CN102358032B - Preparation method for even-orientation-degree organic glass - Google Patents

Abstract

Provided is a preparation method for even-orientation-degree organic glass. A grinded organic glass pouring plate is extended through an X-axis and a Y-axis in 125 DEG C to 160 DEG C. The organic glass pouring plate is methyl methacrylate homopolymerization or copolymerization plate prepared by a body pouring method and contains plasticizers, cross-linking agents or other performance addictives. The organic glass can be grinded flash through grinding equipment including grinders or lapping machines, and the height of grinded flash materials is smaller than 0.3mm. Stretching orientation can be performed through an X-Y double axis oriented stretching machine, and uniformity of the inner temperature of a thermal insulation cavity of the organic glass is smaller than 3 DEG C. The uniformity of orientation degree of prepared oriented stretched organic glass is no larger than 3%.

Description

The preparation method of even-orientation-degree organic glass

Technical field

The present invention relates to a kind of preparation method of oriented organo glass, especially prepare the method for the oriented organo glass of even degree of orientation.

Background technology

The plastic plate that methyl methacrylate is made by the process route of body casting homopolymerization or copolymerization is called lucite moulding plate, is commonly called as lucite.Lucite because of it has excellent optical performance, formability can be good and there is certain mechanical property, and be widely used in aviation, boats and ships, automobile and building field.

Oriented organo glass, also referred to as lucite orientation stretching plate, that polymethyl methacrylate (PMMA is commonly called as lucite) moulding plate (general thickness is more than 12mm, more than length and width size 1200mm) is made through X-Y is biaxial stretch-formed at suitable temperature.Drawing process is be warmed up to lucite softening temperature above and keep a period of time so that sheet material is fully softening after first methacrylate sheet four limits fixture being fixed, then four limit fixtures outwards stretch with certain speed, methacrylate sheet planar dimension is widened, reduced thickness, reaches cooling and shaping after requirement size.Oriented organo glass under free state, be warmed up to lucite softening temperature when above lucite can retract to stretch before size.

By stretching, can make lucite macromolecular chain segment structure be orientated along X-Y draw direction, thereby make the performances such as the impact strength of lucite and toughness all have raising by a relatively large margin, can be used for the moulding of the fields such as aviation required high-performance lucite transparent configuration part.Degree of orientation is commonly referred to lucite degree of orientation, generally adopts oriented organo glass more than draft temperature, to add thermoresilience front and back size changing rate and calculates.The oriented organo glass that is of a size of 2250mm such as length and width becomes length and width size 1500mm after adding thermoresilience, generally claims that sheet material degree of orientation is (2250-1500)/1500=50%.

But because the thickness evenness of lucite moulding plate itself is poor, generally more than 0.5mm (being that in whole poly (methyl methacrylate) plate face, the thinnest point and thickest point thickness difference are greater than 0.5mm), this will cause lucite to carry out occurring that whole plate face degree of orientation is inhomogeneous after orientation stretching, general thickness is poor larger, and degree of orientation is less; Otherwise thickness difference is less, degree of orientation is larger.Therefore methacrylate sheet thickness differs larger, and after stretching, degree of orientation also differs larger, but the average orientation degree of sheet material is constant.The inhomogeneous meeting of whole plate face degree of orientation causes oriented organo glass sheet material macromolecule ordered state inhomogeneous and then cause oriented organo glass mechanical heterogeneity, optical property variation, finally affects outward appearance and the optical quality of plate forming goods.

Summary of the invention

The object of this invention is to provide a kind of method of preparing even-orientation-degree organic glass.

The lucite moulding plate that the present invention uses is methyl methacrylate homopolymerization or the copolymerization sheet material standby through body casting legal system.

The method of preparing even-orientation-degree organic glass of the present invention is: first lucite moulding plate surface is polished to processing, then at 125 ℃～160 ℃, after X-Y is biaxial stretch-formed, make, after the stretch orientation lucite trimming obtaining, point-to-point transmission degree of orientation uniformity is no more than 3% arbitrarily.

Described lucite moulding plate is methyl methacrylate homopolymerization or the copolymerization sheet material standby through body casting legal system.

In described lucite moulding plate, can contain plasticizer or crosslinking agent or other modified additive.

Lucite polishes equipment such as adopting grinder or grinding machine and grinds gained, and the thickness evenness that polishes rear sheet material is not more than 0.3mm, reduces the thinnest point and thickest point thickness difference in poly (methyl methacrylate) plate face.

Described stretch orientation adopts X-Y biaxial oriented stretch machine to carry out, and in drawing process, lucite heat-insulated cavity internal temperature uniformity is not more than 3 ℃.

The invention has the beneficial effects as follows:

By by after lucite moulding plate surface rubbing, reduce the thinnest point and thickest point thickness difference in poly (methyl methacrylate) plate face.The whole plate degree of orientation of the orientation stretching lucite uniformity of preparing that stretches is again no more than 3%, thereby increases substantially mechanical property uniformity and the optical property of stretching sheet material, can guarantee profiled member appearance and size.Traditional orientation stretching lucite preparation is the lucite moulding plate adopting without grinding, and general degree of orientation uniformity is not less than 6%, is difficult to guarantee organic glass blank appearance and size and stability.

Accompanying drawing explanation

Accompanying drawing 1 is sheet material degree of orientation mensuration sample position distribution map.

The specific embodiment

Embodiment 1:

Step 1: 1600 × 1600 × 20mm lucite moulding plate is placed on grinder with 120 ^#sand paper grinds 30min, then, by this sheet material turn-over, another side is ground to 30min equally, takes off, and with sonigauge sheet material measurement thickness, should try one's best and measure and be no less than 81 points equably.

Step 2: sheet material is fixed on the fixture of stretching-machine, carries out orientation stretching under 125 ℃～160 ℃ conditions, guarantee that in heat-insulated cavity, temperature uniformity is not more than 3 ℃ in drawing process, the whole plate abduction elongation of lucite reaches 70% and stops.

Step 3: after having stretched, sheet material is cooled to room temperature, unloads sheet material.By its edge 300mm Partial Resection.Press sampling shown in accompanying drawing 1, measure its degree of orientation.

Comparative example 2:

Operation is with example 1, and difference is that only lucite moulding plate being carried out to one side polishes.

Comparative example 3:

Operation is with example 1, and difference is lucite moulding plate not to be polished.

Thickness evenness and the rear degree of orientation that stretches before table 1 example 1～3 lucite moulding plate stretches

Claims (1)

1. the preparation method of an even-orientation-degree organic glass, it is characterized in that, first lucite moulding plate surface is polished to processing, then at 125 ℃-160 ℃, after X-Y is biaxial stretch-formed, make, after the stretch orientation lucite trimming obtaining, point-to-point transmission degree of orientation uniformity is no more than 3% arbitrarily;

Described lucite moulding plate is methyl methacrylate homopolymerization or the copolymerization sheet material standby through body casting legal system;

Described lucite polishes and adopts grinder or grinding machine to grind gained, and the thickness evenness that polishes rear sheet material is not more than 0.3mm;

Described stretch orientation adopts X-Y biaxial oriented stretch machine to carry out, and in drawing process, lucite heat-insulated cavity internal temperature uniformity is not more than 3 ℃.

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