, " MD direction " refers to the length direction containing hole film, sometimes also " MD direction " is called " longitudinal direction ") the lower limit of 155 DEG C of percent thermal shrinkages be preferably 0%, be more preferably 0.5%.When 155 DEG C of percent thermal shrinkages in MD direction are above-mentioned scope, sometimes from cost aspect grade, in reality, become easy manufacture, uneven thickness diminishes.On the other hand, the upper limit of 155 DEG C of percent thermal shrinkages in MD direction be 9.0%, be preferably 8% (8.0%), be more preferably 7%, more preferably 6%, be particularly preferably 5%, most preferably be 4%.When 155 DEG C of percent thermal shrinkages in MD direction are above-mentioned scope, become easier and use may be exposed in the purposes under about 155 DEG C high temperature.

TD direction containing hole polypropylene film of the present invention is (in this specification sheets, " TD direction " refers to the width containing hole film, sometimes also " TD direction " is called " transverse direction ") 155 DEG C of percent thermal shrinkages lower limit be preferably-5%, be more preferably 0%.When 155 DEG C of percent thermal shrinkages are above-mentioned scope, sometimes from cost aspect grade, in reality, become easy manufacture, uneven thickness diminishes.On the other hand, the upper limit of 155 DEG C of percent thermal shrinkages in MD direction be 9.0%, be preferably 8% (8.0%), be more preferably 7%, more preferably 6%, be particularly preferably 5%, most preferably be 4%.When 155 DEG C of percent thermal shrinkages are above-mentioned scope, become easier and use may be exposed in the purposes under such high temperature that PET uses.It should be noted that, by increasing low molecular weight compositions, adjustment stretching condition, rigid condition, 155 DEG C of percent thermal shrinkages can be reduced further.

The lower limit of 150 DEG C of percent thermal shrinkages in the MD direction containing hole polypropylene film of the present invention is preferably 0.5%, be more preferably 1%, more preferably 1.5%, be particularly preferably 2%, most preferably be 2.5%.When 150 DEG C of percent thermal shrinkages in MD direction are above-mentioned scope, sometimes from cost aspect grade, in reality, become easy manufacture, uneven thickness diminishes.On the other hand, the upper limit of 150 DEG C of percent thermal shrinkages in MD direction be preferably 10%, be more preferably 9%, more preferably 8%, be particularly preferably 7%, most preferably be 6%.When 150 DEG C of percent thermal shrinkages in MD direction are above-mentioned scope, become easier and use may be exposed in the purposes under the high temperature of about 150 DEG C.

The lower limit of 150 DEG C of percent thermal shrinkages in the TD direction containing hole polypropylene film of the present invention is preferably-4.0%, be more preferably-3.0%, more preferably-2.0%, be particularly preferably-1.0%, most preferably be 0.0%.When 150 DEG C of percent thermal shrinkages in TD direction are above-mentioned scope, sometimes from cost aspect grade, in reality, become easy manufacture, uneven thickness diminishes.On the other hand, the upper limit of 150 DEG C of percent thermal shrinkages in TD direction be preferably 12%, be more preferably 11%, more preferably 10%, be particularly preferably 9%.When 150 DEG C of percent thermal shrinkages in TD direction are above-mentioned scope, become easier and use may be exposed in the purposes under the high temperature of about 150 DEG C.It should be noted that, if 150 DEG C of percent thermal shrinkages reach about 2.5%, then can be realized by increase low molecular weight compositions, adjustment stretching condition, rigid condition, but preferably carry out anneal with off-line when reducing percent thermal shrinkage further.But, now likely can lose foaminess.

The lower limit of the apparent specific gravity containing hole polypropylene film of the present invention is preferably 0.60g/cm ³, be more preferably 0.65g/cm ³, be more preferably 0.70g/cm ³.When apparent specific gravity is above-mentioned scope, the sufficient stiffness as film can be obtained, improve treatability.

From the aspect of reality, the upper limit of apparent specific gravity is preferably 0.90g/cm ³, be more preferably 0.85g/cm ³, more preferably 0.80g/cm ³.

Below, about forming the acrylic resin containing hole polypropylene film of the present invention (when there is the laminate film of specified layer stack structure containing hole polypropylene film, for forming containing the acrylic resin of pertusate substrate layer (A)) molecular weight distribution, melt flow rate (MFR), regularity, formation monomer, below be specifically described, but be not limited to these.

(molecular weight distribution of acrylic resin)

One of feature containing hole polypropylene film of the present invention is the molecular weight distribution state of the acrylic resin (when laminate film, being substrate layer (A)) formed.

Form the acrylic resin containing hole polypropylene film of the present invention with such as matter average molecular weight (M _w) be about 100,000 low-molecular-weight composition be main, comprise such as M further _wit is the very high high molecular weight components of molecular weight of about 1,500,000.Can think, by based on low molecular weight compositions, significantly can improve crystallinity, the high rigidity that can in the past do not had, high heat resistance containing hole polypropylene film.On the other hand, the melting tension force of low-molecular-weight acrylic resin when thermoplastic is low, usually can not form stretching foamed thin sheet.Can think: by making wherein to exist the high molecular weight components of a few % ~ tens %, can stretch, and high molecular weight components playing the effect of nucleus, improving the crystallinity of film further, thus realize the effect containing hole film of the present invention.

First the feature forming the acrylic resin containing hole polypropylene film of the present invention is that molecular weight distribution is wide.The width of general molecular weight distribution can with the matter average molecular weight (M using gel permeation chromatography (GPC) to measure _w) and number-average molecular weight (M _n) ratio (M _w/ M _n) represent.

In the present invention, M _w/ M _nlower limit be preferably 4.0.M _w/ M _nlower limit be preferably 5.5, be more preferably 6, more preferably 6.5, be particularly preferably 7, most preferably be 7.2.M _w/ M _nlower than time above-mentioned, the effect of the application such as the low heat shrinkage under high temperature cannot be obtained.On the other hand, M _w/ M _nthe upper limit be preferably 30, be more preferably 25, more preferably 20, be particularly preferably 15, most preferably be 13.M _w/ M _nwhen exceeding above-mentioned, the resin manufacture sometimes in reality becomes difficulty.

In addition, as the molecular-weight average paying attention to high molecular weight components, there is z+1 average molecular weight (the averagemolecularweight) (M using GPC to measure _z+1), according to M _z+1/ M _nthe level of molecular weight distribution can be represented more accurately.

In the present invention, M _z+1/ M _nlower limit be 20 be suitable.M _z+1/ M _nlower limit be preferably 50, be more preferably 60, more preferably 70, be particularly preferably 80, most preferably be 90.M _z+1/ M _nlower than time above-mentioned, the effect of the application such as the low heat shrinkage under high temperature cannot be obtained.On the other hand, M _z+1/ M _nthe upper limit be preferably 300, be more preferably 200.M _z+1/ M _nwhen exceeding above-mentioned, the resin manufacture sometimes in reality becomes difficulty.

The M that the use GPC forming the acrylic resin entirety containing hole polypropylene film of the present invention measures _nlower limit be preferably 20000, be more preferably 22000, more preferably 24000, be particularly preferably 26000, most preferably be 27000.M _nduring for above-mentioned scope, can obtain stretches becomes easily, draft temperature, heat fixation temperature easily improve, the advantage of percent thermal shrinkage step-down and so on.On the other hand, overall M _nthe upper limit be 70000 be suitable.Overall M _nthe upper limit be preferably 65000, be more preferably 60000, more preferably 55000, be particularly preferably 53000, most preferably be 52000.M _nduring for above-mentioned scope, become the effect of the application such as the low heat shrinkage easily obtained under high temperature that low molecular weight compositions plays, stretching becomes easy.

The M that the use GPC forming the acrylic resin entirety containing hole polypropylene film of the present invention measures _wlower limit be preferably 250000, be more preferably 260000, more preferably 270000, be particularly preferably 280000, most preferably be 290000.M _wduring for above-mentioned scope, can obtain stretches becomes easily, draft temperature, heat fixation temperature easily improve, the advantage of percent thermal shrinkage step-down and so on.On the other hand, overall M _wthe upper limit be preferably 500000, be more preferably 450000, more preferably 400000, be particularly preferably 380000, most preferably be 370000.M _wduring for above-mentioned scope, mechanical load diminishes, and stretching becomes easy.

