CN204400888U

CN204400888U - The equipment of foamed sheet, the electric installation using it, electronics and lift-launch touch panel

Info

Publication number: CN204400888U
Application number: CN201420482961.6U
Authority: CN
Inventors: 土井浩平; 长崎国夫; 大塚哲弥; 冈田美佳; 加藤和通; 德山英幸; 北原纲树; 高桥忠男; 松下喜一郎
Original assignee: Nitto Denko Corp
Current assignee: Nitto Denko Corp
Priority date: 2013-08-26
Filing date: 2014-08-25
Publication date: 2015-06-17
Anticipated expiration: 2024-08-25
Also published as: JP5676798B1; JP2015110721A; JP2015110781A; JP5801946B2; KR101500468B1; KR20150024243A; KR20150024294A; CN104419037B; CN104419037A; CN104419036A

Abstract

The utility model relates to foamed sheet, uses its electric installation, electronics and carry the equipment of touch panel.The thickness of foamed sheet of the present utility model is 30 ~ 500 μm, and described foamed sheet is 0.2 ~ 0.4g/cm by density ³foam form.The thickness of other foamed sheets of the present utility model is 30 ~ 500 μm, and the foam that described foamed sheet is 60 ~ 80 volume % by bubble rate is formed.Foamed sheet of the present utility model, its thickness is 30 ~ 500 μm, and described foamed sheet is 0.2 ~ 0.4g/cm by density ³, and radian frequency in Measurement of Dynamic Viscoelasticity is 1rad/s time store elastic modulus and the ratio of loss Young's modulus and loss tangent (tan δ) more than-30 DEG C and the foam in the scope of less than 30 DEG C with peak value form.The mean cell diameter of above-mentioned foam is such as 10 ~ 150 μm.Loss tangent (tan δ) maximum value more than-30 DEG C and in the scope of less than 30 DEG C of preferred above-mentioned foam is more than 0.2.

Description

The equipment of foamed sheet, the electric installation using it, electronics and lift-launch touch panel

Technical field

The foamed sheet that thickness is little even if the utility model relates to, impact absorbency is also excellent and employ the electric/electronic of this foamed sheet.

Background technology

In the past, when the image display member being fixed on the image display devices such as liquid-crystal display, electroluminescent display, plasma display, the optical component such as display member, photographic camera, lens that is installed on so-called " Cell phone ", " smart mobile phone ", " portable information terminal " etc. are fixed on position (such as the basket etc.) of regulation, employ foam material.As such foam material, except using low ratio foamed and the fine unit carbamate system foam with separated foam structure, the foam that the compression molding of high-foaming carbamate obtain, also use has the polyethylene-based foam etc. that the expansion ratio of separated foam is about 30 times.Specifically, use is such as 0.3 ~ 0.5g/cm by density ³polyurethane series foam formed liner (with reference to patent documentation 1), be the electric/electronic sealing material (specially with reference to sharp document 2) etc. that the foamed structures of 1 ~ 500 μm is formed by average bubble footpath.

Prior art document

Patent documentation

Patent documentation 1: Japanese Unexamined Patent Publication 2001-100216 publication

Patent documentation 2: Japanese Unexamined Patent Publication 2002-309198 publication

Utility model content

Utility model problem to be solved

But, in recent years, to thin down type along with the product being provided with optical component (image display device, photographic camera, lens etc.), the gap of the part of foam material can be used to be in the trend tailed off significantly.Reduce along with this gap, need the less thick making this bubble generation member, but for foam material in the past, if make less thick, then cannot give play to enough impact absorbencies.Therefore, need such as when the electric/electronic making " smart mobile phone " etc. with display member drops on ground etc., impact during Absorbable rod collision and prevent the foamed sheet of the breakage of display member.

In addition, along with the multifunction of the electronicss such as PC (PC), panel computer, PDA (personal portable information terminal), Cell phone, and for preventing stacked other components (such as heat-conducting layer) on the impact-absorbing sheet of the breakage of display member etc. from assembling.Due to the further slimming of above-mentioned electronics in recent years, and expect that the components such as the impact-absorbing sheet used in electronics are further thin layer, and urgent expect this impact-absorbing sheet and other components stacked time adhesive linkage thin layer or there is no adhesive linkage.

In addition, in recent years, carry the universal of the equipment of touch panel along with smart mobile phone, portable terminal device etc., user uses the chance of fixture (fingertip) contacts such as finger, felt pen or pressing picture to increase.In addition, these slimmings of equipment of carrying touch panels constantly advance significantly, and the slimming forming the component (being such as the display panel of representative, the touch panel etc. relevant to touched place with LCD) of these equipment is also in continuous propelling.Therefore, when user presses picture, display panel, touch panel are very easy to bend (bending).If bend, then along with this flexure, display panel interferes with inner other components (such as circuit substrate, battery etc.), sometimes produces display irregular (undulatory stain pattern) on a display panel.As the occurrence cause that display is irregular, can think due to following reason, that is, display panel is pressed against other inner components, and thus to display panel stress application, the orientation of liquid crystal molecule gets muddled.

For the display irregular (undulatory stain pattern) because producing this display panel stress application problem, propose following proposal: space is set at display panel periphery, even if thus display panel deforms, also not easily to display panel stress application; Change the design of display panel, touch panel, make it thickening, and not easily bend; Make the rigidity of the basket of the equipment of lift-launch touch panel become large, thus not easily deform.But the equipment of existence lift-launch touch panel is thickening, the heavy such disadvantage of change.Therefore, with regard to carrying the equipment of touch panel, while being desirably in the continuous slimming significantly advanced of reply, solve the problem because of the display irregular (undulatory stain pattern) produced display panel stress application.

Thus, the purpose of this utility model is, even if provide a kind of thickness the very little foamed sheet also can having given play to excellent impact absorbency.

Other object of the present utility model is, even if provide a kind of foamed sheet not only having above-mentioned characteristic but also do not have that when other components stacked adhesive linkage also can prevent from misplacing.

In addition, other object of the present utility model is, though provide a kind of miniaturization, slimming, also not easily because falling time impact and there is damaged electric/electronic.

The utility model further other object is, even if provide the impact absorbency that a kind of thickness is very little, also can give play to excellence, and when the equipment for carrying touch panel, the foamed sheet that the display of the display part produced along with the touch operation of user is irregular can be suppressed to heavens.

The other further object of the utility model is, provide a kind of not easily because falling time impact and the equipment of lift-launch touch panel breakage occurring and inhibits the display of the display part produced along with the touch operation of user irregular to heavens.

For solving the means of problem

The present inventor etc. conduct in-depth research to achieve these goals, found that, if by low-density foam, particularly low density, and the ratio of the store elastic modulus of the radian frequency in Measurement of Dynamic Viscoelasticity when being 1rad/s and loss Young's modulus and loss tangent (tan δ) are more than-30 DEG C and the foam in the scope of less than 30 DEG C with peak value forms foamed sheet, even if be then 30 ~ 500 μm of such thin thickness, impact absorbency is also obviously very excellent, therefore, with regard to employing the electric/electronic of such foamed sheet, even if drop on ground etc., also the breakage of display unit etc. is not easily produced because impact waits, in addition, even if be weak impact, shock absorption rate is also high, therefore, when above-mentioned foamed sheet is used for the equipment carrying touch panel, even if the equipment carrying touch panel is thin, also the generation that the display of the display part produced along with the touch operation of user is irregular can highly be suppressed, so far the utility model is completed.

That is, the utility model provides a kind of foamed sheet, and its thickness is 30 ~ 500 μm, and described foamed sheet is 0.2 ~ 0.4g/cm by density ³foam form.

The utility model also provides a kind of foamed sheet, and its thickness is 30 ~ 500 μm, and the foam that described foamed sheet is 60 ~ 80 volume % by bubble rate is formed.

The utility model also provides a kind of foamed sheet, and its thickness is 30 ~ 500 μm, and described foamed sheet is 0.2 ~ 0.4g/cm by density ³, and radian frequency in Measurement of Dynamic Viscoelasticity is 1rad/s time store elastic modulus and the ratio of loss Young's modulus and loss tangent (tan δ) more than-30 DEG C and the foam in the scope of less than 30 DEG C with peak value form.

With regard to above-mentioned each foamed sheet, the mean cell diameter of preferred above-mentioned foam is 10 ~ 150 μm.In addition, loss tangent (tan δ) maximum value more than-30 DEG C and in the scope of less than 30 DEG C of preferred above-mentioned foam is more than 0.2.

In addition, under 23 DEG C of environment and draw speed is in the tension test of 300mm/min, the initial stage Young's modulus of preferred foam is 5N/mm ²below.

In addition, employ pendulum type shock-testing machine impact absorbency test in, the shock absorption rate (%) that preferred following formula defines divided by thickness (μm) gained of foamed sheet value R impact son weight 28g, put angle 30 ° time be more than 0.15.