Form the M of the acrylic resin entirety containing hole polypropylene film of the present invention _z+1lower limit be 1500000 be suitable.Overall M _z+1lower limit be preferably 2500000, be more preferably 3000000, more preferably 3300000, be particularly preferably 3500000, most preferably be 3700000.M _z+1during for above-mentioned scope, high molecular weight components is abundant, easily obtains effect of the present invention.On the other hand, overall M _z+1the upper limit be preferably 40000000, be more preferably 35000000, more preferably 30000000.M _z+1during for above-mentioned scope, in reality, easily manufacture resin, stretch become easily, flake in film tails off.

Form the peak value (M in the GPC molecular weight distribution curve of the acrylic resin containing hole polypropylene film of the present invention _p) lower limit be preferably 50000, be more preferably 60000, more preferably 70000, be particularly preferably 75000.M _pduring for above-mentioned scope, can obtain stretches becomes easily, draft temperature, heat fixation temperature easily improve, percent thermal shrinkage becomes lower and so on advantage.On the other hand, M _pthe upper limit be preferably 150000, be more preferably 130000, more preferably 120000, be particularly preferably 115000.M _pduring for above-mentioned scope, become the effect of the application such as the low heat shrinkage more easily obtained under the high temperature that plays of low molecular weight compositions, and stretch and also become easy.

When measuring the GPC integrated curve of acrylic resin entirety forming film, the lower limit of the amount of the composition of molecular weight less than 100,000 is preferably 35 quality %, is more preferably 38 quality %, more preferably 40 quality %, be particularly preferably 41 quality %, most preferably be 42 quality %.Molecular weight is the amount of the composition of less than 100,000 when being above-mentioned scope, sometimes becomes the effect of the application such as the low heat shrinkage under the effect and high temperature more easily obtaining low molecular weight compositions, stretching becomes easy.

The upper limit of the amount of the composition of molecular weight less than 100,000 is preferably 65 quality %, is more preferably 60 quality %, more preferably 58 quality %, be particularly preferably 56 quality %, most preferably be 55 quality %.

Molecular weight 10,000 is not contributed the winding between molecular chain with lower horizontal molecule, has the effect that the winding between molecule untied like that by softening agent, therefore, preferably comprises the composition of molecular weight less than 10,000 with specified quantitative.Can think and make the stretching under low tensile stress become possibility thus, as its result, unrelieved stress is also low, can reduce the shrinking percentage under high temperature.

The lower limit of the amount of the composition of molecular weight less than 10,000 is 1.0 quality % is suitable.The lower limit of the amount of the composition of molecular weight less than 10,000 is preferably 2 quality %, is more preferably 2.5 quality %, more preferably 3 quality %, be particularly preferably 3.3 quality %, most preferably be 3.5 quality %.Molecular weight is the amount of the composition of less than 10,000 when being above-mentioned scope, sometimes becomes the effect of the application such as the low heat shrinkage under the effect and high temperature more easily obtaining low molecular weight compositions, stretching becomes easy.

The upper limit of the amount of the composition of the molecular weight less than 10,000 in GPC integrated curve is preferably 20 quality %, is more preferably 17 quality %, more preferably 15 quality %, be particularly preferably 14 quality %, most preferably be 13 quality %.

Be described about the high molecular weight components and low molecular weight compositions that are applicable to be formed the acrylic resin with this weight distributing characteristic, but be not limited thereto for the method widening molecular weight distribution.

(high molecular weight components)

High molecular weight components 230 DEG C, the lower limit of melt flow rate (MFR) (MFR) that measures under 2.16kgf is preferably 0.0001g/10 minute, is more preferably 0.0005g/10 minute, more preferably 0.001g/10 minute, be particularly preferably 0.005g/10 minute.When the MFR of high molecular weight components is above-mentioned scope, in reality, easily manufacture resin, flake containing hole film can be reduced.

It should be noted that, sometimes high molecular weight components 230 DEG C, MFR under 2.16kgf is too small and mensuration in reality becomes difficulty.In this case, measure the high-load MFR under 10 times of load (21.6kgf), now, preferred lower limit be 0.1g/10 minute, be more preferably 0.5g/10 minute, more preferably 1g/10 minute, be particularly preferably 5g/10 minute.

High molecular weight components 230 DEG C, the upper limit of MFR that measures under 2.16kgf is preferably 0.5g/10 minute, is more preferably 0.35g/10 minute, more preferably 0.3g/10 minute, be particularly preferably 0.2g/10 minute, most preferably be 0.1g/10 minute.When the MFR of high molecular weight components is above-mentioned scope, in order to the amount maintaining the high molecular weight components needed for overall MFR is less, become the effect of the application such as the low heat shrinkage under the high temperature that more easily acquisition low molecular weight compositions plays.

The M of high molecular weight components _wlower limit be preferably 500000, be more preferably 600000, more preferably 700000, be particularly preferably 800000, most preferably be 1000000.The M of high molecular weight components _wduring for above-mentioned scope, in order to the amount maintaining the high molecular weight components needed for overall MFR is less, become the effect of the application such as the low heat shrinkage under the high temperature that more easily acquisition low molecular weight compositions plays.On the other hand, the M of high molecular weight components _wthe upper limit be preferably 10000000, be more preferably 8000000, more preferably 6000000, be particularly preferably 5000000.The M of high molecular weight components _wduring for above-mentioned scope, in reality, easily manufacture resin, flake containing hole film can be reduced.

In acrylic resin 100 quality %, the lower limit of the amount of high molecular weight components is preferably 2 quality %, is more preferably 3 quality %, more preferably 4 quality %, be particularly preferably 5 quality %.When the amount of high molecular weight components is above-mentioned scope, not needing the molecular weight improving low molecular weight compositions in order to maintain overall MFR, becoming the effect of the application such as the low heat shrinkage more easily obtained under high temperature.On the other hand, in acrylic resin 100 quality %, the upper limit of the amount of high molecular weight components is preferably 30 quality %, is more preferably 25 quality %, more preferably 22 quality %, be particularly preferably 20 quality %.When the amount of high molecular weight components is above-mentioned scope, become the effect of the application such as the low heat shrinkage more easily obtained under the high temperature that plays of low molecular weight compositions.

(low molecular weight compositions)

Low molecular weight compositions 230 DEG C, the lower limit of MFR that measures under 2.16kgf is preferably 70g/10 minute, is more preferably 80g/10 minute, more preferably 100g/10 minute, be particularly preferably 150g/10 minute, most preferably be 200g/10 minute.When the MFR of low molecular weight compositions is above-mentioned scope, crystallinity becomes good, becomes the effect of the application such as the low heat shrinkage more easily obtained under high temperature.On the other hand, low molecular weight compositions 230 DEG C, the upper limit of MFR that measures under 2.16kgf is preferably 2000g/10 minute, is more preferably 1800g/10 minute, more preferably 1600g/10 minute, be particularly preferably 1500g/10 minute, most preferably be 1400g/10 minute.When the MFR of low molecular weight compositions is above-mentioned scope, become and easily maintain overall MFR, and film-forming properties is excellent.

The M of low molecular weight compositions _wlower limit be preferably 50000, be more preferably 53000, more preferably 55000, be particularly preferably 60000, most preferably be 70000.The M of low molecular weight compositions _wduring for above-mentioned scope, become and easily maintain overall MFR, and film-forming properties is excellent.On the other hand, the M of low molecular weight compositions _wthe upper limit be preferably 150000, be more preferably 140000, more preferably 130000, be particularly preferably 120000, most preferably be 110000.The M of low molecular weight compositions _wduring for above-mentioned scope, crystallinity becomes good, becomes the effect of the application such as the low heat shrinkage more easily obtained under high temperature.

In acrylic resin 100 quality %, the lower limit of the amount of low molecular weight compositions is preferably 35 quality %, is more preferably 40 quality %, more preferably 50 quality %, be particularly preferably 55 quality %, most preferably be 60 quality %.When the amount of low molecular weight compositions is above-mentioned scope, become the effect of the application such as the low heat shrinkage more easily obtained under the high temperature that plays of low molecular weight compositions.On the other hand, in acrylic resin 100 quality %, the upper limit of the amount of low molecular weight compositions is preferably 98 quality %, is more preferably 97 quality %, more preferably 96 quality %, be particularly preferably 95 quality %.When the amount of low molecular weight compositions is above-mentioned scope, not needing the molecular weight improving low molecular weight compositions in order to maintain overall MFR, becoming the effect of the application such as the low heat shrinkage more easily obtained under high temperature.

The lower limit of the ratio of the MFR (g/10 minute) of MFR (g/10 minute)/high molecular weight components of the low molecular weight compositions in acrylic resin is preferably 500, be more preferably 1000, more preferably 2000, be particularly preferably 4000.When the ratio of the MFR (g/10 minute) of MFR (g/10 minute)/high molecular weight components of low molecular weight compositions is above-mentioned scope, become the effect of the application such as the low heat shrinkage more easily obtained under high temperature.On the other hand, the upper limit of the ratio of the MFR of the MFR/ high molecular weight components of low molecular weight compositions is preferably 1000000.

High molecular weight components, low molecular weight compositions also can for being equivalent to the mixture of two or more resin of respective composition, and now, the preferable range of the amount of above-mentioned each composition is the total amount of two or more resin.

In addition, the acrylic resin in the present invention also can in order to adjust the MFR of acrylic resin entirety and composition containing the molecular weight had except above-mentioned high molecular weight components, low molecular weight compositions, such as, can enumerate: M _wlower limit more than 150000, M _wthe upper limit lower than 500000 middle-molecular-weihydroxyethyl composition.Acrylic resin in the present invention also can be only made up of middle-molecular-weihydroxyethyl composition.In addition, in order to make the winding of molecular chain easily untie and regulate stretchiness etc., can also containing below the molecular weight of low molecular weight compositions, particularly molecular weight M _wbe below about 30,000 and then molecular weight M _wit is the acrylic resin below about 10,000.

In order to use high molecular weight components, low molecular weight compositions forms the molecular weight distribution state of preferred acrylic resin, preferably, such as when the molecular weight of low molecular weight compositions is low, the molecular weight of raising high molecular weight components, the amount etc. of increase high molecular weight components adjust distribution, and are adjusted to the MFR easily manufacturing stretching foamed thin sheet.

(melt flow rate (MFR) of acrylic resin)

Importantly, form the acrylic resin containing hole polypropylene film of the present invention overall 230 DEG C, the lower limit of MFR that measures under 2.16kgf is 1g/10 minute.The lower limit of overall MFR is preferably 1.2g/10 minute, is more preferably 1.4g/10 minute, more preferably 1.5g/10 minute, be particularly preferably 1.6g/10 minute.When overall MFR is above-mentioned scope, mechanical load diminishes, and stretching becomes easy.On the other hand, the upper limit of overall MFR is preferably 20g/10 minute, is more preferably 17g/10 minute, more preferably 15g/10 minute, be particularly preferably 14g/10 minute, most preferably be 13g/10 minute.When overall MFR is above-mentioned scope, stretch and become easy, or uneven thickness diminishes, or draft temperature, heat fixation temperature easily improve, percent thermal shrinkage becomes lower.

(regularity of acrylic resin)

It is suitable that the lower limit forming isotaxy five unit component (mesopentadfraction) rate ([mmmm] %) of the acrylic resin containing hole polypropylene film of the present invention is preferably 96%.The lower limit of isotaxy five unit composition ratio number ([mmmm] %) is preferably 96.5%, is more preferably 97%.When isotaxy five unit composition ratio is above-mentioned scope, crystallinity improves, and the percent thermal shrinkage under high temperature can be suppressed lower.The upper limit of isotaxy five unit composition ratio is preferably 99.5%, is more preferably 99.3%, more preferably 99%.When isotaxy five unit composition ratio is above-mentioned scope, in reality, become easy manufacture.

Preferably, the heterogeneous combination less than forming the acrylic resin containing hole polypropylene film of the present invention is confirmed.It should be noted that, confirmation is herein less than referring to use ¹³c-NMR does not observe peak.

The lower limit forming the isotaxy mean chain length (mesoaveragechainlength) of the acrylic resin containing hole polypropylene film of the present invention is preferably 100, is more preferably 120, more preferably 130.When isotaxy mean chain length is above-mentioned scope, crystallinity improves, and the percent thermal shrinkage under high temperature diminishes.On the other hand, from the aspect of reality, the upper limit of isotaxy mean chain length is preferably 5000.

From the aspect of reality, the lower limit forming the xylene soluble component of the acrylic resin containing hole film is preferably 0.1 quality %.On the other hand, the upper limit of xylene soluble component be preferably 7 quality %, be more preferably 6 quality %, more preferably 5 quality %.When xylene soluble component is above-mentioned scope, crystallinity improves, and the percent thermal shrinkage under high temperature diminishes.

(the formation monomer of acrylic resin)

Forming the acrylic resin containing hole polypropylene film of the present invention and most preferably be the homo-polypropylene completely only obtained by propylene monomer, if comonomer is trace, also can be the multipolymer with comonomer.As comonomer type, the alkene such as optimal ethylene, butylene.

Importantly, the upper limit of the amount of comonomers except propylene in acrylic resin is 0.1mol%.The upper limit of amount of comonomers is preferably 0.05mol%, is more preferably 0.01mol%.When amount of comonomers is above-mentioned scope, crystallinity improves, and the percent thermal shrinkage under high temperature diminishes.

It should be noted that, in the past, for containing hole polypropylene film, because the crystallinity of homo-polypropylene is completely high, that the condition and range that rear melting tension force descends degradation to stretch fast is softened in melting is very narrow, therefore be industrially difficult to masking, usually add the copolymer composition (mainly ethene) of about 0.5%.But, as long as the acrylic resin of molecular weight distribution state as described above, though hardly containing or completely not containing copolymer composition, melting soften after tension force reduce also steady, industrial stretching becomes possibility.

Namely, can think, in the present invention, by using the acrylic resin with the molecular weight distribution of feature as described above as the base resin containing hole film, the polypropylene using low molecular weight compositions as main body that in the past cannot fully stretch can be used to carry out stretching foaming, and, higher heat fixation temperature can be adopted, high crystalline can be utilized, synergy that heat-flash is fixed to be to reduce the percent thermal shrinkage under high temperature.

(manufacture method of acrylic resin)

Above-mentioned acrylic resin uses the known catalyzer such as Ziegler-Natta catalyst, metallocene catalyst to make to obtain as the propylene polymerization of raw material.Wherein, in order to eliminate heterogeneous combination, be preferably Ziegler-Natta catalyst, and preferably use the catalyzer that can carry out the high polymerization of taxis.

As the polymerization process of propylene, known method can be utilized, can enumerate: in the non-active solvents such as hexane, heptane, toluene, dimethylbenzene, carry out the method for being polymerized; The method of being polymerized is carried out in the propylene, ethene of liquid state; In gaseous propylene, ethene, add catalyzer and under gas phase state, carry out the method for being polymerized; Or their combinations are carried out the method etc. of being polymerized.

High molecular weight components, low molecular weight compositions can be made to be polymerized rear mixing respectively, also can be used in a series of equipment with staged reactor and to be polymerized with multistage.Particularly preferably be, use the equipment with staged reactor, first high molecular weight components is polymerized, then in the presence by the method for low molecular weight compositions polymerization.It should be noted that, the amount being mixed in the hydrogen in system during polymerization can be utilized to carry out the adjustment of molecular weight.

(whipping agent)

The hole polypropylene film that contains of the present invention is using above-mentioned acrylic resin as main component, and in order to form hole, adding whipping agent is preferred method.

For of the present invention containing hole film, as whipping agent, be preferably the organic system fillers such as the inorganic system such as calcium carbonate, silicon-dioxide filler, polymethyl acrylate.Be particularly preferably calcium carbonate.Can also implement various surface treatment to these filling surfaces, and these fillers are except can be used alone, two or more can also be combinationally used.