Shock absorption rate (%)={ (F ₀-F ₁)/F ₀} × 100

(in above-mentioned formula, F ₀only the surging force of impacting the period of the day from 11 p.m. to 1 a.m is collided to supporting plate, F ₁the supporting plate to the structure be made up of supporting plate and foamed sheet collides the surging force of impacting the period of the day from 11 p.m. to 1 a.m)

At least one face of above-mentioned foam is preferably 0.5N/100mm relative to the shear bond power (23 DEG C, draw speed 50mm/min) of SUS304BA plate ²above.

Above-mentioned foam can be formed by least one resin material be selected from acrylic acid polymer, rubber, carbamate based polymer and vinyl-vinyl acetate copolymer.

Above-mentioned foam can be formed via the operation A making emulsion resin composition mechanically foam.Above-mentioned foam can also be formed via process B, and described process B is coated on by the emulsion resin composition obtained through mechanically foaming on base material and carries out dry operation.Above-mentioned process B can comprise: by the emulsion resin composition of the bubbles be coated on base material more than 50 DEG C and lower than carry out dry preparation drying process B1 at the temperature of 125 DEG C and after preparation drying process B1 further more than 125 DEG C and less than the 200 DEG C trunk drying process B2 carrying out drying.

Above-mentioned foamed sheet can have binder layer at the single or double of foam.

In addition, above-mentioned foamed sheet can be used as electric/electronic impact-absorbing sheet.In addition, above-mentioned foamed sheet can be the foamed sheet of the equipment for carrying touch panel.

The utility model also provides the electric/electronic employing above-mentioned foamed sheet.With regard to this electric/electronic, it is the electric installation or the electronics that possess display member, comprises and has electric installation or the electronics that above-mentioned foamed sheet is clamped in the structure between the basket of this electric installation or electronics and above-mentioned display member.

The utility model also provides the equipment of the lift-launch touch panel employing above-mentioned foamed sheet.In the equipment of this lift-launch touch panel, there is above-mentioned foamed sheet, display panel and touch panel, and can at the above-mentioned foamed sheet of the space matching of the rear side of above-mentioned display panel.

The effect of utility model

Foamed sheet of the present utility model is by low-density foam, store elastic modulus when particularly low density and radian frequency in Measurement of Dynamic Viscoelasticity are 1rad/s and the ratio of loss Young's modulus and loss tangent (tan δ) more than-30 DEG C and the foam in the scope of less than 30 DEG C with peak value form, therefore, even if thickness is thin, impact absorbency is also excellent.In addition, be 0.5N/100mm by least one face of foam relative to the shear bond power of SUS304BA plate ²above foam and other components (such as heat-conducting layer etc.) stacked time, even if not there is adhesive linkage, also can prevent dislocation.Thus, even if the electric/electronic employing foamed sheet of the present utility model is dropped on ground etc., the breakage of the indicating meter produced because of impact etc. can also be prevented.

In addition, foamed sheet of the present utility model is low compression load, therefore, when the equipment for carrying touch panel, along with the touch operation of user, even if display panel, touch panel there occurs bending, distortion, also the power produced with this distortion effectively can be disperseed, absorbed.Thus, foamed sheet of the present utility model can suppress the display irregular (undulatory stain pattern) because of the display part produced display panel stress application to heavens.Therefore, foamed sheet of the present utility model can be suitable for the equipment carrying touch panel.

Accompanying drawing explanation

Fig. 1 is the signal pie graph of pendulum type shock-testing machine (impact test apparatus).

Fig. 2 is the figure that the signal of the retaining member representing pendulum type shock-testing machine (impact test apparatus) is formed.

Fig. 3 is the schematic diagram above that stress relaxes trier.

Fig. 4 is the constructed profile that stress relaxes trier.

Fig. 5 is the tonogram picture showing the pressure acting on impact paper in the test of irregular generation in the confirmation of embodiment 1.

Fig. 6 is the tonogram picture showing the pressure acting on impact paper in the test of irregular generation in the confirmation of embodiment 2.

Fig. 7 is the tonogram picture showing the pressure acting on impact paper in the test of irregular generation in the confirmation of embodiment 3.

Fig. 8 is the tonogram picture showing the pressure acting on impact paper in the test of irregular generation in the confirmation of embodiment 4.

Fig. 9 is the tonogram picture showing the pressure acting on impact paper in the test of irregular generation in the confirmation of embodiment 5.

Figure 10 is the tonogram picture showing the pressure acting on impact paper in the test of irregular generation in the confirmation of comparative example 1.

Figure 11 is the tonogram picture showing the pressure acting on impact paper in the test of irregular generation in the confirmation of comparative example 3.

Figure 12 is the constructed profile of the example representing foamed sheet of the present utility model.

Nomenclature

1, pendulum type shock-testing machine (impact test apparatus)

2, test film (foamed sheet)

3, retaining member

4, impact load component

5, pressure inductor

10, foamed sheet

11, stationary fixture

12, fixture is pressed

16, pressure regulating mechanism

20, pillar

21, arm

22, one end of support rod (axle)

23, support rod (axle)

24, son is impacted

25, electro-magnet

28, supporting plate

A, put angle

6, stress relaxes trier

61, hairclipper

62, visual window lens

63, liquid-crystal display

64, impact paper

65, substrate

661, self adhesive tape

662, self adhesive tape

67, basket

68, foam insertion space

Embodiment

Figure 12 is the constructed profile of the example representing foamed sheet of the present utility model, and 10 is foamed sheet.With regard to foamed sheet of the present utility model, its thickness is 30 ~ 500 μm, and described foamed sheet is 0.2 ~ 0.4g/cm by density ³the foam of (or bubble rate is 60 ~ 80 volume %) is formed.In addition, with regard to preferred foamed sheet, its thickness is 30 ~ 500 μm, and described foamed sheet is 0.2 ~ 0.4g/cm by density ³, and radian frequency in Measurement of Dynamic Viscoelasticity is 1rad/s time store elastic modulus and the ratio of loss Young's modulus and loss tangent (tan δ) more than-30 DEG C and the foam in the scope of less than 30 DEG C with peak value form.Therefore, there is desired impact absorbency.It should be noted that, in this manual, the density of foam refers to " apparent density ".

The thickness of foamed sheet of the present utility model is 30 ~ 500 μm.Its lower limit is preferably 40 μm, be more preferably 50 μm, the upper limit is preferably 400 μm, is more preferably 300 μm, more preferably 200 μm.In the utility model, the thickness of foamed sheet is more than 30 μm, therefore, it is possible to equably containing bubble, can give play to excellent impact absorbency.In addition, the thickness of foamed sheet is less than 500 μm, therefore, even if also can easily follow for minim gap.Although the thickness of foamed sheet of the present utility model be 30 ~ 500 μm thin like this, impact absorbency is excellent.

The density forming the foam of foamed sheet of the present utility model is preferably 0.2 ~ 0.4g/cm ³.It should be noted that, the density of the resin forming foam is set to average 1g/cm ³, obtain preferred bubble rate.The preferred bubble rate of described foam becomes 60 ~ 80 volume %.The lower limit of the density of described foam is preferably 0.21g/cm ³, be more preferably 0.22g/cm ³, the upper limit is preferably 0.39g/cm ³, be more preferably 0.38g/cm ³, more preferably 0.35g/cm ³.Be 0.2g/cm by making the density of foam ³above, thus intensity can be maintained, by being 0.4g/cm ³below, thus higher impact absorbency can have been given play to.In addition, by making the density of foam be 0.2 ~ 0.4g/cm ³scope, thus higher impact absorbency can have been given play to further.

The mean cell diameter of above-mentioned foam is such as 10 ~ 150 μm.Its lower limit is preferably 15 μm, be more preferably 20 μm, the upper limit is preferably 140 μm, is more preferably 130 μm, more preferably 100 μm.By making mean cell diameter be more than 10 μm, thus more excellent impact absorbency can be given play to.In addition, by making mean cell diameter be less than 100 μm, thus make compression restorative also excellent.It should be noted that, the maximum cell diameter of above-mentioned foam is such as 40 ~ 400 μm, its lower limit is preferably 60 μm, be more preferably 80 μm, the upper limit is preferably 300 μm, is more preferably 220 μm.In addition, the smallest bubbles bore dia of above-mentioned foam is such as 5 ~ 70 μm, its lower limit is preferably 8 μm, be more preferably 10 μm, the upper limit is preferably 60 μm, is more preferably 50 μm.

In the utility model, from the view point of impact absorbency, the ratio of the thickness (μm) of mean cell diameter (μm) and foamed sheet (the former/the latter) is preferably in the scope of 0.2 ~ 0.9.The lower limit of the ratio of the thickness (μm) of above-mentioned mean cell diameter (μm) and foamed sheet is preferably 0.25, be more preferably 0.3, the upper limit is preferably 0.85, is more preferably 0.8.