In addition, lower limit containing the compounding content of (when laminate film, in substrate layer (A)) whipping agent in hole polypropylene film is preferably 0.1 quality %, is more preferably 0.3 quality %, more preferably 5 quality %, be particularly preferably 10 quality %.The upper limit of the compounding content of whipping agent is preferably 20 quality %, is more preferably 15 quality %.Whipping agent lower than 0.1 % by weight time, cannot obtain good foaming, hiddenly become difficulty, hole content is also few, and therefore, resiliency reduces.The compounding content of whipping agent more than 20 % by weight time, following problem can be produced: often rupture during foamed thin sheet film forming, often occur foreign matter, and surface appearance inferior, and too high as the voidage containing hole film physical property, interlaminar strength variation etc.As the particle diameter of whipping agent, be preferably 0.5 μm ~ 10 μm, be more preferably 1 μm ~ 10 μm, more preferably 1.0 μm ~ 5 μm, be particularly preferably 1.5 μm ~ 5 μm.When being less than 0.5 μm (especially lower than 0.5 μm), being not easy to produce space, when being more than 10 μm (especially more than 10 μm), the bad order caused because of aggregation can being produced.The median size measured utilizes MicrotracHRAX-100 to implement.

(masking agent)

When of the present invention containing in hole film (at laminate film, being substrate layer (A)), the subparticle of compounding inanimate matter or organic matter disguise can also be increased to make it.As inanimate matter subparticle, can enumerate: titanium dioxide, Tungsten oxide 99.999, silicon-dioxide, zeolite etc., from cost, effect, be particularly preferably titanium dioxide.No matter the shape kind of these subparticles can be spherical, Elliptical round shape, coniform, amorphous, its particle diameter can according to using containing the purposes of hole film, using method, the subparticle of compounding required particle diameter.

In addition, also can implement various surface treatment to these inanimate matter subparticle surfaces, in addition, two or more, except can be used alone, can also combinationally use by these subparticles.In addition, as particle diameter, be preferably 150nm ~ 500nm, be particularly preferably 200nm ~ 400nm.During for below 200nm (especially lower than 150nm), be not easy to play hidden effect, during for more than 500nm (especially more than 500nm), have generation pit (flake) etc. bad.Particle diameter MicrotracHRAX-100 measures.

(additive)

In addition, additive, other resin can be added as required.As additive, such as, can enumerate: antioxidant, UV light absorber, static inhibitor, lubricant, nucleator, tackiness agent, antifogging agent, fire retardant, anti blocking agent, inorganic filler or organic filler etc.

As other resin, can enumerate: except the acrylic resin except the specific acrylic resin used in the present invention; As the random copolymers (random copolymers etc.) of the multipolymer of the alpha-olefin of propylene and ethene and/or carbonatoms more than 4; Various elastomericss etc.

When containing hole film forming with resin combination (at laminate film, for substrate layer A molding resin composition) in 100 mass parts, the addition of additive is preferably below 50 mass parts (being more preferably below 5 mass parts), containing hole film forming with in resin combination 100 mass parts, the addition of other resin is preferably below 80 mass parts (being more preferably below 50 mass parts).They can mix with acrylic resin Henschel mixer etc. or will the standby masterbatch pellet polypropylene of melting mixing mechanism be used in advance to dilute to make it reach normality or be used by total amount melting mixing in advance.

By using the resin combination using acrylic resin as above as main body, the polypropylene using low molecular weight compositions as main body that in the past cannot fully stretch can be stretched, and higher heat fixation temperature can be adopted, high crystalline can be utilized, synergy that heat-flash is fixed and percent thermal shrinkage under reducing high temperature.

In addition, because crystallinity is high, therefore interpolation whipping agent (such as mineral filler) and when stretching and the peeling force of resin uprise, the efficiency making space produce thus becomes good, because the surface-area at interface, space increases, therefore demonstrate highly concealed type.In addition, though due under higher heat fixation space be also difficult to destroy, therefore, excellent disguise can be had when maintaining thermotolerance.In this case, in order to the disguise that the polypropylene maintained with used is identical in the past, equal disguise can be shown with less foaming dosage.The foamed thin sheet that apparent specific gravity is also lower can be obtained.

In addition, the present invention also comprises following containing hole polypropylene film, and described is comprise to be formed using above-mentioned acrylic resin as main body and containing the laminate film of more than 3 layers of pertusate substrate layer (A), following heat sealability resin bonding layer (B) and printed layers (C) containing hole polypropylene film.

(heat sealability resin bonding layer (B))

In addition, in the present invention, resin for heat sealability resin bonding layer (B) is preferably the thermoplastic resin of fusing point less than 150 DEG C, be preferably propylene, be polymerized with ethene and/or more than a kind of being selected from the alpha-olefin system monomer of the carbonatomss such as butylene, amylene, hexene, octene, decene 4 ~ 10 and the random copolymers that obtains, in addition, the multipolymer that difference forms can be used alone or used in combination.

And then it is desirable for making the fusing point of the thermoplastic resin of formation heat sealability resin bonding layer (B) be less than 150 DEG C, being preferably 60 DEG C ~ 150 DEG C.Thus, sufficient heat seal strength can be given to heat-sealable laminated polypropylene based resin film.When the fusing point of the thermoplastic resin of formation heat sealability resin bonding layer (B) is lower than 60 DEG C, the thermotolerance in heat-sealing portion is not enough, during more than 150 DEG C, cannot expect the raising of heat seal strength.

In addition, MFR can the scope of example 0.1 ~ 100g/10 minute, preferably 0.5 ~ 20g/10 minute, more preferably 1.0 ~ 10g/10 minute.

In addition, be not particularly limited the thickness of heat sealability resin bonding layer (B), from the view point of cementability, cost, it is desirable that the thickness of heat sealability resin bonding layer (B) is set to 0.5 ~ 5 μm.

And then, can also adopt and embossed pattern is imposed to heat sealability resin bonding layer (B), the method that air when making in-molded between container and label easily disengages and bubbles as reply.

In addition, in heat sealability resin bonding layer (B), the additive such as static inhibitor, lubricant can be added as required.

(printed layers (C))

For the printing in printed layers (C), implement the printings such as intaglio printing, offset printing, flexible printing, silk screen printing, sealing printing, printed bar code, manufacturers, sales company's title, feature, trade name, using method, scale etc.In addition, in the present invention, be not particularly limited its raw material etc., printed layers (C) is preferred containing acid modified polyolefin.Recommending such as bond layer to contain and the unsaturated carboxylic acids such as polyolefin polymkeric substance (methyl) vinylformic acid, toxilic acid, maleic anhydride, fumaric acid are carried out modification and the acid modified polyolefin obtained, particularly preferably using the material of the graft copolymer obtained containing making the toxilic acid of 0.01 ~ 5 % by mole or maleic anhydride and olefinic polymerization graft copolymers as printed layers.

In addition, be not particularly limited the thickness of printed layers (C), from the view point of black cementability, cost, it is desirable that the thickness of printed layers (C) is set to 0.5 ~ 5 μm.In addition, in printed layers (C), the additive such as static inhibitor, lubricant can be added as required.

And then, the one-tenth of printed layers (C) is grouped into and is not particularly limited, can be appropriately combined as required.

Below, the manufacture method of the biaxial stretch-formed successively foamed thin sheet of the longitudinal stretching-cross directional stretch as more preferred example is described.

First, make acrylic resin and whipping agent heating and melting with single screw extrusion machine or twin screw extruder, be extruded on cooling roller and obtain non-stretched film.When melt extruding, preferably, such as, resin temperature is set to 200 DEG C ~ 280 DEG C, utilizes T mould to be extruded into sheet, carry out cooling curing with the cooling roller of 10 DEG C ~ 100 DEG C of temperature.Then, preferably, such as use the draw roll of 120 DEG C ~ 165 DEG C that film is stretched to 3 ~ 8 times along length (MD) direction, continue at the temperature of 150 DEG C ~ 180 DEG C (preferably 155 DEG C ~ 180 DEG C), to be stretched to 4 ~ 20 times along width (TD) direction.And then preferably, that allows 1 ~ 15% under the atmosphere temperature of preferably 165 DEG C ~ 178 DEG C (preferably 165 DEG C ~ 175 DEG C) laxly implements thermal treatment.In addition, at least can implement Corona discharge Treatment to one side, then, reel with up-coiler, can obtain thus rolling up sample.

When of the present invention containing hole polypropylene film be laminate film, can manufacture by the following method: use known method will by laminated substrate layer (A), heat sealability resin bonding layer (B) and printed layers (C) and obtain containing hole film forming resin combination filming, and the non-stretched film obtained is carried out stretching foaming, wherein, described substrate layer (A) is containing the wide acrylic resin of molecular weight distribution, described heat sealability resin bonding layer (B) is by propylene, with the alpha-olefin copolymer of ethene and/or carbonatoms 4 ~ 10 and the random copolymers obtained, described printed layers (C) is containing acid modified polyolefin.Even if it is also lower containing hole film to obtain under existing 150 DEG C ~ about 155 DEG C of cannot imagine containing hole polypropylene film percent thermal shrinkage.

Namely, the first forcing machine is utilized to be melt extruded by substrate layer (A), the second forcing machine is utilized to be melt extruded by heat sealability resin bonding layer (B), the 3rd forcing machine is utilized printed layers (C) to be melt extruded, in T mould, with become printed layers (C), substrate layer (A), heat sealability resin bonding layer (B) mode carry out stacked, carry out cooling curing with cooling roller and obtain non-stretched sheet.As melt extruding condition, making resin temperature be 200 DEG C ~ 280 DEG C, utilizing T mould to extrude as sheet, carrying out cooling curing with the cooling roller of 10 DEG C ~ 100 DEG C of temperature.Then, with the draw rolls of 120 DEG C ~ 165 DEG C, film is stretched to 3 ~ 8 times (preferably 3 ~ 7 times) along length (MD) direction, continues at the temperature of 150 DEG C ~ 180 DEG C (preferably 155 DEG C ~ 180 DEG C, more preferably 155 DEG C ~ 175 DEG C, further preferably 158 DEG C ~ 170 DEG C), to carry out 4 ~ 20 times (preferably 6 ~ 12 times) along width (TD) direction and stretch.

And then that allows 1 ~ 15% under the atmosphere temperature of 165 DEG C ~ 178 DEG C (preferably 165 DEG C ~ 175 DEG C, more preferably 166 DEG C ~ 173 DEG C) laxly implements thermal treatment.

After Corona discharge Treatment is implemented at least one side of the polypropylene film so obtained, reel with up-coiler, can obtain thus rolling up sample.

Manufacture of the present invention containing hole polypropylene film time, the lower limit of the stretching ratio in MD direction is preferably 3 times, is more preferably 3.5 times.The stretching ratio in MD direction, lower than time above-mentioned, becomes thickness inequality sometimes.On the other hand, the upper limit of the stretching ratio in MD direction is preferably 8 times, is more preferably 7 times.When the stretching ratio in MD direction exceedes above-mentioned, be sometimes difficult to the stretching proceeding TD direction.

The lower limit of the draft temperature of MD is preferably 120 DEG C, is more preferably 125 DEG C, more preferably 130 DEG C.The draft temperature of MD is lower than time above-mentioned, and mechanical load becomes large sometimes, uneven thickness becomes large, produce coarse containing the surface of hole film.

The upper limit of the draft temperature of MD is preferably 165 DEG C, is more preferably 160 DEG C, more preferably 155 DEG C, is particularly preferably 150 DEG C.When temperature is higher, be preferred to reduction percent thermal shrinkage, but be attached to roller sometimes and become cannot carry out stretching, space is destroyed and bubbling efficiency reduces and loses disguise.

The lower limit of the stretching ratio in TD direction is preferably 4 times, is more preferably 5 times, more preferably 6 times.The stretching ratio in TD direction, lower than time above-mentioned, becomes uneven thickness sometimes.On the other hand, the upper limit of TD direction stretching ratio is preferably 20 times, is more preferably 17 times, more preferably 15 times, is particularly preferably 12 times.When the stretching ratio in TD direction exceedes above-mentioned, percent thermal shrinkage uprises, ruptures when stretching sometimes.

When carrying out the stretching in TD direction, preferably carry out preheating, in order to rapidly film temperature is increased near draft temperature, preferably preheating temperature be set higher than draft temperature 10 DEG C ~ 15 DEG C.

Being stretching in of TD direction is carried out containing under hole polypropylene film higher temperature than existing.The lower limit of the draft temperature in TD direction is preferably 150 DEG C, is more preferably 155 DEG C, more preferably 157 DEG C, is particularly preferably 158 DEG C.The draft temperature in TD direction lower than time above-mentioned, sometimes cannot fully soften and rupture, percent thermal shrinkage uprises.On the other hand, the upper limit of the draft temperature in TD direction is preferably 180 DEG C.The upper limit of the draft temperature in TD direction is preferably 175 DEG C, is more preferably 170 DEG C, more preferably 168 DEG C, is particularly preferably 166 DEG C, most preferably is 163 DEG C.In order to reduce percent thermal shrinkage, preferable temperature is higher, but when exceeding above-mentioned, sometimes low molecular weight compositions melt, recrystallization and surface produce coarse, space destroyed and bubbling efficiency reduces and loses disguise.

Foamed thin sheet after stretching preferably carries out heat fixation.Heat fixation can carry out under than existing expanded polypropylene film higher temperature.The lower limit of heat fixation temperature is preferably 165 DEG C, is more preferably 166 DEG C, more preferably 168 DEG C.Heat fixation temperature is lower than time above-mentioned, and percent thermal shrinkage uprises sometimes.In addition, need the long period to reduce percent thermal shrinkage, productivity is poor sometimes.On the other hand, the upper limit of heat fixation temperature is preferably 178 DEG C, is more preferably 175 DEG C, more preferably 173 DEG C.When heat fixation temperature exceedes above-mentioned, low molecular weight compositions melts sometimes, recrystallization and surface produce that coarse, space is destroyed and bubbling efficiency reduces and loses disguise.

During heat fixation, preferably carry out relax (mitigation).Lax lower limit is preferably 1%, be more preferably 2%, more preferably 3%, be particularly preferably 4%, most preferably be 5%.Lax lower than time above-mentioned, percent thermal shrinkage uprises sometimes.On the other hand, the lax upper limit is preferably 15%, is more preferably 10%, more preferably 8%.Lax when exceeding above-mentioned, uneven thickness becomes large sometimes.

Thickness containing hole film sets according to each purposes, and the lower limit containing hole film thickness is preferably 3 μm, is more preferably 5 μm, more preferably 8 μm.If periodically record the preferred value of the upper limit of film thickness, then it is 300 μm, 250 μm, 230 μm, 210 μm, 200 μm, 190 μm, 170 μm, 150 μm, 100 μm.

The lower limit of the fusing point (measuring method according to embodiment) containing hole polypropylene film of the present invention is preferably 168 DEG C, is more preferably 169 DEG C.When fusing point is above-mentioned scope, the percent thermal shrinkage under high temperature diminishes.On the other hand, the upper limit of fusing point is preferably 180 DEG C, is more preferably 177 DEG C, more preferably 175 DEG C.During for above-mentioned scope, in reality, become easy manufacture.By the amount of comonomers that reduces in acrylic resin or be 0 quality %, improve isotaxy five unit composition ratio, reduce normal temperature xylene soluble component, increase low molecular weight compositions, draft temperature, heat fixation temperature are set as the methods such as high temperature, can make fusing point in above-mentioned scope.

Of the present invention when being biaxial stretch-formed foamed thin sheet containing hole polypropylene film, the lower limit of the Young's modulus in the MD direction at 23 DEG C is preferably 1.3GPa, is more preferably 1.4GPa, more preferably 1.5GPa, be particularly preferably 1.6GPa.The upper limit of the Young's modulus in MD direction is not particularly limited, and is preferably 2.6GPa, is more preferably 2.5GPa, more preferably 2.4GPa, is particularly preferably 2.3GPa.When the Young's modulus in MD direction is above-mentioned scope, easily manufacture in reality, MD-TD balance are well.

Of the present invention when being biaxial stretch-formed foamed thin sheet containing hole polypropylene film, the lower limit of the Young's modulus in the TD direction at 23 DEG C is preferably 2.4GPa, is more preferably 2.5GPa, more preferably 2.6GPa, be particularly preferably 2.7GPa.The upper limit of the Young's modulus in TD direction is not particularly limited, and is preferably 4.5GPa, is more preferably 4.4GPa, more preferably 4.3GPa.When the Young's modulus in TD direction is above-mentioned scope, easily manufacture in reality, MD-TD balance are well.