The peak value of the store elastic modulus when radian frequency of preferred above-mentioned foam in Measurement of Dynamic Viscoelasticity is 1rad/s and the ratio of loss Young's modulus and loss tangent (tan δ) is in more than-30 DEG C and the scope of less than 30 DEG C.The lower limit of the temperature range of the peak value existence of above-mentioned loss tangent is preferably-25 DEG C, is more preferably-20 DEG C, more preferably-10 DEG C, and the upper limit is preferably 20 DEG C, is more preferably 10 DEG C.When the material of the peak value for having more than 2 loss tangents, at least one expecting wherein falls in above-mentioned scope.By making peak temperature be more than-30 DEG C, thus it is restorative to have given play to excellent compression.In addition, by making peak temperature be less than 30 DEG C, thus demonstrate high flexibility, given play to excellent impact absorbency.

From the view point of impact absorbency, preferably more than-30 DEG C and peak strength (maximum value) height of loss tangent (tan δ) in the scope of less than 30 DEG C is such as more than 0.2, preferably more than 0.3.The higher limit of above-mentioned peak strength (maximum value) is such as 2.0.

Like this, the peak temperature of above-mentioned loss tangent (tan δ), peak strength contribute to the impact absorbency of foam to a great extent.If the peak value of the store elastic modulus when radian frequency of foam in Measurement of Dynamic Viscoelasticity is 1rad/s and the ratio of loss Young's modulus and loss tangent (tan δ) is present in more than-30 DEG C and in the scope of less than 30 DEG C, then the impact absorbency of foamed sheet uprises, reason about this point is still not clear, but supposition is the cause owing to there is the peak value of above-mentioned loss tangent (tan δ) matchingly with the frequency of impacting.Namely, can infer: above-mentioned loss tangent (tan δ) is more than-30 DEG C and the scope of less than 30 DEG C, the scope of the frequency suitable with the drop impact of works is scaled according to the temperature-time conversion rule in determination of viscoelasticity, therefore, have the foamed sheet of the peak temperature of above-mentioned loss tangent (tan δ) more than-30 DEG C and in the scope of less than 30 DEG C, its impact absorbency uprises.In addition, store elastic modulus is the repulsion relative with the impact energy putting on foamed sheet, if store elastic modulus is high, then and impact of directly rebounding.On the other hand, loss Young's modulus is the physical property impact energy putting on foamed sheet being converted to heat, and loss Young's modulus is higher, impact energy is converted to heat muchly, therefore absorbs impact, and deformation is diminished.Can infer thus, in large quantities impact energy is converted to heat and the little foamed sheet of repulsion, that is, the ratio of store elastic modulus and loss Young's modulus and the large foamed sheet of loss tangent (tan δ), its shock absorption rate is high.

From the view point of impact absorbency, the initial stage Young's modulus of preferred above-mentioned foam is low.This initial stage Young's modulus (under 23 DEG C of environment, draw speed is in the tension test of 300mm/min, the value calculated by slope during 10% strain) is preferably 5N/mm ²below, 3N/mm is more preferably ²below, more preferably 1N/mm ²below.It should be noted that, the lower value of above-mentioned initial stage Young's modulus is such as 0.1N/mm ².

As the foam forming foamed sheet of the present utility model, as long as have above-mentioned characteristic, then its composition, bubble structure etc. are just not particularly limited.As bubble structure, can be any one in continuous air bubbles structure, separated foam structure, semicontinuous semi-independent bubble structure.From the view point of impact absorbency, be preferably continuous air bubbles structure, semicontinuous semi-independent bubble structure.

Foamed sheet of the present utility model is thin and have excellent impact absorbency.In addition, even if for very weak impact, also there is HI high impact absorptivity, the impact of the size be not hit and given play to excellent impact absorbency.Such as, in the impact absorbency test employing pendulum type shock-testing machine, the shock absorption rate (%) that following formula defines, divided by the thickness (μm) of foamed sheet, obtains the shock absorption rate R of per unit thickness.

Shock absorption rate (%)={ (F ₀-F ₁)/F ₀} × 100

By impact son weight 28g, put angle 30 ° time (hereinafter sometimes referred to as " low impact condition (a) ") R be set to R1, by impact son weight 28g, put angle 40 ° time (hereinafter sometimes referred to as " low impact condition (b) ") R be set to R2, by impact son weight 96g, put angle 47 ° time (hereinafter sometimes referred to as " HI high impact condition ") R be set to R3 time, for foamed sheet of the present utility model, R1 is such as more than 0.15, R2 is such as more than 0.15, R3 is such as more than 0.10.The higher limit of above-mentioned R (R1, R2, R3) is such as about 0.5.

It should be noted that, above-mentioned shock absorption rate is different from the thickness etc. of foamed sheet, is generally 5 ~ 80%, lower limit is preferably 7%, the upper limit is preferably 60%.Shock absorption rate (%) under above-mentioned HI high impact condition is preferably more than 14%, is more preferably more than 15%.Shock absorption rate (%) during low impact condition (a) is preferably more than 18%, is more preferably more than 25%.

In addition, in the utility model, as previously mentioned, the size be not hit affects and has excellent impact absorbency.Such as, with regard to foamed sheet of the present utility model, above-mentioned R1 and R3 sum (R1+R3) is generally more than 0.25 (such as 0.25 ~ 1.0), is preferably more than 0.28 (such as 0.28 ~ 1.0), and the ratio (R1/R3) of R1 and R3 is generally 0.5 ~ 3.0, is preferably in the scope of 0.8 ~ 2.8.In addition, with regard to foamed sheet of the present utility model, the difference (R1-R3) of R1 and R3 is generally ± 0.25 within, be preferably within ± 0.21.In addition, above-mentioned R1 and R2 sum (R1+R2) is generally more than 0.40 (such as 0.40 ~ 1.0), is preferably more than 0.45 (such as 0.45 ~ 1.0), and the ratio (R1/R2) of R1 and R2 is generally 0.5 ~ 2.5, is preferably in the scope of 0.8 ~ 2.0.

Signal for pendulum type shock-testing machine (impact test apparatus) is formed, and is described by Fig. 1 and Fig. 2.As shown in Figures 1 and 2, impact test apparatus 1 (pendulum test machine 1) comprising: as with arbitrary confining force to keep the retaining member 3 of the maintaining body of test film 2 (foamed sheet 2); Make the impact load component 4 of test film 2 load impact stress; With the pressure inductor 5 etc. as the surging force feeler mechanism detected the surging force produced based on impact load component 4 pairs of test films 2.In addition, keep the retaining member 3 of test film 2 to be made up of stationary fixture 11 and pressing fixture 12 with arbitrary confining force, pressing fixture 12 is opposed with stationary fixture 11, and to clamp the mode that keeps test film 2 and slidably.In addition, pressing fixture 12 place is provided with press pressure regulating mechanism 16.In addition, the impact load component 4 of the test film 2 load impact power kept by retaining member 3 is made up of support rod 23 (axle 23) and arm 21, one end 22 of support rod 23 is had in another side by the mode that can rotate relative to pillar 20 impact son 24 by axle supporting, and impacts sub 24 is lifted and remain predetermined angular by arm 21.Here, employ steel ball as impact 24, therefore, by arranging electro-magnet 25 in one end of arm, thus can integratedly impact 24 be lifted as predetermined angular.In addition, the surging force of what impact load component 4 produced act on test film 2 carries out the pressure inductor 5 detected, and is arranged at the opposing face side of the test film contact surface of stationary fixture 11.

Impacting son 24 is steel ball (iron balls).In addition, impacting sub 24 angles (pendulum in Fig. 1 plays angle A) lifted by arm 21 is 30 ° ~ about 47 ° (measuring under 3 conditions of 30 °, 40 °, 47 ° in embodiment).The weight of steel ball (iron ball) is about 20 ~ 100g.In embodiment described later, (1) steel ball (iron ball) weight 28g, put angle 30 °, (2) steel ball (iron ball) weight 28g, put angle 40 °, (3) steel ball (iron ball) weight 96g, put these 3 conditions of angle 47 ° under measure.

As shown in Figure 2, test film 2 (foamed sheet 2) is clamped across the supporting plate 28 be made up of resinousness sheet material (acrylic board, polycarbonate plate etc.), the contour elastic plate of metal sheet material between stationary fixture 11 and pressing fixture 12.

Use above-mentioned impact test apparatus, obtain surging force F ₀and surging force F ₁, calculate impact absorbency by above-mentioned formula, wherein, surging force F ₀by make stationary fixture 11 and supporting plate 28 closely sealed fixing after, make impact 24 impact supporting plates 28 and record, surging force F ₁by between stationary fixture 11 and supporting plate 28, insert test film 2 and make its closely sealed fixing after, make impact 24 impact supporting plates 28 and record.It should be noted that, impact test apparatus is the device identical with the embodiment 1 of Japanese Unexamined Patent Publication 2006-47277 publication.

The thickness of foamed sheet large to a certain degree time, impact absorbency regulates by selecting mean cell diameter, density etc., and when the thickness of foamed sheet is very little (such as thickness is 30 ~ 500 μm), only adjustment is carried out to above-mentioned characteristic and fully cannot absorb impact.This is because following cause: when the thickness of foamed sheet is very thin, the bubble in foam breaks immediately because of impact, and the impact buffer function produced by bubble disappears.In the utility model, as mentioned above, the peak value of the store elastic modulus when radian frequency of foam in Measurement of Dynamic Viscoelasticity is 1rad/s and the ratio of loss Young's modulus and loss tangent (tan δ) is present in more than-30 DEG C and in the scope of less than 30 DEG C, therefore, even if after bubbles burst, the constituent material of foam has still been given play to impacting the function cushioned.

Above-mentioned foam can be made up of the resin combination comprising resin material (polymkeric substance).It should be noted that, store elastic modulus when this resin combination [resin combination (solid substance) when not foaming] radian frequency in Measurement of Dynamic Viscoelasticity of non-foamed state is 1rad/s and the ratio of loss Young's modulus and the peak value of loss tangent (tan δ) are preferably in more than-30 DEG C and the scope of less than 30 DEG C.The lower limit of the temperature range existing for the peak value of above-mentioned loss tangent is preferably-25 DEG C, is more preferably-20 DEG C, more preferably-10 DEG C, and the upper limit is preferably 20 DEG C, is more preferably 10 DEG C.When having the material of peak value of more than 2 loss tangents, preferably wherein at least one falls in above-mentioned scope.From the view point of impact absorbency, (this value is equivalent to above-mentioned foam more than-30 DEG C and lower than the peak strength of the loss tangent (tan δ) in the scope of 30 DEG C divided by the density (g/cm of foam to the peak strength of the preferred loss tangent of this resin combination (solid substance) more than-30 DEG C and in the scope of less than 30 DEG C (tan δ) ³) and the value that obtains) high.Such as, the peak strength of the loss tangent of above-mentioned resin combination (solid substance) more than-30 DEG C and in the scope of less than 30 DEG C (tan δ) is preferably 0.9 (g/cm ³) ^-1above, the upper limit is such as about 3.

In addition, expect that the initial stage Young's modulus (23 DEG C, draw speed 300mm/min) of this resin combination (solid substance) of non-foamed state is low, be preferably 50N/mm ²below, 30N/mm is more preferably ²below.It should be noted that, the lower value of above-mentioned initial stage Young's modulus is such as 0.3N/mm ².

As the resin material (polymkeric substance) forming above-mentioned foam, be not particularly limited, the known and even known resin material forming foam can be used.As this resin material, include, for example out acrylic acid polymer, rubber, carbamate based polymer, vinyl-vinyl acetate copolymer etc.Wherein, from the view point of impact absorbency, be preferably acrylic acid polymer, rubber, carbamate based polymer.The resin material (polymkeric substance) forming foam can be independent a kind, also can be two or more.

It should be noted that, in order to store elastic modulus when making the radian frequency of above-mentioned foam in Measurement of Dynamic Viscoelasticity be 1rad/s and the ratio of loss Young's modulus and the peak value of loss tangent (tan δ) are more than-30 DEG C and the scope of less than 30 DEG C, can using the Tg of above-mentioned resin material (polymkeric substance) as index or target.Such as, as above-mentioned resin material (polymkeric substance), more than-50 DEG C can be in from Tg and select lower than the resin material (polymkeric substance) in the scope of 50 DEG C (lower limit is preferably-40 DEG C, is more preferably-30 DEG C, the upper limit is preferably 40 DEG C, is more preferably 30 DEG C).

As aforesaid propylene acid based polymer, be preferably the acrylic acid polymer that to be the monomer of more than-10 DEG C and the Tg of homopolymer using the Tg of homopolymer formed as necessary monomer component lower than the monomer of-10 DEG C.By using such acrylic acid polymer and adjusting with the amount ratio of the latter's monomer the former monomer, thus store elastic modulus when the radian frequency that can obtain with comparalive ease in Measurement of Dynamic Viscoelasticity is 1rad/s and the ratio of loss Young's modulus and the peak value of loss tangent (tan δ) are more than-30 DEG C and the foam of less than 30 DEG C.

It should be noted that, " forming the second-order transition temperature (Tg) during homopolymer " (being sometimes only singly called " Tg of homopolymer ") in the utility model refers to " second-order transition temperature (Tg) of the homopolymer of this monomer ", specifically, numerical value is enumerated in " Polymer Handbook " (the 3rd edition, John Wiley & Sons, Inc, 1987).It should be noted that, the Tg of the homopolymer of the monomer do not recorded in above-mentioned document refers to the value (with reference to Japanese Unexamined Patent Publication 2007-51271 publication) such as obtained by following measuring method.Namely, to in the reactor possessing thermometer, stirrer, nitrogen ingress pipe and reflux cooling pipe, drop into monomer 100 weight part, 2,2 '-Diisopropyl azodicarboxylate 0.2 weight part and ethyl acetate 200 weight part as polymer solvent, while importing nitrogen, stir 1 hour.Thus, by the oxygen removing in polymerization system, be then warming up to 63 DEG C and make it react 10 hours.Then, be cooled to room temperature, obtain the homopolymer solution that solid component concentration is 33 % by weight.Then, this homopolymer solution casting is coated on distance piece, carries out drying, produce the test sample (homopolymer of sheet) of thick about 2mm.Then, this test sample stamping-out is become diameter 7.9mm's is discoid, clamped with parallel plate, use test for viscoelastic machine (ARES, REOMETRIX Inc.), while the shear strain of giving frequency 1Hz, temperature province-70 ~ 150 DEG C, 5 DEG C/min heat-up rate condition under, measure visco-elasticity by shear mode, the peak temperature of tan δ be set to the Tg of homopolymer.It should be noted that, the Tg of above-mentioned resin material (polymkeric substance) also measures by the method.

Tg for homopolymer is the monomer of more than-10 DEG C, and this Tg is such as-10 DEG C ~ 250 DEG C, is preferably 10 ~ 230 DEG C, more preferably 50 ~ 200 DEG C.

Tg as above-mentioned homopolymer is the monomer of more than-10 DEG C, can exemplify such as: (methyl) vinyl cyanide; The monomer of the amide-containings such as (methyl) acrylamide, N-hydroxyethyl (methyl) acrylamide; (methyl) vinylformic acid; The Tg of the homopolymer such as methyl methacrylate, β-dimethyl-aminoethylmethacrylate is (methyl) alkyl acrylate of more than-10 DEG C; (methyl) isobornyl acrylate; NVPs etc. are containing the vinyl monomer of heterocycle; The monomer etc. of the hydroxyls such as HEMA.They can be used alone a kind or combinationally use two or more.Wherein, (methyl) vinyl cyanide (especially vinyl cyanide) is particularly preferably.If use (methyl) vinyl cyanide (especially vinyl cyanide) to be the monomer of more than-10 DEG C as the Tg of homopolymer, then molecular interaction is strong, therefore, it is possible to make the peak strength of the above-mentioned loss tangent (tan δ) of foam become large.

For the Tg of homopolymer lower than the monomer of-10 DEG C, this Tg be such as more than-70 DEG C and lower than-10 DEG C, be preferably-70 DEG C ~-12 DEG C, more preferably-65 DEG C ~-15 DEG C.

As the Tg of above-mentioned homopolymer lower than the monomer of-10 DEG C, the Tg that can list the homopolymer such as such as ethyl propenoate, butyl acrylate, 2-EHA is lower than (methyl) alkyl acrylate etc. of-10 DEG C.They can be used alone a kind, or combinationally use two or more.Wherein, vinylformic acid C is particularly preferably _2-8alkyl ester.

Relative to the whole monomer component (monomer component total amount) forming aforesaid propylene acid based polymer, the Tg of homopolymer is that the content of the monomer of more than-10 DEG C is such as 2 ~ 30 % by weight, lower limit is preferably 3 % by weight, be more preferably 4 % by weight, the upper limit is preferably 25 % by weight, is more preferably 20 % by weight.In addition, relative to the whole monomer component (monomer component total amount) forming aforesaid propylene acid based polymer, the Tg of homopolymer lower than the content of the monomer of-10 DEG C be such as 70 ~ 98 % by weight, lower limit is preferably 75 % by weight, be more preferably 80 % by weight, the upper limit is preferably 97 % by weight, is more preferably 96 % by weight.

As above-mentioned rubber, can be any one in natural rubber, synthetic rubber.As above-mentioned rubber, include, for example out paracril (NBR), methyl methacrylate butadiene rubber (MBR), styrene butadiene rubbers (SBR), acrylic rubber (ACM, ANM), urethane rubber (AU), silicone rubber etc.Wherein, paracril (NBR), methyl methacrylate butadiene rubber (MBR), silicone rubber is preferably.

As above-mentioned carbamate based polymer, include, for example out polycarbonate-based urethane, Polyester urethane, polyethers system urethane etc.

As vinyl-vinyl acetate copolymer, known and even known vinyl-vinyl acetate copolymer can be used.

Form the foam of above-mentioned foamed sheet except resin material (polymkeric substance), tensio-active agent, linking agent, thickening material, rust-preventive agent, other additive can also be contained as required.