It should be noted that, Young's modulus can be improved by improving stretching ratio, when MD-TD stretches, by setting lower by MD stretching ratio and improving TD stretching ratio, the Young's modulus in TD direction can be increased.

For the total light transmittance containing hole polypropylene film of the present invention, as reality value, lower limit is not particularly limited, be preferably 0%, be more preferably 5%, more preferably 10%, be particularly preferably 15%.The upper limit of total light transmittance is 75% is suitable.The upper limit of total light transmittance is preferably 70%, be more preferably 65%, more preferably 40%, be particularly preferably 35%, most preferably be 30%.When total light transmittance is above-mentioned scope, sometimes becomes and easily requiring to use in concealed purposes.Such as, when draft temperature, heat fixation temperature are too high, total light transmittance has the tendency of variation, making total light transmittance in above-mentioned scope, also can adjust the amount of masking agent by regulating these conditions.

Acquisition like this be the volume of width 2000 ~ 12000mm, length about 1000 ~ 50000m containing the usual masking of hole polypropylene film, and be wound as web-like.And then, cut according to each purposes, formed width 300 ~ 2000mm, length about 500 ~ 5000m cut volume for.

Of the present invention have the excellent specific property in the past do not had as above containing hole polypropylene film.

When for packaging film, owing to being high rigidity, therefore, it is possible to sheet, can to reduce costs, lightweight.In addition, because thermotolerance containing hole polypropylene film of the present invention, rigidity are high, therefore curling less, be suitable for and make in-mold labels, moreover, but also can expect without the need in order to prevent the curling and film that uses thickness thicker or not need to use intermediates, as the superiority such as cost reduction of label.

The application goes out No. 2013-152975th, hope and Japanese Patent based on the Japanese Patent that on July 23rd, 2013 files an application and goes out No. 2013-152978th, hope and the Japanese Patent of filing an application on July 29th, 2013 No. 2013-157055th, hope and Japanese Patent goes out hope 2013-157048 CLAIM OF PRIORITY.The application quotes aforementioned Japanese Patent and goes out the full content of the specification sheets of hope No. 2013-152975, No. 2013-152978, No. 2013-157055 and No. 2013-157048 as a reference.

Embodiment

Below, list embodiment and comparative example further illustrates the present invention, but the present invention is not by the restriction of following examples etc., also can carry out suitably change and implement in the scope that can meet above-mentioned/following purport, they are all included in technical scope of the present invention.

It should be noted that, the measuring method of the physical property in following examples, comparative example is as described below.

1) melt flow rate (MFR) (MFR, g/10 minute)

According to JISK7210, measure at temperature 230 DEG C.

2) molecular weight and molecualr weight distribution

Molecular weight and molecualr weight distribution uses gel permeation chromatography (GPC) and obtains according to monodisperse polystyrene benchmark.

The post (column) used during GPC measures, solvent are as described below.

Solvent: 1,2,4-trichlorobenzene

Post: TSKgelGMH _hR-H (20) HT × 3

Flow: 1.0ml/ minute

Detector: RI

Measure temperature: 140 DEG C

Number-average molecular weight (M _n), matter average molecular weight (M _w), z+1 average molecular weight (M _z+1) utilize the molecular weight (M of each stripping position of the GPC curve obtained by molecular weight calibration curve respectively _i) molecule number (N _i) define with following formula.

Number-average molecular weight: M _n=Σ (N _im _i)/Σ N _i

Matter average molecular weight: M _w=Σ (N _im _i ²)/Σ (N _im _i)

(Z+1)-average molecular weight: M _z+1=Σ (N _im _i ⁴)/Σ (N _im _i ³)

Molecular weight distribution: M _w/ M _n, M _z+1/ M _n

In addition, the molecular weight of the peak position of GPC curve is set to M _p.

When baseline is indefinite, until set baseline in scope closest to the extreme lower position in the Plain of the high molecular side at the stripping peak of the high molecular side at the stripping peak of reference material.

Based on the GPC curve obtained, more than 2 compositions different to molecular weight carry out peak separation.The molecular weight distribution of each composition is assumed to be Gaussian function, is set to M in the mode same with common polyacrylic molecular weight distribution _w/ M _n=4.By each molecular-weight average of curve calculation of each composition obtained.

3) taxis

The mensuration of isotaxy five unit composition ratio ([mmmm] %) and isotaxy mean chain length uses ¹³c-NMR carries out.The method that isotaxy five unit composition ratio is recorded according to Zambelli etc., Macromolecules, the 6th volume, 925 pages (1973) calculates, isotaxy mean chain length according to J.C.Randall " PolymerSequenceDistribution " the 2nd the method recorded of chapter (1977) (AcademicPress, NewYork) calculate.

¹³c-NMR measures " AVANCE500 " that use BRUKERCO., LTD to manufacture, makes sample 200mg be dissolved in the mixed solution of 8:2 (volume ratio) of orthodichlorobenzene and deuterated benzene at 135 DEG C, implements to measure at 110 DEG C.

4) cold xylene soluble fractions (CXS) (quality %)

Polypropylene plaques 1g to be dissolved in the dimethylbenzene 200ml of boiling and after naturally cooling, to make its recrystallization 1 hour in the Water Tank with Temp.-controlled of 20 DEG C, the ratio of relative for the quality being dissolved in filtered liquid original sample amount is set to CXS (quality %).

5) fusing point (Tmp, DEG C)

The differential scanning calorimeter DSC-60 using Shimadzu Seisakusho Ltd. to manufacture carries out heat determination.Cut out 5mg sample from containing hole film and be sealed in mensuration aluminium dish.With the ratio of 20 DEG C/min from room temperature to 230 DEG C, using the melting endotherm peak temperature of sample as Tmp.

6) percent thermal shrinkage (%)

Measure according to JISZ1712.

Will containing hole film along MD direction, TD direction respectively with width 20mm and length 200mm cut, hang in hot-air oven heat 5 minutes.Measure the length after heating, the ratio according to the relative original length of length after contraction obtains percent thermal shrinkage.

7) Young's modulus (unit: GPa)

According to JISK7127, at 23 DEG C, measure the Young's modulus of MD and TD.

8) uneven thickness

Cut out from the hole film rolling that contains of winding the foursquare sample that the length of side is 1m, carry out 10 deciles respectively along MD direction and TD direction, thus prepare 100 test samples.The thickness of contact film thickness gauge to the substantially central portion of test sample is used to measure.

Obtain the mean value of 100 data obtained, in addition, obtain the difference (absolute value) of minimum value and maximum value, the value that the absolute value of the difference of minimum value and maximum value obtains divided by mean value is set to the uneven thickness containing hole film.(in table 3, table 5, showing for " thickness evenness (%) ").

9) total light transmittance (unit: %)

Measure according to JISK7375.

10) apparent specific gravity (g/cm ³)

Sample is cut into the size of 280mm × 400mm, use chemical balance gravimetry.Then thickness is measured with dial gauge.These results measured are substituted in following formula (1) and calculates.

Apparent specific gravity (g/cm ³)=weight (g)/(area (cm ²) × thickness (μm)) (1)

11) containing hole film appearance

After biaxial stretch-formed by luminescent lamp fluoroscopic observation 1 containing hole film time, be set to zero by what do not observe the uneven scope that stretches containing hole film, can observe the uneven scope that stretches containing hole film be set to ×.

12) outward appearance is sealed

What tensionless winkler foundation polypropylene P1128 (40 μm) dry lamination utilizing sealing agent Japan to be spun Co., Ltd.'s manufacture was recorded in embodiment obtains duplexer containing on hole film, make 2 duplexers overlapping together toward each other with sealing agent, use TESTERSANGYOCO, .LTD. the TestSealer manufactured, carries out heat-sealing in 1 minute at 160 DEG C.For laminate film, contain hole film overlay by 2 each other by heat sealability resin bonding layer (B), the TestSealer using TESTERSANGYOCO .LTD. to manufacture, at 160 DEG C, carry out heat-sealing in 1 minute.The degree of the appearance change caused because of the contraction containing hole film after being sealed by visual assessment.The sample of scope that is little for the deflection in heat-sealing portion, that do not affect use is set to zero; Be set to causing shrinking the sample large, deflection is large because of heat-sealing ×.