Such as in order to bubble diameter miniaturization, bubble after the stability of bubble, can arbitrary tensio-active agent be contained.As tensio-active agent, be not particularly limited, any one in negatively charged ion system tensio-active agent, positively charged ion system tensio-active agent, nonionic system tensio-active agent, amphoterics etc. can be used, the stability of the bubble after the miniaturization, foaming of bubble diameter, be preferably negatively charged ion system tensio-active agent, be especially more preferably the lipid acid ammonium system tensio-active agents such as ammonium stearate.Tensio-active agent can be used singly or in combination of two or more.In addition, can be used together different types of tensio-active agent, such as can by negatively charged ion system tensio-active agent and nonionic system tensio-active agent and use, negatively charged ion system tensio-active agent and amphoterics are used.

Such as relative to resin material (polymkeric substance) [solids component (nonvolatile component)], 100 weight parts are 0 ~ 10 weight part to the addition [solids component (nonvolatile component)] of tensio-active agent, lower limit is preferably 0.5 weight part, the upper limit is preferably 8 weight parts.

In addition, in order to improve intensity, thermotolerance, the wet fastness of foam, arbitrary linking agent can be contained.Linking agent is not particularly limited, oil soluble can be used, water-soluble in any one.As linking agent, include, for example out epoxy, oxazoline system, isocyanate-based, carbodiimide system, melamine series, burning system etc.Wherein, You Xuan Wei oxazoline system linking agent.

Such as relative to resin material (polymkeric substance) [solids component (nonvolatile component)], 100 weight parts are 0 ~ 10 weight part to the addition [solids component (nonvolatile component)] of linking agent, lower limit is preferably 0.01 weight part, the upper limit is preferably 9 weight parts.

In addition, in order to improve stability, the film-forming properties of the bubble after foaming, arbitrary thickening material can be contained.As thickening material, be not particularly limited, acrylic acid series, carbamate system, polyethenol series etc. can be listed.Wherein, polyacrylic thickening material, carbamate system thickening material is preferably.

Such as relative to resin material (polymkeric substance) [solids component (nonvolatile component)], 100 weight parts are 0 ~ 10 weight part to the addition [solids component (nonvolatile component)] of thickening material, lower limit is preferably 0.1 weight part, the upper limit is preferably 5 weight parts.

In addition, in order to prevent the corrosion of the hardware adjoined with foamed sheet, arbitrary rust-preventive agent can be contained.As this rust-preventive agent, be preferably the compound containing azoles ring.If use the compound containing azoles ring, then can take into account at a high level for the non-corrosibility of metal and the adaptation with adherend.

As the above-mentioned compound containing azoles ring, as long as what contain more than one nitrogen-atoms in ring has pentacyclic compound, include, for example out the compound etc. with diazole (imidazoles, pyrazoles) ring, triazole ring, tetrazole ring, oxazole ring, isoxazole ring, thiazole ring or isothiazole ring.These rings can form condensed ring with aromatic nucleus generation condensations such as phenyl ring.As the above-mentioned compound with condensed ring, the compound etc. such as with benzoglyoxaline ring, benzopyrazoles ring, benzotriazole ring, benzoxazole ring, benzoisoxazole ring, benzothiazole ring or benzisothiazole ring can be listed.

Above-mentioned azoles ring, above-mentioned condensed ring (benzotriazole ring, benzothiazole ring etc.) can have substituting group separately.As this substituting group, include, for example out the alkyl of the carbonatomss 1 ~ 6 (preferred carbonatoms 1 ~ 3) such as methyl, ethyl, propyl group, sec.-propyl, butyl; The alkoxyl group of the carbonatomss 1 ~ 12 (preferred carbonatoms 1 ~ 3) such as methoxyl group, oxyethyl group, isopropoxy, butoxy; The aryl of the carbonatomss 6 ~ 10 such as phenyl, tolyl, naphthyl; Amino; Methylamino, dimethylamino etc. (list or two) C _1-10alkylamino; Amino-the C such as amino methyl, 2-amino-ethyl _1-6alkyl; Single or the two (C such as N, N-diethylamino methyl, two (2-ethylhexyl) amino methyls of N, N- _1-10alkyl) amino-C _1-6alkyl; Sulfydryl; The carbalkoxy of the carbonatoms such as methoxycarbonyl, ethoxycarbonyl 1 ~ 6; Carboxyl; Carboxyl-the C such as carboxymethyl _1-6alkyl; Carboxyl-the C such as 2-propyloic sulfenyl _1-6alkylthio; Two (hydroxyl-the C of N, N-such as two (methylol) amino methyls of N, N- _1-4alkyl) amino-C _1-4alkyl; Sulfo group etc.In addition, the above-mentioned compound containing azoles ring can form the salt such as sodium salt, sylvite.

From the aspect of the rust inhibition to metal, the aromatic nucleus such as preferred azoles ring and phenyl ring define the compound of condensed ring, wherein, benzotriazole based compound (there is the compound of benzotriazole ring), benzothiazole based compound (there is the compound of benzothiazole ring) is particularly preferably.

As above-mentioned benzotriazole based compound, include, for example out 1,2,3-benzotriazole, Methylbenzotriazole, carboxyl benzotriazole, carboxymethyl benzotriazole, 1-[N, two (2-ethylhexyl) amino methyl of N-] benzotriazole, 1-[N, two (2-ethylhexyl) amino methyl of N-] Methylbenzotriazole, 2,2 '-[[(methyl isophthalic acid H-benzotriazole-1-base) methyl] imino-] di-methylcarbinol or their sodium salt etc.

As above-mentioned benzothiazole based compound, such as 2-mercaptobenzothiazole, 3-(2-(benzothiazolyl) sulfo-) propionic acid or their sodium salt etc. can be listed.

Compound containing azoles ring can be used singly, or in combination of two or more kinds.

The addition [solids component (nonvolatile component)] of rust-preventive agent (such as the above-mentioned compound containing azoles ring) [solids component (nonvolatile component)] is not as long as destroying with in the scope of the characteristic of the adaptation of adherend, foam itself, such as relative to resin material (polymkeric substance) [solids component (nonvolatile component)] 100 weight parts, such as, be preferably 0.2 ~ 5 weight part.Its lower limit is more preferably 0.3 weight part, more preferably 0.4 weight part, its upper limit is more preferably 3 weight parts, more preferably 2 weight parts.

In addition, not destroying in the scope of impact absorbency, other suitable arbitrarily compositions can be contained.Other compositions so only containing a kind, also can contain two or more.As these other compositions, include, for example out component of polymer other than the above, tenderizer, oxidation inhibitor, anti-aging agent, gelating agent, solidifying agent, softening agent, weighting agent, strengthening agent, whipping agent, fire retardant, photostabilizer, UV light absorber, tinting material (pigment, dyestuff etc.), pH adjusting agent, solvent (organic solvent), thermal polymerization, Photoepolymerizationinitiater initiater etc.

As above-mentioned weighting agent, include, for example out silicon-dioxide, clay (mica, talcum, terre verte etc.), aluminum oxide, titanium dioxide, zinc oxide, stannic oxide, zeolite, graphite, CNT (carbon nano-tube), inorganic fibre (carbon fiber, glass fibre etc.), organic fibre, metal powder (silver, copper etc.) etc.In addition, as weighting agent, piezoelectric particles (titanium oxide etc.), electroconductive particle, thermal conductivity particle (boron nitride etc.), organic filler (silicone powder etc.) etc. also can be added.

Foamed sheet of the present utility model can manufacture by the resin combination comprising the resin material (polymkeric substance) forming foam is carried out foaming and molding.As foaming method (the formation method of bubble), normally used method in the foaming and molding such as physical method, chemical process can be adopted.In general, physical method makes the gaseous constituent such as air, nitrogen be scattered in polymers soln, and pass through mechanically mixing and form the method for bubble.In addition, chemical process is that the gas produced by the thermolysis because adding the whipping agent in polymeric matrix to forms abscess, thus obtains the method for foam.From viewpoints such as environmental problems, be preferably physical method.The bubble formed by physical method mostly is continuous air bubbles.

As the resin combination of the resin material (polymkeric substance) comprised for foaming and molding, resin material can be used to dissolve the resin solution obtained in a solvent, from the view point of bubble, preferably use the emulsion comprising resin material.As emulsion, can by used in combination for emulsion of more than two kinds.

From the view point of film-forming properties, the solid component concentration of preferred emulsion is high.The solid component concentration of emulsion is preferably more than 30 % by weight, is more preferably more than 40 % by weight, more preferably more than 50 % by weight.

In the utility model, the operation (operation A) of preferably bubbling via making emulsion resin composition mechanically foam makes the method for foam.As foam generating device, be not particularly limited, include, for example out the device such as spray mode of high speed shear mode, mode of vibration, gas under pressure.Wherein, from the view point of miniaturization, the Large Copacity making of bubble diameter, high speed shear mode is preferably.

Bubble when being bubbled by mechanical stirring is the bubble that gas (gas) enters into emulsion.As gas, as long as be inactive relative to emulsion, be just not particularly limited, air, nitrogen, carbonic acid gas etc. can be listed.Wherein, from the view point of economy, be preferably air.

Play the emulsion resin composition of alveolation to be coated on base material via aforesaid method will be utilized and to carry out dry operation (process B), thus foamed sheet of the present utility model can be obtained.As above-mentioned base material, be not particularly limited, the plastic film (the polyethylene terephthalate film etc. after lift-off processing), plastic film (polyethylene terephthalate film etc.), heat-conducting layer (heat-conducting layer described later) etc. such as after lift-off processing can be listed.When being coated with as base material by heat-conducting layer, the adaptation of foam layer and heat-conducting layer can be improved, in addition, also can improve the efficiency of drying process when making foam layer.

In above-mentioned process B, as coating process, drying means, general method can be adopted.Process B preferably includes: by the emulsion resin composition of the bubbles be coated on base material more than 50 DEG C and lower than carry out dry preparation drying process B1 at the temperature of 125 DEG C and after preparation drying process B1 further more than 125 DEG C and less than the 200 DEG C trunk drying process B2 carrying out drying.

By arranging preparation drying process B1 and trunk drying process B2, thus can prevent temperature sharply from rising and the merging of the bubble that causes, the breaking of bubble.Especially for the foamed sheet that thickness is little, the sharply rising of Yin Wendu and cause bubble merge or break, therefore, arranges the significant of preparation drying process B1.Temperature in preparation drying process B1 is preferably more than 50 DEG C and less than 100 DEG C.The time of preparation drying process B1 is such as 0.5 minute ~ 30 minutes, is preferably 1 minute ~ 15 minutes.In addition, the temperature in trunk drying process B2 be preferably more than 130 DEG C and less than 180 DEG C, be more preferably more than 130 DEG C and less than 160 DEG C.The time of trunk drying process B2 is such as 0.5 minute ~ 30 minutes, is preferably 1 minute ~ 15 minutes.

For the mean cell diameter of foam, maximum cell diameter and smallest bubbles bore dia, stirring velocity during kind and amount, adjustment mechanical stirring by adjustment sheet surface-active agent and churning time and obtain the foamed sheet of the mean cell diameter of 10 ~ 150 μm of scopes.

With regard to the density of foam, obtain 0.2 ~ 0.4g/cm by gas (gas) component amount entered in emulsion resin composition during adjustment mechanical stirring ³the foamed sheet of density.

Foamed sheet of the present utility model can have binder layer (bonding coat) at the single or double of foam.As the tackiness agent forming binder layer, being not particularly limited, such as, can be any one in acrylic adhesive, elastomeric adhesive, silicone-based adhesive etc.In addition, when arranging binder layer, can before use, at the release liner of adhesive layer surface stacked guard binder layer.It should be noted that, when the foam forming foamed sheet of the present utility model has microviscosity, also component etc. can be fixed even if do not arrange binder layer.

In foamed sheet of the present utility model, at least one face forming the foam of foamed sheet is 0.5N/100mm relative to the shear bond power (condition determination: 23 DEG C, draw speed 50mm/min) of SUS304BA plate ²above, thus by this foamed sheet and other components (such as heat-conducting layer etc.) are stacked use time, even if do not arrange adhesive linkage on foamed sheet, other components above-mentioned also can not peel off, obtain can prevent misplace effect.In addition, due to adhesive linkage can not be arranged, therefore, it is possible to make the less thick of the duplexer of foamed sheet and other components, thus the further slimming of the electric/electronic of the object as installation etc. can be contributed to.In addition, the manufacture efficiency of this duplexer can be improved, can reduce costs.It should be noted that, as the example that the layer of the duplexer of foamed sheet of the present utility model and other components (such as heat-conducting layer etc.) is formed, such as other component/foaies, other component/binder layer/foaies, foam/other component/foaies, foam/binder layer/other component/binder layer/foaies etc. can be listed.

Above-mentioned foam, relative to the shear bond power of SUS304BA plate, is selected by the kind and its ratio of components such as formation being formed to the monomer of the resin material (polymkeric substance) of above-mentioned foam and is adjusted.Such as, as the monomer of resin material polymkeric substance such as () acrylic acid polymer forming above-mentioned foam, using relative to whole monomer component (monomer component total amount) of resin material polymkeric substance such as () acrylic acid polymer forming above-mentioned foam is such as that 70 ~ 98 % by weight (lower limit is preferably 75 % by weight, the upper limit is preferably 97 % by weight), the Tg of homopolymer is lower than-10 DEG C (such as more than-70 DEG C and lower than-10 DEG C, preferably-70 DEG C ~-12 DEG C,-65 DEG C ~-15 DEG C further preferably) monomer, and the kind of other monomers is suitably selected with amount, above-mentioned foam can be made thus to reach 0.5N/100mm relative to the shear bond power of SUS304BA plate ²above.

Above-mentioned foam is preferably 0.5N/100mm relative to the lower limit of the shear bond power of SUS304BA plate ², more preferably 0.7N/100mm ².In addition, above-mentioned foam is not particularly limited relative to the upper limit of the shear bond power of SUS304BA plate, such as, be 100N/100mm ².

Foamed sheet of the present utility model can be made into the coiling body (roll) being wound into roll and commercially circulates.

Although the thickness of foamed sheet of the present utility model is little but impact absorbency excellent.Therefore, such as in electric/electronic, being useful as various component or parts (such as optical component etc.) being installed the electric/electronic component that (arrangements) use when position (such as the basket etc.) of regulation, is especially useful as impact-absorbing sheet.

Carry out the optical component settling (installation) as foamed sheet of the present utility model can be utilized, can list such as: the image display member (especially compact image display member) installed in the image display devices such as liquid-crystal display, electroluminescent display, plasma display; Be installed on the display members such as the touch panel of the device of the mobile communicating such as so-called " Cell phone ", " smart mobile phone ", " portable information terminal "; Photographic camera, lens (especially minicam or lens) etc.

Electric/electronic of the present utility model employs above-mentioned foamed sheet of the present utility model.Electric/electronic is like this such as the electric/electronic possessing display member, comprises and has electric installation or the electronics that above-mentioned foamed sheet is clamped in the structure between the basket of this electric installation or electronics and above-mentioned display member.As this electric/electronic, include, for example out the device etc. of the mobile communicating such as so-called " Cell phone ", " smart mobile phone ", " portable information terminal ".

In addition, with regard to foamed sheet of the present utility model, its density is extremely low is 0.2 ~ 0.4g/cm ³, and be low compression load, therefore when the equipment for carrying touch panel, even if along with the touch operation of user, display panel, touch panel bend, are out of shape, and also the power that produce with this distortion effectively can be disperseed, are absorbed.Thus, foamed sheet of the present utility model can suppress the display irregular (undulatory stain pattern) of display part sometimes because producing display panel stress application to heavens.Therefore, foamed sheet of the present utility model is suitable for the equipment carrying touch panel.

The equipment of above-mentioned lift-launch touch panel refers to, has display panel and is equipped with the equipment of touch panel.As the equipment carrying touch panel, be not particularly limited, can enumerate such as: Cell phone; Smart mobile phone; Portable information terminal (PDA); Panel computer; Desktop type, notebook type, plate etc. various PC (personal computer); The various indicating meters (watch-dog) such as plasma display, liquid-crystal display, electroluminescent display (OLED display); Pocket game machine; Carried digital audio frequency player; E-book reader (e-book reading device, e-book special purpose terminal); Wearable computer (wearable computer) (wearable device (wearable device)); Digital mark (digital Signage) (electronic signs); Automatic Teller Machine (ATM); Ticket tool, various exchange volume, beverage, food, cigarette, magazine, newspaper etc. peddle used ticket vendor vending machine; TV developing device (TV); Electronic blackboard (interactive white board (interactive white board)) etc.

The above-mentioned foamed sheet of the present utility model of the equipment use of lift-launch touch panel of the present utility model.As the equipment of such lift-launch touch panel, can list and such as there is above-mentioned foamed sheet, display panel and touch panel, and have the equipment of above-mentioned foamed sheet at the space matching of the rear side of above-mentioned display panel.

[embodiment]

Below, enumerate embodiment and the utility model is described in more detail, but the utility model is not by any restriction of these embodiments.It should be noted that, unless otherwise specified, represent that " % " of content refers to % by weight.It should be noted that, coordinate number (weight part) to be all the value that solids component (nonvolatile component) converts.

Embodiment 1

Utilize decollator (" RoboMix " PRIMIX Inc.) to be uniformly mixed synthetic rubber latex (" Lacstar1570 " DIC Inc., solids component amount 42.4%, NBR) 100 weight parts, lipid acid ammonium system tensio-active agent (aqueous dispersions of ammonium stearate, solids component amount 33%) (surfactant A) 3.9 weight part, carbamate system thickening material (" Hydran Asister T10 " DIC Inc., solids component amount 25.1%) 0.74 weight part, make it play alveolation.This foaming composition is coated in the PET film after lift-off processing (thick: 38 μm, Resins Corporation of trade(brand)name " MRF#38 " Mitsubishi system), in 70 DEG C of dryings 4.5 minutes, in 140 DEG C of dryings 4.5 minutes, obtains thick 150 μm, density 0.26g/cm ³, mean cell diameter 55 μm the foam (foamed sheet) of continuous air bubbles structure.