13) film-forming properties

The state that the film in latter 30 minutes that stretched by TD does not rupture is set to zero, the state of fracture 1 time is set to △, the state of fracture more than 2 times be set to ×.

14) amount of curl

For crimp height, the curling internal surface containing hole film is left standstill upward, keep, after 5 minutes, measuring the height of label ends at 155 DEG C.

(embodiment 1-1)

As the acrylic resin formed containing hole film, use M _w/ M _n=8.9, M _z+1/ M _n=110, the alfon " HU300 " (SAMSUNGTOTALPETROCHEMICALSCO., LTD manufacture) (PP-1) of MFR=3.0, [mmmm]=97.1%.By the PP-1 of 91 % by weight, the titania masterbatch (" 7862W " that the smart machine of large Japan of Co., Ltd. manufactures) (MB-T) containing calcium carbonate masterbatch (MB-1) and 4 % by weight of 5 % by weight carries out dry type mixing, wherein, the described calcium carbonate (" PO150B-10 " that standby northern efflorescence Industrial Co., Ltd manufactures) comprising the PP-1 and 50 % by weight of 50 % by weight containing calcium carbonate masterbatch (MB-1), described titania masterbatch comprises SUMITOMONOBLEN " FS2011DG3 " (PP-3) of Sumitomo Chemical Co's manufacture of 40 % by weight and titanium dioxide (Sakai Chemical Industry Co., Ltd.'s manufacture of 60 % by weight, rutile-type), use 60mm forcing machine at 250 DEG C, utilize T mould to be extruded into sheet, after carrying out cooling curing with the cooling rollers of 50 DEG C, 4.5 times are stretched to along its length at 135 DEG C, then two ends fixture is clamped, import in hot-air oven, at 179 DEG C after preheating, 8.2 times are transversely stretched at 167 DEG C, then it is made to relax 6.7% while heat-treat at 170 DEG C.Then, corona treatment is carried out to the one side of film, reels with up-coiler.The thickness of the film of acquisition like this is 50 μm.Physical property shown in compounding amount shown in the molecular structure of acrylic resin shown in table 1, table 2 and film forming condition, table 3.Obtain that percent thermal shrinkage is low, Young's modulus is high, foaminess is good containing hole film.

(embodiment 1-2)

The heat fixation temperature of cross directional stretch is set to 174 DEG C, in addition, obtains film by the method same with embodiment 1-1.The molecular structure of acrylic resin containing hole film obtained is shown in table 1, compounding amount and film forming condition is shown in table 2, physical property is shown in table 3.

(embodiment 1-3)

PP-1 is set to 81 % by weight, is set to 15 % by weight containing calcium carbonate masterbatch (MB-1), in addition, obtain film by the method same with embodiment 1-1.The molecular structure of acrylic resin containing hole film obtained is shown in table 1, compounding amount and film forming condition is shown in table 2, physical property is shown in table 3.

(embodiment 1-4)

PP-1 is set to 95 % by weight, is set to 1 % by weight containing calcium carbonate masterbatch (MB-1), in addition, obtain film by the method same with embodiment 1-1.The molecular structure of acrylic resin containing hole film obtained is shown in table 1, compounding amount and film forming condition is shown in table 2, physical property is shown in table 3.

(embodiment 1-5)

As the acrylic resin formed containing hole film, use M _w/ M _n=7.7, M _z+1/ M _n=140, MFR=5.0g/10 minute, the alfon " SA4L " (JapanPolypropyleneCorporation manufacture) (PP-2) of [mmmm]=97.3%, what PP-2 is set to 91 % by weight, comprises the calcium carbonate of the PP-2 of 50 quality % and 50 quality % (" PO150B-10 " that company of standby northern efflorescence Co., Ltd. manufactures) is set to 5 % by weight containing calcium carbonate masterbatch (MB-2), in addition, film is obtained by the method same with embodiment 1-1.The molecular structure of acrylic resin containing hole film obtained is shown in table 1, compounding amount and film forming condition is shown in table 2, physical property is shown in table 3.

(embodiment 1-6)

As the acrylic resin formed containing hole film, use M _w/ M _n=4.0, M _z+1/ M _n=23, the homopolymer polypropylene PP-3 of MFR=6.0, [mmmm]=98.7%.Use 5 % by weight containing calcium carbonate masterbatch MB-3 (comprising the calcium carbonate (" PO150B-10 " that standby northern efflorescence Industrial Co., Ltd manufactures) of the PP-3 and 50 % by weight of 50 % by weight), and the heat fixation temperature of cross directional stretch is set to 172 DEG C, in addition, film is obtained by the method same with embodiment 1-1.The molecular structure of acrylic resin containing hole film obtained is shown in table 1, compounding amount and film forming condition is shown in table 2, physical property is shown in table 3.

(comparative example 1-1)

As the acrylic resin formed containing hole film, (Sumitomo Chemical Co manufactures, M to use " FS2011DG3 " _w/ M _n=4.0, M _z+1/ M _n=21, MFR=2.5g/10 minute, [mmmm]=97.0%, ethene amount=0.6mol%) (PP-4), by the PP-4 of 91 % by weight, the above-mentioned titania masterbatch (MB-T) containing calcium carbonate masterbatch (MB-4) and 4 % by weight of 5 % by weight carries out dry type mixing, wherein, the described calcium carbonate (" PO150B-10 " that standby northern efflorescence Industrial Co., Ltd manufactures) comprising the PP-4 and 50 % by weight of 50 % by weight containing calcium carbonate masterbatch (MB-4), longitudinal drawing temperature is set to 125 DEG C, the preheating temperature of cross directional stretch is set to 170 DEG C, draft temperature is set to 155 DEG C, heat fixation temperature is set to 165 DEG C, in addition, film is obtained by the method same with embodiment 1-1.The molecular structure of acrylic resin containing hole film obtained is shown in table 1, compounding amount and film forming condition is shown in table 2, physical property is shown in table 3.

(comparative example 1-2)

Heat fixation temperature is set to 168 DEG C, in addition, obtains film by the method same with comparative example 1-1.The molecular structure of acrylic resin containing hole film obtained is shown in table 1, compounding amount and film forming condition is shown in table 2, physical property is shown in table 3.

(comparative example 1-3)

" FS2011DG3 " is set to 81 % by weight, is set to 15 % by weight containing calcium carbonate masterbatch (MB-4), in addition, obtain film by the method same with comparative example 1-1.The molecular structure of acrylic resin containing hole film obtained is shown in table 1, compounding amount and film forming condition is shown in table 2, physical property is shown in table 3.

(comparative example 1-4)

" FS2011DG3 " is set to 95 % by weight, is set to 1 % by weight containing calcium carbonate masterbatch (MB-4), in addition, obtain film by the method same with comparative example 1-1.The molecular structure of acrylic resin containing hole film obtained is shown in table 1, compounding amount and film forming condition is shown in table 2, physical property is shown in table 3.

According to the above results, the thermotolerance containing hole film obtained by embodiment is high, the excellent appearance therefore after heat-sealing, uses during film bag and heat-sealing temperature can be set as higher temperature, or be coated with, printing dry time can carry out high temperature drying, can seek produce high efficiency.In contrast, the performance containing hole film obtained in comparative example is insufficient.

The above results is shown in table 1, table 2, table 3.