Embodiment 2

Utilize decollator (" RoboMix " PRIMIX Inc.) to be uniformly mixed synthetic rubber latex (" Lacstar DM886 " DIC Inc., solids component amount 48.6%, MBR) 100 weight parts, lipid acid ammonium system tensio-active agent (aqueous dispersions of ammonium stearate, solids component amount 33%) 3.4 weight parts, carbamate system thickening material (" Hydran Asister T10 " DIC Inc., solids component amount 25.1%) 0.65 weight part, make it play alveolation.This foaming composition is coated in the PET film after lift-off processing (thick: 38 μm, Resins Corporation of trade(brand)name " MRF#38 " Mitsubishi system), in 70 DEG C of dryings 4.5 minutes, in 140 DEG C of dryings 4.5 minutes, obtains thick 150 μm, density 0.28g/cm ³, mean cell diameter 88 μm the foam (foamed sheet) of continuous air bubbles structure.

Embodiment 3

Utilize decollator (" RoboMix " PRIMIX Inc.) to be uniformly mixed acrylic emulsions solution (solids component amount 55%, ethyl acrylate-acrylic acid butyl ester-acrylonitrile copolymer (weight ratio 45:48:7)) 100 weight parts, lipid acid ammonium system tensio-active agent (aqueous dispersions of ammonium stearate, solids component amount 33%) 3 weight parts, polyacrylic thickening material (ethyl acrylate-acrylic acid multipolymer (vinylformic acid 20 % by weight), solids component amount 28.7%) 1.3 weight parts, make it play alveolation.This foaming composition is coated in the PET film after lift-off processing (thick: 38 μm, Resins Corporation of trade(brand)name " MRF#38 " Mitsubishi system), in 70 DEG C of dryings 4.5 minutes, in 140 DEG C of dryings 4.5 minutes, obtains thick 130 μm, density 0.38g/cm ³, mean cell diameter 68 μm the foam (foamed sheet) of continuous air bubbles structure.

Embodiment 4

Utilize decollator (" RoboMix " PRIMIX Inc.) to acrylic emulsions solution (solids component amount 55%, ethyl acrylate-acrylic acid butyl ester-acrylonitrile copolymer (weight ratio 45:48:7)) 100 weight parts, the lipid acid ammonium system tensio-active agent (aqueous dispersions of ammonium stearate, solids component amount 33%) (surfactant A) 1.5 weight part, carboxy betaine type amphoterics (" Amogen CB-H ", first industrial pharmaceutical Inc.) (surfactant B) 1 weight part, oxazoline system linking agent (" EPOCROS WS-500 " Japanese catalyst Co. system, solids component amount 39%) 0.35 weight part, polyacrylic thickening material (ethyl acrylate-acrylic acid multipolymer (vinylformic acid 20 % by weight), solids component amount 28.7%) 0.78 weight part, benzotriazole system rust-preventive agent (" SEETEC BT-NA ", SHIPRO changes into Inc.) 0.5 weight part is uniformly mixed, and makes it play alveolation.This foaming composition is coated on the PET after lift-off processing (polyethylene terephthalate) film (thick: 38 μm, Resins Corporation of trade(brand)name " MRF#38 " Mitsubishi system), in 70 DEG C of dryings 4.5 minutes, in 140 DEG C of dryings 4.5 minutes, obtain thick 130 μm, density 0.33g/cm ³, maximum cell diameter 110 μm, smallest bubbles bore dia 20 μm, mean cell diameter 45 μm the foam (foamed sheet) of continuous air bubbles structure.

Embodiment 5

Utilize decollator (" RoboMix " PRIMIX Inc.) to acrylic emulsions solution (solids component amount 55%, ethyl acrylate-acrylic acid butyl ester-acrylonitrile copolymer (weight ratio 45:48:7)) 100 weight parts, the lipid acid ammonium system tensio-active agent (aqueous dispersions of ammonium stearate, solids component amount 33%) 3 weight parts, oxazoline system linking agent (" EPOCROS WS-500 " Japanese catalyst Co. system, solids component amount 39%) 2 weight parts, polyacrylic thickening material (ethyl acrylate-acrylic acid multipolymer (vinylformic acid 20 % by weight), solids component amount 28.7%) 0.78 weight part, benzotriazole system rust-preventive agent (" SEETEC BT-NA ", SHIPRO changes into Inc.) 0.5 weight part is uniformly mixed, it is made to play alveolation.This foaming composition is coated on the PET after lift-off processing (polyethylene terephthalate) film (thick: 38 μm, Resins Corporation of trade(brand)name " MRF#38 " Mitsubishi system), in 70 DEG C of dryings 4.5 minutes, in 140 DEG C of dryings 4.5 minutes, obtain thick 130 μm, density 0.24g/cm ³, maximum cell diameter 69.5 μm, smallest bubbles bore dia 15 μm, mean cell diameter 34 μm the foam (foamed sheet) of continuous air bubbles structure.

Comparative example 1

Utilize decollator (" RoboMix " PRIMIX Inc.) to be uniformly mixed acrylic emulsions solution (solids component amount 55%, ethyl acrylate-acrylic acid butyl ester-acrylonitrile copolymer (weight ratio 45:48:7)) 100 weight parts, lipid acid ammonium system tensio-active agent (aqueous dispersions of ammonium stearate, solids component amount 33%) 3 weight parts, polyacrylic thickening material (ethyl acrylate-acrylic acid multipolymer (vinylformic acid 20 % by weight), solids component amount 28.7%) 0.78 weight part, make it play alveolation.This foaming composition is coated in the PET film after lift-off processing (thick: 38 μm, Resins Corporation of trade(brand)name " MRF#38 " Mitsubishi system), in 70 DEG C of dryings 4.5 minutes, in 140 DEG C of dryings 4.5 minutes, obtains thick 130 μm, density 0.62g/cm ³, mean cell diameter 58 μm the foam (foamed sheet) of continuous air bubbles structure.

< evaluates >

Following evaluation is carried out for the foam obtained by embodiment and comparative example (foamed sheet).Show the result in table 1 and table 2.It should be noted that, the cooperation number (weight part) [solids component (nonvolatile component) conversion] of each composition in each embodiment, comparative example shown in table 1." Em " represents acrylic emulsions solution.

(mean cell diameter)

Utilizing rough vacuum scanning electronic microscope (Hightech Science Systems Inc. of " S-3400N type scanning electronic microscope " Hitachi) to obtain the expanded view picture of foam section, obtaining mean cell diameter (μm) by carrying out image analysis.It should be noted that, the number of bubbles parsed is about 10 ~ 20.In addition, utilize the method identical with mean cell diameter, obtain smallest bubbles bore dia (μm) and the maximum cell diameter (μm) of foamed sheet.

(density)

Utilize the blanking knife model tool of 100mm × 100mm to carry out stamping-out to foam (foamed sheet), the size of the sample determined that liquidates measures.In addition, 1/100 dial ga(u)ge that the diameter (φ) measuring terminal is 20mm is utilized to measure thickness.These values are utilized to calculate the volume of foam.

Then, the upper ware Libra of more than minimum scale 0.01g is utilized to measure the weight of foam.Density (the g/cm of foam is calculated according to these values ³).

(dynamic viscoelastic)

Utilize the film stretching mode determination of determination of viscoelasticity device (" ARES 2KFRTN1-FCO " TA Instruments Japan Inc.), carry out temperature dispersion test when radian frequency is 1rad/s.To store elastic modulus E ' now and loss Young's modulus E " ratio and the temperature (DEG C) of peak value of loss tangent (tan δ) and intensity (maximum value) measure.

" tan δ temperature " hurdle of table 2 describes the temperature (DEG C) of the peak value of the loss tangent (tan δ) of foam, " tan δ maximum value " hurdle describes the intensity (maximum value) of this peak value, the value [being equivalent to the peak strength (maximum value) of the tan δ of the material self (beyond bubble removing) forming foam] that the intensity (maximum value) that " tan δ maximum value/density " hurdle describes above-mentioned peak value obtains divided by the density of foam.

(initial stage Young's modulus)

Under 23 DEG C of environment and in the tension test of draw speed 300mm/min, calculate initial stage Young's modulus (N/mm by slope during 10% strain ²), this initial stage Young's modulus is evaluated.

(impact absorbency test)

Above-mentioned pendulum type shock-testing machine (impact test apparatus) (with reference to Fig. 1 and Fig. 2) is used to carry out impact absorbency test.For the foamed sheet obtained in embodiment and comparative example (sample size: 20mm × 20mm), make the iron ball of 28g tilt 30 ° low impact condition (a), make the iron ball of 28g tilt 40 ° low impact condition (b) and the iron ball of 96g is tilted under these three conditions of HI high impact condition of 47 ° carry out shock test, obtain the shock absorption rate (%) under each condition.