[table 1]

[table 2]

[table 3]

(embodiment 2-1)

As forming the acrylic resin of in-mold labels with the substrate layer (A) containing hole polypropylene film, use M _w/ M _n=8.9, M _z+1/ M _n=110, the alfon PP-1 (" HU300 ", fusing point 170 DEG C that SAMSUNGTOTALPETROCHEMICALSCO., LTD manufacture) of MFR=3.0, [mmmm]=97.1%.By the PP-1 of 91 % by weight, the titania masterbatch (" 7862W " that the smart machine of large Japan of Co., Ltd. manufactures) (MB-T) containing calcium carbonate masterbatch (MB-1) and 4 % by weight of 5 % by weight carries out dry type mixing, the first forcing machine is utilized to extrude, as substrate layer (A), wherein, the described calcium carbonate (" PO150B-10 " that standby northern efflorescence Industrial Co., Ltd manufactures) comprising the PP-1 and 50 % by weight of 50 % by weight containing calcium carbonate masterbatch (MB-1), described titania masterbatch comprises SUMITOMONOBLEN " FS2011DG3 " (PP-3) of Sumitomo Chemical Co's manufacture of 40 % by weight and titanium dioxide (Sakai Chemical Industry Co., Ltd.'s manufacture of 60 % by weight, rutile-type), utilize the second forcing machine, by propylene-ethylene-butene random copolymers (Pr-Et-Bu) (the density 0.89g/cm of 85 % by weight ³, MFR4.6g/10 minute, fusing point 128 DEG C, cold xylene soluble component 4.6 % by weight) with 15 % by weight propene-1-butene random copolymers (Pr-Bu) (density 0.89g/cm ³, MFR9.0g/10 minute, fusing point 130 DEG C, cold xylene soluble component 14.0 % by weight) carry out the hybrid resin that dry type is obtained by mixing and extrude, as heat sealability resin bonding layer (B), utilize the 3rd forcing machine, acid modified polyolefin (Admer " QF550 " that Mitsui Chemicals, Inc manufactures) is extruded, as printed layers (C), in mould, to make the mode becoming printed layers (C)/substrate layer (A)/heat sealability resin bonding layer (B), at 250 DEG C, utilize T die melt to be coextruded into sheet, then cooling curing is carried out with the cooling roller of 50 DEG C, then, 4.5 times are stretched to along its length at 135 DEG C, then two ends fixture is clamped, import in hot-air oven, at 179 DEG C after preheating, at 167 DEG C, be transversely stretched to 8.2 times, then make it lax 6.7% heat-treat at 170 DEG C.Then, corona treatment is carried out to the one side of film, reels with up-coiler.The thickness of the film of acquisition like this is 50 μm, and the thickness of printed layers (C) and heat sealability resin bonding layer (B) is respectively 2 μm, the thickness of substrate layer (A) is 46 μm.As shown in table 1, table 4, table 5, obtain that percent thermal shrinkage is low, Young's modulus is high, foaminess is good containing hole film.

(embodiment 2-2)

Be set to the feed/feed ratio identical with embodiment 1, layer forms, the heat fixation temperature of cross directional stretch is set to 174 DEG C, in addition, obtains film by the method same with embodiment 2-1.The physical property containing hole film obtained is shown in table 1, table 4, table 5.

(embodiment 2-3)

Formed with raw material/layer identical with embodiment 1, the PP-1 in substrate layer (A) is set to 81 % by weight, MB-1 is set to 15 % by weight, in addition, obtained film by the method same with embodiment 2-1.The physical property containing hole film obtained is shown in table 1, table 4, table 5.

(embodiment 2-4)

Formed with raw material/layer identical with embodiment 1, the PP-1 in substrate layer (A) is set to 95 % by weight, MB-1 is set to 1 % by weight, in addition, obtained film by the method same with embodiment 2-1.The physical property containing hole film obtained is shown in table 1, table 4, table 5.

(embodiment 2-5)

As forming the acrylic resin of in-mold labels with the substrate layer (A) containing hole polypropylene film, use M _w/ M _n=7.7, M _z+1/ M _n=140, the alfon PP-2 (" SA4L " that JapanPolypropyleneCorporation manufactures) of MFR=5.0, [mmmm]=97.3%, as containing calcium carbonate masterbatch, use the MB-2 comprising the PP-2 of 50 % by weight and " PO150B-10 " of 50 % by weight, in addition, film is obtained by the method same with embodiment 2-1.The physical property containing hole film obtained is shown in table 1, table 4, table 5.

(embodiment 2-6)

As forming the acrylic resin of in-mold labels with the substrate layer (A) containing hole polypropylene film, use M _w/ M _n=4.0, M _z+1/ M _n=23, MFR=6.0g/10 minute, the homopolymer polypropylene PP-3 of [mmmm]=98.7%, as containing calcium carbonate masterbatch, use the MB-3 comprising the PP-3 of 50 % by weight and " PO150B-10 " of 50 % by weight, the heat fixation temperature of cross directional stretch is set to 172 DEG C, in addition, film is obtained by the method same with embodiment 2-1.The physical property containing hole film obtained is shown in table 1, table 4, table 5.

(comparative example 2-1)

As forming the acrylic resin of in-mold labels with the substrate layer (A) containing hole polypropylene film, use SUMITOMONOBLEN " the FS2011DG3 " (M that Sumitomo Chemical Co manufactures _w/ M _n=4.0, M _z+1/ M _n=21, [mmmm]=97.0%, MFR=2.5g/10 minute) (PP-4), as containing calcium carbonate masterbatch, use the MB-4 comprising the PP-4 of 50 % by weight and " PO150B-10 " of 50 % by weight, in addition, obtain film by method similarly to Example 1.Wherein, film stretching condition is: at 125 DEG C, be stretched to 4.5 times along its length, is then clamped by two ends fixture, import in hot-air oven, at 170 DEG C after preheating, at 155 DEG C, be transversely stretched to 8.2 times, then make it lax 6.7% heat-treat at 165 DEG C.The physical property containing hole film obtained is shown in table 1, table 4, table 5.

(comparative example 2-2)

The heat fixation temperature of cross directional stretch is set to 168 DEG C, in addition, obtains film by the method same with comparative example 2-1.The physical property containing hole film obtained is shown in table 1, table 4, table 5.

(comparative example 2-3)

PP-3 is set to 81 % by weight, MB-4 is set to 15 % by weight, in addition, obtain film by the method same with comparative example 2-1.The physical property containing hole film obtained is shown in table 1, table 4, table 5.

(comparative example 2-4)

PP-3 is set to 95 % by weight, MB-4 is set to 1 % by weight, in addition, obtain film by the method same with comparative example 2-1.The physical property containing hole film obtained is shown in table 1, table 4, table 5.

[table 4]

[table 5]

utilizability in industry

The hole polypropylene film that contains of the present invention can be widely used in packaging purposes, and because thermotolerance is high, therefore, such as, excellent appearance after heat-sealing, uses during film bag and can seal at a higher temperature, can realize the high efficiency of producing.

In addition, the unworkable coating agent, ink, laminating adhesive etc. needing high temperature drying in the past can be used, or be also applicable to the industrial use such as the insulation film of film, engine etc. of in-mold labels purposes, the base film of the backboard of solar cell.

In addition, because thermotolerance containing hole polypropylene film of the present invention, rigidity are high, therefore curling less, be suitable for and make in-mold labels, moreover, but also can expect without the need in order to prevent the curling and film using thickness thicker or without the need to using intermediates, as the superiority such as cost reduction of label.

Claims (9)

1., containing a hole polypropylene film, it is characterized in that, its be using acrylic resin formed as main body containing hole film, the MD direction at 155 DEG C and the percent thermal shrinkage in TD direction are less than 9.0%, and apparent specific gravity is less than 0.90.

2. according to claim 1 containing hole polypropylene film, its be using acrylic resin formed as main body containing hole film, the MD direction at 155 DEG C and the percent thermal shrinkage in TD direction are less than 8.0%, and apparent specific gravity is less than 0.90.

3. according to claim 1 and 2 containing hole polypropylene film, it is the laminate film of more than 3 layers comprising substrate layer (A), heat sealability resin bonding layer (B) and printed layers (C), wherein, substrate layer (A) is formed using acrylic resin as main body and is had the low-melting fusing point of the resin than this substrate layer containing hole, heat sealability resin bonding layer (B).

4. according to any one in claims 1 to 3 containing hole polypropylene film, wherein, described film contains whipping agent.

5. according to any one in Claims 1 to 4 containing hole polypropylene film, wherein, the total light transmittance of described film is less than 75%.

6. according to claim 5 containing hole polypropylene film, wherein, total light transmittance is less than 40%.

7. according to any one in claim 1 ~ 6 containing hole polypropylene film, wherein, the Young's modulus in MD direction is more than 1.6GPa, the Young's modulus in TD direction is more than 2.7GPa.

8. according to any one in claim 3 ~ 7 containing hole polypropylene film, it is characterized in that, the resin forming heat sealability resin bonding layer (B) is by propylene, the random copolymer of propylene that formed with the alpha-olefin of ethene and/or carbonatoms more than 4.

9. according to any one in claim 3 ~ 8 containing hole polypropylene film, it is characterized in that, the resin forming printed layers (C) contains the acid modified polyolefin good with the cementability of ink.