Then, with the thickness (μm) of this shock absorption rate (%) divided by foamed sheet, the shock absorption rate R of per unit thickness is obtained.

(shear bond power)

Foamed sheet is cut into 25mm × 25mm, respectively at the double faced adhesive SUS304BA plate of foam, thus makes mensuration sample.The roller of 5kg is made a round trip on the mensuration sample of horizontal positioned crimp.After crimping, place 30 minutes under normal temperature (23 DEG C), then according to making the vertical mode of mensuration sample be fixed in tenter machine (Tensilon), stretching with draw speed 50mm/min, determining the shear bond power that it is the most central.Mensuration sample is determined, using its mean value as shear bond power (N/100mm under the condition of n=2 ²).

(confirming the test of the irregular generation of display)

Commercially available smart mobile phone is taken apart.In this smart mobile phone, Existential Space between display panel bottom and basket, the height in this space is 0.2mm.Using this space as foam insertion space.

Then, insert the sample for evaluating in this foam insertion space, then the smart mobile phone taken apart is assembled.It should be noted that, for comparative example 2, do not insert any sample in foam insertion space.

Start smart mobile phone, with thumb press picture central part.Power is now approximately 12N.Then, be confirmed whether that display occurs irregular, evaluate according to following benchmark.

A: display does not occur irregular.

B: although it is irregular that display occurs, user can recognize no problemly, and can no problem ground operative intelligence mobile phone.

C: irregular owing to showing, thus brings detrimentally affect to identification, user in the operation of smart mobile phone with the sensation of not harmony.

(stress relaxes test)

Use the following stress illustrated to relax trier, insert the sample for evaluating in foam insertion space, counter stress retentivity is evaluated.

Trier is relaxed for stress, is shown in Fig. 3 and Fig. 4.Fig. 3 is the schematic diagram above that stress relaxes trier, and Fig. 4 is the constructed profile (sectional view of the A-A ' line of Fig. 3) that stress relaxes trier.In Fig. 3 and 4,6 is that stress relaxes trier, and 61 are hairclippers (pressure son), 62 are visual window lens (window lense), 63 are liquid-crystal displays (LCD), 64 are impact papers, 65 are substrates (substrate plate), 661 and 662 are self adhesive tapes, 67 is baskets.In addition, foam insertion space is represented with the region 68 that enclosed with dashed lines is come.Stress relaxes trier 6 to be had impact paper 64 in the rear side of liquid-crystal display 63 and has visual window lens 62 in the face side of liquid-crystal display 63.Relax in trier 6 at stress, substrate 65 configures basket 67 by self adhesive tape 662, and by self adhesive tape 661, visual window lens 62 is fixed on basket, thus there is the internal space divided by visual window lens 62, self adhesive tape 661, self adhesive tape 662, basket 67 and substrate 68, the duplexer of liquid-crystal display 63 and impact paper 64 is configured with in this internal space.In addition, the internal space of the bottom of impact paper 64 is provided with foam insertion space 68.

It should be noted that, the visual window lens that this stress relaxes trier can be considered touch panel.

Hairclipper 61 has the front end geometry that diameter is the spheroid of 13mm.As self adhesive tape 661, use double-faced adhesive tape (thick 300 μm, trade(brand)name " double-faced adhesive tape HJ-90130B ", Nitto Denko Corp's system).As self adhesive tape 662, use double-faced adhesive tape (thick 30 μm, trade(brand)name " double-faced adhesive tape No.5603 ", Nitto Denko Corp's system).The thickness of touch panel 62 is 0.8mm.The thickness of liquid-crystal display 63 is 1.7mm.In addition, the thickness of substrate 65 is 5mm.As impact paper 64, use stress determination film (trade(brand)name " PRESCALE " (sheet, the thickness 0.16mm in face of colour developing occurs for two panels, minute-pressure (4LW), Fuji Photo Film Co., Ltd.'s system, the part had through pressurization).

In addition, relax in trier 6 at stress, basket 67 can exchange, and by regulating the height of basket 67, thus can regulate the height in foam insertion space 68.

The height in foam insertion space is set as 200 μm, insert in the foam insertion space that stress relaxes trier for the sample evaluated and PET film (thick: 38 μm, trade(brand)name " MRF#38 ", Resins Corporation of Mitsubishi system) to make total thickness reach near 200 μm, service stress relaxes trier, hairclipper is utilized to apply the load of 12N to the central part of touch panel, confirm the variable color of impact paper, thus counter stress retentivity is evaluated.

It should be noted that, in comparative example 3 in foam insertion space stacked PET film (thick: 38 μm, trade(brand)name " MRF#38 ", Resins Corporation of Mitsubishi system) 5.

The evaluation result that stress relaxes test is shown in Fig. 5 ~ Figure 11.Fig. 5 ~ 11 carry out Digital Signal Processing to the variable color of the impact paper of embodiment 1 ~ 5, comparative example 1 and 3 respectively, the tonogram picture that the pressure making to act on impact paper is visual.

Table 1

As shown in table 2, with regard to the foamed sheet of embodiment, above-mentioned R is more than 0.15, is more than 0.10 under HI high impact condition, under low impact condition, demonstrates HI high impact absorptivity under low impact condition (a) and (b), and the impact of the size be not hit and demonstrate excellent impact absorbency.On the other hand, with regard to the foamed sheet of comparative example, do not meet all benchmark simultaneously.In addition, with regard to the foamed sheet of embodiment, demonstrate high value relative to the shear bond power of SUS304BA plate.Therefore, when using with other components are stacked, even if do not arrange binder layer on this foamed sheet, other components also can not peel off, and can prevent dislocation.

In addition, as shown in Fig. 5 ~ Figure 11, compared by the foamed sheet of embodiment with comparative example, the pressure acting on impact paper is little, stress retentivity excellent.Thus, when the foamed sheet of embodiment is used for the equipment carrying touch panel, the touch operation with user can be suppressed to heavens and the display of display part that produces is irregular.

Claims

1. a foamed sheet, its thickness is 30 ~ 500 μm, and described foamed sheet is 0.2 ~ 0.4g/cm by density ³foam form.

2. a foamed sheet, its thickness is 30 ~ 500 μm, and the foam that described foamed sheet is 60 ~ 80 volume % by bubble rate is formed.

3. a foamed sheet, its thickness is 30 ~ 500 μm, and described foamed sheet is made up of following foam, and the density of described foam is 0.2 ~ 0.4g/cm ³, and radian frequency in Measurement of Dynamic Viscoelasticity is 1rad/s time store elastic modulus and the ratio of loss Young's modulus and losstangenttanδ more than-30 DEG C, in the scope of less than 30 DEG C, there is peak value.

4. the foamed sheet according to any one of claims 1 to 3, wherein, the mean cell diameter of described foam is 10 ~ 150 μm.

5. the foamed sheet according to any one of claims 1 to 3, wherein, the maximum value of the losstangenttanδ of described foam more than-30 DEG C and in the scope of less than 30 DEG C is more than 0.2.

6. the foamed sheet according to any one of claims 1 to 3, wherein, under 23 DEG C of environment and draw speed is in the tension test of 300mm/min, the initial stage Young's modulus of foam is 5N/mm ²below.

7. the foamed sheet according to any one of claims 1 to 3, wherein, in the impact absorbency test employing pendulum type shock-testing machine, the shock absorption rate that following formula defines divided by the thickness gained of foamed sheet value R impact son weight 28g, put angle 30 ° time be more than 0.15, described shock absorption rate is in %, the unit of the thickness of described foamed sheet is μm

Shock absorption rate (%)={ (F ₀-F ₁)/F ₀} × 100

In above-mentioned formula, F ₀only the surging force of impacting the period of the day from 11 p.m. to 1 a.m is collided to supporting plate, F ₁the supporting plate to the structure be made up of supporting plate and foamed sheet collides the surging force of impacting the period of the day from 11 p.m. to 1 a.m.

8. the foamed sheet according to any one of claims 1 to 3, wherein, at least one face of described foam relative to SUS304BA plate shear bond power 23 DEG C, be 0.5N/100mm under the condition of draw speed 50mm/min ²above.

9. the foamed sheet according to any one of claims 1 to 3, wherein, has binder layer at the single or double of foam.

10. the foamed sheet according to any one of claims 1 to 3, it is used as electric installation or electronics impact-absorbing sheet.

11. foamed sheets according to any one of claims 1 to 3, it is for carrying the equipment of touch panel.

12. 1 kinds of electric installations or electronics, it use the foamed sheet according to any one of claims 1 to 3.

13. electric installation according to claim 12 or electronicss, it is the electric installation or the electronics that possess display member, and described electric installation or the electronics foamed sheet had according to any one of claims 1 to 3 is clamped in the structure between the basket of this electric installation or electronics and described display member.

14. 1 kinds of equipment carrying touch panel, it use the foamed sheet according to any one of claims 1 to 3.

The equipment of 15. lift-launch touch panels according to claim 14, it has foamed sheet, display panel and touch panel according to any one of claims 1 to 3, and has described foamed sheet at the space matching of the rear side of described display panel.